https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=172.70.214.95&feedformat=atomexplain xkcd - User contributions [en]2024-03-29T05:26:34ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=2657:_Complex_Vowels&diff=2933402657: Complex Vowels2022-08-24T03:12:35Z<p>172.70.214.95: /* Explanation */ the schwa is not a diphthong</p>
<hr />
<div>{{comic<br />
| number = 2657<br />
| date = August 10, 2022<br />
| title = Complex Vowels<br />
| image = complex_vowels.png<br />
| titletext = Pronouncing [ṡṡċċḣḣẇẇȧȧ] is easy; you just say it like the 'x' in 'fire'.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a ROUNDED TONGUE. Do NOT delete this tag too soon.}}<br />
[[File:Ipa-chart-vowels.png|thumb|200px|The standard IPA vowel chart.]]<br />
This is another one of Randall's [[:Category:Tips|Tips]], this time a Linguistics Tip. The curly-haired linguist, [[:Category:Comics featuring Gretchen McCulloch|Gretchen McCulloch]], manages to produce a cursed sound using complex vowels, that cannot be comprehended by normal humans like [[Cueball]] and [[Megan]], who both seem to get a headache from listening to the sound. The sound she makes was produced by extending the IPA vowel plane along an imaginary axis to form the complex vowels.<br />
<br />
In phonetics based on the {{w|International Phonetic Alphabet}} (IPA), the space of {{w|vocal tract}} articulators determining {{w|vowel}}s <!-- (as opposed to unvoiced consonants) -- nasals and liquids don't care where the tongue is, in any language {acn} --> is represented as three dimensional, from the position of the tongue and lips. The vertical axis represents vowel height or ''closedness'' (i.e., how close or far the tongue is from the top of the mouth), and the horizontal axis represents front-to-back ''place'' (i.e., how close or far the top of the tongue is from the teeth.) The position of the tongue, along with the frequency of the {{w|vocal cords}} vibrating in the larynx from air being exhaled by the diaphragm, are the primary determinants of the fundamental and second {{w|formant}} frequencies of vowel sounds. A third dimension of vowel sounds is the "roundedness" of the lips, represented on the IPA vowel chart to the right by pairs of vowel phoneme {{w|glyph}}s. Other higher-dimensional vowel representations include {{w|diphthong}}s, which are simply two different sequential vowels slurred together; diphones, which represent the last half of one phoneme followed by the first half of the next; {{w|vowel shift}} mappings delineating different accents[https://core.ac.uk/download/pdf/47086396.pdf][https://www.sciencedirect.com/science/article/abs/pii/S0095447010000562] and long-term evolution of voiced phone sounds; and {{w|cepstrum|cepstral}} representations such as {{w|Mel-frequency cepstrum|mel-frequency cepstral coefficients}}.<br />
<br />
[[Randall]] suggests increasing the range of vowel sounds available by using complex notation to indicate an additional dimension with an "imaginary" axis. In mathematics, {{w|complex number}}s are numbers including both real numbers and {{w|imaginary number}}s. A complex number can be expressed as, "''a'' + ''b''i," where ''a'' and ''b'' are real numbers, but the latter imaginary part is combined with 'i,' the square root of negative one, as depicted in the central expression in the comic by √<span style="border-top: 1px solid currentColor">-1</span> indicating a further dimension of coordinates. When expanding the one-dimensional number line with an imaginary axis, it becomes two-dimensional with the "''b''i" component {{w|orthogonal}} to the original "real" number line. Linguists never use the {{w|complex plane}} to represent vowel roundedness or any other higher-dimensional features of phonemes, although the properties of complex numbers could conceivably support representing physiological features of the vocal tract, such as prior position of the articulators.{{cn}}<br />
<br />
This comic conflates complex numbers in mathematics with "complex vowels" in linguistics. Such complex vowels are implied to create sounds which cannot be properly processed by the human brain, and represents one with a heavily modified "schwa" {{w|Ə}} phoneme, mirrored vertically and surrounded by multiple {{w|diacritics}} akin to the {{w|Zalgo text}} meme. The sound of this supposedly alien vowel has Cueball and Megan clutching their heads in pain. Overall, Randall's complex vowels bear similarity to the cliché of "black speech" in {{w|Lovecraftian horror}}, a language created by alien beings with different vocal patterns than humans.<br />
<br />
In linguistics, 'ə' is the {{w|schwa}} symbol, referred to in the title text and the depiction of complex phonemes, the most common vowel sound in English polysyllabic words (the 'a' in "comma" or the second 'e' in "letter.") Production of the schwa sound takes place with the tongue, jaw, and lips all in a relaxed, central position. The pronunciation of "[ṡṡċċḣḣẇẇȧȧ]" in the title text is said to sound like the x in the word fire. In fact, there is no x in fire.{{Citation needed}} This is perhaps in line with the idea that complex sounds are incomprehensible to most humans, and likely also impossible to pronounce by anyone other than experts such as [[:Category:Comics featuring Gretchen McCulloch|Gretchen]].<br />
<br />
Another example of weird diacritics is in [[2619: Crêpe]], and with Zalgo text in [[1647: Diacritics]]. The use of typography to create psychological stress is explored in [[859: (]].<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[A diagram shows the extrusion of the trapezoidal IPA vowel chart upwards into three dimensions. A point near the center is labeled with an equation that shows "ə + ½√-1 " as being equivalent to a made-up symbol that looks like two schwas mirroring each other with other markings above and below.]<br />
<br />
:[Below the diagram, a character with shoulder-length dark wavy hair pronounces the new vowel in a speech bubble with unstable lines surrounding it. Two bystanders to her right are bent over slightly, clutching their heads in apparent anguish.]<br />
<br />
:[Caption below the panel:]<br />
:Linguistics tip: Extend the IPA vowel plane along the imaginary axis to produce the ''complex vowels'', cursed sounds which the human mind cannot comprehend.<br />
<br />
{{comic discussion}}<br />
[[Category:Tips]]<br />
[[Category:Language]]<br />
[[Category:Comics featuring Gretchen McCulloch]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2661:_Age_Milestone_Privileges&diff=2931442661: Age Milestone Privileges2022-08-19T23:52:33Z<p>172.70.214.95: /* Transcript */</p>
<hr />
<div>{{comic<br />
| number = 2661<br />
| date = August 19, 2022<br />
| title = Age Milestone Privileges<br />
| image = age_milestone_privileges.png<br />
| titletext = If you reach 122, you get complete unrevertible editorial control over Jeanne Calment's Wikipedia article.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a BABY GOD-EMPRESS MAKING THE PRESIDENT'S LETTER R-RATED - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
25 years is also the threshold for being allowed to run for the United States House of Representatives, but the fact that other countries have different constitutions with different age-restrictions makes this comic America-centric. Also, this comic is incorrect; one must be at least 30 years old in order to ''become'' Senator, not ''run'' for Senate. Joe Biden was 29 years old when he was elected to Senate but turned 30 before being sworn in.<br />
