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	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3011:_Europa_Clipper&amp;diff=356822</id>
		<title>Talk:3011: Europa Clipper</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3011:_Europa_Clipper&amp;diff=356822"/>
				<updated>2024-11-14T18:36:34Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: reply&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
I'm not brave enough to actually add an explanation myself, quite yet, but ... I guess this is a reference to the fact(?) that Europa looks a bit like a creme brulee', when viewed from space?  https://science.nasa.gov/jupiter/moons/europa/ It does look tasty ... :) [[User:ModelD|ModelD]] ([[User talk:ModelD|talk]]) 12:53, 13 November 2024 (UTC)&lt;br /&gt;
:I suspect it's more due to the need to drill through a couple miles of ice to get to the ocean; much like breaking through the sugar crust on a creme broule! [[User:Seebert|Seebert]] ([[User talk:Seebert|talk]]) 13:16, 13 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Thank you to the people at 9AM Post things on another website to try and explain XKCD Comics. -Forgotten_Mail {{unsigned ip|172.69.33.177|13:30, 13 November 2024}}&amp;lt;!-- also forgotten to sign!--&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The comically large spoon!!!!!!!!!! I love those. -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 16:38, 13 November 2024 (UTC)&lt;br /&gt;
: Don't be sucked in! Protect yourself! https://rathergood.com/2017/02/10/spoonguard/ [[Special:Contributions/141.101.99.105|141.101.99.105]] 10:57, 14 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
I think the &amp;quot;Crème brûlée is from France, France is in Europe, the moon is called Europa&amp;quot; connection is a bit of a stretch...? [[User:Yorkshire Pudding|Yorkshire Pudding]] ([[User talk:Yorkshire Pudding|talk]]) 18:36, 13 November 2024 (UTC)&lt;br /&gt;
: Eh, it's the same etymology. --[[Special:Contributions/172.69.134.230|172.69.134.230]] 11:04, 14 November 2024 (UTC)&lt;br /&gt;
:: The issue of the continent and the moon coming from the same classical source (for different reasons) rather stretches the link between the dish (from the country, from the country's region/continent, from the region of Greece, ''possibly'' from the pantheon) and the moon (directly from the pantheon). I agree with the 'stretch' assessment. You can probably find easier and more plausible (but wrong) links worth alluding to than that, which relies upon several steps and a ''possible'' polysemic pair of original links. [[Special:Contributions/172.70.58.45|172.70.58.45]] 12:12, 14 November 2024 (UTC)&lt;br /&gt;
:::From an American perspective, Europe might seem like a distant, mysterious place that you might want to send a probe to to gather interesting information, and also somewhere that crème brûlée comes from. It's also potentially confusable (by the easily confused) with Europa. That seems like a reasonable enough connection to make to me. The mention of France is essentially by the by.[[Special:Contributions/172.71.26.107|172.71.26.107]] 12:23, 14 November 2024 (UTC)&lt;br /&gt;
:::It keeps getting said that &amp;quot;Europa is named after Europe&amp;quot;, '''which is not correct''' (etymology, BTW, not entomology). I shall have to re-restore some other changes made to the same paragraph in rapid succession whilst I was trying to explain this. Bear with me. [[Special:Contributions/172.70.160.195|172.70.160.195]] 14:57, 14 November 2024 (UTC)&lt;br /&gt;
:::...You don't care, do you. You just keep putting it back in. SMH. Have fun. Someone else will probably be along to correct you ''again'' later. [[Special:Contributions/141.101.68.92|141.101.68.92]] 15:35, 14 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
&amp;quot;only a spoonful&amp;quot; moment 💔 [[User:CalibansCreations|'''&amp;lt;span style=&amp;quot;color:#ff0000;&amp;quot;&amp;gt;Caliban&amp;lt;/span&amp;gt;''']] ([[User talk:CalibansCreations|talk]]) 19:20, 13 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Someone should add a reference to XKCD's previous mention of a Planetary Protection Officer: https://what-if.xkcd.com/117/ [[Special:Contributions/162.158.42.221|162.158.42.221]] 00:09, 14 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
JUICE mentioned!!! cracker ham cheese cracker ham cheese cracker [[User:N-eh|N-eh]] ([[User talk:N-eh|talk]]) 07:31, 14 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Here is a list from NASA about spacecraft instrument deployment failures, they are remarkably frequent: https://ntrs.nasa.gov/api/citations/20210020397/downloads/Alphonzo%20Stewart-%20Final%20Paper.pdf  [[Special:Contributions/162.158.19.50|162.158.19.50]] 13:00, 14 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
I think we need to have a conversation about how the insertion orbit plan is so chaotic that there is a significant chance that the probe might crash in to and pierce the crust of Europa. [[Special:Contributions/162.158.187.56|162.158.187.56]] 14:36, 14 November 2024 (UTC)&lt;br /&gt;
:...and if so, what's the likelihood of hitting just the right angle to scrape off a tasty bit with that spoon? [[User:Transgalactic|Transgalactic]] ([[User talk:Transgalactic|talk]]) 16:04, 14 November 2024 (UTC)&lt;br /&gt;
::What would you like it to be? I can't step on butterflies, but I can certainly act according to the purest form of free will by strapping a noise bridge diode to my corpus callosum. [[Special:Contributions/108.162.246.83|108.162.246.83]] 16:17, 14 November 2024 (UTC)&lt;br /&gt;
:Well we just need Elon to lock in the plan that if it crashes then it automatically becomes a sample return mission, and the first SolarCity sales rep to break out +150% of their quota gets to be the one to crash it. [[Special:Contributions/162.158.42.130|162.158.42.130]] 15:56, 14 November 2024 (UTC)&lt;br /&gt;
::What part of &amp;quot;Attempt No Landing There&amp;quot; is unclear to you? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 18:36, 14 November 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
I can ''not'' believe I got ChatGPT to make this for me:&lt;br /&gt;
{{cot|You have been warned}}&lt;br /&gt;
&lt;br /&gt;
Europa was this smart, ambitious woman just trying to make it out there in the Mediterranean startup scene. She had her plans, her own thing going on, some solid friends, and a bright future. She wasn’t looking for anything too complicated; she just wanted to keep her options open and figure out her next big move.&lt;br /&gt;
&lt;br /&gt;
Enter Zeus. Now, picture him as that intense CEO type—big, powerful, kind of legendary for his influence (and his *questionable* reputation). He’s been around the block a few times, always looking for the next exciting project or, well… person. Zeus saw Europa, and she was exactly his type: sharp, resourceful, had a lot of potential. He was like, &amp;quot;Yeah, I need *that* in my portfolio.&amp;quot;&lt;br /&gt;
&lt;br /&gt;
But Zeus was a little extra with his tactics. Instead of just, you know, scheduling a coffee chat or reaching out on LinkedIn like a normal person, he came up with this elaborate scheme. He disguised himself as this beautiful white bull (yeah, Zeus was *that* guy who would make things way more complicated than necessary). He wandered down to the shore near Europa and her friends, looking majestic and mysterious, and let her come to him.&lt;br /&gt;
&lt;br /&gt;
Europa, understandably, was like, &amp;quot;This bull is kind of weirdly friendly and actually pretty cool.&amp;quot; She got curious, went closer, and Zeus played it super smooth, staying calm and approachable. When she got comfortable enough, she even climbed onto his back for a ride—just for fun! I mean, who hasn’t hopped onto a crazy idea because it seemed cool at the time, right?&lt;br /&gt;
&lt;br /&gt;
But then things got wild. Suddenly, Zeus took off, sprinting across the beach and straight into the sea. He didn’t just want to show her the local scene; he was taking her across the entire Mediterranean to Crete, like some super intense onboarding retreat she hadn’t signed up for. By the time they got there, she was probably exhausted, confused, and questioning her life choices.&lt;br /&gt;
&lt;br /&gt;
And here’s the kicker: once they arrived, Zeus was like, “Oh hey, it’s me! Not just some chill bull—surprise, I’m Zeus.” At this point, Europa realized she was in way deeper than she’d ever expected. She ended up staying in Crete, becoming queen and building a legacy, which, sure, sounds great on paper. But you have to wonder if that’s what she really wanted in the first place, or if she was just swept up in the whirlwind of Zeus's charm and grand promises.&lt;br /&gt;
&lt;br /&gt;
So, in the end, Europa's career ended up in a place she never saw coming. She became a name people would remember for centuries, but not necessarily on her own terms. It’s the classic millennial dilemma: she got a high-profile &amp;quot;role&amp;quot; with Zeus, but did she really get to build her own brand, or was she just another line in Zeus’s impressive (and very long) resume?&lt;br /&gt;
&lt;br /&gt;
Maybe Europa would look back on this “opportunity” and think, “Did I even want this? Or did I just get pulled into someone else’s grand plan?” A classic case of getting lost in the allure of “networking,” and honestly, a pretty good reminder to always check out who’s really behind the bull.&lt;br /&gt;
{{cob}}&lt;br /&gt;
[[Special:Contributions/172.68.23.82|172.68.23.82]] &amp;quot;This bull is kind of weirdly friendly and actually pretty cool&amp;quot; 16:03, 14 November 2024 (UTC)&lt;br /&gt;
:ChatGPT should have learned long ago that it's not cool to reproduce rape culture. But I guess AI just doesn't get better than its training material... [[User:Transgalactic|Transgalactic]] ([[User talk:Transgalactic|talk]]) 16:34, 14 November 2024 (UTC)&lt;br /&gt;
::It is apparently aware of the issue:&lt;br /&gt;
:::&amp;quot;The myth of Zeus and Europa is problematic from a modern perspective, especially concerning consent. Europa willingly approaches and even climbs onto Zeus, who is disguised as a bull, suggesting an initial level of curiosity and comfort. However, Zeus’s sudden abduction of Europa—taking her across the sea to Crete and revealing his true identity only after they arrive—shows a disregard for her autonomy, as she never consented to go with him under those terms. Her actions are based on Zeus’s deception, and without knowing his true intentions, her choice was not fully informed. In Greek mythology, such abductions were common symbols of divine intervention, reflecting a worldview where gods often overpowered human agency, a stark contrast to today’s emphasis on consent and personal autonomy.&amp;quot;&lt;br /&gt;
::The issue with Zeus's behavior was tempered by the story that he gave Europa a kingdom to rule and all the riches and luxuries that came with it. Isn't that the way bad boyfriends are excused in our day and age? [[Special:Contributions/172.70.211.143|172.70.211.143]] 17:45, 14 November 2024 (UTC)&lt;br /&gt;
:::Like [https://krapopolis.fandom.com/wiki/Krapopolis#:~:text=Tyrannis%2C%20the%20mortal%20son%20of,self%2Ddestruction%20and%20questionable%20choices. King Tyrannis] in {{w|Krapopolis}}? All that glitters is not gold. [[Special:Contributions/172.68.22.93|172.68.22.93]] 18:02, 14 November 2024 (UTC)&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3011:_Europa_Clipper&amp;diff=356820</id>
		<title>3011: Europa Clipper</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3011:_Europa_Clipper&amp;diff=356820"/>
				<updated>2024-11-14T18:31:24Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: additional image&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3011&lt;br /&gt;
| date      = November 13, 2024&lt;br /&gt;
| title     = Europa Clipper&lt;br /&gt;
| image     = europa_clipper_2x.png&lt;br /&gt;
| imagesize = 333x356px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = They had BETTER make this a sample return mission.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
&lt;br /&gt;
{{incomplete|Created by a JOVIAN DESSERT. Please consider deleting this tag too soon, but refrain from doing so.}}&lt;br /&gt;
&lt;br /&gt;
[[File:Animation of Europa Clipper trajectory around Jupiter.gif|thumb|right|The ''Europa Clipper's'' projected course around {{w|Jupiter}}, represented as the stationary &amp;lt;span style=&amp;quot;color:green;&amp;quot;&amp;gt;green&amp;lt;/span&amp;gt; dot. In &amp;lt;span style=&amp;quot;color:gold;&amp;quot;&amp;gt;gold&amp;lt;/span&amp;gt; is Jupiter's moon {{w|Callisto (moon)|Callisto}}, in &amp;lt;span style=&amp;quot;color:cyan;&amp;quot;&amp;gt;cyan&amp;lt;/span&amp;gt; is the moon {{w|Europa (moon)|Europa}} &amp;amp;mdash; the primary target of the spacecraft's study &amp;amp;mdash; and in &amp;lt;span style=&amp;quot;color:#FF4500;&amp;quot;&amp;gt;orange-red&amp;lt;/span&amp;gt; is the innermost of Jupiter's four {{w|Galilean moons|&amp;quot;Galilean&amp;quot;}} moons, {{w|Io (moon)|Io}}. The spacecraft's track is shown in &amp;lt;span style=&amp;quot;color:magenta;&amp;quot;&amp;gt;magenta&amp;lt;/span&amp;gt;. Jupiter's largest moon {{w|Ganymede (moon)|Ganymede}} is not shown, but its gravitational pull affects the ''Clipper's'' trajectory. A mission goal is to achieve a 6:1 {{w|orbital resonance}} with Europa by September 2034.[https://www.researchgate.net/profile/Martin-Ozimek/publication/383115312_AAS_24-433_Europa_Clipper_Mission_Analysis_Pump_Down_Trajectory_Design/links/66bcd845311cbb094938dbd6/AAS-24-433-Europa-Clipper-Mission-Analysis-Pump-Down-Trajectory-Design.pdf] ]]&lt;br /&gt;
&lt;br /&gt;
The ''{{w|Europa Clipper}}'' space probe was launched from the {{w|Kennedy Space Center}} in Florida on October 14, 2024. It is expected to arrive at Jupiter and begin exploration of Jupiter's moons, particularly {{w|Europa (moon)|Europa}}, in April of 2030. &lt;br /&gt;
&lt;br /&gt;
Europa is an icy moon. Water ice covers its surface. Beneath the ice, there is expected to be liquid water, which might contain living microbes.[https://europa.nasa.gov/why-europa/ingredients-for-life/] To sample this liquid, its crust (water ice) would need to be broken.&lt;br /&gt;
&lt;br /&gt;
Europa's icy surface may be compared to the caramelized crust on the popular dessert {{w|crème brûlée}}, which is traditionally cracked with a spoon before eating. The caramel cream dessert is believed to have been [https://archive.org/details/lagastronomieaug00sabb/page/272/mode/2up invented in Europe]. In {{w|Greek mythology}}, Europa was a {{w|Phoenician}} princess who {{w|Zeus}}, the king of the gods, abducted after transforming himself into a bull. Both the continent Europe and Jupiter's moon were named after Europa. Thus [[Randall]] suggests the spacecraft might encounter crème brûlée, and has therefore been equipped with a spoon for the purpose of collecting samples, as spoons are the traditional {{w|tableware}} provided for eating such desserts.[https://europa.nasa.gov/mission/about/] Perhaps because the {{w|Cassini-Huygens}} probe, after landing on the surface of Saturn's moon Titan in January of 2005, found that its surface had what was described as [https://www.sciencenews.org/article/world-unveiled-cr%C3%A8me-br%C3%BBl%C3%A9e-titan a &amp;quot;crème brûlée&amp;quot; consistency].&lt;br /&gt;
&lt;br /&gt;
No such spoon is present on the ''Europa Clipper.''{{cn}} Its course is designed to avoid contact with Europa so as to prevent {{w|Planetary protection|contamination by microorganisms from Earth}}. The spacecraft is, however, equipped with a magnetometer at the end of a 8.5 meter deployable boom. Deployable instruments on spacecraft have often failed to deploy correctly, so the successful deployment of any instrument is considered a cause for celebration.&lt;br /&gt;
&lt;br /&gt;
&amp;lt;div style=&amp;quot;display: flex; justify-content: center; align-items: center; margin: 1em 0;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;div style=&amp;quot;text-align: center; margin: 0 1em;&amp;quot;&amp;gt;&lt;br /&gt;
    [[File:Europa_-_Perijove_45_(cropped).png|200px|alt=Europa]]&lt;br /&gt;
    &amp;lt;div&amp;gt;Europa&amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;div style=&amp;quot;text-align: center; margin: 0 1em;&amp;quot;&amp;gt;&lt;br /&gt;
    [[File:2014_0531_Crème_brûlée_Doi_Mae_Salong_(cropped).jpg|200px|alt=Crème brûlée]]&lt;br /&gt;
    &amp;lt;div&amp;gt;Crème brûlée&amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;div style=&amp;quot;text-align: center; margin: 0 1em;&amp;quot;&amp;gt;&lt;br /&gt;
    [[File:Europa_Clipper_spacecraft_model.png|200px|alt=The Europa Clipper spacecraft]]&lt;br /&gt;
    &amp;lt;div&amp;gt;The ''Europa Clipper'' spacecraft&amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;/div&amp;gt;&lt;br /&gt;
&amp;lt;/div&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The title text expands on the joke by stating that the spacecraft &amp;quot;had BETTER&amp;quot; return samples of Europa to Earth. However, the ''Europa Clipper'' is not a {{w|sample-return mission}}.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A space probe with two rectangular solar panels, a circular dish of the front, and a very large spoon extending beneath, longer than the span of both solar panels]&lt;br /&gt;
&lt;br /&gt;
:[Below the panel:]&lt;br /&gt;
:Good news: NASA's '''''Europa Clipper''''' is en route to Europa and has successfully deployed its crème brûlée spoon.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
The Clipper spacecraft was at one point to be developed alongside a lander, which was later dropped from being part of the same (or very closely partnered) mission. The latest version of the {{w|Europa Lander}} proposal is far behind the Clipper in implementation, not yet even being guaranteed funding.&lt;br /&gt;
&lt;br /&gt;
Any actual sample return mission is currently far into the future of {{w|Ocean Worlds Exploration Program|the related plans for exploration}}, along with the possibility of digging deep enough into the ice to finally confirm or dismiss some of the more interesting theories about the world concerned.&lt;br /&gt;
&lt;br /&gt;
In Arthur C Clarke's novel '''2010''', the monolith aliens tell humanity ''&amp;quot;All these worlds are yours - except Europa. Attempt no landing there.&amp;quot;'' Contrary to the suggestion of the comic, no landing or any other physical interaction beyond observation of the surface of Europa is planned.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Space]]&lt;br /&gt;
[[Category:Space probes]]&lt;br /&gt;
[[Category:Food]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3011:_Europa_Clipper&amp;diff=356819</id>
		<title>3011: Europa Clipper</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3011:_Europa_Clipper&amp;diff=356819"/>
				<updated>2024-11-14T18:20:44Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ images&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3011&lt;br /&gt;
| date      = November 13, 2024&lt;br /&gt;
| title     = Europa Clipper&lt;br /&gt;
| image     = europa_clipper_2x.png&lt;br /&gt;
| imagesize = 333x356px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = They had BETTER make this a sample return mission.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
&lt;br /&gt;
{{incomplete|Created by a JOVIAN DESSERT. Please consider deleting this tag too soon, but refrain from doing so.}}&lt;br /&gt;
&lt;br /&gt;
[[File:Animation of Europa Clipper trajectory around Jupiter.gif|thumb|right|The ''Europa Clipper's'' projected course around {{w|Jupiter}}, represented as the stationary &amp;lt;span style=&amp;quot;color:green;&amp;quot;&amp;gt;green&amp;lt;/span&amp;gt; dot. In &amp;lt;span style=&amp;quot;color:gold;&amp;quot;&amp;gt;gold&amp;lt;/span&amp;gt; is Jupiter's moon {{w|Callisto (moon)|Callisto}}, in &amp;lt;span style=&amp;quot;color:cyan;&amp;quot;&amp;gt;cyan&amp;lt;/span&amp;gt; is the moon {{w|Europa (moon)|Europa}} &amp;amp;mdash; the primary target of the spacecraft's study &amp;amp;mdash; and in &amp;lt;span style=&amp;quot;color:#FF4500;&amp;quot;&amp;gt;orange-red&amp;lt;/span&amp;gt; is the innermost of Jupiter's four {{w|Galilean moons|&amp;quot;Galilean&amp;quot;}} moons, {{w|Io (moon)|Io}}. The spacecraft's track is shown in &amp;lt;span style=&amp;quot;color:magenta;&amp;quot;&amp;gt;magenta&amp;lt;/span&amp;gt;. Jupiter's largest moon {{w|Ganymede (moon)|Ganymede}} is not shown, but its gravitational pull affects the ''Clipper's'' trajectory. A mission goal is to achieve a 6:1 {{w|orbital resonance}} with Europa by September 2034.[https://www.researchgate.net/profile/Martin-Ozimek/publication/383115312_AAS_24-433_Europa_Clipper_Mission_Analysis_Pump_Down_Trajectory_Design/links/66bcd845311cbb094938dbd6/AAS-24-433-Europa-Clipper-Mission-Analysis-Pump-Down-Trajectory-Design.pdf] ]]&lt;br /&gt;
&lt;br /&gt;
The ''{{w|Europa Clipper}}'' space probe was launched from the {{w|Kennedy Space Center}} in Florida on October 14, 2024. It is expected to arrive at Jupiter and begin exploration of Jupiter's moons, particularly {{w|Europa (moon)|Europa}}, in April of 2030. &lt;br /&gt;
&lt;br /&gt;
Europa is an icy moon. Water ice covers its surface. Beneath the ice, there is expected to be liquid water, which might contain living microbes.[https://europa.nasa.gov/why-europa/ingredients-for-life/] To sample this liquid, its crust (water ice) would need to be broken.&lt;br /&gt;
&lt;br /&gt;
Europa's icy surface may be compared to the caramelized crust on the popular dessert {{w|crème brûlée}}, which is traditionally cracked with a spoon before eating. The caramel cream dessert is believed to have been [https://archive.org/details/lagastronomieaug00sabb/page/272/mode/2up invented in Europe]. In {{w|Greek mythology}}, Europa was a {{w|Phoenician}} princess who {{w|Zeus}}, the king of the gods, abducted after transforming himself into a bull. Both the continent Europe and Jupiter's moon were named after Europa. Thus [[Randall]] suggests the spacecraft might encounter crème brûlée, and has therefore been equipped with a spoon for the purpose of collecting samples, as spoons are the traditional {{w|tableware}} provided for eating such desserts.[https://europa.nasa.gov/mission/about/] Perhaps because the {{w|Cassini-Huygens}} probe, after landing on the surface of Saturn's moon Titan in January of 2005, found that its surface had what was described as [https://www.sciencenews.org/article/world-unveiled-cr%C3%A8me-br%C3%BBl%C3%A9e-titan a &amp;quot;crème brûlée&amp;quot; consistency].&lt;br /&gt;
&lt;br /&gt;
No such spoon is present on the ''Europa Clipper.''{{cn}} Its course is designed to avoid contact with Europa so as to prevent {{w|Planetary protection|contamination by microorganisms from Earth}}. The spacecraft is, however, equipped with a magnetometer at the end of a 8.5 meter deployable boom. Deployable instruments on spacecraft have often failed to deploy correctly, so the successful deployment of any instrument is considered a cause for celebration.&lt;br /&gt;
&lt;br /&gt;
&amp;lt;div style=&amp;quot;display: flex; justify-content: center; align-items: center; margin: 1em 0;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;div style=&amp;quot;text-align: center; margin: 0 1em;&amp;quot;&amp;gt;&lt;br /&gt;
    [[File:Europa_-_Perijove_45_(cropped).png|200px|alt=Europa]]&lt;br /&gt;
    &amp;lt;div&amp;gt;Europa&amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;div style=&amp;quot;text-align: center; margin: 0 1em;&amp;quot;&amp;gt;&lt;br /&gt;
    [[File:2014_0531_Crème_brûlée_Doi_Mae_Salong_(cropped).jpg|200px|alt=Crème brûlée]]&lt;br /&gt;
    &amp;lt;div&amp;gt;Crème brûlée&amp;lt;/div&amp;gt;&lt;br /&gt;
  &amp;lt;/div&amp;gt;&lt;br /&gt;
&amp;lt;/div&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The title text expands on the joke by stating that the spacecraft &amp;quot;had BETTER&amp;quot; return samples of Europa to Earth. However, the ''Europa Clipper'' is not a {{w|sample-return mission}}.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[A space probe with two rectangular solar panels, a circular dish of the front, and a very large spoon extending beneath, longer than the span of both solar panels]&lt;br /&gt;
&lt;br /&gt;
:[Below the panel:]&lt;br /&gt;
:Good news: NASA's '''''Europa Clipper''''' is en route to Europa and has successfully deployed its crème brûlée spoon.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
The Clipper spacecraft was at one point to be developed alongside a lander, which was later dropped from being part of the same (or very closely partnered) mission. The latest version of the {{w|Europa Lander}} proposal is far behind the Clipper in implementation, not yet even being guaranteed funding.&lt;br /&gt;
&lt;br /&gt;
Any actual sample return mission is currently far into the future of {{w|Ocean Worlds Exploration Program|the related plans for exploration}}, along with the possibility of digging deep enough into the ice to finally confirm or dismiss some of the more interesting theories about the world concerned.&lt;br /&gt;
&lt;br /&gt;
In Arthur C Clarke's novel '''2010''', the monolith aliens tell humanity ''&amp;quot;All these worlds are yours - except Europa. Attempt no landing there.&amp;quot;'' Contrary to the suggestion of the comic, no landing or any other physical interaction beyond observation of the surface of Europa is planned.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Space]]&lt;br /&gt;
[[Category:Space probes]]&lt;br /&gt;
[[Category:Food]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354706</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354706"/>
				<updated>2024-10-26T23:43:12Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ not sure this helps explain anything&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32.&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in the U.S., its territories, the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5.&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5.&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;{{acn}} || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. His scale used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, 34ºN, rapidly boiling water.[https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales] Therefore:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 37 × Newton / 12 if Newton ≤ 12;&amp;lt;br/&amp;gt;or 63 × (Newton – 12) / 22 + 37 if Newton &amp;gt; 12.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = 12 × Celsius / 37 if Celsius ≤ 37;&amp;lt;br/&amp;gt;or 22 × (Celsius – 37) / 63 + 12 if Celsius &amp;gt; 37.&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43] The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0;&amp;lt;br/&amp;gt;or 78 × Galen / 4 + 22 if Galen &amp;gt; 0.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22;&amp;lt;br/&amp;gt;or 4 × (Celsius – 22) / 78 if Celsius &amp;gt; 22.&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 ).&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high and average temperature records increasing almost every year as a result of {{w|climate change}},[https://www.space.com/last-12-months-broke-temperature-records] Randall's new °X scale must be re-calibrated each year. While such °X values for to everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange {{w|human body temperature|human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.1 °N || 0 °N || 34 °N || 12 °N || 0.8 °N || –5.8 °N || 12.7 °N || 26 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, Water freezing point, Water boiling point, Notes, and Cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354704</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354704"/>
				<updated>2024-10-26T23:41:57Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ oops center&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32.&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5.&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5.&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;{{acn}} || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. His scale used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, 34ºN, rapidly boiling water.[https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales] Therefore:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 37 × Newton / 12 if Newton ≤ 12;&amp;lt;br/&amp;gt;or 63 × (Newton – 12) / 22 + 37 if Newton &amp;gt; 12.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = 12 × Celsius / 37 if Celsius ≤ 37;&amp;lt;br/&amp;gt;or 22 × (Celsius – 37) / 63 + 12 if Celsius &amp;gt; 37.&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43] The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0;&amp;lt;br/&amp;gt;or 78 × Galen / 4 + 22 if Galen &amp;gt; 0.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22;&amp;lt;br/&amp;gt;or 4 × (Celsius – 22) / 78 if Celsius &amp;gt; 22.&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 ).&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high and average temperature records increasing almost every year as a result of {{w|climate change}},[https://www.space.com/last-12-months-broke-temperature-records] Randall's new °X scale must be re-calibrated each year. While such °X values for to everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange {{w|human body temperature|human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.1 °N || 0 °N || 34 °N || 12 °N || 0.8 °N || –5.8 °N || 12.7 °N || 26 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, Water freezing point, Water boiling point, Notes, and Cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354698</id>
		<title>File:Temperature Scales.png</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354698"/>
				<updated>2024-10-26T23:40:27Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: Liv2splain uploaded a new version of File:Temperature Scales.png&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;All the scales from [[3001: Temperature Scales]] plus [[1923: Felsius]].&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354697</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354697"/>
				<updated>2024-10-26T23:39:03Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ fix Newton conversions, again&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32.&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5.&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5.&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;{{acn}} || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. His scale used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, 34ºN, rapidly boiling water.[https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales] Therefore:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 37 × Newton / 12 if Newton ≤ 12;&amp;lt;br/&amp;gt;or 63 × (Newton – 12) / 22 + 37 if Newton &amp;gt; 12.&amp;lt;/center&amp;gt;&lt;br /&gt;
Newton = 12 × Celsius / 37 if Celsius ≤ 37;&amp;lt;br/&amp;gt;or 22 × (Celsius – 37) / 63 + 12 if Celsius &amp;gt; 37.&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43] The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0;&amp;lt;br/&amp;gt;or 78 × Galen / 4 + 22 if Galen &amp;gt; 0.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22;&amp;lt;br/&amp;gt;or 4 × (Celsius – 22) / 78 if Celsius &amp;gt; 22.&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 ).&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high and average temperature records increasing almost every year as a result of {{w|climate change}},[https://www.space.com/last-12-months-broke-temperature-records] Randall's new °X scale must be re-calibrated each year. While such °X values for to everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange {{w|human body temperature|human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.1 °N || 0 °N || 34 °N || 12 °N || 0.8 °N || –5.8 °N || 12.7 °N || 26 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, Water freezing point, Water boiling point, Notes, and Cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354696</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354696"/>
				<updated>2024-10-26T23:37:26Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Examples */ fix Newtons, again&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32.&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5.&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5.&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;{{acn}} || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. His scale used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, 34ºN, rapidly boiling water.[https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales] Therefore:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 12 × Newton / 37 if Newton ≤ 12;&amp;lt;br/&amp;gt;or 22 × (Newton – 12) / 63 + 37 if Newton &amp;gt; 12.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = 37 × Celsius / 12 if Celsius ≤ 37;&amp;lt;br/&amp;gt;or 63 × (Celsius – 37) / 22 + 12 if Celsius &amp;gt; 37.&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43] The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0;&amp;lt;br/&amp;gt;or 78 × Galen / 4 + 22 if Galen &amp;gt; 0.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22;&amp;lt;br/&amp;gt;or 4 × (Celsius – 22) / 78 if Celsius &amp;gt; 22.&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 ).&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high and average temperature records increasing almost every year as a result of {{w|climate change}},[https://www.space.com/last-12-months-broke-temperature-records] Randall's new °X scale must be re-calibrated each year. While such °X values for to everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange {{w|human body temperature|human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.1 °N || 0 °N || 34 °N || 12 °N || 0.8 °N || –5.8 °N || 12.7 °N || 26 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, Water freezing point, Water boiling point, Notes, and Cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354695</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354695"/>
				<updated>2024-10-26T23:32:15Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Transcript */ wikicase&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32.&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5.&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5.&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;{{acn}} || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. His scale used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, 34ºN, rapidly boiling water.[https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales] Therefore:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 12 × Newton / 37 if Newton ≤ 12;&amp;lt;br/&amp;gt;or 22 × (Newton – 12) / 63 + 37 if Newton &amp;gt; 12.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = 37 × Celsius / 12 if Celsius ≤ 37;&amp;lt;br/&amp;gt;or 63 × (Celsius – 37) / 22 + 12 if Celsius &amp;gt; 37.&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43] The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0;&amp;lt;br/&amp;gt;or 78 × Galen / 4 + 22 if Galen &amp;gt; 0.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22;&amp;lt;br/&amp;gt;or 4 × (Celsius – 22) / 78 if Celsius &amp;gt; 22.&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 ).&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high and average temperature records increasing almost every year as a result of {{w|climate change}},[https://www.space.com/last-12-months-broke-temperature-records] Randall's new °X scale must be re-calibrated each year. While such °X values for to everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange {{w|human body temperature|human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 67.8 °N || 0 °N || 34 °N || 114.1 °N || 7.7 °N || –55.5 °N || 12.7 °N || 26.0 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, Water freezing point, Water boiling point, Notes, and Cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354694</id>
		<title>Talk:3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354694"/>
				<updated>2024-10-26T23:17:44Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: these are the same section&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
Shouldn't Rankine say &amp;quot;0ºR is set to absolute zero&amp;quot;? {{unsigned ip|172.70.230.29|22:58, 21 October 2024 (UTC)}}&lt;br /&gt;
:Yep. [[Special:Contributions/162.158.186.253|162.158.186.253]] 04:38, 22 October 2024 (UTC)&lt;br /&gt;
:Furthermore, should it be 0°R or just 0R (no °)? I've been told that Kelvin doesn't use degrees because it's an absolute scale, so a) is this true and b) should it apply to Rankine? [[Special:Contributions/172.71.211.54|172.71.211.54]] 14:44, 24 October 2024 (UTC)&lt;br /&gt;
::Kelvin is rather strange, for reasons never totally explained. It's &amp;quot;the Kelvin scale&amp;quot;, but the unit is &amp;quot;kelvin&amp;quot; and I never got on with the official absence of the ° symbol by the &amp;quot;K&amp;quot;. I was always taught to ''say'' &amp;quot;degrees kelvin&amp;quot; (for temperatures) and &amp;quot;kelvin degrees&amp;quot; (for a change/range of temperature) in order to not cause confusion and technical misunderstandings (''perhaps'' easier to contextualise when down in writing?) but no accounting for taste, or possibly official laziness.&lt;br /&gt;
::On the basis that Rankine is not kelvin (whatever the reason for how kelvin is what it is), I would use the degrees, as I would any other absolute scale (whether it be an adjusted form of °Rø or °Ré or whatever else might be invented), because kelvin is just inexplicably (to me, and to others) ''the'' exception to absolutely every other reasonably equivalent contemporary measure, including capitalisation. YMMV! [[Special:Contributions/172.70.162.2|172.70.162.2]] 19:53, 24 October 2024 (UTC)&lt;br /&gt;
:::0ºRa, not 0ºR. [[Special:Contributions/172.70.206.157|172.70.206.157]] 02:16, 25 October 2024 (UTC)&lt;br /&gt;