<br />
Obviously, the god-empress does not actually exist because this comic is visible to people under 45 years old.{{citation needed}}<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
<big>Age Milestones</big><br><br />
and associated privileges<br />
<br />
16&nbsp; Drive<br><br />
17&nbsp; Attend R-rated movies alone<br><br />
18&nbsp; Vote<br><br />
21&nbsp; Buy alcohol<br><br />
25&nbsp; Rent a car<br><br />
32&nbsp; Run for senate<br><br />
35&nbsp; Run for president<br><br />
40&nbsp; Rent a flying car<br><br />
45&nbsp; Learn about the God-Empress<br><br />
50&nbsp; Join AARP<br><br />
52&nbsp; Click to skip captchas<br><br />
55&nbsp; Vote for God-Empress<br><br />
62&nbsp; $80 National parks lifetime pass<br><br />
65&nbsp; Eligible for Medicare<br><br />
67&nbsp; Collect Social Security<br><br />
68&nbsp; See "Skip Ads" button on live TV<br><br />
70&nbsp; Run for God-Empress<br><br />
75&nbsp; Ride any animal in a national park<br><br />
80&nbsp; Eligible for MegaCare<br><br />
85&nbsp; Click to toggle whether any ad is positive or negative about the product<br><br />
90&nbsp; Click to make any movie R-rated<br><br />
100&nbsp; Get a letter from the president<br><br />
102&nbsp; (35+67) Collect a presidential pension<br><br />
105&nbsp; Get a birthday card from the God-Empress<br><br />
111&nbsp; Leave your own birthday party early by putting on a magic ring<br><br />
118&nbsp; Vote 100 times<br><br />
120&nbsp; Collect the pensions of all elected officials<br><br />
125&nbsp; Drink alcohol in an R-rated movie while getting a shingles vaccine from the president<br><br />
128&nbsp; Age rolls over, become a baby again<br />
<br />
{{comic discussion}}<br />
[[Category:Politics]]<br />
[[Category:Comics featuring real people]] <!-- Jeanne Calmert --></div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2659:_Unreliable_Connection&diff=292980Talk:2659: Unreliable Connection2022-08-17T00:27:31Z<p>172.70.214.95: reply</p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
I don’t think this has anything to do with teleconferencing. Am I missing something? [[Special:Contributions/172.70.214.81|172.70.214.81]] 22:46, 15 August 2022 (UTC)<br />
:Yes. The impliction is that people are expecting you to be available for online communications, and you can use the unreliable Internet connection as an excuse to get out of it. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:51, 15 August 2022 (UTC)<br />
::I think it's more about communication in general. He doesn't want anybody calling him or sending him emails, so by saying he has an "unreliable" connection people might assume it will be hard to get in touch with him.<br />
:::Back in the day, email was usually configured so that it could easily overcome such unreliability, and it's still doable,[https://discourse.mailinabox.email/t/running-from-home/6459/7] but today email for most people is a web or local client-server app, as opposed to a local mail store in a peer-to-peer app. Even people in urban areas can suffer unreliable internet, when squirrels or backhoes gnaw through data cables, copper theives strike, or 5G mind control base stations are congested. [[Special:Contributions/172.70.210.143|172.70.210.143]] 23:45, 15 August 2022 (UTC)<br />
:::This could equally cover other instant communication methods where your availability is advertised (e.g. Whatsapp). It could also be about alleviating the social pressure the subject feels to continuously check and immediately respond to messages (including emails), because the immediacy is already hindered by the spotty connection (cf the standard "I will have limited access to email" out of office line, which gives the account owner psychological permission to check it infrequently). [[Special:Contributions/172.70.85.5|172.70.85.5]] 09:02, 16 August 2022 (UTC)<br />
<br />
According to a PhET simulator (https://phet.colorado.edu/sims/html/plinko-probability/latest/plinko-probability_en.html) for this situation, the ideal standard deviation is 1.732 and ideal mean is 6. I don’t feel like doing the calculations :P [[Special:Contributions/172.70.211.134|172.70.211.134]] 23:34, 15 August 2022 (UTC)<br />
:If we assume 50-50 for each bounce, the probability that internet is off will be about (11 choose 3)/(2^11), or 8%.--[[User:Account|Account]] ([[User talk:Account|talk]]) 23:51, 15 August 2022 (UTC)<br />
::My first thought was, why so complicated? ''If'' each of the twelve switches is equally (and solely) likely to be struck by each ball, it's (100/12)% of the time, or 8⅓%.<br />
::Although the equal-chance is wrong, so you're definitely doing "end up with exactly 7 bounce rights and 3 bounce lefts, but in any combination" or similar are you? I'd have summed it differently, though. And not sure where the choose ''3'' comes in... Just one bounce left off any row-end pin 11 sends to 11 if all others bounce right. Three bounces left hits switch 9, not eight. If I'm counting correctly. Or am I doing telegraph-poles/wires miscounting?<br />
::Too early in the morning for me to untangle. The only thing I'm sure about is your division by 2^11 (how many total paths there are to get down). [[Special:Contributions/172.70.91.78|172.70.91.78]] 05:00, 16 August 2022 (UTC)<br />
:::Me again. I hadn't checked that the transcript (which said it was switch #8) was correct. Have now, and found it to be wrong. Have hence also just corrected the Transcript. So I'm gonna assume your 11-choose-3 is entirely correct after all. ;) [[Special:Contributions/172.70.91.78|172.70.91.78]] 05:08, 16 August 2022 (UTC)<br />
<br />
To whomever did [https://www.explainxkcd.com/wiki/index.php?title=2659:_Unreliable_Connection&diff=292862&oldid=292861], doesn't [https://drops.dagstuhl.de/opus/volltexte/2018/8817/pdf/LIPIcs-FUN-2018-26.pdf] prove that symmetrical configurations nearly identical to those shown can produce uniform distributions? They seem to show it's just a matter of horizontal pin spacing. However, I for one can not verify the proof, which uses unusual (novel?) non-Unicode math notation, and a fairly opaque method of proof. [[Special:Contributions/172.70.211.134|172.70.211.134]] 00:07, 16 August 2022 (UTC)<br />
:Not sure, but [https://ja.wikipedia.org/wiki/%E9%87%98%E8%AA%BF%E6%95%B4 this Japanese Wikipedia article] is fascinating. [[Special:Contributions/172.70.206.213|172.70.206.213]] 01:51, 16 August 2022 (UTC)<br />
:Please see section 3.5 on pp. 16-18 of the currently first reference [https://arxiv.org/pdf/1601.05706.pdf]. I am particularly intrigued by, "Open Problem 2: Is every uniform distribution of output probabilities of the form 1/2<sup>k</sup> constructible by a 50-50 Pachinko?" on p. 18. However I haven't dived in enough to even know where the parentheses are supposed to be in that expression, yet. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 17:27, 16 August 2022 (UTC)<br />
: Good question! https://ibb.co/sRwGwB9 don't look triangular, but it seems the proof might suggest much more triangular solutions. Worth thinking about! [[Special:Contributions/172.69.33.115|172.69.33.115]] 21:24, 16 August 2022 (UTC)<br />
<br />
What is the chance that the ball will bounce off the first pin, go down the outside of the pins and miss all the switches?<br />
:Probably quite high if it's a bouncy ball. With idealized physics though it'd just hit the leftmost/rightmost switch. [[Special:Contributions/172.70.254.127|172.70.254.127]] 00:45, 16 August 2022 (UTC)<br />
<br />
I would describe the device as a https://en.wikipedia.org/wiki/Galton_board. [[Special:Contributions/172.70.230.109|172.70.230.109]] 00:30, 16 August 2022 (UTC)<br />
<br />
I was watching the photo and hover-over text and the image disappeared and "Unreliable Connection" showed up in its place. I don't know how often this happens.<br />
: Very neat if not a fluke! Can anyone replicate this experience on https://xkcd.com ? [[Special:Contributions/172.70.211.134|172.70.211.134]] 14:21, 16 August 2022 (UTC)<br />
<br />
"An added source of humour is that Randall could likely achieve the same effect by looking through the router's settings - which most modern ones have a feature to turn on and off at scheduled times - or via purchasing a smart power strip." But by using these other methods, the connection would still be reliable. If it goes out at regular or pre-scheduled intervals then you know when it will be available or not, hence reliable. I think the joke here is that the contraption does in fact make the connection unreliable. [[Special:Contributions/172.70.114.77|172.70.114.77]] 14:18, 16 August 2022 (UTC)<br />
: Addressed at [https://www.explainxkcd.com/wiki/index.php?title=2659:_Unreliable_Connection&diff=292926&oldid=292924]. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 14:44, 16 August 2022 (UTC)<br />
:(Edit conflicted by at least the above, but my answer to the same question...) From a user POV, unless they happen to know that at 11:53 each day (and 12:14, 15:02, 15:07, 16:31, etc...) the scheduler disables tracfic for one (or two, or three) minutes, it is still unreliable, if ultimately predictable ''once you know'' the schedule, having seen it go round a few times and taken note. Similarly a timered power-strip could be used (or even several, in serial, the two or three daily interventions by the first also stopping and delaying the subsequent strips' interventions, making their timings uneven, further down the chain) and until you got the pattern it might as well be 'random', not entirely deterministic. (I'm wondering about some OR-gate-like/etc implementation, so power can pass by at least one parallel timer-shut-off to maintain power at the lower levels while ''some'' mid-way timers get depowered and thus 'shuffled' in interesting ways, and the resulting single output is governed by an intricate multi-dependent set of routes, but I bet an electrician would be wary about wiring that up...)<br />
:You could hack (or patch) the management firmware to be a bit more (pseudo)random about it, though it would still be pseudorandom LFSR/Xorshift with a (long) repetition cycle.<br />
:Or make it dependant upon an external factor (if the modulo 12 of the cumulative sum of all observed packet-destination IPs is zero, shut off for the five times the prior modulo 12 test value, in seconds..?), but that's ''practically'' the pachinko solution but with software hacking rather than hardware-making/hacking as per the comic.<br />
:More effort is needed to make it ultimately unpredictable, but it can still be considered unreliable if it goes out just when you 'want' it.... [[Special:Contributions/172.70.85.5|172.70.85.5]] 15:02, 16 August 2022 (UTC)<br />
<br />
For real though, isn't this kind of a good idea? [[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 14:34, 16 August 2022 (UTC)<br />
:Talk to edtech people in the {{w|MOOC}} space and they will tell you asynchronous is worth it, but talk to people who study educational quality factors like time to receive answers to unanticipated questions, and they will have different ideas. [[User:Liv2splain|Liv2splain]] ([[User talk:Liv2splain|talk]]) 14:44, 16 August 2022 (UTC)<br />
<br />
Does anyone have an openWRT (or other) implementation of this feature yet?<br />
:You can induce it on stock firmware without reflashing, but you need to know the parameters like how often balls come out of the hopper, and what exactly the off switch does. [[Special:Contributions/172.70.214.95|172.70.214.95]] 00:27, 17 August 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2659:_Unreliable_Connection&diff=2928482659: Unreliable Connection2022-08-15T23:10:19Z<p>172.70.214.95: https://arxiv.org/pdf/1601.05706.pdf</p>
<hr />
<div>{{comic<br />
| number = 2659<br />
| date = August 15, 2022<br />
| title = Unreliable Connection<br />
| image = unreliable_connection.png<br />
| titletext = NEGATIVE REVIEWS MENTION: Unreliable internet. POSITIVE REVIEWS MENTION: Unreliable internet.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by ROUND TRIP LATENCY BACKOFF. Do NOT delete this tag too soon.}}<br />
<br />
In this comic, [[Randall]] solves the social problem of demands for {{w|synchronous conferencing|synchronous teleconferencing}} with a deliberately less than optimal internet device which causes {{w|Asynchronous communication|asynchronous}} methods of communication to be relatively more reliable and efficient for personal use. The device appears to be an automated version of {{w|Jin Akiyama}}'s mathematical {{w|pachinko}} device[https://arxiv.org/pdf/1601.05706.pdf] with a series eleven "on" and one "off" switches at the bottom to be pressed by falling balls. This is funny because such a device could likely more easily be implemented in the {{w|firmware}} of the internet or WiFi {{w|modem}} or {{w|Router (computing)|router}}s.<br />
<br />
We don't know the frequency with which new balls are dropped, or the exact probability of each hitting the off switch (which is off-center and thus less likely to be pressed if it were central, based on the configuration shown) so we can't estimate the frequency with which the device is likely to trigger {{w|Session Initiation Protocol}}, {{w|Transmission Control Protocol}}, or similar {{w|Timeout (computing)|timeout}} conditions that would likely close synchronous {{w|VOIP}}, video conferencing, and e.g. {{w|VRChat}} connections. Even if such connections were to survive the induced service interruptions, the {{w|application layer}} call or teleconference quality would suffer during them. The device may cause interruptions rarely enough that the connection is usable for casual purposes, but the user can still reasonably claim that it's unreliable to get out of online obligations.<br />
<br />
The title text reflects on the mild paradox that a nominally unreliable internet connection has advantages for those whose communication schedules, volume, or style preferences make synchronous teleconferencing less practical.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
{{comic discussion}}</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2658:_Coffee_Cup_Holes&diff=2927882658: Coffee Cup Holes2022-08-14T23:39:32Z<p>172.70.214.95: /* Transcript */ physics</p>
<hr />
<div>{{comic<br />
| number = 2658<br />
| date = August 12, 2022<br />
| title = Coffee Cup Holes<br />
| image = coffee_cup_holes.png<br />
| titletext = Theoretical physicist: At the Planck length, uncountably many.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a CAFFEINE MOLECULE WITH A HOLE DRILLED IN ITS SIDE. Do NOT delete this tag too soon.}}<br />
<br />
This comic depicts people in different fields of study answering the question, "How many holes are there in a coffee cup?" This question has different interpretations depending on the definition of a hole.<br />