::::Can be either. Perhaps best to use °Ra (in ambiguous context) to avoid ''possible'' confusion with °Ré and °Rø, but probably less important when both those two are also listed alongside (except for wondering what, if anything, is a typo, bad handwriting or other error). [[Special:Contributions/172.69.194.12|172.69.194.12]] 11:01, 25 October 2024 (UTC)&lt;br /&gt;
::::It's easy if you think about it like &amp;quot;meter&amp;quot;. You usually say &amp;quot;meters&amp;quot; not &amp;quot;the meter scale&amp;quot; although both are correct. Scientists and engineers who use them daily call them &amp;quot;kelvins&amp;quot;, not &amp;quot;kelvin&amp;quot; unless following a number. You wouldn't say &amp;quot;We need to measure this room in meter.&amp;quot; Someone keeps reverting me on this, and they're wrong, but I don't care much anymore. I'll probably fix it next month or something. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 21:10, 25 October 2024 (UTC)&lt;br /&gt;
:::::&amp;quot;Americans typically measure temperatures in Fahrenheits, whilst Europeans use Celsiusses...&amp;quot; hmm, no, that doesn't sound right at all. (Celciuses? No, wait. Celcii! Masculine Nominative Singular changed to the Plural, if I've got my Latin declensions right. But still doesn't sound right. Maybe I also need to use &amp;quot;Fahrenheit''en''&amp;quot;..? Wait, wasn't he born Polish, so that means...)&lt;br /&gt;
:::::Seriously, I think that if you talk of &amp;quot;measured in [the scale of] Celsius&amp;quot; you should probably talk of &amp;quot;... in [the scale of] Kelvin&amp;quot; (using the capital for the scale). According to the {{w|Kelvin#Orthography|orthography}}, you'd be right to specify &amp;quot;50 kelvins&amp;quot; (c.f. &amp;quot;50 degrees [whatever non-Kelvin measure]&amp;quot; ''or'' &amp;quot;50 [whatever non-Kelvin measure] degrees&amp;quot; for a range), but talking ''about'' the scale would definitely call for a simple &amp;quot;Kelvin&amp;quot;. [[Special:Contributions/172.68.205.135|172.68.205.135]] 21:39, 25 October 2024 (UTC) (PS., I'd also say &amp;quot;metre(s)&amp;quot;, but then I'm British... which might also colour (or 'color') my personal grammatical sensibilities. But oh what fun you lot seem to have had with this whole issue!)&lt;br /&gt;
::::::The units are ''degrees'' Celsius or Fahrenheit, but just kelvins, like watts or ohms or amps. It's explained in great detail in the article already. Fun?! Perhaps you should talk to someone who uses kelvins on a regular basis before you impose your imagined usage over the course of a half dozen reverts. [[Special:Contributions/172.70.206.73|172.70.206.73]] 23:16, 25 October 2024 (UTC)&lt;br /&gt;
:::::::Isn't that what was just said? Though I'd say &amp;quot;It's 50 kelvin&amp;quot;, apparently the 'right' way to say that is &amp;quot;It's 50 kelvins&amp;quot; (also &amp;quot;It went up by 50 kelvin&amp;quot;/&amp;quot;it went up by 50 kelvins&amp;quot;... that latter sounds off to me, and isn't how I've ever used it, but the orthography link suggests it's right).&lt;br /&gt;
:::::::But then one can talk about measuring temperatures (or temperature ranges) ''in'' Celsius or Fahrenheit or Delisle or whatever, because you're saying you're measuring things in ''the scale of'' whatever-it-is, so you can equally say you're measuring things in (the scale of) Kelvin. Not too different from saying that you're using the meter or the foot or the kiloparsec or the nanosecond or the coulomb-squared-per-barn or even the fortnight-per-firkin-furlong if you ever so wish. [[Special:Contributions/172.68.205.150|172.68.205.150]] 23:32, 25 October 2024 (UTC)&lt;br /&gt;
::::::::Tell me you never talk about kelvins in everyday work without telling me you never talk about kelvins in everyday work. [[Special:Contributions/172.68.22.98|172.68.22.98]] 13:59, 26 October 2024 (UTC)&lt;br /&gt;
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yo,i thought comic 3000 was anticlimactic so randall would make this one COOL but sadly not&lt;br /&gt;
Same. Hope he does something cool for 3072.[[Special:Contributions/172.69.134.225|172.69.134.225]] 23:44, 21 October 2024 (UTC)&lt;br /&gt;
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really he didn't do anything special for this either? come ON randall if you don't do something cool for comic 3072 i will &amp;lt;b&amp;gt; come to your house personally and yell at you  [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 23:57, 21 October 2024 (UTC)&lt;br /&gt;
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What's random about Fahrenheit? (Answer: nothing.) 0F is the freezing point of brine, 100F (or 98.7) is the human body temperature. [[Special:Contributions/172.68.54.65|172.68.54.65]] 00:00, 22 October 2024 (UTC)&lt;br /&gt;
:What concentration of brine? (And which specific salt... No, not NaCl, as you might presume but NH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Cl!)&lt;br /&gt;
:And body temperature varies a lot ('typically' 36.5–37.5°C or  97.7–99.5°F, though even this range is thought to be too small), across genders, individuals, time of day ''and'' which orifices/surfaces you try to measure it from. (Originally, it was set so that '''90°F''' was to be the 'best guess' of human body temperature. It gradually changed, including via various {{w|Human body temperature#Historical understanding|compounded misunderstandings}} so that the best you can say is that 100°F is arbitrarily ''slightly above'' most afebrile human body temperature measurements.)&lt;br /&gt;
:Celsius might be a bit off (arguments about triple-point or STP freezing, etc), but it still has far more physical logic to it. [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
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Sorry, Randall, for my comfort, Fahrenheit is the least cursed. It's the best scale to use for my personal use, especially when hearing the weather report and deciding what to wear outdoors: temp in the 80's - no jacket. temp in 70's - maybe a windbreaker if it's breezy. 60's - sweater weather. 50's - medium weight coat. 40's - winter coat. 30'3 - winter coat with scarf and gloves. 20's - multiple layers. teens - stay indoors. None of the other scales provide such convenient distinctions for my daily life. Kelvin is great for astro physics or super conductivity, but useless for any common uses. Celsius is great for hanging out with the Euro crowd but still not so useful to scale my home thermostat. I judge Fahrenheit as 1.0 for cursedness. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:19, 22 October 2024 (UTC)&lt;br /&gt;
:I conveniently use Celsius in tens, also. Negative °C: Cold; 0-10°C: Nippy; 10-20°C: Generally pleasant; 20-30°C: Too warm to exert oneself; 30°C+: ''Definitely'' too warm. [[Special:Contributions/172.70.86.205|172.70.86.205]] 15:24, 22 October 2024 (UTC)&lt;br /&gt;
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Personally, I'm most disappointed that {{w|Delisle scale}} was not represented... [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
: I was so hoping for a {{w|Planck temperature}} quip. Like: &amp;quot;Water freezing point: 0; Water boiling point: 0; Notes: 1 = highest possible temperature (1.4E32K) where thermal radiation creates black holes; Cursedness: 0/0&amp;quot; [[Special:Contributions/162.158.164.184|162.158.164.184]] 01:27, 22 October 2024 (UTC)&lt;br /&gt;
:: Same here. Freezing is 0.000000000000000000000000000001928 and boiling is 0.0000000000000000000000000000026338. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 03:38, 22 October 2024 (UTC)&lt;br /&gt;
::: Wow, those are even smaller than the IEEE floating point representations of 1-1.0/3*3! [[Special:Contributions/162.158.90.109|162.158.90.109]] 03:59, 22 October 2024 (UTC)&lt;br /&gt;
:: The Planck temperature quip is definitely well deserved. Good catch! [[User:Mumingpo|Mumingpo]] ([[User talk:Mumingpo|talk]]) 17:24, 23 October 2024 (UTC)&lt;br /&gt;
I guess I was wrong in my comment on the last comic. sigh. -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 01:16, 22 October 2024 (UTC)&lt;br /&gt;
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It's actually spelled {{w|Wedgwood scale}}, not Wedgewood. [[User:Wilh3lm|Wilh3lm]] ([[User talk:Wilh3lm|talk]]) 01:17, 22 October 2024 (UTC)&lt;br /&gt;
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I still call the modern version of the &amp;quot;Celsius&amp;quot; scale &amp;quot;centigrade&amp;quot;, but if people start nitpicking, I'm happy to switch to &amp;quot;Carolus&amp;quot; to avoid ambiguity. For some reason that tends to annoy people more though. [[Special:Contributions/172.68.22.191|172.68.22.191]] 01:32, 22 October 2024 (UTC)&lt;br /&gt;
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Every temperature scale is equally &amp;quot;random&amp;quot; as every other scale. People always say that Celsius is so much better because it's defined by the phase changes of water. Okay, cool...why should THAT of all things be what we use as the base for a system of temperature measurement? And, who cares? I'm a ''Homo sapiens'', not a water molecule. If anything we should use the freezing and melting points of humans as our two reference points for temperature (which, I must say, Fahrenheit approximates better than Celsius, assuming 0 and 100 are your points &amp;quot;A&amp;quot; and &amp;quot;B&amp;quot;). [[User:Pie Guy|Pie Guy]] ([[User talk:Pie Guy|talk]]) 03:42, 22 October 2024 (UTC)&lt;br /&gt;
: Every temperature scale is arbitrary, but since boiling and freezing water is a thing humans have a lot of experience with it makes sense to use that as the reference point. At least it makes more sense than whatever the coldest recorded temperature in Fahrenheit's home town was, because he didn't like negative numbers [[Special:Contributions/172.70.250.23|172.70.250.23]] 03:56, 22 October 2024 (UTC)&lt;br /&gt;
::Planck temperature (as above) is probably the least arbitrary, and some would say it is to some extent free from arbitrariness. However, it's completely impractical for everyday use (as above.) [[Special:Contributions/172.69.34.138|172.69.34.138]] 04:31, 22 October 2024 (UTC)&lt;br /&gt;
:::Do the physics of black holes or neutron stars involve Planck temperatures greater than 0.0000001? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:23, 22 October 2024 (UTC)&lt;br /&gt;
::::Chat Gippity told me:&lt;br /&gt;
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:::::Black holes and neutron stars do not typically involve temperatures reaching the Planck scale. While both objects exhibit extreme physical conditions, their temperatures are far below the Planck temperature, even though they can be incredibly high compared to everyday phenomena.&lt;br /&gt;
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::::: - **Neutron stars** have surface temperatures in the range of millions of Kelvin, and the core can reach even higher, possibly up to a few billion Kelvin. These temperatures are still vastly lower than the Planck temperature.&lt;br /&gt;
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::::: - **Black holes**, especially the smaller ones, can emit Hawking radiation, with temperatures inversely proportional to their mass. However, the temperature of even a very small black hole is still far below the Planck temperature. Hawking radiation is not expected to reach temperatures close to the Planck scale under normal circumstances.&lt;br /&gt;
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::::: The Planck temperature (TP=1) represents an energy scale so extreme that no known physical models, including those describing black holes and neutron stars, operate near or above this threshold. Temperatures reaching **0.0000001 TP** (or 1.416 × 10^26 K) would still be beyond current observational and theoretical frameworks related to these cosmic objects. A quantum theory of gravity would be required to describe physics at or near the Planck temperature, which remains speculative and is far beyond the conditions found in black holes or neutron stars.&lt;br /&gt;
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::::[[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:46, 22 October 2024 (UTC)&lt;br /&gt;
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If the °X scale is based on the temperatures of Earth from all time (for some definition of &amp;quot;Earth&amp;quot;), then the scale is very hard to define and highly impractical. The earth appears to have gotten to more than 2,300 Kelvin (hot enough to melt steel and platinum and to boil lead) and while I can't find any sources for the lowest temperature, I imagine it is lower than -100°C. The recorded minimum, maximum and average temperatures appear to be around -89.2 °C, 56.7 °C and 15 °C respectively. This would make the scale somewhat useful, but this would make typical values between 41 °X (cold winter's day) and 68 °X (hot summers day) which I think is pretty cursed. I recommend the clearly superior °Y, based around average temp at 0 °Y, low at -100 °Y and high at 100 °Y. These would be measured by the yearly high, low and mean temperatures averaged per person. Then saying &amp;quot;It's 2 times colder than yesterday&amp;quot; would have some reasonable meaning. --[[Special:Contributions/198.41.236.147|198.41.236.147]] 04:01, 22 October 2024 (UTC)&lt;br /&gt;
:&amp;quot;''Record'' ... surface temperature&amp;quot; implies it was recorded. [[Special:Contributions/172.68.22.9|172.68.22.9]] 04:08, 22 October 2024 (UTC)&lt;br /&gt;
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How do you all feel about adding an additional column for room temperature 22C/72F?&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
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Or 0.00000000000000000000000000000208 °Planck, lol. [[Special:Contributions/108.162.245.211|108.162.245.211]] 05:36, 22 October 2024 (UTC)&lt;br /&gt;
:I feel like decigalens would be the most practical unit. Who's with me? [[Special:Contributions/162.158.186.5|162.158.186.5]] 06:20, 22 October 2024 (UTC)&lt;br /&gt;
::It's interesting; calculating the equilibrium temperature (with 2.05 and 4.24 being used for the heat capacities of ice and boiling water) gives 67... If I use water that's about to freeze and steam, I get 31. [[Special:Contributions/172.69.0.178|172.69.0.178]] 07:59, 22 October 2024 (UTC)&lt;br /&gt;
:::Would you please explain in more detail? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:03, 22 October 2024 (UTC)&lt;br /&gt;
:::: The equilibrium temperature of a mixture (?) of equal quantities of ice at 0 C and water at 100 C (with the heat capacities 2.05 and 4.24) is 67 C; if I use the data for water at 0 C and steam, I get 31 C. Additionally, if I use equal volumes, I get 68 (which isn't much different.) [[Special:Contributions/172.69.0.178|172.69.0.178]] 17:15, 22 October 2024 (UTC)&lt;br /&gt;
:::: One can obtain 0 = 22 C by setting the heat capacity of ice to be 39 and that of water to be 11. For any particular &amp;quot;normal temperature&amp;quot; ''R'' °C (that is, the temperature at 0 is ''R'',), I find that ''x'' °C = 50''R''(''x''+4)/(''x''(''R''-50)+200). In particular, for ''R'' = 22, we get (1100+275''x'')/(50-7''x''). [[Special:Contributions/198.41.236.163|198.41.236.163]] 05:58, 23 October 2024 (UTC)&lt;br /&gt;
::How about Tnew=0.1694×degC+46.25; degC=(Tnew-46.25)/0.1694, where 0 is absolute zero and 50 is room temperature? (Freezing point of water: 46.25; Boiling point of water: 63.19) [[Special:Contributions/162.158.186.248|162.158.186.248]] 05:21, 24 October 2024 (UTC)&lt;br /&gt;
:I would absolutely pull the trigger on an additional column if I didn't think it would further screw up what are most probably extremely cursed mobile portrait renderings of the table. How about a Trivia section? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:44, 24 October 2024 (UTC)&lt;br /&gt;
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Question regarding the X scale - when it‘s defined by *three* (somewhat, implying average is real and not just calculated by (max-min)/2)) independent points, how will linearity be achieved? [[Special:Contributions/162.158.155.76|162.158.155.76]] 05:43, 22 October 2024 (UTC)&lt;br /&gt;
[[File:Explanation length.png|right|thumb|Or click &amp;quot;[Expand]&amp;quot; in the bottom right table cell Derivation.]]&lt;br /&gt;
:Please see [[2701: Change in Slope]]. [[Special:Contributions/172.70.206.179|172.70.206.179]] 05:50, 22 October 2024 (UTC)&lt;br /&gt;
:Sure, &amp;quot;a linear scale between each point&amp;quot;:&lt;br /&gt;
[[File:XvsC.png|thumb|left|Here you go. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 06:33, 22 October 2024 (UTC)]]&lt;br /&gt;
{{clear}}&lt;br /&gt;
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The reference for the average surface temperature, https://www.space.com/17816-earth-temperature.html, suggests it has increased above 15°C. What value should we use in late 2024? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:30, 22 October 2024 (UTC)&lt;br /&gt;
:The [https://wmo.int/media/news/earth-experiences-warmest-day-recent-history World Meteorological Organization], [https://www.carbonbrief.org/state-of-the-climate-2024-now-very-likely-to-be-warmest-year-on-record/ Carbon Brief], and [https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024 Copernicus Climate Change Service] suggest 17.16°C. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:42, 22 October 2024 (UTC)&lt;br /&gt;
::Updated water temperatures, Derivation, and graph. So we've already had more than the +2°C warming we were trying to avoid in 2019? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:05, 22 October 2024 (UTC)&lt;br /&gt;
::: The +2°C (or +1.5°C that we were originally supposed to be avoiding) is over some (undefined) number of years, though, which allows us to ignore the fact that we're cooking ourselves by repeatedly saying 'Oh, but it doesn't count ''yet''.' [[Special:Contributions/172.70.91.62|172.70.91.62]] 11:13, 23 October 2024 (UTC)&lt;br /&gt;
Regarding [https://www.explainxkcd.com/wiki/index.php?title=3001%3A_Temperature_Scales&amp;amp;type=revision&amp;amp;diff=353635&amp;amp;oldid=353632], are the average surface temperatures from the sources supposed to be yearly or overall averages? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:06, 22 October 2024 (UTC)&lt;br /&gt;
:According to https://climate.copernicus.eu/climate-indicators/temperature the global average near-surface temperature in 2023 was 14.4 + 0.4 = 14.8°C. (see Figure 1 and click &amp;quot;Increase above: [1991–2020 reference period].&amp;quot;) [[Special:Contributions/172.68.22.8|172.68.22.8]] 21:06, 23 October 2024 (UTC)&lt;br /&gt;
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where is the interactive epic 3000 comic we should've gotten? This one's cool but 1000 seemed to have more effort in it and 2000 was at least tangetially related. Does Randall just not like making these anymore and is only making more comics as a business? [[Special:Contributions/108.162.238.185|108.162.238.185]] 12:14, 22 October 2024 (UTC)&lt;br /&gt;
:The comic is free on the website and it doesn't have ads; although the comic is part of his &amp;quot;brand&amp;quot; there are many more profitable things he could be doing with his time, and yet he continues to update it every Monday, Wednesday, and Friday.  I just don't like the idea of claiming that a creative person &amp;quot;should&amp;quot; produce any particular thing to satisfy their fans.  He's a busy guy!  Maybe he's working on a book, or a Scientific American article, or a TV show.  He's under no obligation to give us anything, and maybe one day he'll stop making xkcd altogether; that's his choice.  Sorry to single you out; I know a lot of people feel the same way as you do, but to me it doesn't make sense.  He's not a content machine--he's a guy who started posting sketches on the internet. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 15:23, 22 October 2024 (UTC)&lt;br /&gt;
::Sorry if I sounded overly brash, I wasn't trying to imply &amp;quot;wahhh no special entry wahhh&amp;quot;, I was just wondering if Randall still likes to make these or if he doesn't, mainly because he just didn't do anything special, which feels like he just didn't care. I wasn't trying to imply Randall should just do it for the fans[[Special:Contributions/108.162.238.80|108.162.238.80]] 17:52, 22 October 2024 (UTC)&lt;br /&gt;
:::It ''could'' be that 3000 (or even 3001) ''was'' going to be special but, as fairly frequently with April Fool 'specials', it just wasn't doable on time. (If it's still considered fixablez it might pop up sometime before 3020 or so. Or, if transferable to another occasion (rebranding the obvious &amp;quot;3000!&amp;quot;ness), held over until Haloween, Christmas, April or 4000, perhaps with additional perfections.)&lt;br /&gt;
:::Hard to know, unless Randall (or his technical collaborators) say anything. And it's probably not worth doing so right now. Maybe &amp;quot;Hey guys, this ''was'' going to be #3000!&amp;quot; might accompany its eventual emergence, but also maybe not. Does it really matter? [[Special:Contributions/172.70.85.139|172.70.85.139]] 13:03, 23 October 2024 (UTC)&lt;br /&gt;
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Is this the first list-style comic where every single entry is real? (Usually he has several joke entries.) [[Special:Contributions/172.70.114.182|172.70.114.182]] 14:26, 22 October 2024 (UTC)&lt;br /&gt;
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Where would [[1923: Felsius|Felsius]] go on this list?&lt;br /&gt;
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One can find a smooth function for °X, namely, (477879''x''-17634840)/(3341''x''+197700), which takes °X and returns °C. The inverse is (-197700''x''-17634840)/(3341''x''-477879). Should this be included in the wiki article? Or maybe another way of fitting it (like exponential) should be used.  [[Special:Contributions/172.69.0.165|172.69.0.165]] 06:27, 23 October 2024 (UTC)&lt;br /&gt;
:It says &amp;quot;a linear scale between each point&amp;quot;. [[Special:Contributions/172.70.210.130|172.70.210.130]] 21:09, 23 October 2024 (UTC)&lt;br /&gt;
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Should it be noted that in the first _What If?_ book, there's a reference to units and how much Randall loathes rankine? Someone can go take the book and cite it; it's in one of the early pages [[Special:Contributions/172.64.236.10|172.64.236.10]] 08:45, 23 October 2024 (UTC)&lt;br /&gt;
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I remember it being drummed into us in school physics (admittedly over 50 years ago) that 0 Celsius is defined as the melting point of ice, not the freezing point of water (presumably because of supercooling). [[Special:Contributions/172.70.160.189|172.70.160.189]] 08:49, 23 October 2024 (UTC)&lt;br /&gt;
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It seems he wrote &amp;quot;Earths'&amp;quot; (plural possessive) instead of &amp;quot;Earth's&amp;quot;. [[Special:Contributions/141.101.98.151|141.101.98.151]] 08:58, 23 October 2024 (UTC)&lt;br /&gt;
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What?  No gas mark?  It's linear for temperatures over 275°F but inverse powers of 2 below  That's pretty cursed, but I still put it in my unit conversion app.  It's only used in gas stoves in a few countries, so it doesn't come up very often.  By the way, boiling is 1/5.7358 and freezing/melting is 1/843.3572.  Interestingly, France has it's own stove temperature scale that seems to be based on °F.&lt;br /&gt;
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Also, my understanding is that 7.5 and 32 aren't random.  Both Romer and Fahrenheit put numbers on things so that freezing/melting of water and &amp;quot;Normal human body temperature&amp;quot;, which was thought to be standard at the time, would be some number X (15 for Romer and 64 for Fahrenheit) and the water thing would be to be X/2 and NHBT would be X/2+X.  Pretty nerdy.  Sadly, the calibration was off and 212 degrees for boiling was found to be less cursed.  But I could be wrong.[[Special:Contributions/172.68.54.138|172.68.54.138]] 20:39, 23 October 2024 (UTC)&lt;br /&gt;
:Re: water/ice point 'random number', I think it's more that it wasn't considered &amp;quot;special&amp;quot;, such that &amp;quot;On my scale, that will be zero&amp;quot; (or whatever choice of handily round number, including zero, some scale-setters allocated to the BP of water).&lt;br /&gt;
:After all the other messing about (&amp;quot;my zero will be that of brine!&amp;quot;, etc), obviously then the ~0°C equivalent would ''have'' a number, and ''perhaps''  there would then be a slight change to make it a ''whole'' (or easy-fraction) number for convenience's sake, but (before the concept of binary computers) there's not much special about landing on the number 32, for what is actually a temperature that is quite significant to the human experience, and less so with 7-''and-a-half''.&lt;br /&gt;
:Maybe landing on 90°F (at one time) for body temperature (and 180 F° ''between'' MP and BP) was considered useful as the analogue to angular-degrees where 90 (and 180) indeed features significantly, but I don't think there'd have been too much fuss if the value would have turned out to be 60(/120), also with plenty of handy factors to divide by, 70(/140), without so much, or whatever number(s) happened to depict one realistic real-world measurement that (overall) has no reason to have a factor-based relationship with various quite separate phenomenon measurements.&lt;br /&gt;
:''And'' it went through several {{w|Human body temperature#Historical understanding|'corrective' iterations}} so that even its handy relationship with 'about 100°F' can be said to be an incidental accident, at best, unless we do something like Randall's °X scale and actively triple-tie the central value of the slope(s) to be exactly something useful by using the &amp;quot;currently accepted mean human body temperature (given various complicated caveats)&amp;quot;.&lt;br /&gt;
:It's pretty much all random, in the same way that only because of anthropocentric choices of 'standard' time and distance measurements is the speed of light 'pretty much' 3×10⁸ m/s (a handily round value that works well enough for most purposes, even after back-standardising its component SI measurements to make &amp;quot;actually, &amp;lt;u&amp;gt;precisely&amp;lt;/u&amp;gt; 299792458&amp;quot; the ''proper'' answer, and [https://conversion.org/speed/speed-of-light/furlong-per-fortnight it could be far worse...]). Avagadro's number never had it so good (6.022(+change)×10&amp;lt;sup&amp;gt;23&amp;lt;/sup&amp;gt;...? ...where's the handily mnemonic value in that?), and Pi (in this universe's system of fundemental mathematics) clearly never ever had a chance! And, on {{w|Mount Everest#19th century|at least one occasion}}, such happenstance numeric roundedness in its exactitude (29''',000''' ft) was considered actually quite awkward... [[Special:Contributions/172.70.91.90|172.70.91.90]] 21:33, 23 October 2024 (UTC)&lt;br /&gt;
::My understanding is that the brine thing was an ad-hoc justification when the scale was presented to the Royal Society.  It may have seemed less cursed.  But yes, there's a BIG reason for using 32 or 64, halving a distance is trivial and as an instument maker, Fahrenheit would have found that attractive.  Mind you, I'm getting this from the Straight Dope, so I could be a dope getting it straight. https://www.straightdope.com/21344240/did-cecil-err-in-explaining-the-significance-of-zero-fahrenheit [[Special:Contributions/162.158.10.189|162.158.10.189]] 20:04, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Ok, then, regarding {{diff|353895|this edit}} (and the original IP-led one(s) that even made huge and revert-necessary changes), was it ''really'' intended to get rid of whole paragraphs such as &amp;quot;Randall also fails to specify what happens with temperatures[...]&amp;quot; that had nothing to do with the numeric adjustments? When I see that, I see mistakes (especially in light of the &amp;quot;clobber&amp;quot; that happened, where typos reappeared and other things became unexplained/worse-explained once more). — Basically, if your edit summary is nust about updating baseline data, and the resulting maths, I don't expect (maybe good, maybe bad) edits to unrelated bits. Or I may (and have) presumed accidental (or deliberate?) carelessness that I'd rather not try to go back to first principles to re-re-check for the editor concerned. That is all. At least try to justify enough of your edit in its own way, even if it means diving in several times to get enough space to summarise your whole &amp;quot;why&amp;quot; to each tweak. [[Special:Contributions/172.68.186.104|172.68.186.104]] 22:44, 23 October 2024 (UTC)&lt;br /&gt;
:Yes. I have re-removed the removals piecemeal with individual edit summaries for clarity. Many of them involved detailed obscure technical misunderstandings, such as whether the Vostok and Death Valley measurements were surface temperatures (the WMO says they are, and there are the WMO's photos of the observation stations in the linked references now) which combined with the incorrect yearly average global mean temperature, added five paragraphs unnecessarily. [[Special:Contributions/172.68.23.152|172.68.23.152]] 01:46, 24 October 2024 (UTC)&lt;br /&gt;
::Definitely some points made (some incorrect, &amp;quot;ne er&amp;quot; was ''obviously'' more just a basic typo of &amp;quot;never&amp;quot;, not my attempt to use &amp;quot;ne'er&amp;quot; for no good reason, and my attempt to fix that and some other bits ran into a set of Edit Conflicts ...hope I caught all the remaining ones when I finally could try again on the settled-down page) and I've blended answers to your objections in while giving back what useful nuances (from a number of past editors, only a couple of bits even having had my own hand primarilly behind them as they were) really needn't have been removed. I dispute the terms of your objections (as summarised) behind {{diff|353937|some changes}}, but have rephrased based upon what I ''think'' you mean, giving you should prefer and wouldn't feel the need to be as randomly censorious about. [[Special:Contributions/172.69.195.173|172.69.195.173]] 02:54, 24 October 2024 (UTC)&lt;br /&gt;
:::Figure 1 in https://climate.copernicus.eu/climate-indicators/temperature does not seem like a random walk to me. [[Special:Contributions/172.69.33.118|172.69.33.118]] 05:02, 24 October 2024 (UTC)&lt;br /&gt;
::::Added the &amp;quot;Random Walk&amp;quot; because, ignoring long-term trends, year-on-year the measured average is going to blip up and down for all kinds of reasons (physical and measuring issues, both), so it will be lower than expected or higher than expected compared to the smoother track it actually takes on a rolling average. I think one of the versions I replaced had partial suggestion that the average was effectively constant (in °C, not just °X), and while records adjusted every now and then (or every year!), it all just rather settled down at the °X midpoint. Which it doesn't. (And also that it's ''possible'' that Average and Minimum change such that the projected Absolute Zero ''doesn't'' move so much, one year, although mostly the fulcrum will be closer to 0°X rather than 0K.)&lt;br /&gt;
::::But I've yet to see what's been changed (maybe improved) since I was last looking at it. Maybe this is an out-of-date explanation. [[Special:Contributions/172.70.90.202|172.70.90.202]] 12:04, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
When I originally designed my unit conversion app I almost made a unit up that was based on the ideal gas law and one mass pound of said gas in a one cubic foot container.  It seemed more quixotic than anything else so I didn't pull the trigger on it.  Maybe I should have.[[Special:Contributions/172.70.111.33|172.70.111.33]] 20:38, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Is x based off of elon musk changing twitter to X? [[Special:Contributions/172.71.254.50|172.71.254.50]] 23:22, 24 October 2024 (UTC)&lt;br /&gt;
:Too many things were already &amp;quot;X&amp;quot; (X marks the spot, Planet X, The X-Men, Xmas...), I see no need to presume that Elon has successfully claimed ownership of one entire letter of the alphabet due to a car-crash business deal and a self-obsessive personality. To paraphrase Freud, &amp;quot;sometimes an X is just an X&amp;quot;, and with no references at all to anything Twitter-like I don't see any other intent than just as a traditional placeholder character. [[Special:Contributions/172.70.90.209|172.70.90.209]] 09:40, 25 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Ummm... why do we have the Explanation give the idea that the record highest global temperature is rising ''every year'' (or almost), when the actual reference temperature that the Explanation (and calculation) uses (with supporting reference to wikipedia) was apparently in 1913? I think we've been confused by the ''average'' global temperature rising year-on-year, but somewhat hit the buffers on what (non-controversial) highest just-off-the-ground air temperature we can actually currently get (at least without much stranger solar activity starting to dominate).&lt;br /&gt;
&amp;lt;br/&amp;gt;Incidentally, plotted against years, this means that the above-average temperature gradient is lessening over time, and the below-average gradient (excepting any future surprises at Vostok) is increasing over time... making me wonder if we had a time when °X was completely linear (50°X was precisely central to 0°X and 100°X, with no inflection point forced). Not going to follow thaat idea up, as probably you'd need a historical record of records that went back to before a reasonable global accuracy/completion of data was available. [[Special:Contributions/162.158.33.224|162.158.33.224]] 17:32, 26 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
== Division by zero ==&lt;br /&gt;
&lt;br /&gt;
I saw this in an edit summary: &amp;quot;10/0 is not ∞, it's also an error, not NaN according to the IEEE. It's closer to {+∞, -∞} than NaN but it's still neither because you can't make limits work&amp;quot;&lt;br /&gt;
&lt;br /&gt;
Actually, IEEE floating point 10/0 can be an error, +∞, or NaN depending on the rounding mode. This is one of the reasons why mathemeticians don't appreciate the IEEE as much as they might. Division by zero is strictly undefined because of the problems with limits alluded to in the summary. https://www.youtube.com/watch?v=dHdg1yn1SgE [[Special:Contributions/108.162.245.66|108.162.245.66]] 03:48, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
:&amp;quot;When considering division by zero through limits, assigning {+∞, -∞} as potential results is insufficient because limits require consistency and well-defined behavior. In the case of dividing a number by values approaching zero, the results differ depending on whether zero is approached from the positive or negative direction. As a divisor approaches zero from the positive side, the quotient grows towards +∞, and from the negative side, it tends towards -∞. Since limits must converge to a single value for consistency, this disparity leads to an undefined result. Moreover, in many mathematical contexts, infinity is not a number but rather a concept describing unbounded growth, meaning operations involving infinity, like addition or multiplication, are not well-defined in the same way as with finite numbers. This inconsistency in approaching zero prevents {+∞, -∞} from being an adequate solution set for division by zero. Defining division by zero as infinity would create contradictions in both arithmetic and algebraic contexts, as it disrupts fundamental properties like continuity and field structures in mathematics. Hence, division by zero remains undefined to preserve mathematical rigor and coherence.&amp;quot;&lt;br /&gt;
:[Chat Gippity 4o] [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:53, 24 October 2024 (UTC)&lt;br /&gt;
::https://imgflip.com/i/7yd7gz [[Special:Contributions/172.71.150.131|172.71.150.131]] 09:06, 24 October 2024 (UTC)&lt;br /&gt;
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== Examples section table values? ==&lt;br /&gt;
&lt;br /&gt;
Someone please double-check the &amp;lt;s&amp;gt;Trivia&amp;lt;/s&amp;gt; ''Examples'' section temperatures. I am not convinced they are entirely correct or consistent. I'm least sure about the Galen row. And Wedgwood obviously needs more digits of precision. [[Special:Contributions/162.158.41.28|162.158.41.28]] 13:10, 24 October 2024 (UTC)&lt;br /&gt;
:LGTM. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 20:55, 25 October 2024 (UTC)&lt;br /&gt;
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The Newton scale isn't linear: see https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales and https://instrulearning.com/temperature/temperature-scales/ ... not sure how we should address this in the framework of the explanation. [[Special:Contributions/162.158.42.64|162.158.42.64]] 22:43, 26 October 2024 (UTC)&lt;br /&gt;
:Fixed for the nonlinearities of Newton and Galen scales. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 23:17, 26 October 2024 (UTC)&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354693</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354693"/>