<br />
[[File:Mug and Torus morph.gif|thumb|200px|The coffee mug and donut shown in this animation both have topological genus one.]]<br />
<br />
[[Ponytail]], a {{w|topology|topologist}}, states the coffee cup belongs in the {{w|Genus (mathematics)#Topology|genus}} of one hole. A common joke is that topologists can't tell the difference between a coffee cup and a donut since they're homeomorphic to each other — meaning they have the same genus. From the topologist's point of view, the coffee cup definitely has one hole. See [[2625: Field Topology]] for more information about topology.<br />
<br />
[[Hairy]], a normal person, is not sure (the acronym "IDK" stands for "I don't know") and asks for clarification about whether the opening at the top counts as a hole. This shows flaws in the question, which suffers from the mathematically imprecise, ambiguous common usage of the word hole. Topologists would refer to the opening as a concavity, not a hole, and while they consider such geometrical properties generally outside their field, most practical applications of topology do involve geometric components.<br />
<br />
[[File:Double torus illustration.png|thumb|left|200px|A genus two surface]]<br />
<br />
[[Hairbun]], a philosopher, answers the question with an elucidating counter-question, considering a hypothetical scenario. Drilling a new hole should increase the number of holes by one. After the hole has been drilled, a common teacup or mug has two holes according to topologists. Therefore, the philosopher's question requires the original questioner to reveal the answer to their own question. (Also, she asks how many holes there are ''now'' rather than ''after we do that'', an ambiguity.)<br />
<br />
[[Image:Point cloud torus.gif|thumb|200px|A point cloud of a genus one surface]]<br />
<br />
[[Cueball]], a chemist, looks at the coffee in the cup on a molecular level, which means it has very many holes: 1,000,000,000,000,000,000,000 (10<sup>21</sup> or 1 sextillion) “in the [https://chemapps.stolaf.edu/jmol/jmol.php?model=CN1C%3DNC2%3DC1C%28%3DO%29N%28C%28%3DO%29N2C%29C caffeine] alone.” One molecule of caffeine has two rings of bonds with holes in them, so Cueball is talking about 500 quintillion molecules, or 0.00083 {{w|mole (unit)|moles}}. As the molecular mass of {{w|caffeine}} is about 194 grams per mole, [[Randall]] must think that the mass of caffeine in a typical cup of coffee is 161 milligrams. The coffee could have other holes, depending on the type of coffee; for example, espresso contains significant amounts of niacin and riboflavin, which have one and three rings in their chemical structure, respectively. However, bonds are not sticks as portrayed in many molecular models. The "holes" in the middle of a molecule's rings are not completely empty but instead merely have lower electron probability density through the middle than other parts of the bonds. So the point-cloud duality of {{w|Bonding molecular orbital|electron orbitals and bonds}} might not satisfy a topologist's, normal person's, or philosopher's criteria for a connected substrate in which holes may be formed.<br />
<br />
[[Image:World lines and world sheet.svg|left|thumb|200px|{{w|String theory}} describes the {{w|worldline}}s of point-like particles as {{w|worldsheet}}s of "closed strings," forming topological holes.]]<br />
<br />
In the title text, a theoretical physicist looks even deeper, at the subatomic scale of {{w|Planck units}}. Since fundamental particle interaction is governed by fundamental forces and collision (per the {{w|Pauli exclusion principle}}) instead of tensile or ductile solid connectedness, the theoretical physicist posits that any definition providing for a single hole would also describe a number of holes akin to the factorial of the number of particles in the universe,[https://tel.archives-ouvertes.fr/tel-02341882/document] or at least within the cup's {{w|light cone}}, which is a number impractical to accurately count, but not uncountable in a mathematical sense.<br />
<br />
Part of the joke could be that all five methods of inquiry don't discern between a {{w|cup}} (as described) and a {{w|mug}} (as depicted), the cliché being that topologists are unusual because they don't. Or, as many people use the terms interchangeably, Randall may too. A cup without a looped handle is topologically equivalent to either a flat disk (if the cup' walls are assumed to have no thickness) or an amorphous sphere (if the cup's walls have thickness).<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[The first panel has text only. The "Q:" below is a large letter Q representing a question, not a character name.]<br />
:Q:<br />
:How many holes are there in a coffee cup?<br />
<br />
:[Each of the next four panels has a caption at the top to indicate the kind of person answering the question.]<br />
:Caption: Topologist<br />
:[Ponytail stands holding a coffee mug.]<br />
:Ponytail: One.<br />
<br />
:Caption: Normal person<br />
:[Hairy stands to the right of Ponytail, holding a coffee mug at an angle to look into it.]<br />
:Hairy: IDK, does the opening count as a hole?<br />
<br />
:Caption: Philosopher<br />
:[Hairbun is shown in closeup, with two drawings of coffee mugs to her left.]<br />
:Hairbun: To answer that question, consider another: If we drill a hole in the side, how many holes are there now?<br />
<br />
:Caption: Chemist<br />
:[Cueball stands with a drawing of a caffeine molecule above him and to the right.]<br />
:Cueball: 10<sup>21</sup> in the caffeine alone<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Hairy]]<br />
[[Category:Comics featuring Hairbun]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Math]]<br />
[[Category:Food]]<br />
[[Category:Chemistry]]<br />
[[Category:Philosophy]]<br />
[[Category:Physics]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2658:_Coffee_Cup_Holes&diff=2927052658: Coffee Cup Holes2022-08-13T04:20:03Z<p>172.70.214.95: /* Explanation */ move up</p>
<hr />
<div>{{comic<br />
| number = 2658<br />
| date = August 12, 2022<br />
| title = Coffee Cup Holes<br />
| image = coffee_cup_holes.png<br />
| titletext = Theoretical physicist: At the Planck length, uncountably many.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a CAFFEINE MOLECULE WITH A HOLE DRILLED IN ITS SIDE. Do NOT delete this tag too soon.}}<br />
<br />
[[File:Mug and Torus morph.gif|thumb|150px|The coffee cup and donut shown in this animation both have genus one.]]<br />
<br />
This comic depicts multiple people in different fields of study answering the question “How many holes are there in a coffee cup?” This question can have multiple interpretations, in particular concerning the definition of a hole.<br />
<br />
[[Ponytail]], a {{w|topology|topologist}}, states the coffee cup belongs in the {{w|Genus (mathematics)#Topology|genus}} of one hole. A common joke is that topologists can't tell the difference between a coffee cup and a donut since they're homeomorphic to each other — they have the same genus. <!-- From the point of view of (reduced) [https://en.wikipedia.org/wiki/Homology_(mathematics)#Informal_examples homology] (in this case also homotopy), the coffee cup has one 1 dimensional hole and no other dimensional holes. Hence.... -- Way too jargony, topology is too obscure to reasonably ask this of readers. --> From the topologist's point of view, the coffee cup definitely has one hole. See [[2625: Field Topology]] for more information about topology. <br />
<br />
[[Hairy]], a normal person, asks for clarification about whether the opening at the top counts as a hole. This shows flaws in the question, which suffers from the mathematically imprecise, ambiguous common usage of the word hole. Topologists would refer to the opening as a concavity, not a hole, and while they consider such geometrical properties generally outside their field, most practical applications of topolgy do involve geometrical components.{{cn}}<br />
<br />
[[File:Double torus illustration.png|thumb|150px|A genus-2 surface]]<br />
<br />
[[Hairbun]], a philosopher, answers the question with an elucidating counter-question, considering a hypothetical scenario. Drilling a new hole should increase the number of holes by one, and after the hole has been drilled, a common teacup or mug has two holes according to topologists. Since drilling a hole increases the number of holes by one, the philosopher's question requires the original questioner to reveal the answer to their own question.<br />
<br />
[[Cueball]], a chemist, looks at the cup on a molecular level, which naturally means it has lots and lots of holes: 1,000,000,000,000,000,000,000 (10<sup>21</sup> or 1 sextillion) “in the caffeine alone.” The implication is that there are more in the cup itself, depending on what material it’s made out of. Also, the coffee itself could have other holes, depending on the type of coffee. For example, espresso contains significant amounts of niacin and riboflavin, each of which has at least one hole in its chemical structure. However, this ignores the fact that bonds are not discrete sticks as portrayed in many molecular models. The "holes" in the middle of a caffeine molecule are not completely empty but instead merely have lower electron densities/probabilities. In a {{w|space-filling model}}, a caffeine molecule has zero holes. So the point-cloud duality of electron orbitals and bonds might not satisfy a topologist's, normal person's, or philosopher's criteria for a connected substrate in which holes may be formed.<br />
<br />
In the title text, the theoretical physicist looks even deeper, at a subatomic level. Since fundamental particle interaction is governed by fundamental forces and collision instead of tensile or ductile solid connectedness, the theoretical physicist posits that any definition providing for a single hole would also describe a number of holes akin to the factorial of the number of particles in the universe, or at least within the cup's {{w|light cone}}, which is a number impractical to accurately count, but not uncountable in a mathematical sense.<br />
<br />
Part of the joke is that all five methods of inquiry don't discern between a cup (as described) and a mug (as depicted), the original cliché being that topologists are unusual because they don't.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[The first panel has text only. The "Q:" below is a large letter Q representing a question, not a character name.]<br />
:Q:<br />
:How many holes are there in a coffee cup?<br />
<br />
:[Each of the next four panels has a caption at the top to indicate the kind of person answering the question.]<br />
:Caption: Topologist<br />
:[Ponytail stands holding a coffee mug.]<br />
:Ponytail: One.<br />
<br />
:Caption: Normal person<br />
:[Hairy stands to the right of Ponytail, holding a coffee mug at an angle to look into it.]<br />
:Hairy: IDK, does the opening count as a hole?<br />
<br />
:Caption: Philosopher<br />
:[Hairbun is shown in closeup, with two drawings of coffee mugs to her left.]<br />
:Hairbun: To answer that question, consider another: If we drill a hole in the side, how many holes are there now?<br />
<br />
:Caption: Chemist<br />
:[Cueball stands with a drawing of a caffeine molecule above him and to the right.]<br />
:Cueball: 10<sup>21</sup> in the caffeine alone<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Hairy]]<br />
[[Category:Comics featuring Hairbun]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Math]]<br />
[[Category:Food]]<br />
[[Category:Science]]<br />
[[Category:Chemistry]]<br />
[[Category:Philosophy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2658:_Coffee_Cup_Holes&diff=2927042658: Coffee Cup Holes2022-08-13T04:18:46Z<p>172.70.214.95: /* Explanation */ homogenize</p>
<hr />
<div>{{comic<br />
| number = 2658<br />
| date = August 12, 2022<br />
| title = Coffee Cup Holes<br />
| image = coffee_cup_holes.png<br />
| titletext = Theoretical physicist: At the Planck length, uncountably many.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a CAFFEINE MOLECULE WITH A HOLE DRILLED IN ITS SIDE. Do NOT delete this tag too soon.}}<br />
<br />
This comic depicts multiple people in different fields of study answering the question “How many holes are there in a coffee cup?” This question can have multiple interpretations, in particular concerning the definition of a hole.<br />
<br />
[[File:Mug and Torus morph.gif|thumb|150px|The coffee cup and donut shown in this animation both have genus one.]]<br />
<br />
[[Ponytail]], a {{w|topology|topologist}}, states the coffee cup belongs in the {{w|Genus (mathematics)#Topology|genus}} of one hole. A common joke is that topologists can't tell the difference between a coffee cup and a donut since they're homeomorphic to each other — they have the same genus. <!-- From the point of view of (reduced) [https://en.wikipedia.org/wiki/Homology_(mathematics)#Informal_examples homology] (in this case also homotopy), the coffee cup has one 1 dimensional hole and no other dimensional holes. Hence.... -- Way too jargony, topology is too obscure to reasonably ask this of readers. --> From the topologist's point of view, the coffee cup definitely has one hole. See [[2625: Field Topology]] for more information about topology. <br />
<br />
[[Hairy]], a normal person, asks for clarification about whether the opening at the top counts as a hole. This shows flaws in the question, which suffers from the mathematically imprecise, ambiguous common usage of the word hole. Topologists would refer to the opening as a concavity, not a hole, and while they consider such geometrical properties generally outside their field, most practical applications of topolgy do involve geometrical components.{{cn}}<br />
<br />
[[File:Double torus illustration.png|thumb|150px|A genus-2 surface]]<br />
<br />
[[Hairbun]], a philosopher, answers the question with an elucidating counter-question, considering a hypothetical scenario. Drilling a new hole should increase the number of holes by one, and after the hole has been drilled, a common teacup or mug has two holes according to topologists. Since drilling a hole increases the number of holes by one, the philosopher's question requires the original questioner to reveal the answer to their own question.<br />
<br />
[[Cueball]], a chemist, looks at the cup on a molecular level, which naturally means it has lots and lots of holes: 1,000,000,000,000,000,000,000 (10<sup>21</sup> or 1 sextillion) “in the caffeine alone.” The implication is that there are more in the cup itself, depending on what material it’s made out of. Also, the coffee itself could have other holes, depending on the type of coffee. For example, espresso contains significant amounts of niacin and riboflavin, each of which has at least one hole in its chemical structure. However, this ignores the fact that bonds are not discrete sticks as portrayed in many molecular models. The "holes" in the middle of a caffeine molecule are not completely empty but instead merely have lower electron densities/probabilities. In a {{w|space-filling model}}, a caffeine molecule has zero holes. So the point-cloud duality of electron orbitals and bonds might not satisfy a topologist's, normal person's, or philosopher's criteria for a connected substrate in which holes may be formed.<br />