				<updated>2024-10-26T23:16:24Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Examples */ fix Newton and Galen as nonlinear scales, but actually calculating them this time&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1745 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. They use the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, they can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32.&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F. 100°F is {{w|Human body temperature#Historical understanding|close to normal human body temperature}} (the original intent was to set 90°F as exactly this, 90 being a quarter of 360). The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5.&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5.&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;{{acn}} || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}} because his scale is nonlinear. His scale used three fixed-points: 0ºN, the temperature of air when water begins to freeze, 12ºN, the heat of blood in the human body, 34ºN, rapidly boiling water.[https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales] Therefore:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 12 × Newton / 37 if Newton ≤ 12;&amp;lt;br/&amp;gt;or 22 × (Newton – 12) / 63 + 37 if Newton &amp;gt; 12.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = 37 × Celsius / 12 if Celsius ≤ 37;&amp;lt;br/&amp;gt;or 63 × (Celsius – 37) / 22 + 12 if Celsius &amp;gt; 37.&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43] The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8.&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. Assuming his extremes were those points, Galen's scale is also nonlinear:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 22 × (Galen + 4) / 4 if Galen ≤ 0;&amp;lt;br/&amp;gt;or 78 × Galen / 4 + 22 if Galen &amp;gt; 0.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = 4 × Celsius / 22 – 4 if Celsius ≤ 22;&amp;lt;br/&amp;gt;or 4 × (Celsius – 22) / 78 if Celsius &amp;gt; 22.&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness, and cursedness itself, is not clear. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42×10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius.&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 ).&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale. || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high and average temperature records increasing almost every year as a result of {{w|climate change}},[https://www.space.com/last-12-months-broke-temperature-records] Randall's new °X scale must be re-calibrated each year. While such °X values for to everyday temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange {{w|human body temperature|human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 67.8 °N || 0 °N || 34 °N || 114.1 °N || 7.7 °N || –55.5 °N || 12.7 °N || 26.0 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.7 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –4 || 4 || 0.8 || –3.5 || –7.3 || 0.9 || 2.8&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4.&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16.&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354692</id>
		<title>File:Temperature Scales.png</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354692"/>
				<updated>2024-10-26T23:09:58Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: Liv2splain uploaded a new version of File:Temperature Scales.png&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;All the scales from [[3001: Temperature Scales]] plus [[1923: Felsius]].&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354640</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354640"/>
				<updated>2024-10-26T16:09:41Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Examples */ from #1923&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. So, as a linear appproximation:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius – 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50.0;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.0&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange core {{w|human body temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || –5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.70 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –1.76 || 6.24 || 1.20 || –1.56 || –3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X scale || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 47 || 16 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354638</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354638"/>
				<updated>2024-10-26T16:05:52Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Examples */ Felsius conversion formulas&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. So, as a linear appproximation:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius – 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50.0;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.0&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange core {{w|human body temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || –5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.70 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –1.76 || 6.24 || 1.20 || –1.56 || –3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X scale || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 46.8 || 16.0 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
Here are the conversion formulas for the [[1923: Felsius|Felsius scale from comic 1923]]:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354635</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354635"/>
				<updated>2024-10-26T15:14:38Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Examples */ Felsius conversions introduction/link&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. So, as a linear appproximation:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius – 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50.0;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.0&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange core {{w|human body temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || –5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.70 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –1.76 || 6.24 || 1.20 || –1.56 || –3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X scale || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| Felsius || 46.8 || 16.0 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
[[1923: Felsius]] scale conversion formulas:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354634</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354634"/>
				<updated>2024-10-26T15:12:41Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: en dashes&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit – 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer – 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine – 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. So, as a linear appproximation:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) – 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius – 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying –100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 – real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 – Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; – 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X – 42.9) / 0.48 if °X &amp;lt; 50.0;&amp;lt;br/&amp;gt;or (°X – 32.4) / 1.19 if °X ≥ 50.0&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}}&lt;br /&gt;
! Midrange core {{w|human body temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || –18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || –14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || –2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || –5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || –7.71 °W || –8 °W || –6.70 °W || –7.52 °W || –7.97 °W || –8.23 °W || –7.49 °W || –7 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0 || –1.76 || 6.24 || 1.20 || –1.56 || –3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || –21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X scale || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| [[1923: Felsius]] || 46.8 || 16.0 || 156 || 67.8 || 19.5 || –9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354633</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354633"/>
				<updated>2024-10-26T15:08:25Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Examples */ Felsius conversions&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|Kelvin}} scale, which uses the same degrees as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius (which, along with degrees Fahrenheit, is now defined relative to kelvins.) The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales (except Randall's new °X scale defined in the title text) are real, but most are obsolete. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvins (plural with a lowercase 'k' as a temperature unit, like meters, ohms, watts, and amps; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) are a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same degrees as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvins are very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. So, as a linear appproximation:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,[https://doi.org/10.4236/jamp.2024.1210198] will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (°X - 42.9) / 0.48 if °X &amp;lt; 50.0;&amp;lt;br/&amp;gt;or (°X - 32.4) / 1.19 if °X ≥ 50.0&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;°X = 0.48 × Celsius + 42.9 if Celsius &amp;lt; 14.8;&amp;lt;br/&amp;gt;or 1.19 × Celsius + 32.4 if Celsius ≥ 14.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
&lt;br /&gt;
(&amp;quot;Surface&amp;quot; temperatures are measured 1.5 meters above ground inside a shaded shelter, to accurately represent air temperature, because measurements closer to the ground are usually quite different due to sunlight, {{w|albedo}}, and the thermal capacity of soil.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
===Examples===&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Typical {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Human body temperature}} (range midpoint)&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}[https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature]&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}[https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety]&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X scale || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|-&lt;br /&gt;
| [[1923: Felsius]] || 46.8 || 16.0 || 156 || 67.8 || 19.5 || -9.2 || 70.6 || 123.8&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Felsius − 16) / 1.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Felsius = Celsius * 7/5 + 16&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
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{{comic discussion}}&lt;br /&gt;
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[[Category:Charts]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354632</id>
		<title>File:Temperature Scales.png</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354632"/>
				<updated>2024-10-26T15:03:49Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: Liv2splain uploaded a new version of File:Temperature Scales.png&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;All the scales from [[3001: Temperature Scales]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354486</id>
		<title>Talk:3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354486"/>
				<updated>2024-10-25T21:11:14Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: correct&lt;/p&gt;
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&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
Shouldn't Rankine say &amp;quot;0ºR is set to absolute zero&amp;quot;? {{unsigned ip|172.70.230.29|22:58, 21 October 2024 (UTC)}}&lt;br /&gt;
:Yep. [[Special:Contributions/162.158.186.253|162.158.186.253]] 04:38, 22 October 2024 (UTC)&lt;br /&gt;
:Furthermore, should it be 0°R or just 0R (no °)? I've been told that Kelvin doesn't use degrees because it's an absolute scale, so a) is this true and b) should it apply to Rankine? [[Special:Contributions/172.71.211.54|172.71.211.54]] 14:44, 24 October 2024 (UTC)&lt;br /&gt;
::Kelvin is rather strange, for reasons never totally explained. It's &amp;quot;the Kelvin scale&amp;quot;, but the unit is &amp;quot;kelvin&amp;quot; and I never got on with the official absence of the ° symbol by the &amp;quot;K&amp;quot;. I was always taught to ''say'' &amp;quot;degrees kelvin&amp;quot; (for temperatures) and &amp;quot;kelvin degrees&amp;quot; (for a change/range of temperature) in order to not cause confusion and technical misunderstandings (''perhaps'' easier to contextualise when down in writing?) but no accounting for taste, or possibly official laziness.&lt;br /&gt;
::On the basis that Rankine is not kelvin (whatever the reason for how kelvin is what it is), I would use the degrees, as I would any other absolute scale (whether it be an adjusted form of °Rø or °Ré or whatever else might be invented), because kelvin is just inexplicably (to me, and to others) ''the'' exception to absolutely every other reasonably equivalent contemporary measure, including capitalisation. YMMV! [[Special:Contributions/172.70.162.2|172.70.162.2]] 19:53, 24 October 2024 (UTC)&lt;br /&gt;
:::0ºRa, not 0ºR. [[Special:Contributions/172.70.206.157|172.70.206.157]] 02:16, 25 October 2024 (UTC)&lt;br /&gt;
::::Can be either. Perhaps best to use °Ra (in ambiguous context) to avoid ''possible'' confusion with °Ré and °Rø, but probably less important when both those two are also listed alongside (except for wondering what, if anything, is a typo, bad handwriting or other error). [[Special:Contributions/172.69.194.12|172.69.194.12]] 11:01, 25 October 2024 (UTC)&lt;br /&gt;
::::It's easy if you think about it like &amp;quot;meter&amp;quot;. You usually say &amp;quot;meters&amp;quot; not &amp;quot;the meter scale&amp;quot; although both are correct. Scientists and engineers who use them daily call them &amp;quot;kelvins&amp;quot;, not &amp;quot;kelvin&amp;quot; unless following a number. You wouldn't say &amp;quot;We need to measure this room in meter.&amp;quot; Someone keeps reverting me on this, and they're wrong, but I don't care much anymore. I'll probably fix it next month or something. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 21:10, 25 October 2024 (UTC)&lt;br /&gt;
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yo,i thought comic 3000 was anticlimactic so randall would make this one COOL but sadly not&lt;br /&gt;
Same. Hope he does something cool for 3072.[[Special:Contributions/172.69.134.225|172.69.134.225]] 23:44, 21 October 2024 (UTC)&lt;br /&gt;
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really he didn't do anything special for this either? come ON randall if you don't do something cool for comic 3072 i will &amp;lt;b&amp;gt; come to your house personally and yell at you  [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 23:57, 21 October 2024 (UTC)&lt;br /&gt;
&amp;lt;/b&amp;gt;&lt;br /&gt;
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What's random about Fahrenheit? (Answer: nothing.) 0F is the freezing point of brine, 100F (or 98.7) is the human body temperature. [[Special:Contributions/172.68.54.65|172.68.54.65]] 00:00, 22 October 2024 (UTC)&lt;br /&gt;
:What concentration of brine? (And which specific salt... No, not NaCl, as you might presume but NH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Cl!)&lt;br /&gt;
:And body temperature varies a lot ('typically' 36.5–37.5°C or  97.7–99.5°F, though even this range is thought to be too small), across genders, individuals, time of day ''and'' which orifices/surfaces you try to measure it from. (Originally, it was set so that '''90°F''' was to be the 'best guess' of human body temperature. It gradually changed, including via various {{w|Human body temperature#Historical understanding|compounded misunderstandings}} so that the best you can say is that 100°F is arbitrarily ''slightly above'' most afebrile human body temperature measurements.)&lt;br /&gt;
:Celsius might be a bit off (arguments about triple-point or STP freezing, etc), but it still has far more physical logic to it. [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
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Sorry, Randall, for my comfort, Fahrenheit is the least cursed. It's the best scale to use for my personal use, especially when hearing the weather report and deciding what to wear outdoors: temp in the 80's - no jacket. temp in 70's - maybe a windbreaker if it's breezy. 60's - sweater weather. 50's - medium weight coat. 40's - winter coat. 30'3 - winter coat with scarf and gloves. 20's - multiple layers. teens - stay indoors. None of the other scales provide such convenient distinctions for my daily life. Kelvin is great for astro physics or super conductivity, but useless for any common uses. Celsius is great for hanging out with the Euro crowd but still not so useful to scale my home thermostat. I judge Fahrenheit as 1.0 for cursedness. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:19, 22 October 2024 (UTC)&lt;br /&gt;
:I conveniently use Celsius in tens, also. Negative °C: Cold; 0-10°C: Nippy; 10-20°C: Generally pleasant; 20-30°C: Too warm to exert oneself; 30°C+: ''Definitely'' too warm. [[Special:Contributions/172.70.86.205|172.70.86.205]] 15:24, 22 October 2024 (UTC)&lt;br /&gt;
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Personally, I'm most disappointed that {{w|Delisle scale}} was not represented... [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
: I was so hoping for a {{w|Planck temperature}} quip. Like: &amp;quot;Water freezing point: 0; Water boiling point: 0; Notes: 1 = highest possible temperature (1.4E32K) where thermal radiation creates black holes; Cursedness: 0/0&amp;quot; [[Special:Contributions/162.158.164.184|162.158.164.184]] 01:27, 22 October 2024 (UTC)&lt;br /&gt;
:: Same here. Freezing is 0.000000000000000000000000000001928 and boiling is 0.0000000000000000000000000000026338. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 03:38, 22 October 2024 (UTC)&lt;br /&gt;
::: Wow, those are even smaller than the IEEE floating point representations of 1-1.0/3*3! [[Special:Contributions/162.158.90.109|162.158.90.109]] 03:59, 22 October 2024 (UTC)&lt;br /&gt;
:: The Planck temperature quip is definitely well deserved. Good catch! [[User:Mumingpo|Mumingpo]] ([[User talk:Mumingpo|talk]]) 17:24, 23 October 2024 (UTC)&lt;br /&gt;
I guess I was wrong in my comment on the last comic. sigh. -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 01:16, 22 October 2024 (UTC)&lt;br /&gt;
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It's actually spelled {{w|Wedgwood scale}}, not Wedgewood. [[User:Wilh3lm|Wilh3lm]] ([[User talk:Wilh3lm|talk]]) 01:17, 22 October 2024 (UTC)&lt;br /&gt;
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I still call the modern version of the &amp;quot;Celsius&amp;quot; scale &amp;quot;centigrade&amp;quot;, but if people start nitpicking, I'm happy to switch to &amp;quot;Carolus&amp;quot; to avoid ambiguity. For some reason that tends to annoy people more though. [[Special:Contributions/172.68.22.191|172.68.22.191]] 01:32, 22 October 2024 (UTC)&lt;br /&gt;
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Every temperature scale is equally &amp;quot;random&amp;quot; as every other scale. People always say that Celsius is so much better because it's defined by the phase changes of water. Okay, cool...why should THAT of all things be what we use as the base for a system of temperature measurement? And, who cares? I'm a ''Homo sapiens'', not a water molecule. If anything we should use the freezing and melting points of humans as our two reference points for temperature (which, I must say, Fahrenheit approximates better than Celsius, assuming 0 and 100 are your points &amp;quot;A&amp;quot; and &amp;quot;B&amp;quot;). [[User:Pie Guy|Pie Guy]] ([[User talk:Pie Guy|talk]]) 03:42, 22 October 2024 (UTC)&lt;br /&gt;
: Every temperature scale is arbitrary, but since boiling and freezing water is a thing humans have a lot of experience with it makes sense to use that as the reference point. At least it makes more sense than whatever the coldest recorded temperature in Fahrenheit's home town was, because he didn't like negative numbers [[Special:Contributions/172.70.250.23|172.70.250.23]] 03:56, 22 October 2024 (UTC)&lt;br /&gt;
::Planck temperature (as above) is probably the least arbitrary, and some would say it is to some extent free from arbitrariness. However, it's completely impractical for everyday use (as above.) [[Special:Contributions/172.69.34.138|172.69.34.138]] 04:31, 22 October 2024 (UTC)&lt;br /&gt;
:::Do the physics of black holes or neutron stars involve Planck temperatures greater than 0.0000001? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:23, 22 October 2024 (UTC)&lt;br /&gt;
::::Chat Gippity told me:&lt;br /&gt;
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:::::Black holes and neutron stars do not typically involve temperatures reaching the Planck scale. While both objects exhibit extreme physical conditions, their temperatures are far below the Planck temperature, even though they can be incredibly high compared to everyday phenomena.&lt;br /&gt;
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::::: - **Neutron stars** have surface temperatures in the range of millions of Kelvin, and the core can reach even higher, possibly up to a few billion Kelvin. These temperatures are still vastly lower than the Planck temperature.&lt;br /&gt;
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::::: - **Black holes**, especially the smaller ones, can emit Hawking radiation, with temperatures inversely proportional to their mass. However, the temperature of even a very small black hole is still far below the Planck temperature. Hawking radiation is not expected to reach temperatures close to the Planck scale under normal circumstances.&lt;br /&gt;
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::::: The Planck temperature (TP=1) represents an energy scale so extreme that no known physical models, including those describing black holes and neutron stars, operate near or above this threshold. Temperatures reaching **0.0000001 TP** (or 1.416 × 10^26 K) would still be beyond current observational and theoretical frameworks related to these cosmic objects. A quantum theory of gravity would be required to describe physics at or near the Planck temperature, which remains speculative and is far beyond the conditions found in black holes or neutron stars.&lt;br /&gt;
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::::[[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:46, 22 October 2024 (UTC)&lt;br /&gt;
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If the °X scale is based on the temperatures of Earth from all time (for some definition of &amp;quot;Earth&amp;quot;), then the scale is very hard to define and highly impractical. The earth appears to have gotten to more than 2,300 Kelvin (hot enough to melt steel and platinum and to boil lead) and while I can't find any sources for the lowest temperature, I imagine it is lower than -100°C. The recorded minimum, maximum and average temperatures appear to be around -89.2 °C, 56.7 °C and 15 °C respectively. This would make the scale somewhat useful, but this would make typical values between 41 °X (cold winter's day) and 68 °X (hot summers day) which I think is pretty cursed. I recommend the clearly superior °Y, based around average temp at 0 °Y, low at -100 °Y and high at 100 °Y. These would be measured by the yearly high, low and mean temperatures averaged per person. Then saying &amp;quot;It's 2 times colder than yesterday&amp;quot; would have some reasonable meaning. --[[Special:Contributions/198.41.236.147|198.41.236.147]] 04:01, 22 October 2024 (UTC)&lt;br /&gt;
:&amp;quot;''Record'' ... surface temperature&amp;quot; implies it was recorded. [[Special:Contributions/172.68.22.9|172.68.22.9]] 04:08, 22 October 2024 (UTC)&lt;br /&gt;
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How do you all feel about adding an additional column for room temperature 22C/72F?&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
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Or 0.00000000000000000000000000000208 °Planck, lol. [[Special:Contributions/108.162.245.211|108.162.245.211]] 05:36, 22 October 2024 (UTC)&lt;br /&gt;
:I feel like decigalens would be the most practical unit. Who's with me? [[Special:Contributions/162.158.186.5|162.158.186.5]] 06:20, 22 October 2024 (UTC)&lt;br /&gt;
::It's interesting; calculating the equilibrium temperature (with 2.05 and 4.24 being used for the heat capacities of ice and boiling water) gives 67... If I use water that's about to freeze and steam, I get 31. [[Special:Contributions/172.69.0.178|172.69.0.178]] 07:59, 22 October 2024 (UTC)&lt;br /&gt;
:::Would you please explain in more detail? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:03, 22 October 2024 (UTC)&lt;br /&gt;
:::: The equilibrium temperature of a mixture (?) of equal quantities of ice at 0 C and water at 100 C (with the heat capacities 2.05 and 4.24) is 67 C; if I use the data for water at 0 C and steam, I get 31 C. Additionally, if I use equal volumes, I get 68 (which isn't much different.) [[Special:Contributions/172.69.0.178|172.69.0.178]] 17:15, 22 October 2024 (UTC)&lt;br /&gt;
:::: One can obtain 0 = 22 C by setting the heat capacity of ice to be 39 and that of water to be 11. For any particular &amp;quot;normal temperature&amp;quot; ''R'' °C (that is, the temperature at 0 is ''R'',), I find that ''x'' °C = 50''R''(''x''+4)/(''x''(''R''-50)+200). In particular, for ''R'' = 22, we get (1100+275''x'')/(50-7''x''). [[Special:Contributions/198.41.236.163|198.41.236.163]] 05:58, 23 October 2024 (UTC)&lt;br /&gt;
::How about Tnew=0.1694×degC+46.25; degC=(Tnew-46.25)/0.1694, where 0 is absolute zero and 50 is room temperature? (Freezing point of water: 46.25; Boiling point of water: 63.19) [[Special:Contributions/162.158.186.248|162.158.186.248]] 05:21, 24 October 2024 (UTC)&lt;br /&gt;
:I would absolutely pull the trigger on an additional column if I didn't think it would further screw up what are most probably extremely cursed mobile portrait renderings of the table. How about a Trivia section? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:44, 24 October 2024 (UTC)&lt;br /&gt;
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Question regarding the X scale - when it‘s defined by *three* (somewhat, implying average is real and not just calculated by (max-min)/2)) independent points, how will linearity be achieved? [[Special:Contributions/162.158.155.76|162.158.155.76]] 05:43, 22 October 2024 (UTC)&lt;br /&gt;
[[File:Explanation length.png|right|thumb|Or click &amp;quot;[Expand]&amp;quot; in the bottom right table cell Derivation.]]&lt;br /&gt;
:Please see [[2701: Change in Slope]]. [[Special:Contributions/172.70.206.179|172.70.206.179]] 05:50, 22 October 2024 (UTC)&lt;br /&gt;
:Sure, &amp;quot;a linear scale between each point&amp;quot;:&lt;br /&gt;
[[File:XvsC.png|thumb|left|Here you go. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 06:33, 22 October 2024 (UTC)]]&lt;br /&gt;
{{clear}}&lt;br /&gt;
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The reference for the average surface temperature, https://www.space.com/17816-earth-temperature.html, suggests it has increased above 15°C. What value should we use in late 2024? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:30, 22 October 2024 (UTC)&lt;br /&gt;
:The [https://wmo.int/media/news/earth-experiences-warmest-day-recent-history World Meteorological Organization], [https://www.carbonbrief.org/state-of-the-climate-2024-now-very-likely-to-be-warmest-year-on-record/ Carbon Brief], and [https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024 Copernicus Climate Change Service] suggest 17.16°C. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:42, 22 October 2024 (UTC)&lt;br /&gt;
::Updated water temperatures, Derivation, and graph. So we've already had more than the +2°C warming we were trying to avoid in 2019? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:05, 22 October 2024 (UTC)&lt;br /&gt;
::: The +2°C (or +1.5°C that we were originally supposed to be avoiding) is over some (undefined) number of years, though, which allows us to ignore the fact that we're cooking ourselves by repeatedly saying 'Oh, but it doesn't count ''yet''.' [[Special:Contributions/172.70.91.62|172.70.91.62]] 11:13, 23 October 2024 (UTC)&lt;br /&gt;
Regarding [https://www.explainxkcd.com/wiki/index.php?title=3001%3A_Temperature_Scales&amp;amp;type=revision&amp;amp;diff=353635&amp;amp;oldid=353632], are the average surface temperatures from the sources supposed to be yearly or overall averages? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:06, 22 October 2024 (UTC)&lt;br /&gt;
:According to https://climate.copernicus.eu/climate-indicators/temperature the global average near-surface temperature in 2023 was 14.4 + 0.4 = 14.8°C. (see Figure 1 and click &amp;quot;Increase above: [1991–2020 reference period].&amp;quot;) [[Special:Contributions/172.68.22.8|172.68.22.8]] 21:06, 23 October 2024 (UTC)&lt;br /&gt;
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where is the interactive epic 3000 comic we should've gotten? This one's cool but 1000 seemed to have more effort in it and 2000 was at least tangetially related. Does Randall just not like making these anymore and is only making more comics as a business? [[Special:Contributions/108.162.238.185|108.162.238.185]] 12:14, 22 October 2024 (UTC)&lt;br /&gt;
:The comic is free on the website and it doesn't have ads; although the comic is part of his &amp;quot;brand&amp;quot; there are many more profitable things he could be doing with his time, and yet he continues to update it every Monday, Wednesday, and Friday.  I just don't like the idea of claiming that a creative person &amp;quot;should&amp;quot; produce any particular thing to satisfy their fans.  He's a busy guy!  Maybe he's working on a book, or a Scientific American article, or a TV show.  He's under no obligation to give us anything, and maybe one day he'll stop making xkcd altogether; that's his choice.  Sorry to single you out; I know a lot of people feel the same way as you do, but to me it doesn't make sense.  He's not a content machine--he's a guy who started posting sketches on the internet. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 15:23, 22 October 2024 (UTC)&lt;br /&gt;
::Sorry if I sounded overly brash, I wasn't trying to imply &amp;quot;wahhh no special entry wahhh&amp;quot;, I was just wondering if Randall still likes to make these or if he doesn't, mainly because he just didn't do anything special, which feels like he just didn't care. I wasn't trying to imply Randall should just do it for the fans[[Special:Contributions/108.162.238.80|108.162.238.80]] 17:52, 22 October 2024 (UTC)&lt;br /&gt;
:::It ''could'' be that 3000 (or even 3001) ''was'' going to be special but, as fairly frequently with April Fool 'specials', it just wasn't doable on time. (If it's still considered fixablez it might pop up sometime before 3020 or so. Or, if transferable to another occasion (rebranding the obvious &amp;quot;3000!&amp;quot;ness), held over until Haloween, Christmas, April or 4000, perhaps with additional perfections.)&lt;br /&gt;
:::Hard to know, unless Randall (or his technical collaborators) say anything. And it's probably not worth doing so right now. Maybe &amp;quot;Hey guys, this ''was'' going to be #3000!&amp;quot; might accompany its eventual emergence, but also maybe not. Does it really matter? [[Special:Contributions/172.70.85.139|172.70.85.139]] 13:03, 23 October 2024 (UTC)&lt;br /&gt;
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Is this the first list-style comic where every single entry is real? (Usually he has several joke entries.) [[Special:Contributions/172.70.114.182|172.70.114.182]] 14:26, 22 October 2024 (UTC)&lt;br /&gt;
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Where would [[1923: Felsius|Felsius]] go on this list?&lt;br /&gt;
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One can find a smooth function for °X, namely, (477879''x''-17634840)/(3341''x''+197700), which takes °X and returns °C. The inverse is (-197700''x''-17634840)/(3341''x''-477879). Should this be included in the wiki article? Or maybe another way of fitting it (like exponential) should be used.  [[Special:Contributions/172.69.0.165|172.69.0.165]] 06:27, 23 October 2024 (UTC)&lt;br /&gt;
:It says &amp;quot;a linear scale between each point&amp;quot;. [[Special:Contributions/172.70.210.130|172.70.210.130]] 21:09, 23 October 2024 (UTC)&lt;br /&gt;
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Should it be noted that in the first _What If?_ book, there's a reference to units and how much Randall loathes rankine? Someone can go take the book and cite it; it's in one of the early pages [[Special:Contributions/172.64.236.10|172.64.236.10]] 08:45, 23 October 2024 (UTC)&lt;br /&gt;
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I remember it being drummed into us in school physics (admittedly over 50 years ago) that 0 Celsius is defined as the melting point of ice, not the freezing point of water (presumably because of supercooling). [[Special:Contributions/172.70.160.189|172.70.160.189]] 08:49, 23 October 2024 (UTC)&lt;br /&gt;
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It seems he wrote &amp;quot;Earths'&amp;quot; (plural possessive) instead of &amp;quot;Earth's&amp;quot;. [[Special:Contributions/141.101.98.151|141.101.98.151]] 08:58, 23 October 2024 (UTC)&lt;br /&gt;
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What?  No gas mark?  It's linear for temperatures over 275°F but inverse powers of 2 below  That's pretty cursed, but I still put it in my unit conversion app.  It's only used in gas stoves in a few countries, so it doesn't come up very often.  By the way, boiling is 1/5.7358 and freezing/melting is 1/843.3572.  Interestingly, France has it's own stove temperature scale that seems to be based on °F.&lt;br /&gt;
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Also, my understanding is that 7.5 and 32 aren't random.  Both Romer and Fahrenheit put numbers on things so that freezing/melting of water and &amp;quot;Normal human body temperature&amp;quot;, which was thought to be standard at the time, would be some number X (15 for Romer and 64 for Fahrenheit) and the water thing would be to be X/2 and NHBT would be X/2+X.  Pretty nerdy.  Sadly, the calibration was off and 212 degrees for boiling was found to be less cursed.  But I could be wrong.[[Special:Contributions/172.68.54.138|172.68.54.138]] 20:39, 23 October 2024 (UTC)&lt;br /&gt;
:Re: water/ice point 'random number', I think it's more that it wasn't considered &amp;quot;special&amp;quot;, such that &amp;quot;On my scale, that will be zero&amp;quot; (or whatever choice of handily round number, including zero, some scale-setters allocated to the BP of water).&lt;br /&gt;
:After all the other messing about (&amp;quot;my zero will be that of brine!&amp;quot;, etc), obviously then the ~0°C equivalent would ''have'' a number, and ''perhaps''  there would then be a slight change to make it a ''whole'' (or easy-fraction) number for convenience's sake, but (before the concept of binary computers) there's not much special about landing on the number 32, for what is actually a temperature that is quite significant to the human experience, and less so with 7-''and-a-half''.&lt;br /&gt;
:Maybe landing on 90°F (at one time) for body temperature (and 180 F° ''between'' MP and BP) was considered useful as the analogue to angular-degrees where 90 (and 180) indeed features significantly, but I don't think there'd have been too much fuss if the value would have turned out to be 60(/120), also with plenty of handy factors to divide by, 70(/140), without so much, or whatever number(s) happened to depict one realistic real-world measurement that (overall) has no reason to have a factor-based relationship with various quite separate phenomenon measurements.&lt;br /&gt;
:''And'' it went through several {{w|Human body temperature#Historical understanding|'corrective' iterations}} so that even its handy relationship with 'about 100°F' can be said to be an incidental accident, at best, unless we do something like Randall's °X scale and actively triple-tie the central value of the slope(s) to be exactly something useful by using the &amp;quot;currently accepted mean human body temperature (given various complicated caveats)&amp;quot;.&lt;br /&gt;
:It's pretty much all random, in the same way that only because of anthropocentric choices of 'standard' time and distance measurements is the speed of light 'pretty much' 3×10⁸ m/s (a handily round value that works well enough for most purposes, even after back-standardising its component SI measurements to make &amp;quot;actually, &amp;lt;u&amp;gt;precisely&amp;lt;/u&amp;gt; 299792458&amp;quot; the ''proper'' answer, and [https://conversion.org/speed/speed-of-light/furlong-per-fortnight it could be far worse...]). Avagadro's number never had it so good (6.022(+change)×10&amp;lt;sup&amp;gt;23&amp;lt;/sup&amp;gt;...? ...where's the handily mnemonic value in that?), and Pi (in this universe's system of fundemental mathematics) clearly never ever had a chance! And, on {{w|Mount Everest#19th century|at least one occasion}}, such happenstance numeric roundedness in its exactitude (29''',000''' ft) was considered actually quite awkward... [[Special:Contributions/172.70.91.90|172.70.91.90]] 21:33, 23 October 2024 (UTC)&lt;br /&gt;
::My understanding is that the brine thing was an ad-hoc justification when the scale was presented to the Royal Society.  It may have seemed less cursed.  But yes, there's a BIG reason for using 32 or 64, halving a distance is trivial and as an instument maker, Fahrenheit would have found that attractive.  Mind you, I'm getting this from the Straight Dope, so I could be a dope getting it straight. https://www.straightdope.com/21344240/did-cecil-err-in-explaining-the-significance-of-zero-fahrenheit [[Special:Contributions/162.158.10.189|162.158.10.189]] 20:04, 24 October 2024 (UTC)&lt;br /&gt;
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Ok, then, regarding {{diff|353895|this edit}} (and the original IP-led one(s) that even made huge and revert-necessary changes), was it ''really'' intended to get rid of whole paragraphs such as &amp;quot;Randall also fails to specify what happens with temperatures[...]&amp;quot; that had nothing to do with the numeric adjustments? When I see that, I see mistakes (especially in light of the &amp;quot;clobber&amp;quot; that happened, where typos reappeared and other things became unexplained/worse-explained once more). — Basically, if your edit summary is nust about updating baseline data, and the resulting maths, I don't expect (maybe good, maybe bad) edits to unrelated bits. Or I may (and have) presumed accidental (or deliberate?) carelessness that I'd rather not try to go back to first principles to re-re-check for the editor concerned. That is all. At least try to justify enough of your edit in its own way, even if it means diving in several times to get enough space to summarise your whole &amp;quot;why&amp;quot; to each tweak. [[Special:Contributions/172.68.186.104|172.68.186.104]] 22:44, 23 October 2024 (UTC)&lt;br /&gt;
:Yes. I have re-removed the removals piecemeal with individual edit summaries for clarity. Many of them involved detailed obscure technical misunderstandings, such as whether the Vostok and Death Valley measurements were surface temperatures (the WMO says they are, and there are the WMO's photos of the observation stations in the linked references now) which combined with the incorrect yearly average global mean temperature, added five paragraphs unnecessarily. [[Special:Contributions/172.68.23.152|172.68.23.152]] 01:46, 24 October 2024 (UTC)&lt;br /&gt;
::Definitely some points made (some incorrect, &amp;quot;ne er&amp;quot; was ''obviously'' more just a basic typo of &amp;quot;never&amp;quot;, not my attempt to use &amp;quot;ne'er&amp;quot; for no good reason, and my attempt to fix that and some other bits ran into a set of Edit Conflicts ...hope I caught all the remaining ones when I finally could try again on the settled-down page) and I've blended answers to your objections in while giving back what useful nuances (from a number of past editors, only a couple of bits even having had my own hand primarilly behind them as they were) really needn't have been removed. I dispute the terms of your objections (as summarised) behind {{diff|353937|some changes}}, but have rephrased based upon what I ''think'' you mean, giving you should prefer and wouldn't feel the need to be as randomly censorious about. [[Special:Contributions/172.69.195.173|172.69.195.173]] 02:54, 24 October 2024 (UTC)&lt;br /&gt;
:::Figure 1 in https://climate.copernicus.eu/climate-indicators/temperature does not seem like a random walk to me. [[Special:Contributions/172.69.33.118|172.69.33.118]] 05:02, 24 October 2024 (UTC)&lt;br /&gt;
::::Added the &amp;quot;Random Walk&amp;quot; because, ignoring long-term trends, year-on-year the measured average is going to blip up and down for all kinds of reasons (physical and measuring issues, both), so it will be lower than expected or higher than expected compared to the smoother track it actually takes on a rolling average. I think one of the versions I replaced had partial suggestion that the average was effectively constant (in °C, not just °X), and while records adjusted every now and then (or every year!), it all just rather settled down at the °X midpoint. Which it doesn't. (And also that it's ''possible'' that Average and Minimum change such that the projected Absolute Zero ''doesn't'' move so much, one year, although mostly the fulcrum will be closer to 0°X rather than 0K.)&lt;br /&gt;
::::But I've yet to see what's been changed (maybe improved) since I was last looking at it. Maybe this is an out-of-date explanation. [[Special:Contributions/172.70.90.202|172.70.90.202]] 12:04, 24 October 2024 (UTC)&lt;br /&gt;
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When I originally designed my unit conversion app I almost made a unit up that was based on the ideal gas law and one mass pound of said gas in a one cubic foot container.  It seemed more quixotic than anything else so I didn't pull the trigger on it.  Maybe I should have.[[Special:Contributions/172.70.111.33|172.70.111.33]] 20:38, 24 October 2024 (UTC)&lt;br /&gt;
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Is x based off of elon musk changing twitter to X? [[Special:Contributions/172.71.254.50|172.71.254.50]] 23:22, 24 October 2024 (UTC)&lt;br /&gt;
:Too many things were already &amp;quot;X&amp;quot; (X marks the spot, Planet X, The X-Men, Xmas...), I see no need to presume that Elon has successfully claimed ownership of one entire letter of the alphabet due to a car-crash business deal and a self-obsessive personality. To paraphrase Freud, &amp;quot;sometimes an X is just an X&amp;quot;, and with no references at all to anything Twitter-like I don't see any other intent than just as a traditional placeholder character. [[Special:Contributions/172.70.90.209|172.70.90.209]] 09:40, 25 October 2024 (UTC)&lt;br /&gt;
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== Division by zero ==&lt;br /&gt;
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I saw this in an edit summary: &amp;quot;10/0 is not ∞, it's also an error, not NaN according to the IEEE. It's closer to {+∞, -∞} than NaN but it's still neither because you can't make limits work&amp;quot;&lt;br /&gt;
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Actually, IEEE floating point 10/0 can be an error, +∞, or NaN depending on the rounding mode. This is one of the reasons why mathemeticians don't appreciate the IEEE as much as they might. Division by zero is strictly undefined because of the problems with limits alluded to in the summary. https://www.youtube.com/watch?v=dHdg1yn1SgE [[Special:Contributions/108.162.245.66|108.162.245.66]] 03:48, 24 October 2024 (UTC)&lt;br /&gt;
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:&amp;quot;When considering division by zero through limits, assigning {+∞, -∞} as potential results is insufficient because limits require consistency and well-defined behavior. In the case of dividing a number by values approaching zero, the results differ depending on whether zero is approached from the positive or negative direction. As a divisor approaches zero from the positive side, the quotient grows towards +∞, and from the negative side, it tends towards -∞. Since limits must converge to a single value for consistency, this disparity leads to an undefined result. Moreover, in many mathematical contexts, infinity is not a number but rather a concept describing unbounded growth, meaning operations involving infinity, like addition or multiplication, are not well-defined in the same way as with finite numbers. This inconsistency in approaching zero prevents {+∞, -∞} from being an adequate solution set for division by zero. Defining division by zero as infinity would create contradictions in both arithmetic and algebraic contexts, as it disrupts fundamental properties like continuity and field structures in mathematics. Hence, division by zero remains undefined to preserve mathematical rigor and coherence.&amp;quot;&lt;br /&gt;
:[Chat Gippity 4o] [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:53, 24 October 2024 (UTC)&lt;br /&gt;
::https://imgflip.com/i/7yd7gz [[Special:Contributions/172.71.150.131|172.71.150.131]] 09:06, 24 October 2024 (UTC)&lt;br /&gt;
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== Trivia section table values? ==&lt;br /&gt;
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Someone please double-check the Trivia section temperatures. I am not convinced they are entirely correct or consistent. I'm least sure about the Galen row. And Wedgwood obviously needs more digits of precision. [[Special:Contributions/162.158.41.28|162.158.41.28]] 13:10, 24 October 2024 (UTC)&lt;br /&gt;
:LGTM. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 20:55, 25 October 2024 (UTC)&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354484</id>
		<title>Talk:3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354484"/>
				<updated>2024-10-25T21:10:49Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: kelvinS&lt;/p&gt;
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&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
Shouldn't Rankine say &amp;quot;0ºR is set to absolute zero&amp;quot;? {{unsigned ip|172.70.230.29|22:58, 21 October 2024 (UTC)}}&lt;br /&gt;
:Yep. [[Special:Contributions/162.158.186.253|162.158.186.253]] 04:38, 22 October 2024 (UTC)&lt;br /&gt;
:Furthermore, should it be 0°R or just 0R (no °)? I've been told that Kelvin doesn't use degrees because it's an absolute scale, so a) is this true and b) should it apply to Rankine? [[Special:Contributions/172.71.211.54|172.71.211.54]] 14:44, 24 October 2024 (UTC)&lt;br /&gt;
::Kelvin is rather strange, for reasons never totally explained. It's &amp;quot;the Kelvin scale&amp;quot;, but the unit is &amp;quot;kelvin&amp;quot; and I never got on with the official absence of the ° symbol by the &amp;quot;K&amp;quot;. I was always taught to ''say'' &amp;quot;degrees kelvin&amp;quot; (for temperatures) and &amp;quot;kelvin degrees&amp;quot; (for a change/range of temperature) in order to not cause confusion and technical misunderstandings (''perhaps'' easier to contextualise when down in writing?) but no accounting for taste, or possibly official laziness.&lt;br /&gt;
::On the basis that Rankine is not kelvin (whatever the reason for how kelvin is what it is), I would use the degrees, as I would any other absolute scale (whether it be an adjusted form of °Rø or °Ré or whatever else might be invented), because kelvin is just inexplicably (to me, and to others) ''the'' exception to absolutely every other reasonably equivalent contemporary measure, including capitalisation. YMMV! [[Special:Contributions/172.70.162.2|172.70.162.2]] 19:53, 24 October 2024 (UTC)&lt;br /&gt;
:::0ºRa, not 0ºR. [[Special:Contributions/172.70.206.157|172.70.206.157]] 02:16, 25 October 2024 (UTC)&lt;br /&gt;
::::Can be either. Perhaps best to use °Ra (in ambiguous context) to avoid ''possible'' confusion with °Ré and °Rø, but probably less important when both those two are also listed alongside (except for wondering what, if anything, is a typo, bad handwriting or other error). [[Special:Contributions/172.69.194.12|172.69.194.12]] 11:01, 25 October 2024 (UTC)&lt;br /&gt;
::::It's easy if you think about it like &amp;quot;meter&amp;quot;. You usually say &amp;quot;meters&amp;quot; not &amp;quot;the meters scale&amp;quot; although both are correct. Scientists and engineers who use them daily call them &amp;quot;kelvins&amp;quot;, not &amp;quot;kelvin&amp;quot; unless following a number. You wouldn't say &amp;quot;We need to measure this room in meter.&amp;quot; Someone keeps reverting me on this, and they're wrong, but I don't care much anymore. I'll probably fix it next month or something. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 21:10, 25 October 2024 (UTC)&lt;br /&gt;
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yo,i thought comic 3000 was anticlimactic so randall would make this one COOL but sadly not&lt;br /&gt;
Same. Hope he does something cool for 3072.[[Special:Contributions/172.69.134.225|172.69.134.225]] 23:44, 21 October 2024 (UTC)&lt;br /&gt;
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really he didn't do anything special for this either? come ON randall if you don't do something cool for comic 3072 i will &amp;lt;b&amp;gt; come to your house personally and yell at you  [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 23:57, 21 October 2024 (UTC)&lt;br /&gt;
&amp;lt;/b&amp;gt;&lt;br /&gt;
&amp;lt;br&amp;gt;&lt;br /&gt;
What's random about Fahrenheit? (Answer: nothing.) 0F is the freezing point of brine, 100F (or 98.7) is the human body temperature. [[Special:Contributions/172.68.54.65|172.68.54.65]] 00:00, 22 October 2024 (UTC)&lt;br /&gt;
:What concentration of brine? (And which specific salt... No, not NaCl, as you might presume but NH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Cl!)&lt;br /&gt;
:And body temperature varies a lot ('typically' 36.5–37.5°C or  97.7–99.5°F, though even this range is thought to be too small), across genders, individuals, time of day ''and'' which orifices/surfaces you try to measure it from. (Originally, it was set so that '''90°F''' was to be the 'best guess' of human body temperature. It gradually changed, including via various {{w|Human body temperature#Historical understanding|compounded misunderstandings}} so that the best you can say is that 100°F is arbitrarily ''slightly above'' most afebrile human body temperature measurements.)&lt;br /&gt;
:Celsius might be a bit off (arguments about triple-point or STP freezing, etc), but it still has far more physical logic to it. [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
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Sorry, Randall, for my comfort, Fahrenheit is the least cursed. It's the best scale to use for my personal use, especially when hearing the weather report and deciding what to wear outdoors: temp in the 80's - no jacket. temp in 70's - maybe a windbreaker if it's breezy. 60's - sweater weather. 50's - medium weight coat. 40's - winter coat. 30'3 - winter coat with scarf and gloves. 20's - multiple layers. teens - stay indoors. None of the other scales provide such convenient distinctions for my daily life. Kelvin is great for astro physics or super conductivity, but useless for any common uses. Celsius is great for hanging out with the Euro crowd but still not so useful to scale my home thermostat. I judge Fahrenheit as 1.0 for cursedness. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:19, 22 October 2024 (UTC)&lt;br /&gt;
:I conveniently use Celsius in tens, also. Negative °C: Cold; 0-10°C: Nippy; 10-20°C: Generally pleasant; 20-30°C: Too warm to exert oneself; 30°C+: ''Definitely'' too warm. [[Special:Contributions/172.70.86.205|172.70.86.205]] 15:24, 22 October 2024 (UTC)&lt;br /&gt;
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Personally, I'm most disappointed that {{w|Delisle scale}} was not represented... [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
: I was so hoping for a {{w|Planck temperature}} quip. Like: &amp;quot;Water freezing point: 0; Water boiling point: 0; Notes: 1 = highest possible temperature (1.4E32K) where thermal radiation creates black holes; Cursedness: 0/0&amp;quot; [[Special:Contributions/162.158.164.184|162.158.164.184]] 01:27, 22 October 2024 (UTC)&lt;br /&gt;
:: Same here. Freezing is 0.000000000000000000000000000001928 and boiling is 0.0000000000000000000000000000026338. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 03:38, 22 October 2024 (UTC)&lt;br /&gt;
::: Wow, those are even smaller than the IEEE floating point representations of 1-1.0/3*3! [[Special:Contributions/162.158.90.109|162.158.90.109]] 03:59, 22 October 2024 (UTC)&lt;br /&gt;
:: The Planck temperature quip is definitely well deserved. Good catch! [[User:Mumingpo|Mumingpo]] ([[User talk:Mumingpo|talk]]) 17:24, 23 October 2024 (UTC)&lt;br /&gt;
I guess I was wrong in my comment on the last comic. sigh. -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 01:16, 22 October 2024 (UTC)&lt;br /&gt;
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It's actually spelled {{w|Wedgwood scale}}, not Wedgewood. [[User:Wilh3lm|Wilh3lm]] ([[User talk:Wilh3lm|talk]]) 01:17, 22 October 2024 (UTC)&lt;br /&gt;
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I still call the modern version of the &amp;quot;Celsius&amp;quot; scale &amp;quot;centigrade&amp;quot;, but if people start nitpicking, I'm happy to switch to &amp;quot;Carolus&amp;quot; to avoid ambiguity. For some reason that tends to annoy people more though. [[Special:Contributions/172.68.22.191|172.68.22.191]] 01:32, 22 October 2024 (UTC)&lt;br /&gt;
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Every temperature scale is equally &amp;quot;random&amp;quot; as every other scale. People always say that Celsius is so much better because it's defined by the phase changes of water. Okay, cool...why should THAT of all things be what we use as the base for a system of temperature measurement? And, who cares? I'm a ''Homo sapiens'', not a water molecule. If anything we should use the freezing and melting points of humans as our two reference points for temperature (which, I must say, Fahrenheit approximates better than Celsius, assuming 0 and 100 are your points &amp;quot;A&amp;quot; and &amp;quot;B&amp;quot;). [[User:Pie Guy|Pie Guy]] ([[User talk:Pie Guy|talk]]) 03:42, 22 October 2024 (UTC)&lt;br /&gt;
: Every temperature scale is arbitrary, but since boiling and freezing water is a thing humans have a lot of experience with it makes sense to use that as the reference point. At least it makes more sense than whatever the coldest recorded temperature in Fahrenheit's home town was, because he didn't like negative numbers [[Special:Contributions/172.70.250.23|172.70.250.23]] 03:56, 22 October 2024 (UTC)&lt;br /&gt;
::Planck temperature (as above) is probably the least arbitrary, and some would say it is to some extent free from arbitrariness. However, it's completely impractical for everyday use (as above.) [[Special:Contributions/172.69.34.138|172.69.34.138]] 04:31, 22 October 2024 (UTC)&lt;br /&gt;
:::Do the physics of black holes or neutron stars involve Planck temperatures greater than 0.0000001? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:23, 22 October 2024 (UTC)&lt;br /&gt;
::::Chat Gippity told me:&lt;br /&gt;
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:::::Black holes and neutron stars do not typically involve temperatures reaching the Planck scale. While both objects exhibit extreme physical conditions, their temperatures are far below the Planck temperature, even though they can be incredibly high compared to everyday phenomena.&lt;br /&gt;
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::::: - **Neutron stars** have surface temperatures in the range of millions of Kelvin, and the core can reach even higher, possibly up to a few billion Kelvin. These temperatures are still vastly lower than the Planck temperature.&lt;br /&gt;
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::::: - **Black holes**, especially the smaller ones, can emit Hawking radiation, with temperatures inversely proportional to their mass. However, the temperature of even a very small black hole is still far below the Planck temperature. Hawking radiation is not expected to reach temperatures close to the Planck scale under normal circumstances.&lt;br /&gt;
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::::: The Planck temperature (TP=1) represents an energy scale so extreme that no known physical models, including those describing black holes and neutron stars, operate near or above this threshold. Temperatures reaching **0.0000001 TP** (or 1.416 × 10^26 K) would still be beyond current observational and theoretical frameworks related to these cosmic objects. A quantum theory of gravity would be required to describe physics at or near the Planck temperature, which remains speculative and is far beyond the conditions found in black holes or neutron stars.&lt;br /&gt;
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::::[[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:46, 22 October 2024 (UTC)&lt;br /&gt;
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If the °X scale is based on the temperatures of Earth from all time (for some definition of &amp;quot;Earth&amp;quot;), then the scale is very hard to define and highly impractical. The earth appears to have gotten to more than 2,300 Kelvin (hot enough to melt steel and platinum and to boil lead) and while I can't find any sources for the lowest temperature, I imagine it is lower than -100°C. The recorded minimum, maximum and average temperatures appear to be around -89.2 °C, 56.7 °C and 15 °C respectively. This would make the scale somewhat useful, but this would make typical values between 41 °X (cold winter's day) and 68 °X (hot summers day) which I think is pretty cursed. I recommend the clearly superior °Y, based around average temp at 0 °Y, low at -100 °Y and high at 100 °Y. These would be measured by the yearly high, low and mean temperatures averaged per person. Then saying &amp;quot;It's 2 times colder than yesterday&amp;quot; would have some reasonable meaning. --[[Special:Contributions/198.41.236.147|198.41.236.147]] 04:01, 22 October 2024 (UTC)&lt;br /&gt;
:&amp;quot;''Record'' ... surface temperature&amp;quot; implies it was recorded. [[Special:Contributions/172.68.22.9|172.68.22.9]] 04:08, 22 October 2024 (UTC)&lt;br /&gt;
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How do you all feel about adding an additional column for room temperature 22C/72F?&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
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Or 0.00000000000000000000000000000208 °Planck, lol. [[Special:Contributions/108.162.245.211|108.162.245.211]] 05:36, 22 October 2024 (UTC)&lt;br /&gt;
:I feel like decigalens would be the most practical unit. Who's with me? [[Special:Contributions/162.158.186.5|162.158.186.5]] 06:20, 22 October 2024 (UTC)&lt;br /&gt;
::It's interesting; calculating the equilibrium temperature (with 2.05 and 4.24 being used for the heat capacities of ice and boiling water) gives 67... If I use water that's about to freeze and steam, I get 31. [[Special:Contributions/172.69.0.178|172.69.0.178]] 07:59, 22 October 2024 (UTC)&lt;br /&gt;
:::Would you please explain in more detail? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:03, 22 October 2024 (UTC)&lt;br /&gt;
:::: The equilibrium temperature of a mixture (?) of equal quantities of ice at 0 C and water at 100 C (with the heat capacities 2.05 and 4.24) is 67 C; if I use the data for water at 0 C and steam, I get 31 C. Additionally, if I use equal volumes, I get 68 (which isn't much different.) [[Special:Contributions/172.69.0.178|172.69.0.178]] 17:15, 22 October 2024 (UTC)&lt;br /&gt;
:::: One can obtain 0 = 22 C by setting the heat capacity of ice to be 39 and that of water to be 11. For any particular &amp;quot;normal temperature&amp;quot; ''R'' °C (that is, the temperature at 0 is ''R'',), I find that ''x'' °C = 50''R''(''x''+4)/(''x''(''R''-50)+200). In particular, for ''R'' = 22, we get (1100+275''x'')/(50-7''x''). [[Special:Contributions/198.41.236.163|198.41.236.163]] 05:58, 23 October 2024 (UTC)&lt;br /&gt;
::How about Tnew=0.1694×degC+46.25; degC=(Tnew-46.25)/0.1694, where 0 is absolute zero and 50 is room temperature? (Freezing point of water: 46.25; Boiling point of water: 63.19) [[Special:Contributions/162.158.186.248|162.158.186.248]] 05:21, 24 October 2024 (UTC)&lt;br /&gt;
:I would absolutely pull the trigger on an additional column if I didn't think it would further screw up what are most probably extremely cursed mobile portrait renderings of the table. How about a Trivia section? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:44, 24 October 2024 (UTC)&lt;br /&gt;
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Question regarding the X scale - when it‘s defined by *three* (somewhat, implying average is real and not just calculated by (max-min)/2)) independent points, how will linearity be achieved? [[Special:Contributions/162.158.155.76|162.158.155.76]] 05:43, 22 October 2024 (UTC)&lt;br /&gt;
[[File:Explanation length.png|right|thumb|Or click &amp;quot;[Expand]&amp;quot; in the bottom right table cell Derivation.]]&lt;br /&gt;
:Please see [[2701: Change in Slope]]. [[Special:Contributions/172.70.206.179|172.70.206.179]] 05:50, 22 October 2024 (UTC)&lt;br /&gt;
:Sure, &amp;quot;a linear scale between each point&amp;quot;:&lt;br /&gt;
[[File:XvsC.png|thumb|left|Here you go. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 06:33, 22 October 2024 (UTC)]]&lt;br /&gt;
{{clear}}&lt;br /&gt;
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The reference for the average surface temperature, https://www.space.com/17816-earth-temperature.html, suggests it has increased above 15°C. What value should we use in late 2024? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:30, 22 October 2024 (UTC)&lt;br /&gt;
:The [https://wmo.int/media/news/earth-experiences-warmest-day-recent-history World Meteorological Organization], [https://www.carbonbrief.org/state-of-the-climate-2024-now-very-likely-to-be-warmest-year-on-record/ Carbon Brief], and [https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024 Copernicus Climate Change Service] suggest 17.16°C. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:42, 22 October 2024 (UTC)&lt;br /&gt;
::Updated water temperatures, Derivation, and graph. So we've already had more than the +2°C warming we were trying to avoid in 2019? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:05, 22 October 2024 (UTC)&lt;br /&gt;
::: The +2°C (or +1.5°C that we were originally supposed to be avoiding) is over some (undefined) number of years, though, which allows us to ignore the fact that we're cooking ourselves by repeatedly saying 'Oh, but it doesn't count ''yet''.' [[Special:Contributions/172.70.91.62|172.70.91.62]] 11:13, 23 October 2024 (UTC)&lt;br /&gt;
Regarding [https://www.explainxkcd.com/wiki/index.php?title=3001%3A_Temperature_Scales&amp;amp;type=revision&amp;amp;diff=353635&amp;amp;oldid=353632], are the average surface temperatures from the sources supposed to be yearly or overall averages? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:06, 22 October 2024 (UTC)&lt;br /&gt;
:According to https://climate.copernicus.eu/climate-indicators/temperature the global average near-surface temperature in 2023 was 14.4 + 0.4 = 14.8°C. (see Figure 1 and click &amp;quot;Increase above: [1991–2020 reference period].&amp;quot;) [[Special:Contributions/172.68.22.8|172.68.22.8]] 21:06, 23 October 2024 (UTC)&lt;br /&gt;
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where is the interactive epic 3000 comic we should've gotten? This one's cool but 1000 seemed to have more effort in it and 2000 was at least tangetially related. Does Randall just not like making these anymore and is only making more comics as a business? [[Special:Contributions/108.162.238.185|108.162.238.185]] 12:14, 22 October 2024 (UTC)&lt;br /&gt;
:The comic is free on the website and it doesn't have ads; although the comic is part of his &amp;quot;brand&amp;quot; there are many more profitable things he could be doing with his time, and yet he continues to update it every Monday, Wednesday, and Friday.  I just don't like the idea of claiming that a creative person &amp;quot;should&amp;quot; produce any particular thing to satisfy their fans.  He's a busy guy!  Maybe he's working on a book, or a Scientific American article, or a TV show.  He's under no obligation to give us anything, and maybe one day he'll stop making xkcd altogether; that's his choice.  Sorry to single you out; I know a lot of people feel the same way as you do, but to me it doesn't make sense.  He's not a content machine--he's a guy who started posting sketches on the internet. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 15:23, 22 October 2024 (UTC)&lt;br /&gt;
::Sorry if I sounded overly brash, I wasn't trying to imply &amp;quot;wahhh no special entry wahhh&amp;quot;, I was just wondering if Randall still likes to make these or if he doesn't, mainly because he just didn't do anything special, which feels like he just didn't care. I wasn't trying to imply Randall should just do it for the fans[[Special:Contributions/108.162.238.80|108.162.238.80]] 17:52, 22 October 2024 (UTC)&lt;br /&gt;
:::It ''could'' be that 3000 (or even 3001) ''was'' going to be special but, as fairly frequently with April Fool 'specials', it just wasn't doable on time. (If it's still considered fixablez it might pop up sometime before 3020 or so. Or, if transferable to another occasion (rebranding the obvious &amp;quot;3000!&amp;quot;ness), held over until Haloween, Christmas, April or 4000, perhaps with additional perfections.)&lt;br /&gt;
:::Hard to know, unless Randall (or his technical collaborators) say anything. And it's probably not worth doing so right now. Maybe &amp;quot;Hey guys, this ''was'' going to be #3000!&amp;quot; might accompany its eventual emergence, but also maybe not. Does it really matter? [[Special:Contributions/172.70.85.139|172.70.85.139]] 13:03, 23 October 2024 (UTC)&lt;br /&gt;
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Is this the first list-style comic where every single entry is real? (Usually he has several joke entries.) [[Special:Contributions/172.70.114.182|172.70.114.182]] 14:26, 22 October 2024 (UTC)&lt;br /&gt;
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Where would [[1923: Felsius|Felsius]] go on this list?&lt;br /&gt;
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One can find a smooth function for °X, namely, (477879''x''-17634840)/(3341''x''+197700), which takes °X and returns °C. The inverse is (-197700''x''-17634840)/(3341''x''-477879). Should this be included in the wiki article? Or maybe another way of fitting it (like exponential) should be used.  [[Special:Contributions/172.69.0.165|172.69.0.165]] 06:27, 23 October 2024 (UTC)&lt;br /&gt;
:It says &amp;quot;a linear scale between each point&amp;quot;. [[Special:Contributions/172.70.210.130|172.70.210.130]] 21:09, 23 October 2024 (UTC)&lt;br /&gt;
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Should it be noted that in the first _What If?_ book, there's a reference to units and how much Randall loathes rankine? Someone can go take the book and cite it; it's in one of the early pages [[Special:Contributions/172.64.236.10|172.64.236.10]] 08:45, 23 October 2024 (UTC)&lt;br /&gt;
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I remember it being drummed into us in school physics (admittedly over 50 years ago) that 0 Celsius is defined as the melting point of ice, not the freezing point of water (presumably because of supercooling). [[Special:Contributions/172.70.160.189|172.70.160.189]] 08:49, 23 October 2024 (UTC)&lt;br /&gt;
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It seems he wrote &amp;quot;Earths'&amp;quot; (plural possessive) instead of &amp;quot;Earth's&amp;quot;. [[Special:Contributions/141.101.98.151|141.101.98.151]] 08:58, 23 October 2024 (UTC)&lt;br /&gt;
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What?  No gas mark?  It's linear for temperatures over 275°F but inverse powers of 2 below  That's pretty cursed, but I still put it in my unit conversion app.  It's only used in gas stoves in a few countries, so it doesn't come up very often.  By the way, boiling is 1/5.7358 and freezing/melting is 1/843.3572.  Interestingly, France has it's own stove temperature scale that seems to be based on °F.&lt;br /&gt;
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Also, my understanding is that 7.5 and 32 aren't random.  Both Romer and Fahrenheit put numbers on things so that freezing/melting of water and &amp;quot;Normal human body temperature&amp;quot;, which was thought to be standard at the time, would be some number X (15 for Romer and 64 for Fahrenheit) and the water thing would be to be X/2 and NHBT would be X/2+X.  Pretty nerdy.  Sadly, the calibration was off and 212 degrees for boiling was found to be less cursed.  But I could be wrong.[[Special:Contributions/172.68.54.138|172.68.54.138]] 20:39, 23 October 2024 (UTC)&lt;br /&gt;
:Re: water/ice point 'random number', I think it's more that it wasn't considered &amp;quot;special&amp;quot;, such that &amp;quot;On my scale, that will be zero&amp;quot; (or whatever choice of handily round number, including zero, some scale-setters allocated to the BP of water).&lt;br /&gt;
:After all the other messing about (&amp;quot;my zero will be that of brine!&amp;quot;, etc), obviously then the ~0°C equivalent would ''have'' a number, and ''perhaps''  there would then be a slight change to make it a ''whole'' (or easy-fraction) number for convenience's sake, but (before the concept of binary computers) there's not much special about landing on the number 32, for what is actually a temperature that is quite significant to the human experience, and less so with 7-''and-a-half''.&lt;br /&gt;
:Maybe landing on 90°F (at one time) for body temperature (and 180 F° ''between'' MP and BP) was considered useful as the analogue to angular-degrees where 90 (and 180) indeed features significantly, but I don't think there'd have been too much fuss if the value would have turned out to be 60(/120), also with plenty of handy factors to divide by, 70(/140), without so much, or whatever number(s) happened to depict one realistic real-world measurement that (overall) has no reason to have a factor-based relationship with various quite separate phenomenon measurements.&lt;br /&gt;
:''And'' it went through several {{w|Human body temperature#Historical understanding|'corrective' iterations}} so that even its handy relationship with 'about 100°F' can be said to be an incidental accident, at best, unless we do something like Randall's °X scale and actively triple-tie the central value of the slope(s) to be exactly something useful by using the &amp;quot;currently accepted mean human body temperature (given various complicated caveats)&amp;quot;.&lt;br /&gt;
:It's pretty much all random, in the same way that only because of anthropocentric choices of 'standard' time and distance measurements is the speed of light 'pretty much' 3×10⁸ m/s (a handily round value that works well enough for most purposes, even after back-standardising its component SI measurements to make &amp;quot;actually, &amp;lt;u&amp;gt;precisely&amp;lt;/u&amp;gt; 299792458&amp;quot; the ''proper'' answer, and [https://conversion.org/speed/speed-of-light/furlong-per-fortnight it could be far worse...]). Avagadro's number never had it so good (6.022(+change)×10&amp;lt;sup&amp;gt;23&amp;lt;/sup&amp;gt;...? ...where's the handily mnemonic value in that?), and Pi (in this universe's system of fundemental mathematics) clearly never ever had a chance! And, on {{w|Mount Everest#19th century|at least one occasion}}, such happenstance numeric roundedness in its exactitude (29''',000''' ft) was considered actually quite awkward... [[Special:Contributions/172.70.91.90|172.70.91.90]] 21:33, 23 October 2024 (UTC)&lt;br /&gt;
::My understanding is that the brine thing was an ad-hoc justification when the scale was presented to the Royal Society.  It may have seemed less cursed.  But yes, there's a BIG reason for using 32 or 64, halving a distance is trivial and as an instument maker, Fahrenheit would have found that attractive.  Mind you, I'm getting this from the Straight Dope, so I could be a dope getting it straight. https://www.straightdope.com/21344240/did-cecil-err-in-explaining-the-significance-of-zero-fahrenheit [[Special:Contributions/162.158.10.189|162.158.10.189]] 20:04, 24 October 2024 (UTC)&lt;br /&gt;
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Ok, then, regarding {{diff|353895|this edit}} (and the original IP-led one(s) that even made huge and revert-necessary changes), was it ''really'' intended to get rid of whole paragraphs such as &amp;quot;Randall also fails to specify what happens with temperatures[...]&amp;quot; that had nothing to do with the numeric adjustments? When I see that, I see mistakes (especially in light of the &amp;quot;clobber&amp;quot; that happened, where typos reappeared and other things became unexplained/worse-explained once more). — Basically, if your edit summary is nust about updating baseline data, and the resulting maths, I don't expect (maybe good, maybe bad) edits to unrelated bits. Or I may (and have) presumed accidental (or deliberate?) carelessness that I'd rather not try to go back to first principles to re-re-check for the editor concerned. That is all. At least try to justify enough of your edit in its own way, even if it means diving in several times to get enough space to summarise your whole &amp;quot;why&amp;quot; to each tweak. [[Special:Contributions/172.68.186.104|172.68.186.104]] 22:44, 23 October 2024 (UTC)&lt;br /&gt;
:Yes. I have re-removed the removals piecemeal with individual edit summaries for clarity. Many of them involved detailed obscure technical misunderstandings, such as whether the Vostok and Death Valley measurements were surface temperatures (the WMO says they are, and there are the WMO's photos of the observation stations in the linked references now) which combined with the incorrect yearly average global mean temperature, added five paragraphs unnecessarily. [[Special:Contributions/172.68.23.152|172.68.23.152]] 01:46, 24 October 2024 (UTC)&lt;br /&gt;
::Definitely some points made (some incorrect, &amp;quot;ne er&amp;quot; was ''obviously'' more just a basic typo of &amp;quot;never&amp;quot;, not my attempt to use &amp;quot;ne'er&amp;quot; for no good reason, and my attempt to fix that and some other bits ran into a set of Edit Conflicts ...hope I caught all the remaining ones when I finally could try again on the settled-down page) and I've blended answers to your objections in while giving back what useful nuances (from a number of past editors, only a couple of bits even having had my own hand primarilly behind them as they were) really needn't have been removed. I dispute the terms of your objections (as summarised) behind {{diff|353937|some changes}}, but have rephrased based upon what I ''think'' you mean, giving you should prefer and wouldn't feel the need to be as randomly censorious about. [[Special:Contributions/172.69.195.173|172.69.195.173]] 02:54, 24 October 2024 (UTC)&lt;br /&gt;
:::Figure 1 in https://climate.copernicus.eu/climate-indicators/temperature does not seem like a random walk to me. [[Special:Contributions/172.69.33.118|172.69.33.118]] 05:02, 24 October 2024 (UTC)&lt;br /&gt;
::::Added the &amp;quot;Random Walk&amp;quot; because, ignoring long-term trends, year-on-year the measured average is going to blip up and down for all kinds of reasons (physical and measuring issues, both), so it will be lower than expected or higher than expected compared to the smoother track it actually takes on a rolling average. I think one of the versions I replaced had partial suggestion that the average was effectively constant (in °C, not just °X), and while records adjusted every now and then (or every year!), it all just rather settled down at the °X midpoint. Which it doesn't. (And also that it's ''possible'' that Average and Minimum change such that the projected Absolute Zero ''doesn't'' move so much, one year, although mostly the fulcrum will be closer to 0°X rather than 0K.)&lt;br /&gt;