<br />
In the title text, the theoretical physicist looks even deeper, at a subatomic level. Since fundamental particle interaction is governed by fundamental forces and collision instead of tensile or ductile solid connectedness, the theoretical physicist posits that any definition providing for a single hole would also describe a number of holes akin to the factorial of the number of particles in the universe, or at least within the cup's {{w|light cone}}, which is a number impractical to accurately count, but not uncountable in a mathematical sense.<br />
<br />
Part of the joke is that all five methods of inquiry don't discern between a cup (as described) and a mug (as depicted), the original cliché being that topologists are unusual because they don't.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[The first panel has text only. The "Q:" below is a large letter Q representing a question, not a character name.]<br />
:Q:<br />
:How many holes are there in a coffee cup?<br />
<br />
:[Each of the next four panels has a caption at the top to indicate the kind of person answering the question.]<br />
:Caption: Topologist<br />
:[Ponytail stands holding a coffee mug.]<br />
:Ponytail: One.<br />
<br />
:Caption: Normal person<br />
:[Hairy stands to the right of Ponytail, holding a coffee mug at an angle to look into it.]<br />
:Hairy: IDK, does the opening count as a hole?<br />
<br />
:Caption: Philosopher<br />
:[Hairbun is shown in closeup, with two drawings of coffee mugs to her left.]<br />
:Hairbun: To answer that question, consider another: If we drill a hole in the side, how many holes are there now?<br />
<br />
:Caption: Chemist<br />
:[Cueball stands with a drawing of a caffeine molecule above him and to the right.]<br />
:Cueball: 10<sup>21</sup> in the caffeine alone<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Hairy]]<br />
[[Category:Comics featuring Hairbun]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Math]]<br />
[[Category:Food]]<br />
[[Category:Science]]<br />
[[Category:Chemistry]]<br />
[[Category:Philosophy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2658:_Coffee_Cup_Holes&diff=2927032658: Coffee Cup Holes2022-08-13T04:17:30Z<p>172.70.214.95: /* Explanation */ animation and depiction</p>
<hr />
<div>{{comic<br />
| number = 2658<br />
| date = August 12, 2022<br />
| title = Coffee Cup Holes<br />
| image = coffee_cup_holes.png<br />
| titletext = Theoretical physicist: At the Planck length, uncountably many.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a CAFFEINE MOLECULE WITH A HOLE DRILLED IN ITS SIDE. Do NOT delete this tag too soon.}}<br />
<br />
This comic depicts multiple people in different fields of study answering the question “How many holes are there in a coffee cup?” This question can have multiple interpretations, in particular concerning the definition of a hole.<br />
<br />
[[File:Mug and Torus morph.gif|thumb|The coffee cup and donut shown in this animation both have genus one.]]<br />
<br />
[[Ponytail]], a {{w|topology|topologist}}, states the coffee cup belongs in the {{w|Genus (mathematics)#Topology|genus}} of one hole. A common joke is that topologists can't tell the difference between a coffee cup and a donut since they're homeomorphic to each other — they have the same genus. <!-- From the point of view of (reduced) [https://en.wikipedia.org/wiki/Homology_(mathematics)#Informal_examples homology] (in this case also homotopy), the coffee cup has one 1 dimensional hole and no other dimensional holes. Hence.... -- Way too jargony, topology is too obscure to reasonably ask this of readers. --> From the topologist's point of view, the coffee cup definitely has one hole. See [[2625: Field Topology]] for more information about topology. <br />
<br />
[[Hairy]], a normal person, asks for clarification about whether the opening at the top counts as a hole. This shows flaws in the question, which suffers from the mathematically imprecise, ambiguous common usage of the word hole. Topologists would refer to the opening as a concavity, not a hole, and while they consider such geometrical properties generally outside their field, most practical applications of topolgy do involve geometrical components.{{cn}}<br />
<br />
[[File:Double torus illustration.png|thumb|A genus-2 surface]]<br />
<br />
[[Hairbun]], a philosopher, answers the question with an elucidating counter-question, considering a hypothetical scenario. Drilling a new hole should increase the number of holes by one, and after the hole has been drilled, a common teacup or mug has two holes according to topologists. Since drilling a hole increases the number of holes by one, the philosopher's question requires the original questioner to reveal the answer to their own question.<br />
<br />
[[Cueball]], a chemist, looks at the cup on a molecular level, which naturally means it has lots and lots of holes: 1,000,000,000,000,000,000,000 (10<sup>21</sup> or 1 sextillion) “in the caffeine alone.” The implication is that there are more in the cup itself, depending on what material it’s made out of. Also, the coffee itself could have other holes, depending on the type of coffee. For example, espresso contains significant amounts of niacin and riboflavin, each of which has at least one hole in its chemical structure. However, this ignores the fact that bonds are not discrete sticks as portrayed in many molecular models. The "holes" in the middle of a caffeine molecule are not completely empty but instead merely have lower electron densities/probabilities. In a {{w|space-filling model}}, a caffeine molecule has zero holes. So the point-cloud duality of electron orbitals and bonds might not satisfy a topologist's, normal person's, or philosopher's criteria for a connected substrate in which holes may be formed.<br />
<br />
In the title text, the theoretical physicist looks even deeper, at a subatomic level. Since fundamental particle interaction is governed by fundamental forces and collision instead of tensile or ductile solid connectedness, the theoretical physicist posits that any definition providing for a single hole would also describe a number of holes akin to the factorial of the number of particles in the universe, or at least within the cup's {{w|light cone}}, which is a number impractical to accurately count, but not uncountable in a mathematical sense.<br />
<br />
Part of the joke is that all five methods of inquiry don't discern between a cup (as described) and a mug (as depicted), the original cliché being that topologists are unusual because they don't.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[The first panel has text only. The "Q:" below is a large letter Q representing a question, not a character name.]<br />
:Q:<br />
:How many holes are there in a coffee cup?<br />
<br />
:[Each of the next four panels has a caption at the top to indicate the kind of person answering the question.]<br />