::::But I've yet to see what's been changed (maybe improved) since I was last looking at it. Maybe this is an out-of-date explanation. [[Special:Contributions/172.70.90.202|172.70.90.202]] 12:04, 24 October 2024 (UTC)&lt;br /&gt;
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When I originally designed my unit conversion app I almost made a unit up that was based on the ideal gas law and one mass pound of said gas in a one cubic foot container.  It seemed more quixotic than anything else so I didn't pull the trigger on it.  Maybe I should have.[[Special:Contributions/172.70.111.33|172.70.111.33]] 20:38, 24 October 2024 (UTC)&lt;br /&gt;
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Is x based off of elon musk changing twitter to X? [[Special:Contributions/172.71.254.50|172.71.254.50]] 23:22, 24 October 2024 (UTC)&lt;br /&gt;
:Too many things were already &amp;quot;X&amp;quot; (X marks the spot, Planet X, The X-Men, Xmas...), I see no need to presume that Elon has successfully claimed ownership of one entire letter of the alphabet due to a car-crash business deal and a self-obsessive personality. To paraphrase Freud, &amp;quot;sometimes an X is just an X&amp;quot;, and with no references at all to anything Twitter-like I don't see any other intent than just as a traditional placeholder character. [[Special:Contributions/172.70.90.209|172.70.90.209]] 09:40, 25 October 2024 (UTC)&lt;br /&gt;
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== Division by zero ==&lt;br /&gt;
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I saw this in an edit summary: &amp;quot;10/0 is not ∞, it's also an error, not NaN according to the IEEE. It's closer to {+∞, -∞} than NaN but it's still neither because you can't make limits work&amp;quot;&lt;br /&gt;
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Actually, IEEE floating point 10/0 can be an error, +∞, or NaN depending on the rounding mode. This is one of the reasons why mathemeticians don't appreciate the IEEE as much as they might. Division by zero is strictly undefined because of the problems with limits alluded to in the summary. https://www.youtube.com/watch?v=dHdg1yn1SgE [[Special:Contributions/108.162.245.66|108.162.245.66]] 03:48, 24 October 2024 (UTC)&lt;br /&gt;
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:&amp;quot;When considering division by zero through limits, assigning {+∞, -∞} as potential results is insufficient because limits require consistency and well-defined behavior. In the case of dividing a number by values approaching zero, the results differ depending on whether zero is approached from the positive or negative direction. As a divisor approaches zero from the positive side, the quotient grows towards +∞, and from the negative side, it tends towards -∞. Since limits must converge to a single value for consistency, this disparity leads to an undefined result. Moreover, in many mathematical contexts, infinity is not a number but rather a concept describing unbounded growth, meaning operations involving infinity, like addition or multiplication, are not well-defined in the same way as with finite numbers. This inconsistency in approaching zero prevents {+∞, -∞} from being an adequate solution set for division by zero. Defining division by zero as infinity would create contradictions in both arithmetic and algebraic contexts, as it disrupts fundamental properties like continuity and field structures in mathematics. Hence, division by zero remains undefined to preserve mathematical rigor and coherence.&amp;quot;&lt;br /&gt;
:[Chat Gippity 4o] [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:53, 24 October 2024 (UTC)&lt;br /&gt;
::https://imgflip.com/i/7yd7gz [[Special:Contributions/172.71.150.131|172.71.150.131]] 09:06, 24 October 2024 (UTC)&lt;br /&gt;
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== Trivia section table values? ==&lt;br /&gt;
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Someone please double-check the Trivia section temperatures. I am not convinced they are entirely correct or consistent. I'm least sure about the Galen row. And Wedgwood obviously needs more digits of precision. [[Special:Contributions/162.158.41.28|162.158.41.28]] 13:10, 24 October 2024 (UTC)&lt;br /&gt;
:LGTM. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 20:55, 25 October 2024 (UTC)&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354482</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354482"/>
				<updated>2024-10-25T21:05:02Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: ref&lt;/p&gt;
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&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
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==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
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Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|kelvin}}, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvin). The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.&lt;br /&gt;
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The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvin is very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.&amp;lt;ref&amp;gt;https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43&amp;lt;/ref&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,&amp;lt;ref&amp;gt;https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml&amp;lt;/ref&amp;gt; when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum attainable physical temperature,&amp;lt;ref&amp;gt;https://doi.org/10.4236/jamp.2024.1210198&amp;lt;/ref&amp;gt; will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-lowest-temperature&amp;lt;/ref&amp;gt; The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)&amp;lt;ref&amp;gt;https://climate.copernicus.eu/climate-indicators/temperature&amp;lt;/ref&amp;gt; The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-highest-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to effect of absorbing sunlight (or a lack thereof, e.g. at night or under clouds), and the thermal capacity of soil.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Sample {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Human body temperature|Average human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}&amp;lt;ref&amp;gt;https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}&amp;lt;ref&amp;gt;https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Typical warm bath temperature&amp;lt;ref&amp;gt;https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354479</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354479"/>
				<updated>2024-10-25T20:59:44Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Trivia */ graph of all&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|kelvin}}, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvin). The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvin is very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.&amp;lt;ref&amp;gt;https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43&amp;lt;/ref&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,&amp;lt;ref&amp;gt;https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml&amp;lt;/ref&amp;gt; when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (possibly to the equivalent of 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, considered [https://doi.org/10.4236/jamp.2024.1210198 the maximum attainable physical temperature]) will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-lowest-temperature&amp;lt;/ref&amp;gt; The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)&amp;lt;ref&amp;gt;https://climate.copernicus.eu/climate-indicators/temperature&amp;lt;/ref&amp;gt; The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-highest-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to effect of absorbing sunlight (or a lack thereof, e.g. at night or under clouds), and the thermal capacity of soil.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
[[File:Temperature Scales.png|center|600px]]&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
Here are some various temperatures in the above scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Sample {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Human body temperature|Average human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}&amp;lt;ref&amp;gt;https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}&amp;lt;ref&amp;gt;https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Typical warm bath temperature&amp;lt;ref&amp;gt;https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354478</id>
		<title>File:Temperature Scales.png</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354478"/>
				<updated>2024-10-25T20:57:53Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: oops&lt;/p&gt;
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&lt;div&gt;All the scales from [[3001: Temperature Scales]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354477</id>
		<title>File:Temperature Scales.png</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=File:Temperature_Scales.png&amp;diff=354477"/>
				<updated>2024-10-25T20:57:15Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: All the scales from 3000: Temperature Scales&lt;/p&gt;
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&lt;div&gt;All the scales from [[3000: Temperature Scales]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354476</id>
		<title>Talk:3001: Temperature Scales</title>
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				<updated>2024-10-25T20:55:35Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Trivia section table values? */&lt;/p&gt;
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Shouldn't Rankine say &amp;quot;0ºR is set to absolute zero&amp;quot;? {{unsigned ip|172.70.230.29|22:58, 21 October 2024 (UTC)}}&lt;br /&gt;
:Yep. [[Special:Contributions/162.158.186.253|162.158.186.253]] 04:38, 22 October 2024 (UTC)&lt;br /&gt;
:Furthermore, should it be 0°R or just 0R (no °)? I've been told that Kelvin doesn't use degrees because it's an absolute scale, so a) is this true and b) should it apply to Rankine? [[Special:Contributions/172.71.211.54|172.71.211.54]] 14:44, 24 October 2024 (UTC)&lt;br /&gt;
::Kelvin is rather strange, for reasons never totally explained. It's &amp;quot;the Kelvin scale&amp;quot;, but the unit is &amp;quot;kelvin&amp;quot; and I never got on with the official absence of the ° symbol by the &amp;quot;K&amp;quot;. I was always taught to ''say'' &amp;quot;degrees kelvin&amp;quot; (for temperatures) and &amp;quot;kelvin degrees&amp;quot; (for a change/range of temperature) in order to not cause confusion and technical misunderstandings (''perhaps'' easier to contextualise when down in writing?) but no accounting for taste, or possibly official laziness.&lt;br /&gt;
::On the basis that Rankine is not kelvin (whatever the reason for how kelvin is what it is), I would use the degrees, as I would any other absolute scale (whether it be an adjusted form of °Rø or °Ré or whatever else might be invented), because kelvin is just inexplicably (to me, and to others) ''the'' exception to absolutely every other reasonably equivalent contemporary measure, including capitalisation. YMMV! [[Special:Contributions/172.70.162.2|172.70.162.2]] 19:53, 24 October 2024 (UTC)&lt;br /&gt;
:::0ºRa, not 0ºR. [[Special:Contributions/172.70.206.157|172.70.206.157]] 02:16, 25 October 2024 (UTC)&lt;br /&gt;
::::Can be either. Perhaps best to use °Ra (in ambiguous context) to avoid ''possible'' confusion with °Ré and °Rø, but probably less important when both those two are also listed alongside (except for wondering what, if anything, is a typo, bad handwriting or other error). [[Special:Contributions/172.69.194.12|172.69.194.12]] 11:01, 25 October 2024 (UTC)&lt;br /&gt;
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yo,i thought comic 3000 was anticlimactic so randall would make this one COOL but sadly not&lt;br /&gt;
Same. Hope he does something cool for 3072.[[Special:Contributions/172.69.134.225|172.69.134.225]] 23:44, 21 October 2024 (UTC)&lt;br /&gt;
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really he didn't do anything special for this either? come ON randall if you don't do something cool for comic 3072 i will &amp;lt;b&amp;gt; come to your house personally and yell at you  [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 23:57, 21 October 2024 (UTC)&lt;br /&gt;
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What's random about Fahrenheit? (Answer: nothing.) 0F is the freezing point of brine, 100F (or 98.7) is the human body temperature. [[Special:Contributions/172.68.54.65|172.68.54.65]] 00:00, 22 October 2024 (UTC)&lt;br /&gt;
:What concentration of brine? (And which specific salt... No, not NaCl, as you might presume but NH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Cl!)&lt;br /&gt;
:And body temperature varies a lot ('typically' 36.5–37.5°C or  97.7–99.5°F, though even this range is thought to be too small), across genders, individuals, time of day ''and'' which orifices/surfaces you try to measure it from. (Originally, it was set so that '''90°F''' was to be the 'best guess' of human body temperature. It gradually changed, including via various {{w|Human body temperature#Historical understanding|compounded misunderstandings}} so that the best you can say is that 100°F is arbitrarily ''slightly above'' most afebrile human body temperature measurements.)&lt;br /&gt;
:Celsius might be a bit off (arguments about triple-point or STP freezing, etc), but it still has far more physical logic to it. [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
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Sorry, Randall, for my comfort, Fahrenheit is the least cursed. It's the best scale to use for my personal use, especially when hearing the weather report and deciding what to wear outdoors: temp in the 80's - no jacket. temp in 70's - maybe a windbreaker if it's breezy. 60's - sweater weather. 50's - medium weight coat. 40's - winter coat. 30'3 - winter coat with scarf and gloves. 20's - multiple layers. teens - stay indoors. None of the other scales provide such convenient distinctions for my daily life. Kelvin is great for astro physics or super conductivity, but useless for any common uses. Celsius is great for hanging out with the Euro crowd but still not so useful to scale my home thermostat. I judge Fahrenheit as 1.0 for cursedness. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:19, 22 October 2024 (UTC)&lt;br /&gt;
:I conveniently use Celsius in tens, also. Negative °C: Cold; 0-10°C: Nippy; 10-20°C: Generally pleasant; 20-30°C: Too warm to exert oneself; 30°C+: ''Definitely'' too warm. [[Special:Contributions/172.70.86.205|172.70.86.205]] 15:24, 22 October 2024 (UTC)&lt;br /&gt;
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Personally, I'm most disappointed that {{w|Delisle scale}} was not represented... [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
: I was so hoping for a {{w|Planck temperature}} quip. Like: &amp;quot;Water freezing point: 0; Water boiling point: 0; Notes: 1 = highest possible temperature (1.4E32K) where thermal radiation creates black holes; Cursedness: 0/0&amp;quot; [[Special:Contributions/162.158.164.184|162.158.164.184]] 01:27, 22 October 2024 (UTC)&lt;br /&gt;
:: Same here. Freezing is 0.000000000000000000000000000001928 and boiling is 0.0000000000000000000000000000026338. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 03:38, 22 October 2024 (UTC)&lt;br /&gt;
::: Wow, those are even smaller than the IEEE floating point representations of 1-1.0/3*3! [[Special:Contributions/162.158.90.109|162.158.90.109]] 03:59, 22 October 2024 (UTC)&lt;br /&gt;
:: The Planck temperature quip is definitely well deserved. Good catch! [[User:Mumingpo|Mumingpo]] ([[User talk:Mumingpo|talk]]) 17:24, 23 October 2024 (UTC)&lt;br /&gt;
I guess I was wrong in my comment on the last comic. sigh. -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 01:16, 22 October 2024 (UTC)&lt;br /&gt;
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It's actually spelled {{w|Wedgwood scale}}, not Wedgewood. [[User:Wilh3lm|Wilh3lm]] ([[User talk:Wilh3lm|talk]]) 01:17, 22 October 2024 (UTC)&lt;br /&gt;
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I still call the modern version of the &amp;quot;Celsius&amp;quot; scale &amp;quot;centigrade&amp;quot;, but if people start nitpicking, I'm happy to switch to &amp;quot;Carolus&amp;quot; to avoid ambiguity. For some reason that tends to annoy people more though. [[Special:Contributions/172.68.22.191|172.68.22.191]] 01:32, 22 October 2024 (UTC)&lt;br /&gt;
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Every temperature scale is equally &amp;quot;random&amp;quot; as every other scale. People always say that Celsius is so much better because it's defined by the phase changes of water. Okay, cool...why should THAT of all things be what we use as the base for a system of temperature measurement? And, who cares? I'm a ''Homo sapiens'', not a water molecule. If anything we should use the freezing and melting points of humans as our two reference points for temperature (which, I must say, Fahrenheit approximates better than Celsius, assuming 0 and 100 are your points &amp;quot;A&amp;quot; and &amp;quot;B&amp;quot;). [[User:Pie Guy|Pie Guy]] ([[User talk:Pie Guy|talk]]) 03:42, 22 October 2024 (UTC)&lt;br /&gt;
: Every temperature scale is arbitrary, but since boiling and freezing water is a thing humans have a lot of experience with it makes sense to use that as the reference point. At least it makes more sense than whatever the coldest recorded temperature in Fahrenheit's home town was, because he didn't like negative numbers [[Special:Contributions/172.70.250.23|172.70.250.23]] 03:56, 22 October 2024 (UTC)&lt;br /&gt;
::Planck temperature (as above) is probably the least arbitrary, and some would say it is to some extent free from arbitrariness. However, it's completely impractical for everyday use (as above.) [[Special:Contributions/172.69.34.138|172.69.34.138]] 04:31, 22 October 2024 (UTC)&lt;br /&gt;
:::Do the physics of black holes or neutron stars involve Planck temperatures greater than 0.0000001? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:23, 22 October 2024 (UTC)&lt;br /&gt;
::::Chat Gippity told me:&lt;br /&gt;
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:::::Black holes and neutron stars do not typically involve temperatures reaching the Planck scale. While both objects exhibit extreme physical conditions, their temperatures are far below the Planck temperature, even though they can be incredibly high compared to everyday phenomena.&lt;br /&gt;
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::::: - **Neutron stars** have surface temperatures in the range of millions of Kelvin, and the core can reach even higher, possibly up to a few billion Kelvin. These temperatures are still vastly lower than the Planck temperature.&lt;br /&gt;
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::::: - **Black holes**, especially the smaller ones, can emit Hawking radiation, with temperatures inversely proportional to their mass. However, the temperature of even a very small black hole is still far below the Planck temperature. Hawking radiation is not expected to reach temperatures close to the Planck scale under normal circumstances.&lt;br /&gt;
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::::: The Planck temperature (TP=1) represents an energy scale so extreme that no known physical models, including those describing black holes and neutron stars, operate near or above this threshold. Temperatures reaching **0.0000001 TP** (or 1.416 × 10^26 K) would still be beyond current observational and theoretical frameworks related to these cosmic objects. A quantum theory of gravity would be required to describe physics at or near the Planck temperature, which remains speculative and is far beyond the conditions found in black holes or neutron stars.&lt;br /&gt;
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::::[[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:46, 22 October 2024 (UTC)&lt;br /&gt;
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If the °X scale is based on the temperatures of Earth from all time (for some definition of &amp;quot;Earth&amp;quot;), then the scale is very hard to define and highly impractical. The earth appears to have gotten to more than 2,300 Kelvin (hot enough to melt steel and platinum and to boil lead) and while I can't find any sources for the lowest temperature, I imagine it is lower than -100°C. The recorded minimum, maximum and average temperatures appear to be around -89.2 °C, 56.7 °C and 15 °C respectively. This would make the scale somewhat useful, but this would make typical values between 41 °X (cold winter's day) and 68 °X (hot summers day) which I think is pretty cursed. I recommend the clearly superior °Y, based around average temp at 0 °Y, low at -100 °Y and high at 100 °Y. These would be measured by the yearly high, low and mean temperatures averaged per person. Then saying &amp;quot;It's 2 times colder than yesterday&amp;quot; would have some reasonable meaning. --[[Special:Contributions/198.41.236.147|198.41.236.147]] 04:01, 22 October 2024 (UTC)&lt;br /&gt;
:&amp;quot;''Record'' ... surface temperature&amp;quot; implies it was recorded. [[Special:Contributions/172.68.22.9|172.68.22.9]] 04:08, 22 October 2024 (UTC)&lt;br /&gt;
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How do you all feel about adding an additional column for room temperature 22C/72F?&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
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Or 0.00000000000000000000000000000208 °Planck, lol. [[Special:Contributions/108.162.245.211|108.162.245.211]] 05:36, 22 October 2024 (UTC)&lt;br /&gt;
:I feel like decigalens would be the most practical unit. Who's with me? [[Special:Contributions/162.158.186.5|162.158.186.5]] 06:20, 22 October 2024 (UTC)&lt;br /&gt;
::It's interesting; calculating the equilibrium temperature (with 2.05 and 4.24 being used for the heat capacities of ice and boiling water) gives 67... If I use water that's about to freeze and steam, I get 31. [[Special:Contributions/172.69.0.178|172.69.0.178]] 07:59, 22 October 2024 (UTC)&lt;br /&gt;
:::Would you please explain in more detail? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:03, 22 October 2024 (UTC)&lt;br /&gt;
:::: The equilibrium temperature of a mixture (?) of equal quantities of ice at 0 C and water at 100 C (with the heat capacities 2.05 and 4.24) is 67 C; if I use the data for water at 0 C and steam, I get 31 C. Additionally, if I use equal volumes, I get 68 (which isn't much different.) [[Special:Contributions/172.69.0.178|172.69.0.178]] 17:15, 22 October 2024 (UTC)&lt;br /&gt;
:::: One can obtain 0 = 22 C by setting the heat capacity of ice to be 39 and that of water to be 11. For any particular &amp;quot;normal temperature&amp;quot; ''R'' °C (that is, the temperature at 0 is ''R'',), I find that ''x'' °C = 50''R''(''x''+4)/(''x''(''R''-50)+200). In particular, for ''R'' = 22, we get (1100+275''x'')/(50-7''x''). [[Special:Contributions/198.41.236.163|198.41.236.163]] 05:58, 23 October 2024 (UTC)&lt;br /&gt;
::How about Tnew=0.1694×degC+46.25; degC=(Tnew-46.25)/0.1694, where 0 is absolute zero and 50 is room temperature? (Freezing point of water: 46.25; Boiling point of water: 63.19) [[Special:Contributions/162.158.186.248|162.158.186.248]] 05:21, 24 October 2024 (UTC)&lt;br /&gt;
:I would absolutely pull the trigger on an additional column if I didn't think it would further screw up what are most probably extremely cursed mobile portrait renderings of the table. How about a Trivia section? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:44, 24 October 2024 (UTC)&lt;br /&gt;
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Question regarding the X scale - when it‘s defined by *three* (somewhat, implying average is real and not just calculated by (max-min)/2)) independent points, how will linearity be achieved? [[Special:Contributions/162.158.155.76|162.158.155.76]] 05:43, 22 October 2024 (UTC)&lt;br /&gt;
[[File:Explanation length.png|right|thumb|Or click &amp;quot;[Expand]&amp;quot; in the bottom right table cell Derivation.]]&lt;br /&gt;
:Please see [[2701: Change in Slope]]. [[Special:Contributions/172.70.206.179|172.70.206.179]] 05:50, 22 October 2024 (UTC)&lt;br /&gt;
:Sure, &amp;quot;a linear scale between each point&amp;quot;:&lt;br /&gt;
[[File:XvsC.png|thumb|left|Here you go. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 06:33, 22 October 2024 (UTC)]]&lt;br /&gt;
{{clear}}&lt;br /&gt;
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The reference for the average surface temperature, https://www.space.com/17816-earth-temperature.html, suggests it has increased above 15°C. What value should we use in late 2024? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:30, 22 October 2024 (UTC)&lt;br /&gt;
:The [https://wmo.int/media/news/earth-experiences-warmest-day-recent-history World Meteorological Organization], [https://www.carbonbrief.org/state-of-the-climate-2024-now-very-likely-to-be-warmest-year-on-record/ Carbon Brief], and [https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024 Copernicus Climate Change Service] suggest 17.16°C. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:42, 22 October 2024 (UTC)&lt;br /&gt;
::Updated water temperatures, Derivation, and graph. So we've already had more than the +2°C warming we were trying to avoid in 2019? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:05, 22 October 2024 (UTC)&lt;br /&gt;
::: The +2°C (or +1.5°C that we were originally supposed to be avoiding) is over some (undefined) number of years, though, which allows us to ignore the fact that we're cooking ourselves by repeatedly saying 'Oh, but it doesn't count ''yet''.' [[Special:Contributions/172.70.91.62|172.70.91.62]] 11:13, 23 October 2024 (UTC)&lt;br /&gt;
Regarding [https://www.explainxkcd.com/wiki/index.php?title=3001%3A_Temperature_Scales&amp;amp;type=revision&amp;amp;diff=353635&amp;amp;oldid=353632], are the average surface temperatures from the sources supposed to be yearly or overall averages? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:06, 22 October 2024 (UTC)&lt;br /&gt;
:According to https://climate.copernicus.eu/climate-indicators/temperature the global average near-surface temperature in 2023 was 14.4 + 0.4 = 14.8°C. (see Figure 1 and click &amp;quot;Increase above: [1991–2020 reference period].&amp;quot;) [[Special:Contributions/172.68.22.8|172.68.22.8]] 21:06, 23 October 2024 (UTC)&lt;br /&gt;
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where is the interactive epic 3000 comic we should've gotten? This one's cool but 1000 seemed to have more effort in it and 2000 was at least tangetially related. Does Randall just not like making these anymore and is only making more comics as a business? [[Special:Contributions/108.162.238.185|108.162.238.185]] 12:14, 22 October 2024 (UTC)&lt;br /&gt;
:The comic is free on the website and it doesn't have ads; although the comic is part of his &amp;quot;brand&amp;quot; there are many more profitable things he could be doing with his time, and yet he continues to update it every Monday, Wednesday, and Friday.  I just don't like the idea of claiming that a creative person &amp;quot;should&amp;quot; produce any particular thing to satisfy their fans.  He's a busy guy!  Maybe he's working on a book, or a Scientific American article, or a TV show.  He's under no obligation to give us anything, and maybe one day he'll stop making xkcd altogether; that's his choice.  Sorry to single you out; I know a lot of people feel the same way as you do, but to me it doesn't make sense.  He's not a content machine--he's a guy who started posting sketches on the internet. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 15:23, 22 October 2024 (UTC)&lt;br /&gt;
::Sorry if I sounded overly brash, I wasn't trying to imply &amp;quot;wahhh no special entry wahhh&amp;quot;, I was just wondering if Randall still likes to make these or if he doesn't, mainly because he just didn't do anything special, which feels like he just didn't care. I wasn't trying to imply Randall should just do it for the fans[[Special:Contributions/108.162.238.80|108.162.238.80]] 17:52, 22 October 2024 (UTC)&lt;br /&gt;
:::It ''could'' be that 3000 (or even 3001) ''was'' going to be special but, as fairly frequently with April Fool 'specials', it just wasn't doable on time. (If it's still considered fixablez it might pop up sometime before 3020 or so. Or, if transferable to another occasion (rebranding the obvious &amp;quot;3000!&amp;quot;ness), held over until Haloween, Christmas, April or 4000, perhaps with additional perfections.)&lt;br /&gt;
:::Hard to know, unless Randall (or his technical collaborators) say anything. And it's probably not worth doing so right now. Maybe &amp;quot;Hey guys, this ''was'' going to be #3000!&amp;quot; might accompany its eventual emergence, but also maybe not. Does it really matter? [[Special:Contributions/172.70.85.139|172.70.85.139]] 13:03, 23 October 2024 (UTC)&lt;br /&gt;
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Is this the first list-style comic where every single entry is real? (Usually he has several joke entries.) [[Special:Contributions/172.70.114.182|172.70.114.182]] 14:26, 22 October 2024 (UTC)&lt;br /&gt;
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Where would [[1923: Felsius|Felsius]] go on this list?&lt;br /&gt;
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One can find a smooth function for °X, namely, (477879''x''-17634840)/(3341''x''+197700), which takes °X and returns °C. The inverse is (-197700''x''-17634840)/(3341''x''-477879). Should this be included in the wiki article? Or maybe another way of fitting it (like exponential) should be used.  [[Special:Contributions/172.69.0.165|172.69.0.165]] 06:27, 23 October 2024 (UTC)&lt;br /&gt;
:It says &amp;quot;a linear scale between each point&amp;quot;. [[Special:Contributions/172.70.210.130|172.70.210.130]] 21:09, 23 October 2024 (UTC)&lt;br /&gt;
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Should it be noted that in the first _What If?_ book, there's a reference to units and how much Randall loathes rankine? Someone can go take the book and cite it; it's in one of the early pages [[Special:Contributions/172.64.236.10|172.64.236.10]] 08:45, 23 October 2024 (UTC)&lt;br /&gt;
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I remember it being drummed into us in school physics (admittedly over 50 years ago) that 0 Celsius is defined as the melting point of ice, not the freezing point of water (presumably because of supercooling). [[Special:Contributions/172.70.160.189|172.70.160.189]] 08:49, 23 October 2024 (UTC)&lt;br /&gt;
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It seems he wrote &amp;quot;Earths'&amp;quot; (plural possessive) instead of &amp;quot;Earth's&amp;quot;. [[Special:Contributions/141.101.98.151|141.101.98.151]] 08:58, 23 October 2024 (UTC)&lt;br /&gt;
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What?  No gas mark?  It's linear for temperatures over 275°F but inverse powers of 2 below  That's pretty cursed, but I still put it in my unit conversion app.  It's only used in gas stoves in a few countries, so it doesn't come up very often.  By the way, boiling is 1/5.7358 and freezing/melting is 1/843.3572.  Interestingly, France has it's own stove temperature scale that seems to be based on °F.&lt;br /&gt;
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Also, my understanding is that 7.5 and 32 aren't random.  Both Romer and Fahrenheit put numbers on things so that freezing/melting of water and &amp;quot;Normal human body temperature&amp;quot;, which was thought to be standard at the time, would be some number X (15 for Romer and 64 for Fahrenheit) and the water thing would be to be X/2 and NHBT would be X/2+X.  Pretty nerdy.  Sadly, the calibration was off and 212 degrees for boiling was found to be less cursed.  But I could be wrong.[[Special:Contributions/172.68.54.138|172.68.54.138]] 20:39, 23 October 2024 (UTC)&lt;br /&gt;
:Re: water/ice point 'random number', I think it's more that it wasn't considered &amp;quot;special&amp;quot;, such that &amp;quot;On my scale, that will be zero&amp;quot; (or whatever choice of handily round number, including zero, some scale-setters allocated to the BP of water).&lt;br /&gt;
:After all the other messing about (&amp;quot;my zero will be that of brine!&amp;quot;, etc), obviously then the ~0°C equivalent would ''have'' a number, and ''perhaps''  there would then be a slight change to make it a ''whole'' (or easy-fraction) number for convenience's sake, but (before the concept of binary computers) there's not much special about landing on the number 32, for what is actually a temperature that is quite significant to the human experience, and less so with 7-''and-a-half''.&lt;br /&gt;
:Maybe landing on 90°F (at one time) for body temperature (and 180 F° ''between'' MP and BP) was considered useful as the analogue to angular-degrees where 90 (and 180) indeed features significantly, but I don't think there'd have been too much fuss if the value would have turned out to be 60(/120), also with plenty of handy factors to divide by, 70(/140), without so much, or whatever number(s) happened to depict one realistic real-world measurement that (overall) has no reason to have a factor-based relationship with various quite separate phenomenon measurements.&lt;br /&gt;
:''And'' it went through several {{w|Human body temperature#Historical understanding|'corrective' iterations}} so that even its handy relationship with 'about 100°F' can be said to be an incidental accident, at best, unless we do something like Randall's °X scale and actively triple-tie the central value of the slope(s) to be exactly something useful by using the &amp;quot;currently accepted mean human body temperature (given various complicated caveats)&amp;quot;.&lt;br /&gt;
:It's pretty much all random, in the same way that only because of anthropocentric choices of 'standard' time and distance measurements is the speed of light 'pretty much' 3×10⁸ m/s (a handily round value that works well enough for most purposes, even after back-standardising its component SI measurements to make &amp;quot;actually, &amp;lt;u&amp;gt;precisely&amp;lt;/u&amp;gt; 299792458&amp;quot; the ''proper'' answer, and [https://conversion.org/speed/speed-of-light/furlong-per-fortnight it could be far worse...]). Avagadro's number never had it so good (6.022(+change)×10&amp;lt;sup&amp;gt;23&amp;lt;/sup&amp;gt;...? ...where's the handily mnemonic value in that?), and Pi (in this universe's system of fundemental mathematics) clearly never ever had a chance! And, on {{w|Mount Everest#19th century|at least one occasion}}, such happenstance numeric roundedness in its exactitude (29''',000''' ft) was considered actually quite awkward... [[Special:Contributions/172.70.91.90|172.70.91.90]] 21:33, 23 October 2024 (UTC)&lt;br /&gt;
::My understanding is that the brine thing was an ad-hoc justification when the scale was presented to the Royal Society.  It may have seemed less cursed.  But yes, there's a BIG reason for using 32 or 64, halving a distance is trivial and as an instument maker, Fahrenheit would have found that attractive.  Mind you, I'm getting this from the Straight Dope, so I could be a dope getting it straight. https://www.straightdope.com/21344240/did-cecil-err-in-explaining-the-significance-of-zero-fahrenheit [[Special:Contributions/162.158.10.189|162.158.10.189]] 20:04, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Ok, then, regarding {{diff|353895|this edit}} (and the original IP-led one(s) that even made huge and revert-necessary changes), was it ''really'' intended to get rid of whole paragraphs such as &amp;quot;Randall also fails to specify what happens with temperatures[...]&amp;quot; that had nothing to do with the numeric adjustments? When I see that, I see mistakes (especially in light of the &amp;quot;clobber&amp;quot; that happened, where typos reappeared and other things became unexplained/worse-explained once more). — Basically, if your edit summary is nust about updating baseline data, and the resulting maths, I don't expect (maybe good, maybe bad) edits to unrelated bits. Or I may (and have) presumed accidental (or deliberate?) carelessness that I'd rather not try to go back to first principles to re-re-check for the editor concerned. That is all. At least try to justify enough of your edit in its own way, even if it means diving in several times to get enough space to summarise your whole &amp;quot;why&amp;quot; to each tweak. [[Special:Contributions/172.68.186.104|172.68.186.104]] 22:44, 23 October 2024 (UTC)&lt;br /&gt;
:Yes. I have re-removed the removals piecemeal with individual edit summaries for clarity. Many of them involved detailed obscure technical misunderstandings, such as whether the Vostok and Death Valley measurements were surface temperatures (the WMO says they are, and there are the WMO's photos of the observation stations in the linked references now) which combined with the incorrect yearly average global mean temperature, added five paragraphs unnecessarily. [[Special:Contributions/172.68.23.152|172.68.23.152]] 01:46, 24 October 2024 (UTC)&lt;br /&gt;
::Definitely some points made (some incorrect, &amp;quot;ne er&amp;quot; was ''obviously'' more just a basic typo of &amp;quot;never&amp;quot;, not my attempt to use &amp;quot;ne'er&amp;quot; for no good reason, and my attempt to fix that and some other bits ran into a set of Edit Conflicts ...hope I caught all the remaining ones when I finally could try again on the settled-down page) and I've blended answers to your objections in while giving back what useful nuances (from a number of past editors, only a couple of bits even having had my own hand primarilly behind them as they were) really needn't have been removed. I dispute the terms of your objections (as summarised) behind {{diff|353937|some changes}}, but have rephrased based upon what I ''think'' you mean, giving you should prefer and wouldn't feel the need to be as randomly censorious about. [[Special:Contributions/172.69.195.173|172.69.195.173]] 02:54, 24 October 2024 (UTC)&lt;br /&gt;
:::Figure 1 in https://climate.copernicus.eu/climate-indicators/temperature does not seem like a random walk to me. [[Special:Contributions/172.69.33.118|172.69.33.118]] 05:02, 24 October 2024 (UTC)&lt;br /&gt;
::::Added the &amp;quot;Random Walk&amp;quot; because, ignoring long-term trends, year-on-year the measured average is going to blip up and down for all kinds of reasons (physical and measuring issues, both), so it will be lower than expected or higher than expected compared to the smoother track it actually takes on a rolling average. I think one of the versions I replaced had partial suggestion that the average was effectively constant (in °C, not just °X), and while records adjusted every now and then (or every year!), it all just rather settled down at the °X midpoint. Which it doesn't. (And also that it's ''possible'' that Average and Minimum change such that the projected Absolute Zero ''doesn't'' move so much, one year, although mostly the fulcrum will be closer to 0°X rather than 0K.)&lt;br /&gt;
::::But I've yet to see what's been changed (maybe improved) since I was last looking at it. Maybe this is an out-of-date explanation. [[Special:Contributions/172.70.90.202|172.70.90.202]] 12:04, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
When I originally designed my unit conversion app I almost made a unit up that was based on the ideal gas law and one mass pound of said gas in a one cubic foot container.  It seemed more quixotic than anything else so I didn't pull the trigger on it.  Maybe I should have.[[Special:Contributions/172.70.111.33|172.70.111.33]] 20:38, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Is x based off of elon musk changing twitter to X? [[Special:Contributions/172.71.254.50|172.71.254.50]] 23:22, 24 October 2024 (UTC)&lt;br /&gt;
:Too many things were already &amp;quot;X&amp;quot; (X marks the spot, Planet X, The X-Men, Xmas...), I see no need to presume that Elon has successfully claimed ownership of one entire letter of the alphabet due to a car-crash business deal and a self-obsessive personality. To paraphrase Freud, &amp;quot;sometimes an X is just an X&amp;quot;, and with no references at all to anything Twitter-like I don't see any other intent than just as a traditional placeholder character. [[Special:Contributions/172.70.90.209|172.70.90.209]] 09:40, 25 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
== Division by zero ==&lt;br /&gt;
&lt;br /&gt;
I saw this in an edit summary: &amp;quot;10/0 is not ∞, it's also an error, not NaN according to the IEEE. It's closer to {+∞, -∞} than NaN but it's still neither because you can't make limits work&amp;quot;&lt;br /&gt;
&lt;br /&gt;
Actually, IEEE floating point 10/0 can be an error, +∞, or NaN depending on the rounding mode. This is one of the reasons why mathemeticians don't appreciate the IEEE as much as they might. Division by zero is strictly undefined because of the problems with limits alluded to in the summary. https://www.youtube.com/watch?v=dHdg1yn1SgE [[Special:Contributions/108.162.245.66|108.162.245.66]] 03:48, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
:&amp;quot;When considering division by zero through limits, assigning {+∞, -∞} as potential results is insufficient because limits require consistency and well-defined behavior. In the case of dividing a number by values approaching zero, the results differ depending on whether zero is approached from the positive or negative direction. As a divisor approaches zero from the positive side, the quotient grows towards +∞, and from the negative side, it tends towards -∞. Since limits must converge to a single value for consistency, this disparity leads to an undefined result. Moreover, in many mathematical contexts, infinity is not a number but rather a concept describing unbounded growth, meaning operations involving infinity, like addition or multiplication, are not well-defined in the same way as with finite numbers. This inconsistency in approaching zero prevents {+∞, -∞} from being an adequate solution set for division by zero. Defining division by zero as infinity would create contradictions in both arithmetic and algebraic contexts, as it disrupts fundamental properties like continuity and field structures in mathematics. Hence, division by zero remains undefined to preserve mathematical rigor and coherence.&amp;quot;&lt;br /&gt;
:[Chat Gippity 4o] [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:53, 24 October 2024 (UTC)&lt;br /&gt;
::https://imgflip.com/i/7yd7gz [[Special:Contributions/172.71.150.131|172.71.150.131]] 09:06, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
== Trivia section table values? ==&lt;br /&gt;
&lt;br /&gt;
Someone please double-check the Trivia section temperatures. I am not convinced they are entirely correct or consistent. I'm least sure about the Galen row. And Wedgwood obviously needs more digits of precision. [[Special:Contributions/162.158.41.28|162.158.41.28]] 13:10, 24 October 2024 (UTC)&lt;br /&gt;
:LGTM. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 20:55, 25 October 2024 (UTC)&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354475</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354475"/>
				<updated>2024-10-25T20:54:40Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Trivia */ refs&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|kelvin}}, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvin). The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvin is very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.&amp;lt;ref&amp;gt;https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43&amp;lt;/ref&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,&amp;lt;ref&amp;gt;https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml&amp;lt;/ref&amp;gt; when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (possibly to the equivalent of 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, considered [https://doi.org/10.4236/jamp.2024.1210198 the maximum attainable physical temperature]) will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-lowest-temperature&amp;lt;/ref&amp;gt; The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)&amp;lt;ref&amp;gt;https://climate.copernicus.eu/climate-indicators/temperature&amp;lt;/ref&amp;gt; The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-highest-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to effect of absorbing sunlight (or a lack thereof, e.g. at night or under clouds), and the thermal capacity of soil.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
In the various scales, this is a table of several benchmark temperatures.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Sample {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Human body temperature|Average human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}}&amp;lt;ref&amp;gt;https://www.realsimple.com/food-recipes/shopping-storing/food/refrigerator-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}}&amp;lt;ref&amp;gt;https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/freezing-and-food-safety&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Typical warm bath temperature&amp;lt;ref&amp;gt;https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/&amp;lt;/ref&amp;gt;&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || 0 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354474</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354474"/>
				<updated>2024-10-25T20:49:53Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Trivia */ ok&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|kelvin}}, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvin). The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvin is very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.&amp;lt;ref&amp;gt;https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43&amp;lt;/ref&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,&amp;lt;ref&amp;gt;https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml&amp;lt;/ref&amp;gt; when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (possibly to the equivalent of 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, considered [https://doi.org/10.4236/jamp.2024.1210198 the maximum attainable physical temperature]) will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-lowest-temperature&amp;lt;/ref&amp;gt; The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)&amp;lt;ref&amp;gt;https://climate.copernicus.eu/climate-indicators/temperature&amp;lt;/ref&amp;gt; The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-highest-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to effect of absorbing sunlight (or a lack thereof, e.g. at night or under clouds), and the thermal capacity of soil.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
In the various scales, this is a table of several benchmark temperatures.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Sample {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Human body temperature|Average human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! Typical warm bath temperature[https://www.kohlerwalkinbath.com/blog/everything-you-need-to-know-about-the-ideal-bath-temperature/]&lt;br /&gt;
! Typical {{w|Coffee#Brewing|hot coffee}} temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || -0.4 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354473</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354473"/>
				<updated>2024-10-25T20:48:06Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Trivia */ oops&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|kelvin}}, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvin). The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvin is very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.&amp;lt;ref&amp;gt;https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43&amp;lt;/ref&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,&amp;lt;ref&amp;gt;https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml&amp;lt;/ref&amp;gt; when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (possibly to the equivalent of 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, considered [https://doi.org/10.4236/jamp.2024.1210198 the maximum attainable physical temperature]) will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-lowest-temperature&amp;lt;/ref&amp;gt; The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)&amp;lt;ref&amp;gt;https://climate.copernicus.eu/climate-indicators/temperature&amp;lt;/ref&amp;gt; The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-highest-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to effect of absorbing sunlight (or a lack thereof, e.g. at night or under clouds), and the thermal capacity of soil.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
In the various scales, this is a table of several benchmark temperatures.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Sample {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Human body temperature|Average human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! &amp;quot;Warm bath&amp;quot; temperature &amp;lt;!-- go on, find a decent link in something like https://en.wikipedia.org/wiki/Bathing - I challenge you! --&amp;gt;&lt;br /&gt;
! &amp;quot;{{w|Coffee#Brewing|Hot coffee}}&amp;quot; temperature &amp;lt;!-- best I could do... over to you! --&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || -0.4 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354472</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354472"/>
				<updated>2024-10-25T20:47:24Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Trivia */ oh I see what you're trying to say&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|kelvin}}, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvin). The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvin is very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.&amp;lt;ref&amp;gt;https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43&amp;lt;/ref&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,&amp;lt;ref&amp;gt;https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml&amp;lt;/ref&amp;gt; when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (possibly to the equivalent of 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, considered [https://doi.org/10.4236/jamp.2024.1210198 the maximum attainable physical temperature]) will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-lowest-temperature&amp;lt;/ref&amp;gt; The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)&amp;lt;ref&amp;gt;https://climate.copernicus.eu/climate-indicators/temperature&amp;lt;/ref&amp;gt; The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-highest-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to effect of absorbing sunlight (or a lack thereof, e.g. at night or under clouds), and the thermal capacity of soil.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
In the various scales, this is a table of several benchmark temperatures.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Sample {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Average human body temperature|Human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! &amp;quot;Warm bath&amp;quot; temperature &amp;lt;!-- go on, find a decent link in something like https://en.wikipedia.org/wiki/Bathing - I challenge you! --&amp;gt;&lt;br /&gt;
! &amp;quot;{{w|Coffee#Brewing|Hot coffee}}&amp;quot; temperature &amp;lt;!-- best I could do... over to you! --&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || -0.4 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354471</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354471"/>
				<updated>2024-10-25T20:46:25Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Trivia */ body temperature isn't a midpoint, it's a maximum, relative to usually cooler (more ambient) extremities and e.g. skin, hair, nail, etc. It's called &amp;quot;core&amp;quot; if you need another adjective&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses the 1742 {{w|Celsius}} scale for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}} (or the related {{w|United States customary units|US customary system}}), which uses the 1724 {{w|Fahrenheit}} scale. The other widely used temperature scale is the 1848 {{w|kelvin}}, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvin). The Kelvin scale has been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale, also known as &amp;quot;centigrade&amp;quot;, was devised by Swedish astronomer {{w|Anders Celsius}} in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of kelvin. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.)&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = kelvin - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;kelvin = Celsius + 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
While kelvin is very useful for calculations in {{w|thermodynamics}} and material physics, it can be unintuitive to laypersons.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead originally setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Fahrenheit - 32) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Fahrenheit = Celsius × 9/5 + 32&amp;lt;/center&amp;gt;&lt;br /&gt;
Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries, possibly because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is {{w|Human body temperature#Historical understanding|coincidentally close to normal human body temperature}}. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Réaumur / 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Réaumur = Celsius × 0.8&amp;lt;/center&amp;gt;&lt;br /&gt;
The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rømer - 7.5) × 40/21&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rømer = Celsius × 21/40 + 7.5&amp;lt;/center&amp;gt;&lt;br /&gt;
The Rømer scale is  considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°Ra] set to absolute zero  || 6/10 || The Rankine scale (°R or °Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvin is to Celsius, an absolute (rather than a relative) scale. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Rankine - 491.67) × 5/9&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Rankine = (Celsius + 273.15) × 9/5&amp;lt;/center&amp;gt;&lt;br /&gt;
Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isaac Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = Newton × 100/33&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Newton = Celsius × 33/100&amp;lt;/center&amp;gt;&lt;br /&gt;
Very few scientists other than Newton ever used this scale,{{Actual citation needed}} but it did appear on commercial thermometers around 1758.&amp;lt;ref&amp;gt;https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43&amp;lt;/ref&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inconsistent.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Wedgwood + 8) × 100/1.3&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Wedgwood = (Celsius × 1.3/100) - 8&amp;lt;/center&amp;gt;&lt;br /&gt;
The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,&amp;lt;ref&amp;gt;https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml&amp;lt;/ref&amp;gt; when he was a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = (Galen × 100 / 8) + 22&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Galen = ((Celsius - 22) / 100) × 8&amp;lt;/center&amp;gt;&lt;br /&gt;
This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (possibly to the equivalent of 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, considered [https://doi.org/10.4236/jamp.2024.1210198 the maximum attainable physical temperature]) will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined (see [[2295: Garbage Math]]) and may be interpreted in a number of counter-intuitive ways.&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 100 - real_Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;real_Celsius = 100 - Celsius&amp;lt;/center&amp;gt;&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a {{w|Millimetre of mercury|column of mercury}} at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}} devised in 1732 by French astronomer {{w|Joseph-Nicolas Delisle}}, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was changed, to more or less the form already described above, after his death in 1745. Delisle's scale was never reversed.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:&lt;br /&gt;
&amp;lt;center&amp;gt;Celsius = 273.15 × ''e''&amp;lt;sup&amp;gt;(Dalton / 320.55)&amp;lt;/sup&amp;gt; - 273.15&amp;lt;/center&amp;gt;&lt;br /&gt;
&amp;lt;center&amp;gt;Dalton = 320.55 × {{w|Natural logarithm|''ln''(}} (Celsius + 273.15) / 273.15 )&amp;lt;/center&amp;gt;&lt;br /&gt;
There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton equates to 50 degrees Celsius — i.e., it could be said to be 107.8% (even more than entirely) cursed.&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [''sic''] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || Randall has not stated the cursedness of his new scale || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-lowest-temperature&amp;lt;/ref&amp;gt; The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)&amp;lt;ref&amp;gt;https://climate.copernicus.eu/climate-indicators/temperature&amp;lt;/ref&amp;gt; The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.&amp;lt;ref&amp;gt;https://wmo.asu.edu/content/world-highest-temperature&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to effect of absorbing sunlight (or a lack thereof, e.g. at night or under clouds), and the thermal capacity of soil.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high temperature records increasing almost every year (and similarly the trend in average temperatures) as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While the subsequent °X value being given to everyday benchmark temperatures will vary over time, more extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift vastly more.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
In the various scales, this is a table of several benchmark temperatures.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align: center;&amp;quot;&lt;br /&gt;
! Unit scale&lt;br /&gt;
! Sample {{w|room temperature}}&lt;br /&gt;
! {{w|Properties of water#Melting point|Freezing point of water}}&lt;br /&gt;
! {{w|Boiling point#Boiling point of water with elevation|Boiling point of water}} &amp;lt;!-- do you know how hard it is to find two (non-general) links for (F|M)P and BP of water? --&amp;gt;&lt;br /&gt;
! {{w|Human body temperature|Human body core temperature}}&lt;br /&gt;
! Recommended {{w|Refrigerator#Temperature zones and ratings|refrigerator temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! Recommended {{w|Refrigerator#Freezer|freezer temperature}} &amp;lt;!-- &amp;quot;Recommended&amp;quot; needs some thought/research here... --&amp;gt;&lt;br /&gt;
! &amp;quot;Warm bath&amp;quot; temperature &amp;lt;!-- go on, find a decent link in something like https://en.wikipedia.org/wiki/Bathing - I challenge you! --&amp;gt;&lt;br /&gt;
! &amp;quot;{{w|Coffee#Brewing|Hot coffee}}&amp;quot; temperature &amp;lt;!-- best I could do... over to you! --&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22 °C || 0 °C || 100 °C || 37 °C || 2.5 °C || -18 °C || 39 °C || 77 °C&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295 K || 273 K || 373 K || 310 K || 276 K || 255 K || 312 K || 350 K&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72 °F || 32 °F || 212 °F || 98.6 °F || 36.5 °F || -0.4 °F || 102 °F || 171 °F&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 17.6 °Ré || 0 °Ré || 80 °Ré || 29.6 °Ré || 2 °Ré || -14.4 °Ré || 31.2 °Ré || 61.6 °Ré&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 19.1 °Rø || 7.5 °Rø || 60 °Rø || 26.9 °Rø || 8.8 °Rø || -2 °Rø || 28 °Rø || 47.9 °Rø&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531 °Ra || 492 °Ra || 672 °Ra || 558 °Ra || 496 °Ra || 459 °Ra || 562 °Ra || 630 °Ra&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7.3 °N || 0 °N || 33 °N || 12.2 °N || 0.8 °N || -5.9 °N || 12.9 °N || 25.4 °N&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7.71 °W || -8.00 °W || -6.70 °W || -7.52 °W || -7.97 °W || -8.23 °W || -7.49 °W || -7.00 °W&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0.00 || -1.76 || 6.24 || 1.20 || -1.56 || -3.20 || 1.36 || 4.40&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78 || 100 || 0 || 63 || 98 || 118 || 61 || 23&lt;br /&gt;
|-&lt;br /&gt;
| Dalton || 24.8 || 0 || 100 || 40.7 || 2.9 || -21.9 || 42.8 || 79.6&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59 °X || 43 °X || 151 °X || 76.4 °X || 44.1 °X || 34.3 °X || 78.8 °X || 124 °X&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
==References==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354078</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354078"/>
				<updated>2024-10-24T09:02:32Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ embolden&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] during his time as a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the freezing point is 42.9 °X.'''&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, '''the boiling point is 151.4 °X.'''&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
=== Trivia ===&lt;br /&gt;
&lt;br /&gt;
Here are the {{w|room temperature}} values for those scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354077</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354077"/>
				<updated>2024-10-24T09:01:27Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ wikicase&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] during his time as a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and boiling points of water&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
=== Trivia ===&lt;br /&gt;
&lt;br /&gt;
Here are the {{w|room temperature}} values for those scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354076</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354076"/>
				<updated>2024-10-24T08:59:03Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ unnecessary hyphen&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] during his time as a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
=== Trivia ===&lt;br /&gt;
&lt;br /&gt;
Here are the {{w|room temperature}} values for those scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
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==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
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:Temperature Scales&lt;br /&gt;
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:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
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:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354075</id>
		<title>Talk:3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354075"/>
				<updated>2024-10-24T08:53:11Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Division by zero */ elaborate&lt;/p&gt;
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&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
Shouldn't Rankine say &amp;quot;0ºR is set to absolute zero&amp;quot;? {{unsigned ip|172.70.230.29|22:58, 21 October 2024 (UTC)}}&lt;br /&gt;
:Yep. [[Special:Contributions/162.158.186.253|162.158.186.253]] 04:38, 22 October 2024 (UTC)&lt;br /&gt;
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yo,i thought comic 3000 was anticlimactic so randall would make this one COOL but sadly not&lt;br /&gt;
Same. Hope he does something cool for 3072.[[Special:Contributions/172.69.134.225|172.69.134.225]] 23:44, 21 October 2024 (UTC)&lt;br /&gt;
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really he didn't do anything special for this either? come ON randall if you don't do something cool for comic 3072 i will &amp;lt;b&amp;gt; come to your house personally and yell at you  [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 23:57, 21 October 2024 (UTC)&lt;br /&gt;
&amp;lt;/b&amp;gt;&lt;br /&gt;
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What's random about Fahrenheit? (Answer: nothing.) 0F is the freezing point of brine, 100F (or 98.7) is the human body temperature. [[Special:Contributions/172.68.54.65|172.68.54.65]] 00:00, 22 October 2024 (UTC)&lt;br /&gt;
:What concentration of brine? (And which specific salt... No, not NaCl, as you might presume but NH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Cl!)&lt;br /&gt;
:And body temperature varies a lot ('typically' 36.5–37.5°C or  97.7–99.5°F, though even this range is thought to be too small), across genders, individuals, time of day ''and'' which orifices/surfaces you try to measure it from. (Originally, it was set so that '''90°F''' was to be the 'best guess' of human body temperature. It gradually changed, including via various {{w|Human body temperature#Historical understanding|compounded misunderstandings}} so that the best you can say is that 100°F is arbitrarily ''slightly above'' most afebrile human body temperature measurements.)&lt;br /&gt;
:Celsius might be a bit off (arguments about triple-point or STP freezing, etc), but it still has far more physical logic to it. [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
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Sorry, Randall, for my comfort, Fahrenheit is the least cursed. It's the best scale to use for my personal use, especially when hearing the weather report and deciding what to wear outdoors: temp in the 80's - no jacket. temp in 70's - maybe a windbreaker if it's breezy. 60's - sweater weather. 50's - medium weight coat. 40's - winter coat. 30'3 - winter coat with scarf and gloves. 20's - multiple layers. teens - stay indoors. None of the other scales provide such convenient distinctions for my daily life. Kelvin is great for astro physics or super conductivity, but useless for any common uses. Celsius is great for hanging out with the Euro crowd but still not so useful to scale my home thermostat. I judge Fahrenheit as 1.0 for cursedness. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:19, 22 October 2024 (UTC)&lt;br /&gt;
:I conveniently use Celsius in tens, also. Negative °C: Cold; 0-10°C: Nippy; 10-20°C: Generally pleasant; 20-30°C: Too warm to exert oneself; 30°C+: ''Definitely'' too warm. [[Special:Contributions/172.70.86.205|172.70.86.205]] 15:24, 22 October 2024 (UTC)&lt;br /&gt;
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Personally, I'm most disappointed that {{w|Delisle scale}} was not represented... [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
: I was so hoping for a {{w|Planck temperature}} quip. Like: &amp;quot;Water freezing point: 0; Water boiling point: 0; Notes: 1 = highest possible temperature (1.4E32K) where thermal radiation creates black holes; Cursedness: 0/0&amp;quot; [[Special:Contributions/162.158.164.184|162.158.164.184]] 01:27, 22 October 2024 (UTC)&lt;br /&gt;
:: Same here. Freezing is 0.000000000000000000000000000001928 and boiling is 0.0000000000000000000000000000026338. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 03:38, 22 October 2024 (UTC)&lt;br /&gt;
::: Wow, those are even smaller than the IEEE floating point representations of 1-1.0/3*3! [[Special:Contributions/162.158.90.109|162.158.90.109]] 03:59, 22 October 2024 (UTC)&lt;br /&gt;
:: The Planck temperature quip is definitely well deserved. Good catch! [[User:Mumingpo|Mumingpo]] ([[User talk:Mumingpo|talk]]) 17:24, 23 October 2024 (UTC)&lt;br /&gt;
I guess I was wrong in my comment on the last comic. sigh. -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 01:16, 22 October 2024 (UTC)&lt;br /&gt;
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It's actually spelled {{w|Wedgwood scale}}, not Wedgewood. [[User:Wilh3lm|Wilh3lm]] ([[User talk:Wilh3lm|talk]]) 01:17, 22 October 2024 (UTC)&lt;br /&gt;
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I still call the modern version of the &amp;quot;Celsius&amp;quot; scale &amp;quot;centigrade&amp;quot;, but if people start nitpicking, I'm happy to switch to &amp;quot;Carolus&amp;quot; to avoid ambiguity. For some reason that tends to annoy people more though. [[Special:Contributions/172.68.22.191|172.68.22.191]] 01:32, 22 October 2024 (UTC)&lt;br /&gt;
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Every temperature scale is equally &amp;quot;random&amp;quot; as every other scale. People always say that Celsius is so much better because it's defined by the phase changes of water. Okay, cool...why should THAT of all things be what we use as the base for a system of temperature measurement? And, who cares? I'm a ''Homo sapiens'', not a water molecule. If anything we should use the freezing and melting points of humans as our two reference points for temperature (which, I must say, Fahrenheit approximates better than Celsius, assuming 0 and 100 are your points &amp;quot;A&amp;quot; and &amp;quot;B&amp;quot;). [[User:Pie Guy|Pie Guy]] ([[User talk:Pie Guy|talk]]) 03:42, 22 October 2024 (UTC)&lt;br /&gt;
: Every temperature scale is arbitrary, but since boiling and freezing water is a thing humans have a lot of experience with it makes sense to use that as the reference point. At least it makes more sense than whatever the coldest recorded temperature in Fahrenheit's home town was, because he didn't like negative numbers [[Special:Contributions/172.70.250.23|172.70.250.23]] 03:56, 22 October 2024 (UTC)&lt;br /&gt;
::Planck temperature (as above) is probably the least arbitrary, and some would say it is to some extent free from arbitrariness. However, it's completely impractical for everyday use (as above.) [[Special:Contributions/172.69.34.138|172.69.34.138]] 04:31, 22 October 2024 (UTC)&lt;br /&gt;
:::Do the physics of black holes or neutron stars involve Planck temperatures greater than 0.0000001? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:23, 22 October 2024 (UTC)&lt;br /&gt;
::::Chat Gippity told me:&lt;br /&gt;
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:::::Black holes and neutron stars do not typically involve temperatures reaching the Planck scale. While both objects exhibit extreme physical conditions, their temperatures are far below the Planck temperature, even though they can be incredibly high compared to everyday phenomena.&lt;br /&gt;
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::::: - **Neutron stars** have surface temperatures in the range of millions of Kelvin, and the core can reach even higher, possibly up to a few billion Kelvin. These temperatures are still vastly lower than the Planck temperature.&lt;br /&gt;
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::::: - **Black holes**, especially the smaller ones, can emit Hawking radiation, with temperatures inversely proportional to their mass. However, the temperature of even a very small black hole is still far below the Planck temperature. Hawking radiation is not expected to reach temperatures close to the Planck scale under normal circumstances.&lt;br /&gt;
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::::: The Planck temperature (TP=1) represents an energy scale so extreme that no known physical models, including those describing black holes and neutron stars, operate near or above this threshold. Temperatures reaching **0.0000001 TP** (or 1.416 × 10^26 K) would still be beyond current observational and theoretical frameworks related to these cosmic objects. A quantum theory of gravity would be required to describe physics at or near the Planck temperature, which remains speculative and is far beyond the conditions found in black holes or neutron stars.&lt;br /&gt;
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::::[[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:46, 22 October 2024 (UTC)&lt;br /&gt;
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If the °X scale is based on the temperatures of Earth from all time (for some definition of &amp;quot;Earth&amp;quot;), then the scale is very hard to define and highly impractical. The earth appears to have gotten to more than 2,300 Kelvin (hot enough to melt steel and platinum and to boil lead) and while I can't find any sources for the lowest temperature, I imagine it is lower than -100°C. The recorded minimum, maximum and average temperatures appear to be around -89.2 °C, 56.7 °C and 15 °C respectively. This would make the scale somewhat useful, but this would make typical values between 41 °X (cold winter's day) and 68 °X (hot summers day) which I think is pretty cursed. I recommend the clearly superior °Y, based around average temp at 0 °Y, low at -100 °Y and high at 100 °Y. These would be measured by the yearly high, low and mean temperatures averaged per person. Then saying &amp;quot;It's 2 times colder than yesterday&amp;quot; would have some reasonable meaning. --[[Special:Contributions/198.41.236.147|198.41.236.147]] 04:01, 22 October 2024 (UTC)&lt;br /&gt;
:&amp;quot;''Record'' ... surface temperature&amp;quot; implies it was recorded. [[Special:Contributions/172.68.22.9|172.68.22.9]] 04:08, 22 October 2024 (UTC)&lt;br /&gt;
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How do you all feel about adding an additional column for room temperature 22C/72F?&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
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Or 0.00000000000000000000000000000208 °Planck, lol. [[Special:Contributions/108.162.245.211|108.162.245.211]] 05:36, 22 October 2024 (UTC)&lt;br /&gt;
:I feel like decigalens would be the most practical unit. Who's with me? [[Special:Contributions/162.158.186.5|162.158.186.5]] 06:20, 22 October 2024 (UTC)&lt;br /&gt;
::It's interesting; calculating the equilibrium temperature (with 2.05 and 4.24 being used for the heat capacities of ice and boiling water) gives 67... If I use water that's about to freeze and steam, I get 31. [[Special:Contributions/172.69.0.178|172.69.0.178]] 07:59, 22 October 2024 (UTC)&lt;br /&gt;
:::Would you please explain in more detail? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:03, 22 October 2024 (UTC)&lt;br /&gt;
:::: The equilibrium temperature of a mixture (?) of equal quantities of ice at 0 C and water at 100 C (with the heat capacities 2.05 and 4.24) is 67 C; if I use the data for water at 0 C and steam, I get 31 C. Additionally, if I use equal volumes, I get 68 (which isn't much different.) [[Special:Contributions/172.69.0.178|172.69.0.178]] 17:15, 22 October 2024 (UTC)&lt;br /&gt;
:::: One can obtain 0 = 22 C by setting the heat capacity of ice to be 39 and that of water to be 11. For any particular &amp;quot;normal temperature&amp;quot; ''R'' °C (that is, the temperature at 0 is ''R'',), I find that ''x'' °C = 50''R''(''x''+4)/(''x''(''R''-50)+200). In particular, for ''R'' = 22, we get (1100+275''x'')/(50-7''x''). [[Special:Contributions/198.41.236.163|198.41.236.163]] 05:58, 23 October 2024 (UTC)&lt;br /&gt;
::How about 0.1694×C+46.25, where 0 is absolute zero and 50 is room temperature? (Freezing point of water: 46.25; Boiling point of water: 63.19) [[Special:Contributions/162.158.186.248|162.158.186.248]] 05:21, 24 October 2024 (UTC)&lt;br /&gt;
:I would absolutely pull the trigger on an additional column if I didn't think it would further screw up what are most probably extremely cursed mobile portrait renderings of the table. How about a Trivia section? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:44, 24 October 2024 (UTC)&lt;br /&gt;
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Question regarding the X scale - when it‘s defined by *three* (somewhat, implying average is real and not just calculated by (max-min)/2)) independent points, how will linearity be achieved? [[Special:Contributions/162.158.155.76|162.158.155.76]] 05:43, 22 October 2024 (UTC)&lt;br /&gt;