:Caption: Topologist<br />
:[Ponytail stands holding a coffee mug.]<br />
:Ponytail: One.<br />
<br />
:Caption: Normal person<br />
:[Hairy stands to the right of Ponytail, holding a coffee mug at an angle to look into it.]<br />
:Hairy: IDK, does the opening count as a hole?<br />
<br />
:Caption: Philosopher<br />
:[Hairbun is shown in closeup, with two drawings of coffee mugs to her left.]<br />
:Hairbun: To answer that question, consider another: If we drill a hole in the side, how many holes are there now?<br />
<br />
:Caption: Chemist<br />
:[Cueball stands with a drawing of a caffeine molecule above him and to the right.]<br />
:Cueball: 10<sup>21</sup> in the caffeine alone<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Hairy]]<br />
[[Category:Comics featuring Hairbun]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Math]]<br />
[[Category:Food]]<br />
[[Category:Science]]<br />
[[Category:Chemistry]]<br />
[[Category:Philosophy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2654:_Chemtrails&diff=2919742654: Chemtrails2022-08-04T11:08:41Z<p>172.70.214.95: /* Explanation */ someone didn't click on the links</p>
<hr />
<div>{{comic<br />
| number = 2654<br />
| date = August 3, 2022<br />
| title = Chemtrails<br />
| image = chemtrails.png<br />
| titletext = Ants have reverse chemtrails--regular citizens spraying chemicals everywhere they go to control the government.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by an INKJET PRINTER FILLED WITH PERFUME. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Ant}}s, studied along with other insects by {{w|entomologist}}s, leave trails of signalling secretions such as {{w|pheromones}}, natural chemicals that they emit along the trail to and from food sources and other events. These chemical trails guide other ants in the colony to return to food, but are not generally refered to as chemtrails by biologists except informally. <br />
<br />
[[Cueball]] is intentionally conflating these with {{w|chemtrails}}, the subject of a conspiracy theory that the government controls the population by spraying toxic or mind-/body-transformative chemicals from high-flying aircraft. This myth may be partly based on the practice of {{w|cloud seeding}}, which uses chemical flares containing silver nitrate to attempt to increase precipitation,[https://www.vox.com/videos/23290459/cloud-seeding-manmade-rain-future-perfect] on studies of chemical mind control among ants,[https://www.sciencedirect.com/science/article/abs/pii/S0022191016301640] or both. Please see also [[1677: Contrails]] — contrail is short for "condensation trail" which are cloud-like lines in the sky created by jet engines. Such linear cloud-formations arise from temperature and pressure disturbances of the passing engines rather than any deliberate release, but are highly visible (in the right cloud-free conditions that produce otherwise clear skies) to those who live under busy flightpaths, and may have the appearance of some active "spraying" activity.<br />
<br />
Chemical manipulation of unwitting people is not uncommon, but is more a general mood-enhancing effect that works within a specific location[https://www.businessnewsdaily.com/3469-smells-shoppers-spend-more.html] and doesn't involve high-altitude airplanes. There is very little evidence that sophisticated mind control posited by chemtrail conspiracists is possible.{{Actual citation needed}}<br />
<br />
[[Ponytail]] specifically studies ant navigation, conceivably as a professional entomologist who once worked with an editor who inserted the word "chemtrails" in one of her [https://link.springer.com/article/10.1007/s00359-019-01363-z comparative physiology] or [https://link.springer.com/article/10.1007/s10071-020-01354-7 ''Animal Cognition''] drafts competing before a peer review panel with papers by [https://bio.kuleuven.be/ento/pdfs/billen_procnev_2006_signal_variety.pdf Johan Bilen] of the Leuven University Zoological Institute and Harvard's [https://www.hup.harvard.edu/catalog.php?isbn=9780674045880 Rüdiger Wehner]. [[Cueball]] knows she will be annoyed when he tells her, "So, I hear you're really into chemtrails?" Indeed, he gets the reaction he hoped for when she objects strongly and rejects this with a loud, "'''No!!'''" Terminology is often a sore spot for those who study "slave-making" socially parasitic species.[https://evolve.community.uaf.edu/2015/04/23/emantcipation-when-captured-ants-rise-against-their-captors/] [[Randall]] writes in the caption that this is how to annoy people like Ponytail. Whether ant gland secretion signalling is {{w|Turing completeness|Turing-equivalent}} was explored in Douglas Hofstadter's ''{{w|Gödel, Escher, Bach|Gödel, Escher, Bach: an Eternal Golden Braid}}''.<br />
<br />
The title text contrasts individual ants instinctively deciding how the whole colony behaves by using chemicals to indicate routes to food or dangers to motivate the colony to react to their individual experiences, with the human fear of loss of personal independence by being regulated by otherwise disconnected ruling elites, as depicted in the ant-technology interaction speculative fiction-themed rock music video by the band ''Placebo'' entitled [https://www.youtube.com/watch?v=fISvc-yUU1A "Infrared."]<br />
<br />
Ants are a recurring theme, as are those who study them. See for instance [[1610: Fire Ants]]. Chemtrails was also the subject of [[966: Jet Fuel]], [[1677: Contrails]], and were mentioned in [[1803: Location Reviews]]. This comic has a similar format to [[2036: Edgelord]]: a simple one-panel interaction consisting of a (likely deliberate) misuse of a term in regards to a professional's work, followed immediately by the professional's upset outburst, and Randall's caption spelling out "How to annoy" the professional. Both of these seems to be related to Randall's [[:Category:My Hobby|hobbies]], as this is something he seems to think about a lot — how to annoy specific groups of people, which is necessary information for minimizing overall annoyance production.{{cn}}<br />
<br />
==Transcript==<br />
:[Cueball stands talking to Ponytail, who has her arms raised and has small lines above her head to indicate annoyance.]<br />
:Cueball: So, I hear you're really into chemtrails?<br />
:Ponytail: '''''No!!'''''<br />
<br />
:[Caption below the panel:]<br />
:How to annoy entomologists who study ant navigation<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Animals]]<br />
[[Category:Biology]]<br />
[[Category:Puns]]<br />
[[Category:Conspiracy theory]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2654:_Chemtrails&diff=2919372654: Chemtrails2022-08-04T08:38:26Z<p>172.70.214.95: /* Explanation */ edit conflict, will backfill any clobbers I promise</p>
<hr />
<div>{{comic<br />
| number = 2654<br />
| date = August 3, 2022<br />
| title = Chemtrails<br />
| image = chemtrails.png<br />
| titletext = Ants have reverse chemtrails--regular citizens spraying chemicals everywhere they go to control the government.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by an INKJET PRINTER FILLED WITH PERFUME. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Ant}}s, studied along with other insects by {{w|entomologist}}s, leave trails of signalling secretions such as {{w|pheromones}}, natural chemicals that they emit along the trail to and from food sources and other events. These chemical trails guide other ants in the colony to return to food, but are not generally refered to as chemtrails by biologists except informally. Please see also [[1677: Contrails]] — contrail is short for "condensation trail" which are cloud-like lines in the sky created by jet engines.<br />