[[File:Explanation length.png|right|thumb|Or click &amp;quot;[Expand]&amp;quot; in the bottom right table cell Derivation.]]&lt;br /&gt;
:Please see [[2701: Change in Slope]]. [[Special:Contributions/172.70.206.179|172.70.206.179]] 05:50, 22 October 2024 (UTC)&lt;br /&gt;
:Sure, &amp;quot;a linear scale between each point&amp;quot;:&lt;br /&gt;
[[File:XvsC.png|thumb|left|Here you go. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 06:33, 22 October 2024 (UTC)]]&lt;br /&gt;
{{clear}}&lt;br /&gt;
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The reference for the average surface temperature, https://www.space.com/17816-earth-temperature.html, suggests it has increased above 15°C. What value should we use in late 2024? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:30, 22 October 2024 (UTC)&lt;br /&gt;
:The [https://wmo.int/media/news/earth-experiences-warmest-day-recent-history World Meteorological Organization], [https://www.carbonbrief.org/state-of-the-climate-2024-now-very-likely-to-be-warmest-year-on-record/ Carbon Brief], and [https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024 Copernicus Climate Change Service] suggest 17.16°C. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:42, 22 October 2024 (UTC)&lt;br /&gt;
::Updated water temperatures, Derivation, and graph. So we've already had more than the +2°C warming we were trying to avoid in 2019? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:05, 22 October 2024 (UTC)&lt;br /&gt;
::: The +2°C (or +1.5°C that we were originally supposed to be avoiding) is over some (undefined) number of years, though, which allows us to ignore the fact that we're cooking ourselves by repeatedly saying 'Oh, but it doesn't count ''yet''.' [[Special:Contributions/172.70.91.62|172.70.91.62]] 11:13, 23 October 2024 (UTC)&lt;br /&gt;
Regarding [https://www.explainxkcd.com/wiki/index.php?title=3001%3A_Temperature_Scales&amp;amp;type=revision&amp;amp;diff=353635&amp;amp;oldid=353632], are the average surface temperatures from the sources supposed to be yearly or overall averages? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:06, 22 October 2024 (UTC)&lt;br /&gt;
:According to https://climate.copernicus.eu/climate-indicators/temperature the global average near-surface temperature in 2023 was 14.4 + 0.4 = 14.8°C. (see Figure 1 and click &amp;quot;Increase above: [1991–2020 reference period].&amp;quot;) [[Special:Contributions/172.68.22.8|172.68.22.8]] 21:06, 23 October 2024 (UTC)&lt;br /&gt;
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where is the interactive epic 3000 comic we should've gotten? This one's cool but 1000 seemed to have more effort in it and 2000 was at least tangetially related. Does Randall just not like making these anymore and is only making more comics as a business? [[Special:Contributions/108.162.238.185|108.162.238.185]] 12:14, 22 October 2024 (UTC)&lt;br /&gt;
:The comic is free on the website and it doesn't have ads; although the comic is part of his &amp;quot;brand&amp;quot; there are many more profitable things he could be doing with his time, and yet he continues to update it every Monday, Wednesday, and Friday.  I just don't like the idea of claiming that a creative person &amp;quot;should&amp;quot; produce any particular thing to satisfy their fans.  He's a busy guy!  Maybe he's working on a book, or a Scientific American article, or a TV show.  He's under no obligation to give us anything, and maybe one day he'll stop making xkcd altogether; that's his choice.  Sorry to single you out; I know a lot of people feel the same way as you do, but to me it doesn't make sense.  He's not a content machine--he's a guy who started posting sketches on the internet. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 15:23, 22 October 2024 (UTC)&lt;br /&gt;
::Sorry if I sounded overly brash, I wasn't trying to imply &amp;quot;wahhh no special entry wahhh&amp;quot;, I was just wondering if Randall still likes to make these or if he doesn't, mainly because he just didn't do anything special, which feels like he just didn't care. I wasn't trying to imply Randall should just do it for the fans[[Special:Contributions/108.162.238.80|108.162.238.80]] 17:52, 22 October 2024 (UTC)&lt;br /&gt;
:::It ''could'' be that 3000 (or even 3001) ''was'' going to be special but, as fairly frequently with April Fool 'specials', it just wasn't doable on time. (If it's still considered fixablez it might pop up sometime before 3020 or so. Or, if transferable to another occasion (rebranding the obvious &amp;quot;3000!&amp;quot;ness), held over until Haloween, Christmas, April or 4000, perhaps with additional perfections.)&lt;br /&gt;
:::Hard to know, unless Randall (or his technical collaborators) say anything. And it's probably not worth doing so right now. Maybe &amp;quot;Hey guys, this ''was'' going to be #3000!&amp;quot; might accompany its eventual emergence, but also maybe not. Does it really matter? [[Special:Contributions/172.70.85.139|172.70.85.139]] 13:03, 23 October 2024 (UTC)&lt;br /&gt;
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Is this the first list-style comic where every single entry is real? (Usually he has several joke entries.) [[Special:Contributions/172.70.114.182|172.70.114.182]] 14:26, 22 October 2024 (UTC)&lt;br /&gt;
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Where would [[1923: Felsius|Felsius]] go on this list?&lt;br /&gt;
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One can find a smooth function for °X, namely, (477879''x''-17634840)/(3341''x''+197700), which takes °X and returns °C. The inverse is (-197700''x''-17634840)/(3341''x''-477879). Should this be included in the wiki article? Or maybe another way of fitting it (like exponential) should be used.  [[Special:Contributions/172.69.0.165|172.69.0.165]] 06:27, 23 October 2024 (UTC)&lt;br /&gt;
:It says &amp;quot;a linear scale between each point&amp;quot;. [[Special:Contributions/172.70.210.130|172.70.210.130]] 21:09, 23 October 2024 (UTC)&lt;br /&gt;
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Should it be noted that in the first _What If?_ book, there's a reference to units and how much Randall loathes rankine? Someone can go take the book and cite it; it's in one of the early pages [[Special:Contributions/172.64.236.10|172.64.236.10]] 08:45, 23 October 2024 (UTC)&lt;br /&gt;
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I remember it being drummed into us in school physics (admittedly over 50 years ago) that 0 Celsius is defined as the melting point of ice, not the freezing point of water (presumably because of supercooling). [[Special:Contributions/172.70.160.189|172.70.160.189]] 08:49, 23 October 2024 (UTC)&lt;br /&gt;
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It seems he wrote &amp;quot;Earths'&amp;quot; (plural possessive) instead of &amp;quot;Earth's&amp;quot;. [[Special:Contributions/141.101.98.151|141.101.98.151]] 08:58, 23 October 2024 (UTC)&lt;br /&gt;
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What?  No gas mark?  It's linear for temperatures over 275°F but inverse powers of 2 below  That's pretty cursed, but I still put it in my unit conversion app.  It's only used in gas stoves in a few countries, so it doesn't come up very often.  By the way, boiling is 1/5.7358 and freezing/melting is 1/843.3572.  Interestingly, France has it's own stove temperature scale that seems to be based on °F.&lt;br /&gt;
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Also, my understanding is that 7.5 and 32 aren't random.  Both Romer and Fahrenheit put numbers on things so that freezing/melting of water and &amp;quot;Normal human body temperature&amp;quot;, which was thought to be standard at the time, would be some number X (15 for Romer and 64 for Fahrenheit) and the water thing would be to be X/2 and NHBT would be X/2+X.  Pretty nerdy.  Sadly, the calibration was off and 212 degrees for boiling was found to be less cursed.  But I could be wrong.[[Special:Contributions/172.68.54.138|172.68.54.138]] 20:39, 23 October 2024 (UTC)&lt;br /&gt;
:Re: water/ice point 'random number', I think it's more that it wasn't considered &amp;quot;special&amp;quot;, such that &amp;quot;On my scale, that will be zero&amp;quot; (or whatever choice of handily round number, including zero, some scale-setters allocated to the BP of water).&lt;br /&gt;
:After all the other messing about (&amp;quot;my zero will be that of brine!&amp;quot;, etc), obviously then the ~0°C equivalent would ''have'' a number, and ''perhaps''  there would then be a slight change to make it a ''whole'' (or easy-fraction) number for convenience's sake, but (before the concept of binary computers) there's not much special about landing on the number 32, for what is actually a temperature that is quite significant to the human experience, and less so with 7-''and-a-half''.&lt;br /&gt;
:Maybe landing on 90°F (at one time) for body temperature (and 180 F° ''between'' MP and BP) was considered useful as the analogue to angular-degrees where 90 (and 180) indeed features significantly, but I don't think there'd have been too much fuss if the value would have turned out to be 60(/120), also with plenty of handy factors to divide by, 70(/140), without so much, or whatever number(s) happened to depict one realistic real-world measurement that (overall) has no reason to have a factor-based relationship with various quite separate phenomenon measurements.&lt;br /&gt;
:''And'' it went through several {{w|Human body temperature#Historical understanding|'corrective' iterations}} so that even its handy relationship with 'about 100°F' can be said to be an incidental accident, at best, unless we do something like Randall's °X scale and actively triple-tie the central value of the slope(s) to be exactly something useful by using the &amp;quot;currently accepted mean human body temperature (given various complicated caveats)&amp;quot;.&lt;br /&gt;
:It's pretty much all random, in the same way that only because of anthropocentric choices of 'standard' time and distance measurements is the speed of light 'pretty much' 3×10⁸ m/s (a handily round value that works well enough for most purposes, even after back-standardising its component SI measurements to make &amp;quot;actually, &amp;lt;u&amp;gt;precisely&amp;lt;/u&amp;gt; 299792458&amp;quot; the ''proper'' answer, and [https://conversion.org/speed/speed-of-light/furlong-per-fortnight it could be far worse...]). Avagadro's number never had it so good (6.022(+change)×10&amp;lt;sup&amp;gt;23&amp;lt;/sup&amp;gt;...? ...where's the handily mnemonic value in that?), and Pi (in this universe's system of fundemental mathematics) clearly never ever had a chance! And, on {{w|Mount Everest#19th century|at least one occasion}}, such happenstance numeric roundedness in its exactitude (29''',000''' ft) was considered actually quite awkward... [[Special:Contributions/172.70.91.90|172.70.91.90]] 21:33, 23 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Ok, then, regarding {{diff|353895|this edit}} (and the original IP-led one(s) that even made huge and revert-necessary changes), was it ''really'' intended to get rid of whole paragraphs such as &amp;quot;Randall also fails to specify what happens with temperatures[...]&amp;quot; that had nothing to do with the numeric adjustments? When I see that, I see mistakes (especially in light of the &amp;quot;clobber&amp;quot; that happened, where typos reappeared and other things became unexplained/worse-explained once more). — Basically, if your edit summary is nust about updating baseline data, and the resulting maths, I don't expect (maybe good, maybe bad) edits to unrelated bits. Or I may (and have) presumed accidental (or deliberate?) carelessness that I'd rather not try to go back to first principles to re-re-check for the editor concerned. That is all. At least try to justify enough of your edit in its own way, even if it means diving in several times to get enough space to summarise your whole &amp;quot;why&amp;quot; to each tweak. [[Special:Contributions/172.68.186.104|172.68.186.104]] 22:44, 23 October 2024 (UTC)&lt;br /&gt;
:Yes. I have re-removed the removals piecemeal with individual edit summaries for clarity. Many of them involved detailed obscure technical misunderstandings, such as whether the Vostok and Death Valley measurements were surface temperatures (the WMO says they are, and there are the WMO's photos of the observation stations in the linked references now) which combined with the incorrect yearly average global mean temperature, added five paragraphs unnecessarily. [[Special:Contributions/172.68.23.152|172.68.23.152]] 01:46, 24 October 2024 (UTC)&lt;br /&gt;
::Definitely some points made (some incorrect, &amp;quot;ne er&amp;quot; was ''obviously'' more just a basic typo of &amp;quot;never&amp;quot;, not my attempt to use &amp;quot;ne'er&amp;quot; for no good reason, and my attempt to fix that and some other bits ran into a set of Edit Conflicts ...hope I caught all the remaining ones when I finally could try again on the settled-down page) and I've blended answers to your objections in while giving back what useful nuances (from a number of past editors, only a couple of bits even having had my own hand primarilly behind them as they were) really needn't have been removed. I dispute the terms of your objections (as summarised) behind {{diff|353937|some changes}}, but have rephrased based upon what I ''think'' you mean, giving you should prefer and wouldn't feel the need to be as randomly censorious about. [[Special:Contributions/172.69.195.173|172.69.195.173]] 02:54, 24 October 2024 (UTC)&lt;br /&gt;
:::Figure 1 in https://climate.copernicus.eu/climate-indicators/temperature does not seem like a random walk to me. [[Special:Contributions/172.69.33.118|172.69.33.118]] 05:02, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
== Division by zero ==&lt;br /&gt;
&lt;br /&gt;
I saw this in an edit summary: &amp;quot;10/0 is not ∞, it's also an error, not NaN according to the IEEE. It's closer to {+∞, -∞} than NaN but it's still neither because you can't make limits work&amp;quot;&lt;br /&gt;
&lt;br /&gt;
Actually, IEEE floating point 10/0 can be an error, +∞, or NaN depending on the rounding mode. This is one of the reasons why mathemeticians don't appreciate the IEEE as much as they might. Division by zero is strictly undefined because of the problems with limits alluded to in the summary. https://www.youtube.com/watch?v=dHdg1yn1SgE [[Special:Contributions/108.162.245.66|108.162.245.66]] 03:48, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
:&amp;quot;When considering division by zero through limits, assigning {+∞, -∞} as potential results is insufficient because limits require consistency and well-defined behavior. In the case of dividing a number by values approaching zero, the results differ depending on whether zero is approached from the positive or negative direction. As a divisor approaches zero from the positive side, the quotient grows towards +∞, and from the negative side, it tends towards -∞. Since limits must converge to a single value for consistency, this disparity leads to an undefined result. Moreover, in many mathematical contexts, infinity is not a number but rather a concept describing unbounded growth, meaning operations involving infinity, like addition or multiplication, are not well-defined in the same way as with finite numbers. This inconsistency in approaching zero prevents {+∞, -∞} from being an adequate solution set for division by zero. Defining division by zero as infinity would create contradictions in both arithmetic and algebraic contexts, as it disrupts fundamental properties like continuity and field structures in mathematics. Hence, division by zero remains undefined to preserve mathematical rigor and coherence.&amp;quot;&lt;br /&gt;
:[Chat Gippity 4o] [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:53, 24 October 2024 (UTC)&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354074</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354074"/>
				<updated>2024-10-24T08:45:53Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ room temperatures&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] during his time as a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
=== Trivia ===&lt;br /&gt;
&lt;br /&gt;
Here are the {{w|room temperature}} values for those scales:&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
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{{comic discussion}}&lt;br /&gt;
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[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354073</id>
		<title>Talk:3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:3001:_Temperature_Scales&amp;diff=354073"/>
				<updated>2024-10-24T08:44:09Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: Trivia?&lt;/p&gt;
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&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
Shouldn't Rankine say &amp;quot;0ºR is set to absolute zero&amp;quot;? {{unsigned ip|172.70.230.29|22:58, 21 October 2024 (UTC)}}&lt;br /&gt;
:Yep. [[Special:Contributions/162.158.186.253|162.158.186.253]] 04:38, 22 October 2024 (UTC)&lt;br /&gt;
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yo,i thought comic 3000 was anticlimactic so randall would make this one COOL but sadly not&lt;br /&gt;
Same. Hope he does something cool for 3072.[[Special:Contributions/172.69.134.225|172.69.134.225]] 23:44, 21 October 2024 (UTC)&lt;br /&gt;
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really he didn't do anything special for this either? come ON randall if you don't do something cool for comic 3072 i will &amp;lt;b&amp;gt; come to your house personally and yell at you  [[User:RadiantRainwing|RadiantRainwing]] ([[User talk:RadiantRainwing|talk]]) 23:57, 21 October 2024 (UTC)&lt;br /&gt;
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What's random about Fahrenheit? (Answer: nothing.) 0F is the freezing point of brine, 100F (or 98.7) is the human body temperature. [[Special:Contributions/172.68.54.65|172.68.54.65]] 00:00, 22 October 2024 (UTC)&lt;br /&gt;
:What concentration of brine? (And which specific salt... No, not NaCl, as you might presume but NH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Cl!)&lt;br /&gt;
:And body temperature varies a lot ('typically' 36.5–37.5°C or  97.7–99.5°F, though even this range is thought to be too small), across genders, individuals, time of day ''and'' which orifices/surfaces you try to measure it from. (Originally, it was set so that '''90°F''' was to be the 'best guess' of human body temperature. It gradually changed, including via various {{w|Human body temperature#Historical understanding|compounded misunderstandings}} so that the best you can say is that 100°F is arbitrarily ''slightly above'' most afebrile human body temperature measurements.)&lt;br /&gt;
:Celsius might be a bit off (arguments about triple-point or STP freezing, etc), but it still has far more physical logic to it. [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
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Sorry, Randall, for my comfort, Fahrenheit is the least cursed. It's the best scale to use for my personal use, especially when hearing the weather report and deciding what to wear outdoors: temp in the 80's - no jacket. temp in 70's - maybe a windbreaker if it's breezy. 60's - sweater weather. 50's - medium weight coat. 40's - winter coat. 30'3 - winter coat with scarf and gloves. 20's - multiple layers. teens - stay indoors. None of the other scales provide such convenient distinctions for my daily life. Kelvin is great for astro physics or super conductivity, but useless for any common uses. Celsius is great for hanging out with the Euro crowd but still not so useful to scale my home thermostat. I judge Fahrenheit as 1.0 for cursedness. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 14:19, 22 October 2024 (UTC)&lt;br /&gt;
:I conveniently use Celsius in tens, also. Negative °C: Cold; 0-10°C: Nippy; 10-20°C: Generally pleasant; 20-30°C: Too warm to exert oneself; 30°C+: ''Definitely'' too warm. [[Special:Contributions/172.70.86.205|172.70.86.205]] 15:24, 22 October 2024 (UTC)&lt;br /&gt;
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Personally, I'm most disappointed that {{w|Delisle scale}} was not represented... [[Special:Contributions/172.70.160.188|172.70.160.188]] 01:14, 22 October 2024 (UTC)&lt;br /&gt;
: I was so hoping for a {{w|Planck temperature}} quip. Like: &amp;quot;Water freezing point: 0; Water boiling point: 0; Notes: 1 = highest possible temperature (1.4E32K) where thermal radiation creates black holes; Cursedness: 0/0&amp;quot; [[Special:Contributions/162.158.164.184|162.158.164.184]] 01:27, 22 October 2024 (UTC)&lt;br /&gt;
:: Same here. Freezing is 0.000000000000000000000000000001928 and boiling is 0.0000000000000000000000000000026338. [[User:DanielLC|DanielLC]] ([[User talk:DanielLC|talk]]) 03:38, 22 October 2024 (UTC)&lt;br /&gt;
::: Wow, those are even smaller than the IEEE floating point representations of 1-1.0/3*3! [[Special:Contributions/162.158.90.109|162.158.90.109]] 03:59, 22 October 2024 (UTC)&lt;br /&gt;
:: The Planck temperature quip is definitely well deserved. Good catch! [[User:Mumingpo|Mumingpo]] ([[User talk:Mumingpo|talk]]) 17:24, 23 October 2024 (UTC)&lt;br /&gt;
I guess I was wrong in my comment on the last comic. sigh. -[[User:Psychoticpotato|P?sych??otic?pot??at???o ]] ([[User talk:Psychoticpotato|talk]]) 01:16, 22 October 2024 (UTC)&lt;br /&gt;
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It's actually spelled {{w|Wedgwood scale}}, not Wedgewood. [[User:Wilh3lm|Wilh3lm]] ([[User talk:Wilh3lm|talk]]) 01:17, 22 October 2024 (UTC)&lt;br /&gt;
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I still call the modern version of the &amp;quot;Celsius&amp;quot; scale &amp;quot;centigrade&amp;quot;, but if people start nitpicking, I'm happy to switch to &amp;quot;Carolus&amp;quot; to avoid ambiguity. For some reason that tends to annoy people more though. [[Special:Contributions/172.68.22.191|172.68.22.191]] 01:32, 22 October 2024 (UTC)&lt;br /&gt;
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Every temperature scale is equally &amp;quot;random&amp;quot; as every other scale. People always say that Celsius is so much better because it's defined by the phase changes of water. Okay, cool...why should THAT of all things be what we use as the base for a system of temperature measurement? And, who cares? I'm a ''Homo sapiens'', not a water molecule. If anything we should use the freezing and melting points of humans as our two reference points for temperature (which, I must say, Fahrenheit approximates better than Celsius, assuming 0 and 100 are your points &amp;quot;A&amp;quot; and &amp;quot;B&amp;quot;). [[User:Pie Guy|Pie Guy]] ([[User talk:Pie Guy|talk]]) 03:42, 22 October 2024 (UTC)&lt;br /&gt;
: Every temperature scale is arbitrary, but since boiling and freezing water is a thing humans have a lot of experience with it makes sense to use that as the reference point. At least it makes more sense than whatever the coldest recorded temperature in Fahrenheit's home town was, because he didn't like negative numbers [[Special:Contributions/172.70.250.23|172.70.250.23]] 03:56, 22 October 2024 (UTC)&lt;br /&gt;
::Planck temperature (as above) is probably the least arbitrary, and some would say it is to some extent free from arbitrariness. However, it's completely impractical for everyday use (as above.) [[Special:Contributions/172.69.34.138|172.69.34.138]] 04:31, 22 October 2024 (UTC)&lt;br /&gt;
:::Do the physics of black holes or neutron stars involve Planck temperatures greater than 0.0000001? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:23, 22 October 2024 (UTC)&lt;br /&gt;
::::Chat Gippity told me:&lt;br /&gt;
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:::::Black holes and neutron stars do not typically involve temperatures reaching the Planck scale. While both objects exhibit extreme physical conditions, their temperatures are far below the Planck temperature, even though they can be incredibly high compared to everyday phenomena.&lt;br /&gt;
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::::: - **Neutron stars** have surface temperatures in the range of millions of Kelvin, and the core can reach even higher, possibly up to a few billion Kelvin. These temperatures are still vastly lower than the Planck temperature.&lt;br /&gt;
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::::: - **Black holes**, especially the smaller ones, can emit Hawking radiation, with temperatures inversely proportional to their mass. However, the temperature of even a very small black hole is still far below the Planck temperature. Hawking radiation is not expected to reach temperatures close to the Planck scale under normal circumstances.&lt;br /&gt;
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::::: The Planck temperature (TP=1) represents an energy scale so extreme that no known physical models, including those describing black holes and neutron stars, operate near or above this threshold. Temperatures reaching **0.0000001 TP** (or 1.416 × 10^26 K) would still be beyond current observational and theoretical frameworks related to these cosmic objects. A quantum theory of gravity would be required to describe physics at or near the Planck temperature, which remains speculative and is far beyond the conditions found in black holes or neutron stars.&lt;br /&gt;
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::::[[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:46, 22 October 2024 (UTC)&lt;br /&gt;
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If the °X scale is based on the temperatures of Earth from all time (for some definition of &amp;quot;Earth&amp;quot;), then the scale is very hard to define and highly impractical. The earth appears to have gotten to more than 2,300 Kelvin (hot enough to melt steel and platinum and to boil lead) and while I can't find any sources for the lowest temperature, I imagine it is lower than -100°C. The recorded minimum, maximum and average temperatures appear to be around -89.2 °C, 56.7 °C and 15 °C respectively. This would make the scale somewhat useful, but this would make typical values between 41 °X (cold winter's day) and 68 °X (hot summers day) which I think is pretty cursed. I recommend the clearly superior °Y, based around average temp at 0 °Y, low at -100 °Y and high at 100 °Y. These would be measured by the yearly high, low and mean temperatures averaged per person. Then saying &amp;quot;It's 2 times colder than yesterday&amp;quot; would have some reasonable meaning. --[[Special:Contributions/198.41.236.147|198.41.236.147]] 04:01, 22 October 2024 (UTC)&lt;br /&gt;
:&amp;quot;''Record'' ... surface temperature&amp;quot; implies it was recorded. [[Special:Contributions/172.68.22.9|172.68.22.9]] 04:08, 22 October 2024 (UTC)&lt;br /&gt;
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How do you all feel about adding an additional column for room temperature 22C/72F?&lt;br /&gt;
{| class=wikitable style=&amp;quot;text-align:right;&amp;quot;&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Room temperature&lt;br /&gt;
|-&lt;br /&gt;
| Celsius || 22&lt;br /&gt;
|-&lt;br /&gt;
| Kelvin || 295&lt;br /&gt;
|-&lt;br /&gt;
| Fahrenheit || 72&lt;br /&gt;
|-&lt;br /&gt;
| Réaumur || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rømer || 18&lt;br /&gt;
|-&lt;br /&gt;
| Rankine || 531&lt;br /&gt;
|-&lt;br /&gt;
| Newton || 7&lt;br /&gt;
|-&lt;br /&gt;
| Wedgwood || -7&lt;br /&gt;
|-&lt;br /&gt;
| Galen || 0&lt;br /&gt;
|-&lt;br /&gt;
| ''Real'' Celsius || 78&lt;br /&gt;
|-&lt;br /&gt;
| °X || 59&lt;br /&gt;
|}&lt;br /&gt;
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Or 0.00000000000000000000000000000208 °Planck, lol. [[Special:Contributions/108.162.245.211|108.162.245.211]] 05:36, 22 October 2024 (UTC)&lt;br /&gt;
:I feel like decigalens would be the most practical unit. Who's with me? [[Special:Contributions/162.158.186.5|162.158.186.5]] 06:20, 22 October 2024 (UTC)&lt;br /&gt;
::It's interesting; calculating the equilibrium temperature (with 2.05 and 4.24 being used for the heat capacities of ice and boiling water) gives 67... If I use water that's about to freeze and steam, I get 31. [[Special:Contributions/172.69.0.178|172.69.0.178]] 07:59, 22 October 2024 (UTC)&lt;br /&gt;
:::Would you please explain in more detail? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:03, 22 October 2024 (UTC)&lt;br /&gt;
:::: The equilibrium temperature of a mixture (?) of equal quantities of ice at 0 C and water at 100 C (with the heat capacities 2.05 and 4.24) is 67 C; if I use the data for water at 0 C and steam, I get 31 C. Additionally, if I use equal volumes, I get 68 (which isn't much different.) [[Special:Contributions/172.69.0.178|172.69.0.178]] 17:15, 22 October 2024 (UTC)&lt;br /&gt;
:::: One can obtain 0 = 22 C by setting the heat capacity of ice to be 39 and that of water to be 11. For any particular &amp;quot;normal temperature&amp;quot; ''R'' °C (that is, the temperature at 0 is ''R'',), I find that ''x'' °C = 50''R''(''x''+4)/(''x''(''R''-50)+200). In particular, for ''R'' = 22, we get (1100+275''x'')/(50-7''x''). [[Special:Contributions/198.41.236.163|198.41.236.163]] 05:58, 23 October 2024 (UTC)&lt;br /&gt;
::How about 0.1694×C+46.25, where 0 is absolute zero and 50 is room temperature? (Freezing point of water: 46.25; Boiling point of water: 63.19) [[Special:Contributions/162.158.186.248|162.158.186.248]] 05:21, 24 October 2024 (UTC)&lt;br /&gt;
:I would absolutely pull the trigger on an additional column if I didn't think it would further screw up what are most probably extremely cursed mobile portrait renderings of the table. How about a Trivia section? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:44, 24 October 2024 (UTC)&lt;br /&gt;
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Question regarding the X scale - when it‘s defined by *three* (somewhat, implying average is real and not just calculated by (max-min)/2)) independent points, how will linearity be achieved? [[Special:Contributions/162.158.155.76|162.158.155.76]] 05:43, 22 October 2024 (UTC)&lt;br /&gt;
[[File:Explanation length.png|right|thumb|Or click &amp;quot;[Expand]&amp;quot; in the bottom right table cell Derivation.]]&lt;br /&gt;
:Please see [[2701: Change in Slope]]. [[Special:Contributions/172.70.206.179|172.70.206.179]] 05:50, 22 October 2024 (UTC)&lt;br /&gt;
:Sure, &amp;quot;a linear scale between each point&amp;quot;:&lt;br /&gt;
[[File:XvsC.png|thumb|left|Here you go. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 06:33, 22 October 2024 (UTC)]]&lt;br /&gt;
{{clear}}&lt;br /&gt;
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The reference for the average surface temperature, https://www.space.com/17816-earth-temperature.html, suggests it has increased above 15°C. What value should we use in late 2024? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:30, 22 October 2024 (UTC)&lt;br /&gt;
:The [https://wmo.int/media/news/earth-experiences-warmest-day-recent-history World Meteorological Organization], [https://www.carbonbrief.org/state-of-the-climate-2024-now-very-likely-to-be-warmest-year-on-record/ Carbon Brief], and [https://climate.copernicus.eu/new-record-daily-global-average-temperature-reached-july-2024 Copernicus Climate Change Service] suggest 17.16°C. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 07:42, 22 October 2024 (UTC)&lt;br /&gt;
::Updated water temperatures, Derivation, and graph. So we've already had more than the +2°C warming we were trying to avoid in 2019? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 08:05, 22 October 2024 (UTC)&lt;br /&gt;
::: The +2°C (or +1.5°C that we were originally supposed to be avoiding) is over some (undefined) number of years, though, which allows us to ignore the fact that we're cooking ourselves by repeatedly saying 'Oh, but it doesn't count ''yet''.' [[Special:Contributions/172.70.91.62|172.70.91.62]] 11:13, 23 October 2024 (UTC)&lt;br /&gt;
Regarding [https://www.explainxkcd.com/wiki/index.php?title=3001%3A_Temperature_Scales&amp;amp;type=revision&amp;amp;diff=353635&amp;amp;oldid=353632], are the average surface temperatures from the sources supposed to be yearly or overall averages? [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 09:06, 22 October 2024 (UTC)&lt;br /&gt;
:According to https://climate.copernicus.eu/climate-indicators/temperature the global average near-surface temperature in 2023 was 14.4 + 0.4 = 14.8°C. (see Figure 1 and click &amp;quot;Increase above: [1991–2020 reference period].&amp;quot;) [[Special:Contributions/172.68.22.8|172.68.22.8]] 21:06, 23 October 2024 (UTC)&lt;br /&gt;
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where is the interactive epic 3000 comic we should've gotten? This one's cool but 1000 seemed to have more effort in it and 2000 was at least tangetially related. Does Randall just not like making these anymore and is only making more comics as a business? [[Special:Contributions/108.162.238.185|108.162.238.185]] 12:14, 22 October 2024 (UTC)&lt;br /&gt;
:The comic is free on the website and it doesn't have ads; although the comic is part of his &amp;quot;brand&amp;quot; there are many more profitable things he could be doing with his time, and yet he continues to update it every Monday, Wednesday, and Friday.  I just don't like the idea of claiming that a creative person &amp;quot;should&amp;quot; produce any particular thing to satisfy their fans.  He's a busy guy!  Maybe he's working on a book, or a Scientific American article, or a TV show.  He's under no obligation to give us anything, and maybe one day he'll stop making xkcd altogether; that's his choice.  Sorry to single you out; I know a lot of people feel the same way as you do, but to me it doesn't make sense.  He's not a content machine--he's a guy who started posting sketches on the internet. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 15:23, 22 October 2024 (UTC)&lt;br /&gt;
::Sorry if I sounded overly brash, I wasn't trying to imply &amp;quot;wahhh no special entry wahhh&amp;quot;, I was just wondering if Randall still likes to make these or if he doesn't, mainly because he just didn't do anything special, which feels like he just didn't care. I wasn't trying to imply Randall should just do it for the fans[[Special:Contributions/108.162.238.80|108.162.238.80]] 17:52, 22 October 2024 (UTC)&lt;br /&gt;
:::It ''could'' be that 3000 (or even 3001) ''was'' going to be special but, as fairly frequently with April Fool 'specials', it just wasn't doable on time. (If it's still considered fixablez it might pop up sometime before 3020 or so. Or, if transferable to another occasion (rebranding the obvious &amp;quot;3000!&amp;quot;ness), held over until Haloween, Christmas, April or 4000, perhaps with additional perfections.)&lt;br /&gt;
:::Hard to know, unless Randall (or his technical collaborators) say anything. And it's probably not worth doing so right now. Maybe &amp;quot;Hey guys, this ''was'' going to be #3000!&amp;quot; might accompany its eventual emergence, but also maybe not. Does it really matter? [[Special:Contributions/172.70.85.139|172.70.85.139]] 13:03, 23 October 2024 (UTC)&lt;br /&gt;
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Is this the first list-style comic where every single entry is real? (Usually he has several joke entries.) [[Special:Contributions/172.70.114.182|172.70.114.182]] 14:26, 22 October 2024 (UTC)&lt;br /&gt;
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Where would [[1923: Felsius|Felsius]] go on this list?&lt;br /&gt;
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One can find a smooth function for °X, namely, (477879''x''-17634840)/(3341''x''+197700), which takes °X and returns °C. The inverse is (-197700''x''-17634840)/(3341''x''-477879). Should this be included in the wiki article? Or maybe another way of fitting it (like exponential) should be used.  [[Special:Contributions/172.69.0.165|172.69.0.165]] 06:27, 23 October 2024 (UTC)&lt;br /&gt;
:It says &amp;quot;a linear scale between each point&amp;quot;. [[Special:Contributions/172.70.210.130|172.70.210.130]] 21:09, 23 October 2024 (UTC)&lt;br /&gt;
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Should it be noted that in the first _What If?_ book, there's a reference to units and how much Randall loathes rankine? Someone can go take the book and cite it; it's in one of the early pages [[Special:Contributions/172.64.236.10|172.64.236.10]] 08:45, 23 October 2024 (UTC)&lt;br /&gt;
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I remember it being drummed into us in school physics (admittedly over 50 years ago) that 0 Celsius is defined as the melting point of ice, not the freezing point of water (presumably because of supercooling). [[Special:Contributions/172.70.160.189|172.70.160.189]] 08:49, 23 October 2024 (UTC)&lt;br /&gt;
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It seems he wrote &amp;quot;Earths'&amp;quot; (plural possessive) instead of &amp;quot;Earth's&amp;quot;. [[Special:Contributions/141.101.98.151|141.101.98.151]] 08:58, 23 October 2024 (UTC)&lt;br /&gt;
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What?  No gas mark?  It's linear for temperatures over 275°F but inverse powers of 2 below  That's pretty cursed, but I still put it in my unit conversion app.  It's only used in gas stoves in a few countries, so it doesn't come up very often.  By the way, boiling is 1/5.7358 and freezing/melting is 1/843.3572.  Interestingly, France has it's own stove temperature scale that seems to be based on °F.&lt;br /&gt;
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Also, my understanding is that 7.5 and 32 aren't random.  Both Romer and Fahrenheit put numbers on things so that freezing/melting of water and &amp;quot;Normal human body temperature&amp;quot;, which was thought to be standard at the time, would be some number X (15 for Romer and 64 for Fahrenheit) and the water thing would be to be X/2 and NHBT would be X/2+X.  Pretty nerdy.  Sadly, the calibration was off and 212 degrees for boiling was found to be less cursed.  But I could be wrong.[[Special:Contributions/172.68.54.138|172.68.54.138]] 20:39, 23 October 2024 (UTC)&lt;br /&gt;
:Re: water/ice point 'random number', I think it's more that it wasn't considered &amp;quot;special&amp;quot;, such that &amp;quot;On my scale, that will be zero&amp;quot; (or whatever choice of handily round number, including zero, some scale-setters allocated to the BP of water).&lt;br /&gt;
:After all the other messing about (&amp;quot;my zero will be that of brine!&amp;quot;, etc), obviously then the ~0°C equivalent would ''have'' a number, and ''perhaps''  there would then be a slight change to make it a ''whole'' (or easy-fraction) number for convenience's sake, but (before the concept of binary computers) there's not much special about landing on the number 32, for what is actually a temperature that is quite significant to the human experience, and less so with 7-''and-a-half''.&lt;br /&gt;
:Maybe landing on 90°F (at one time) for body temperature (and 180 F° ''between'' MP and BP) was considered useful as the analogue to angular-degrees where 90 (and 180) indeed features significantly, but I don't think there'd have been too much fuss if the value would have turned out to be 60(/120), also with plenty of handy factors to divide by, 70(/140), without so much, or whatever number(s) happened to depict one realistic real-world measurement that (overall) has no reason to have a factor-based relationship with various quite separate phenomenon measurements.&lt;br /&gt;
:''And'' it went through several {{w|Human body temperature#Historical understanding|'corrective' iterations}} so that even its handy relationship with 'about 100°F' can be said to be an incidental accident, at best, unless we do something like Randall's °X scale and actively triple-tie the central value of the slope(s) to be exactly something useful by using the &amp;quot;currently accepted mean human body temperature (given various complicated caveats)&amp;quot;.&lt;br /&gt;
:It's pretty much all random, in the same way that only because of anthropocentric choices of 'standard' time and distance measurements is the speed of light 'pretty much' 3×10⁸ m/s (a handily round value that works well enough for most purposes, even after back-standardising its component SI measurements to make &amp;quot;actually, &amp;lt;u&amp;gt;precisely&amp;lt;/u&amp;gt; 299792458&amp;quot; the ''proper'' answer, and [https://conversion.org/speed/speed-of-light/furlong-per-fortnight it could be far worse...]). Avagadro's number never had it so good (6.022(+change)×10&amp;lt;sup&amp;gt;23&amp;lt;/sup&amp;gt;...? ...where's the handily mnemonic value in that?), and Pi (in this universe's system of fundemental mathematics) clearly never ever had a chance! And, on {{w|Mount Everest#19th century|at least one occasion}}, such happenstance numeric roundedness in its exactitude (29''',000''' ft) was considered actually quite awkward... [[Special:Contributions/172.70.91.90|172.70.91.90]] 21:33, 23 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
Ok, then, regarding {{diff|353895|this edit}} (and the original IP-led one(s) that even made huge and revert-necessary changes), was it ''really'' intended to get rid of whole paragraphs such as &amp;quot;Randall also fails to specify what happens with temperatures[...]&amp;quot; that had nothing to do with the numeric adjustments? When I see that, I see mistakes (especially in light of the &amp;quot;clobber&amp;quot; that happened, where typos reappeared and other things became unexplained/worse-explained once more). — Basically, if your edit summary is nust about updating baseline data, and the resulting maths, I don't expect (maybe good, maybe bad) edits to unrelated bits. Or I may (and have) presumed accidental (or deliberate?) carelessness that I'd rather not try to go back to first principles to re-re-check for the editor concerned. That is all. At least try to justify enough of your edit in its own way, even if it means diving in several times to get enough space to summarise your whole &amp;quot;why&amp;quot; to each tweak. [[Special:Contributions/172.68.186.104|172.68.186.104]] 22:44, 23 October 2024 (UTC)&lt;br /&gt;
:Yes. I have re-removed the removals piecemeal with individual edit summaries for clarity. Many of them involved detailed obscure technical misunderstandings, such as whether the Vostok and Death Valley measurements were surface temperatures (the WMO says they are, and there are the WMO's photos of the observation stations in the linked references now) which combined with the incorrect yearly average global mean temperature, added five paragraphs unnecessarily. [[Special:Contributions/172.68.23.152|172.68.23.152]] 01:46, 24 October 2024 (UTC)&lt;br /&gt;
::Definitely some points made (some incorrect, &amp;quot;ne er&amp;quot; was ''obviously'' more just a basic typo of &amp;quot;never&amp;quot;, not my attempt to use &amp;quot;ne'er&amp;quot; for no good reason, and my attempt to fix that and some other bits ran into a set of Edit Conflicts ...hope I caught all the remaining ones when I finally could try again on the settled-down page) and I've blended answers to your objections in while giving back what useful nuances (from a number of past editors, only a couple of bits even having had my own hand primarilly behind them as they were) really needn't have been removed. I dispute the terms of your objections (as summarised) behind {{diff|353937|some changes}}, but have rephrased based upon what I ''think'' you mean, giving you should prefer and wouldn't feel the need to be as randomly censorious about. [[Special:Contributions/172.69.195.173|172.69.195.173]] 02:54, 24 October 2024 (UTC)&lt;br /&gt;
:::Figure 1 in https://climate.copernicus.eu/climate-indicators/temperature does not seem like a random walk to me. [[Special:Contributions/172.69.33.118|172.69.33.118]] 05:02, 24 October 2024 (UTC)&lt;br /&gt;
&lt;br /&gt;
== Division by zero ==&lt;br /&gt;
&lt;br /&gt;
I saw this in an edit summary: &amp;quot;10/0 is not ∞, it's also an error, not NaN according to the IEEE. It's closer to {+∞, -∞} than NaN but it's still neither because you can't make limits work&amp;quot;&lt;br /&gt;
&lt;br /&gt;
Actually, IEEE floating point 10/0 can be an error, +∞, or NaN depending on the rounding mode. This is one of the reasons why mathemeticians don't appreciate the IEEE as much as they might. Division by zero is strictly undefined because of the problems with limits alluded to in the summary. https://www.youtube.com/watch?v=dHdg1yn1SgE [[Special:Contributions/108.162.245.66|108.162.245.66]] 03:48, 24 October 2024 (UTC)&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354072</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354072"/>
				<updated>2024-10-24T08:38:13Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ honestly, who among us doesn't spend most of their time thinking about the Roman Empire?&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] during his time as a prominent physician in the {{w|Roman Empire}}. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354071</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354071"/>
				<updated>2024-10-24T08:36:05Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ source for Galen&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D.,[https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml] created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354070</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354070"/>
				<updated>2024-10-24T08:34:52Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ 180 A.D. is not ancient&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The Greek physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature around 180 A.D., created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354069</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354069"/>
				<updated>2024-10-24T08:30:47Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ territories&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country) and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354066</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354066"/>
				<updated>2024-10-24T08:29:09Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ reword&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the widely adopted official {{w|metric system}} since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country), the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354065</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354065"/>
				<updated>2024-10-24T08:26:57Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ dates&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins have been part of the {{w|metric system}} which has been widely adopted for official use since 1954. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature devised by {{w|Lord Kelvin}} in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country), the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354064</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354064"/>
				<updated>2024-10-24T08:20:38Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ no abbreviation&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins are part of the {{w|metric system}} that has been widely adopted for official use. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature created by {{w|Lord Kelvin}}. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country), the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. There is no standard abbreviation for Dalton's scale.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354063</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354063"/>
				<updated>2024-10-24T08:17:59Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ single quotes around special glyphs&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins are part of the {{w|metric system}} that has been widely adopted for official use. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature created by {{w|Lord Kelvin}}. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country), the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354062</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354062"/>
				<updated>2024-10-24T08:16:41Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ comic comma&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins are part of the {{w|metric system}} that has been widely adopted for official use. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature created by {{w|Lord Kelvin}}. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country), the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]], expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the &amp;quot;°W&amp;quot; scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354060</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354060"/>
				<updated>2024-10-24T08:15:45Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ inventor, date, pluralization&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins are part of the {{w|metric system}} that has been widely adopted for official use. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature created by {{w|Lord Kelvin}}. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country), the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || The Rankine scale (°Ra), devised in 1859 by {{w|William Rankine}}, is to Fahrenheit what kelvins are to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]] expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the &amp;quot;°W&amp;quot; scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354058</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=354058"/>
				<updated>2024-10-24T08:12:37Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ date and related work&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the {{w|thermometer}}, a number of different {{w|temperature}} scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements. A small number of countries (the USA and {{w|Territories of the United States|its territories}}, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the {{w|Imperial units|imperial system}}, which uses the {{w|Fahrenheit}} scale, which preceded Celsius by just under two decades. The other widely used temperature scale is {{w|kelvin}}s, which uses the same scale as degrees Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins.) Kelvins are part of the {{w|metric system}} that has been widely adopted for official use. Even in countries that use Fahrenheit, scientific measurements are usually done in degrees Celsius or kelvins.&lt;br /&gt;
&lt;br /&gt;
The comic compares these scales, and a number of others, on [[Randall]]'s scale of &amp;quot;cursedness.&amp;quot; The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also [[1923: Felsius]], a combination of degrees Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || The Celsius (°C) scale was devised by Swedish astronomer {{w|Anders Celsius}} in 1742, and revised to its current version after his death in 1745. 0°C represents the freezing point of water, and 100°C represents the boiling point, both under {{w|standard atmospheric pressure}}. The Celsius scale is now defined in terms of the Kelvin scale. By the given &amp;quot;cursedness,&amp;quot; it is regarded as one of the two least problematic temperature scales.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin (written with a lowercase 'k' as a unit, or as 'K', without the degrees symbol '°') is a unit of temperature created by {{w|Lord Kelvin}}. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the {{w|Boltzmann constant}}.) While kelvins are very useful for {{w|thermodynamics}} and material physics, it can be unintuitive. Kelvin and Celsius are the most commonly used units in scientific measurements and calculations.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, {{w|Daniel Fahrenheit}} chose not to base 0° on the freezing point of water, instead setting it at the coldest temperature he could achieve: the freezing point of an {{w|ammonium chloride}} {{w|brine}} solution. Although these reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity especially in Anglophone countries, likely because it aligns with everyday weather conditions and is intuitively useful. Its range covers typical temperatures across various latitudes and seasons, and 100°F is close to normal human body temperature. The Fahrenheit scale remains commonly used only in the U.S. (Randall's home country), the Bahamas, Belize, the Cayman Islands, Liberia, and Palau.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || Abbreviated as °Ré, this system devised by {{w|René Antoine Ferchault de Réaumur}} in 1730 was used in some places until the early 20th century, mostly for cheese-making. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Abbreviated as °Rø, this scale was created by the Danish astronomer {{w|Ole Rømer}} around 1702. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to fix it to 7.5.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || As the chart mentions, Rankine (°Ra) is to Fahrenheit what kelvin is to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more practical zero-point. Another comic, [[2292: Thermometer]] expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || The famous scientist and mathematician {{w|Isacc Newton}} published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of {{w|heat}}. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition. Very few scientists other than Newton ever used this scale,{{cn}} but it did appear on commercial thermometers around 1758.[https://www.scienceandsociety.co.uk/results.asp?image=10413117&amp;amp;wwwflag=&amp;amp;imagepos=43]&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by the potter {{w|Josiah Wedgwood}} in 1782, the &amp;quot;°W&amp;quot; scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood, without the second 'e'. &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || The ancient Green physician {{w|Galen}} suggested a &amp;quot;neutral&amp;quot; temperature, created by mixing equal parts of boiling water and ice. On either side of this neutral point, he described four degrees of heat and four degrees of cold. This range from +4 to –4 is humorously described as implying –100% cursedness, which while technically the least cursed of all the listed scales, is still as unclear as the idea of negative cursedness or cursedness itself. There is no standard abbreviation for Galen's scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original 1742 specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (through 1.42x10&amp;lt;sup&amp;gt;32&amp;lt;/sup&amp;gt;K, the maximum physical temperature[https://doi.org/10.4236/jamp.2024.1210198]) will be negative. The cursedness rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. Division by zero is strictly undefined.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This orientation survives in the historic {{w|Delisle scale}}, which predates (and arguably helped inspire) the Celsius scale. The scale originally used by Professor Celsius was only corrected posthumously in 1745, but Delisle's scale was not.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale in 1802 during his work on what became {{w|Charles's Law}}. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X || 42.9 || 151.4 || '''Title text:''' &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || ''not provided'' || The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature] &amp;quot;Surface&amp;quot; temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often much different.&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Due to high and average temperature records now being broken nearly every year as a result of {{w|climate change}}, Randall's new °X scale must be re-calibrated each year. While extreme values like absolute zero or the {{w|Tungsten#Physical properties|melting point of tungsten}} will shift more significantly over time, everyday temperatures will vary less.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=File:XvsC.png&amp;diff=354056</id>
		<title>File:XvsC.png</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=File:XvsC.png&amp;diff=354056"/>
				<updated>2024-10-24T07:57:46Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: Liv2splain uploaded a new version of File:XvsC.png&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Re [[3001: Temperature Scales]], chart showing the relationship between the °X and °C temperature scales.&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=353902</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=353902"/>
				<updated>2024-10-23T22:41:32Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ remove extranialia and opinion&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the thermometer, a number of different temperature scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements, as it is part of the {{w|metric system}} that has been widely adopted for official uses. A small number of countries (namely Liberia, the USA and its three associated free states in the Pacific) retain the US customary (or 'imperial') system, which uses the ''slightly'' older {{w|Fahrenheit}} scale (°F was initially defined in 1724, the general current form of °C was created in 1743). The other widely used temperature scale is {{w|Kelvin}}, which uses the same scale as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius. Even in countries that use Fahrenheit regularly, scientific measurements are typically done in Celsius and/or Kelvin.&lt;br /&gt;
&lt;br /&gt;
The strip proceeds to compare these scales, and a number of others, on a scaled of &amp;quot;cursed&amp;quot;-ness. The joke is highlighting how strange and generally difficult to use many older proposed systems were. All of the listed scales are real, but may be considered obsolete to varying degrees. See also [[1923: Felsius]], a combination of Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || Celsius is defined (indirectly, these days, by way of comparison to Kelvin) so that the freezing and boiling points of pure water at standard atmospheric pressure are 0 and 100 degrees respectively. This (along with Kelvin) is considered the least cursed temperature system.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin is a scientific unit of measure invented by {{w|Lord Kelvin}} that intends to use the same scale as degrees Celsius, but is offset by 273.15, in order to set the zero point at absolute zero (by way of using the {{w|Boltzmann constant}}, as of 2019). This is very practical for the math of thermodynamics, but unintuitive for non-expert users. Kelvin and Celsius are, by far, the most common units used in scientific measurements and calculations. Their utility and inherent logic is likely what makes them the least &amp;quot;cursed&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit is officially used in several countries across the globe, and unofficially in several others. It was derived in an era where factors of 360 were more popular in science than powers of ten, so water freezing and water boiling were calibrated to be 180° apart. In addition, Daniel Fahrenheit believed that pure water freezing was not worthy of the 0° benchmark and resolved to set 0° to the coldest possible temperature he could create: the freezing point of ammonium chloride brine. While modern scholars find these benchmarks arbitrary and outdated, it gained usage, primarily in Anglophone countries, likely due to the scale being considered intuitively useful for some common functions (the range roughly matches the typical span of weather conditions, for various ranges of climate, and the 100 point is quite near normal human body temperature, even though 90 was initially presumed to be this). While it was largely displaced by the Celsius scale, the US, [[Randall]]'s home country, continues to typically use it. It is ranked as slightly more cursed than Celsius.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || A historical French system used in some places until the early 20th century. In modern times mostly used in cheesemaking. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labelling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Created by the Danish astronomer Ole Christensen Rømer in around 1702, while the Fahrenheit scale was proposed in 1724. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Ole Rømer, but the scale was later updated to fix it to 7.5.  The scale is also the last common ancestor of Celsius and Fahrenheit, as Reuamur was inspired by it, and Celsius by Reamur, and Fahrenheit specifically wanted a Rømer scale with more steps to avoid using decimals.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || As the chart mentions, Rankine is to Fahrenheit what Kelvin is to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. [[2292: Thermometer]] expresses disdain for this scale.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || Created by Isaac Newton, measuring &amp;quot;degrees of heat&amp;quot;. The cussedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by potter Josiah Wedgwood in the 18th century. The measurement was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood (''without the e''). &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || {{w|Galen}}, in his medical writings, is said to have proposed a standard &amp;quot;neutral&amp;quot; temperature made up of equal quantities of boiling water and ice; on either side of this temperature were four degrees of heat and four degrees of cold, respectively. The rating (4/–4) is a joke about the scale being defined between positive and negative 4, and could be interpreted as –100% cursedness, though it's not clear what negative cursedness would mean.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (an indefinite range of them) will be negative. The rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This direction 'survives' in the historic {{w|Delisle scale}}, which predates (and arguably helped greatly inspire, though with a different factor) the classic version of °C. The version originally used by Anders was only 'corrected' posthumously, but nobody seemed bothered enough to do the same with Delisle's scale.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e. the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X (Randall's new temperature scale as defined in the title text) || 42.9 || 151.4 || Title text: &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || N/A (but likely very high)|| The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.4°C (57.2°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Since average and high temperature records are being broken frequently due to {{w|climate change}}, this scale is defined as being re-calibrated annually.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=353901</id>
		<title>3001: Temperature Scales</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&amp;diff=353901"/>
				<updated>2024-10-23T22:36:46Z</updated>
		
		<summary type="html">&lt;p&gt;Liv2splain: /* Explanation */ wikilink first ref and remove statements of opinion irrelevant to explanation&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 3001&lt;br /&gt;
| date      = October 21, 2024&lt;br /&gt;
| title     = Temperature Scales&lt;br /&gt;
| image     = temperature_scales_2x.png&lt;br /&gt;
| imagesize = 740x535px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an EXPONENTIAL TEMPERATURE SYSTEM. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Since the invention of the thermometer, a number of different temperature scales have been proposed. In modern times, most of the world uses {{w|Celsius}} for everyday temperature measurements, as it is part of the {{w|metric system}} that has been widely adopted for official uses. A small number of countries (namely Liberia, the USA and its three associated free states in the Pacific) retain the US customary (or 'imperial') system, which uses the ''slightly'' older {{w|Fahrenheit}} scale (°F was initially defined in 1724, the general current form of °C was created in 1743). The other widely used temperature scale is {{w|Kelvin}}, which uses the same scale as Celsius, but is rooted at {{w|absolute zero}}, making it both useful in scientific calculations and easy to convert to and from Celsius. Even in countries that use Fahrenheit regularly, scientific measurements are typically done in Celsius and/or Kelvin.&lt;br /&gt;
&lt;br /&gt;
The strip proceeds to compare these scales, and a number of others, on a scaled of &amp;quot;cursed&amp;quot;-ness. The joke is highlighting how strange and generally difficult to use many older proposed systems were. All of the listed scales are real, but may be considered obsolete to varying degrees. See also [[1923: Felsius]], a combination of Fahrenheit and Celsius.&lt;br /&gt;
&lt;br /&gt;
{| class=wikitable&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Unit&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Freezes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Water Boils&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Notes&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Cursedness&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; | Explanation&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius}} || 0 || 100 || Used in most of the world || 2/10 || Celsius is defined (indirectly, these days, by way of comparison to Kelvin) so that the freezing and boiling points of pure water at standard atmospheric pressure are 0 and 100 degrees respectively. This (along with Kelvin) is considered the least cursed temperature system.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Kelvin}} || 273.15 || 373.15 || 0K is absolute zero || 2/10 || Kelvin is a scientific unit of measure invented by {{w|Lord Kelvin}} that intends to use the same scale as degrees Celsius, but is offset by 273.15, in order to set the zero point at absolute zero (by way of using the {{w|Boltzmann constant}}, as of 2019). This is very practical for the math of thermodynamics, but unintuitive for non-expert users. Kelvin and Celsius are, by far, the most common units used in scientific measurements and calculations. Their utility and inherent logic is likely what makes them the least &amp;quot;cursed&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Fahrenheit}} || 32 || 212 || Outdoors in most places is between 0–100 || 3/10 || Fahrenheit is officially used in several countries across the globe, and unofficially in several others. It was derived in an era where factors of 360 were more popular in science than powers of ten, so water freezing and water boiling were calibrated to be 180° apart. In addition, Daniel Fahrenheit believed that pure water freezing was not worthy of the 0° benchmark and resolved to set 0° to the coldest possible temperature he could create: the freezing point of ammonium chloride brine. While modern scholars find these benchmarks arbitrary and outdated, it gained usage, primarily in Anglophone countries, likely due to the scale being considered intuitively useful for some common functions (the range roughly matches the typical span of weather conditions, for various ranges of climate, and the 100 point is quite near normal human body temperature, even though 90 was initially presumed to be this). While it was largely displaced by the Celsius scale, the US, [[Randall]]'s home country, continues to typically use it. It is ranked as slightly more cursed than Celsius.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Réaumur scale|Réaumur}} || 0 || 80 || Like Celsius, but with 80 instead of 100 || 3/8 || A historical French system used in some places until the early 20th century. In modern times mostly used in cheesemaking. The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labelling it as more cursed than Fahrenheit but less so than Rømer.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rømer scale|Rømer}} || 7.5 || 60 || Fahrenheit precursor with similarly random design || 4/10 || Created by the Danish astronomer Ole Christensen Rømer in around 1702, while the Fahrenheit scale was proposed in 1724. Much like Fahrenheit, it uses the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Ole Rømer, but the scale was later updated to fix it to 7.5.  The scale is also the last common ancestor of Celsius and Fahrenheit, as Reuamur was inspired by it, and Celsius by Reamur, and Fahrenheit specifically wanted a Rømer scale with more steps to avoid using decimals.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Rankine scale|Rankine}} || 491.7 || 671.7 || Fahrenheit, but with 0°F [''sic;'' should be 0°R] set to absolute zero  || 6/10 || As the chart mentions, Rankine is to Fahrenheit what Kelvin is to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required.&lt;br /&gt;
Randall has shown disdain for this scale before, in [[2292: Thermometer]].&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Newton scale|Newton}} || 0 || 33-ish || Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot; || 7-ish/10 || Created by Isaac Newton, measuring &amp;quot;degrees of heat&amp;quot;. The rating (7-ish/10) is a joke about the vagueness of the scale's definition.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Wedgwood scale|Wedgwood}} || –8 || –6.7 || Intended for comparing the melting points of metals, all of which it was very wrong about || 9/10 || Created by potter Josiah Wedgwood in the 18th century. The measurement was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate. The comic has a typo, as the scale is called Wedgwood (''without the e''). &lt;br /&gt;
|-&lt;br /&gt;
| Galen || –4? || 4?? || Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?) || 4/–4 || {{w|Galen}}, in his medical writings, is said to have proposed a standard &amp;quot;neutral&amp;quot; temperature made up of equal quantities of boiling water and ice; on either side of this temperature were four degrees of heat and four degrees of cold, respectively. The rating (4/–4) is a joke about the scale being defined between positive and negative 4, and could be interpreted as –100% cursedness, though it's not clear what negative cursedness would mean. Of course it is not actually clear what &amp;quot;cursedness&amp;quot; means, so maybe that is not an issue.&lt;br /&gt;
|-&lt;br /&gt;
| {{w|Celsius#History|''Real'' Celsius}} || 100 || 0 || In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it || 10/0 || Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (an indefinite range of them) will be negative. The rating (10/0) is a joke on the scale &amp;quot;flipping&amp;quot; the fixed points of modern Celsius. This might be interpreted as &amp;quot;infinitely cursed&amp;quot;, or else just {{w|NaN|Not a Number}}.&lt;br /&gt;
The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it ''reduced'' in height under cooler conditions. This direction 'survives' in the historic {{w|Delisle scale}}, which predates (and arguably helped greatly inspire, though with a different factor) the classic version of °C. The version originally used by Anders was only 'corrected' posthumously, but nobody seemed bothered enough to do the same with Delisle's scale.&lt;br /&gt;
|-&lt;br /&gt;
| [https://physics.stackexchange.com/questions/459851/john-daltons-temperature-scale#459863 Dalton] || 0 || 100 || A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton || 53.9/50 || {{w|John Dalton}} proposed a logarithmic temperature scale. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures.&lt;br /&gt;
&lt;br /&gt;
The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e. the cursedness could be understood as 50/50 (or 10/10, entirely cursed), but perhaps instead as 107.8% (even more than entirely cursed).&lt;br /&gt;
|-&lt;br /&gt;
| °X (Randall's new temperature scale as defined in the title text) || 42.9 || 151.4 || Title text: &amp;quot;In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.&amp;quot; || N/A (but likely very high)|| The {{w|Lowest temperature recorded on Earth|record lowest surface temperature on Earth}} as of 2024 is –89.2°C (–128.6°F), recorded at the {{w|Vostok Station|Vostok Research Station}} in Antarctica on July 21, 1983.[https://wmo.asu.edu/content/world-lowest-temperature] The average surface temperature as of 2023, the most recent available, is 14.4°C (57.2°F.)[https://climate.copernicus.eu/climate-indicators/temperature] The {{w|Highest temperature recorded on Earth|record highest temperature}} is 56.7°C (134.1°F), recorded on July 10, 1913 at {{w|Furnace Creek, California|Furnace Creek Ranch}} in Death Valley, California.[https://wmo.asu.edu/content/world-highest-temperature]&lt;br /&gt;
&lt;br /&gt;
{{cot|Derivation and graph}}&lt;br /&gt;
To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:&lt;br /&gt;
&lt;br /&gt;
1. Below 14.8°C (from –89.2°C to 14.8°C):&lt;br /&gt;
* 0 °X corresponds to –89.2°C&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 0.48 × 14.8 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 7.1 + b₁&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₁ = 50 – 7.1 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''below 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 0.48 × C + 42.9'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
2. Above 14.8°C (from 14.8°C to 56.7°C):&lt;br /&gt;
* 50 °X corresponds to 14.8°C&lt;br /&gt;
* 100 °X corresponds to 56.7°C&lt;br /&gt;
&lt;br /&gt;
We calculate the slope m₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 1.19 × 14.8 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;50 = 17.6 + b₂&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;b₂ = 50 – 17.6 = 32.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Thus, the equation for temperatures '''above 14.8°C''' is:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;'''X = 1.19 × C + 32.4'''&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Freezing and Boiling Points&lt;br /&gt;
&lt;br /&gt;
Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 0.48 × 0 + 42.9 = 42.9&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the freezing point is 42.9 °X.&lt;br /&gt;
&lt;br /&gt;
Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;center&amp;gt;X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4&amp;lt;/center&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So, the boiling point is 151.4 °X.&lt;br /&gt;
&lt;br /&gt;
[[File:XvsC.png|400px|center]]&lt;br /&gt;
&lt;br /&gt;
See also [[2701: Change in Slope]] for a general discussion of separate linear scales between three points.&lt;br /&gt;
{{cob}}&lt;br /&gt;
Since average and high temperature records are being broken frequently due to {{w|climate change}}, this scale is defined as being re-calibrated annually.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:Temperature Scales&lt;br /&gt;
&lt;br /&gt;
:[A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]&lt;br /&gt;
&lt;br /&gt;
:[Row 1:] Celsius, 0, 100, Used in most of the world, 2/10&lt;br /&gt;
:[Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10&lt;br /&gt;
:[Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10&lt;br /&gt;
:[Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8&lt;br /&gt;
:[Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,&lt;br /&gt;
:[Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10&lt;br /&gt;
:[Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like &amp;quot;the hottest water you can hold your hand in&amp;quot;, 7-ish/10&lt;br /&gt;
:[Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10&lt;br /&gt;
:[Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is &amp;quot;normal&amp;quot;(?), 4/–4&lt;br /&gt;
:[Row 10:] ''Real'' Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are ''colder''; others later flipped it, 10/0&lt;br /&gt;
:[Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Science]]&lt;/div&gt;</summary>
		<author><name>Liv2splain</name></author>	</entry>

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