<br />
[[Cueball]] is intentionally conflating these with {{w|chemtrails}}, the subject of a conspiracy theory that the government controls the population by spraying toxic or mind-/body-transformative chemicals from high-flying aircraft. This myth may be based on the practice of {{w|cloud seeding}}, which uses chemical flares containing silver nitrate to increase precipitation up to 15%.[https://www.vox.com/videos/23290459/cloud-seeding-manmade-rain-future-perfect] Chemical manipulation of unwitting people is not uncommon, but usually doesn't involve airplanes.[https://www.businessnewsdaily.com/3469-smells-shoppers-spend-more.html]<br />
<br />
[[Ponytail]] specifically studies ant navigation, possibly as a professional entomologist who once worked with an editor who inserted the word "chemtrails" in her papers on ant navigation by trail gland secretion signalling for navigation their vocabulary and grammar.[https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.186.3565&rep=rep1&type=pdf] [[Cueball]] knows she will be annoyed when he tells her "So, I hear you're really into chemtrails?" And he gets the reaction he hoped for when she objects strongly and rejects this with a loud '''No!!''' [[Randall]] then notes in the caption that this is thy way to annoy people like Ponytail. <br />
<br />
This comic has a similar format to [[2036: Edgelord]]: a simple one-panel interaction consisting of a (likely deliberate) misuse of a term in regards to a professional's work, followed immediately by the professional's upset outburst, and Randall's caption spelling out "How to annoy" the professional. Both of these seems to be related to Randall's [[:Category:My Hobby|hobbies]], as this is something he seems to think about a lot — how to annoy specific people.<br />
<br />
The title text contrasts that with the actual ants, where the individual insects instinctively decide how the whole colony behaves by using chemicals to indicate routes to food or dangers to motivate the colony to react to their individual experiences, the reverse of the human fear about personal independence being regulated by an otherwise disconnected ruling 'elite'.<br />
<br />
Ants is a recurring theme, as well as those that study them, see for instance [[1610: Fire Ants]]. Chemtrails was also the subject of [[966: Jet Fuel]] and [[1677: Contrails]] and was mentioned in [[1803: Location Reviews]].<br />
<br />
==Transcript==<br />
:[Cueball stands talking to Ponytail, who has her arms raised and has small lines above her head to indicate annoyance.]<br />
:Cueball: So, I hear you're really into chemtrails?<br />
:Ponytail: '''''No!!'''''<br />
<br />
:[Caption below the panel:]<br />
:How to annoy entomologists who study ant navigation<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Animals]]<br />
[[Category:Biology]]<br />
[[Category:Puns]]<br />
[[Category:Conspiracy theory]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2653:_Omnitaur&diff=2917952653: Omnitaur2022-08-02T17:01:00Z<p>172.70.214.95: /* Speculative implications */ adjust headings</p>
<hr />
<div>{{comic<br />
| number = 2653<br />
| date = August 1, 2022<br />
| title = Omnitaur<br />
| image = omnitaur.png<br />
| titletext = "My parents were both omnitaurs, which is how I got interested in recombination," said the normal human.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by AN OMNITAUR ZYGOTE IN A FETUS'S BODY. Do NOT delete this tag too soon.}}<br />
Omnitaur is an {{w|anagram}} of {{w|minotaur}}, a mythical creature that was part man, part bull. "{{wiktionary|omni}}" is a prefix that means "all" that is, for instance, known from the word {{w|omnivore}}, meaning 'all eating' as compared to {{w|carnivore}} or {{w|herbivore}} — only eating meat or plant respectively. Given the combination of animals used to create the omnitaur, it could be expected that it was also an omnivore. "taur" usually means "bull", but besides "minotaur" it also appears in "{{w|centaur}}", another mythical creature which has the upper body of a human and the lower body and legs of a horse. Thus Randall is taking "taur" to mean any hybrid of different animals.<br />
<br />
An "omnitaur" would suggest that it would encompass all real and mythical creatures, or perhaps some random assortment of such. In this instance, it appears to be a hybrid, or {{w|Chimera (genetics)|genetic chimera}}, combined from eleven different creatures: {{w|fish}}, {{w|lion}}, {{w|snake}}, {{w|shark}}, {{w|bull}}, {{w|dragon}} (a mythical creature in its own right), {{w|horse}}, {{w|leopard}}, {{w|Sheep|ram}} (male sheep), {{w|human}} and {{w|bird}}. Chimerism is not as uncommon at the genetic level, for example humans have about 145 genes (out of around 30,000) originating from bacteria, other single-celled organisms, and viruses.[https://www.science.org/content/article/humans-may-harbor-more-100-genes-other-organisms] {{w|Mitochondria}}, the powerhouse of the cell, were originally chimeric bacteria {{w|symbiosis|symbionts}}. But chimeras of larger organisms are rare, usually involving fraternal twins whose {{w|zygote}}s or {{w|embryo}}s combined, as in {{w|conjoined twins}} but resulting in less distinct {{w|phenotype|phenotypical}} expression. Artificial human chimeras with viruses, mice, pigs, and monkeys have been the subject of ethics controversies in recent years.[https://www.theguardian.com/technology/2019/aug/11/the-five-chimeras-human-monkey-hybrid-genetic][https://jme.bmj.com/content/45/7/440.abstract]<br />
<br />
The title text is a comment by a human whose parents were both omnitaurs. It would be funny that such parents would not produce offspring that was still omnitaur. It suggests that this may be the result of {{w|genetic recombination}}, which is the exchange of genetic material between different organisms leading to production of offspring with combinations of traits that differ from those found in either parent. In this case, seemingly, they inherited ''only'' the human elements of each parent, yet sufficient to develop into a whole human with no missing or chimeric elements. Both omnitaur parents probably had human germlines and compatible reproductive organs<br />
<br />
===Phenotypical chimeras in folklore===<br />
<br />
In addition to the minotaur and centaur, many other potential inspirations can be found in mythology, like the {{w|manticore}}, with a body of a lion and human face; a {{w|griffin}}, with a lion's body and a eagle's head; a {{w|mermaid}}, with a lower body of a fish and upper body of a human; a {{w|Hippocampus (mythology)|hippocampus}}, with the upper body of a horse and a lower body of a fish; a {{w|qilin}}, with a body that resembles both a horse and a dragon; or the mythological {{w|chimera (mythology)|chimera}}, for which the genetic chimera is named, which has lion, snake, and goat body parts. Ultimately, there are {{w|List of hybrid creatures in folklore|lots of hybrid creatures in mythology}} with {{w|phenotype}}s combined from multiple animals. Usually, genetic hybridization produces much more smoothly blended phenotypes instead of dividing the body into large distinctly chimeric regions, although {{w|Mosaic (genetics)|mosaicism}} of fur, skin or {{w|Heterochromia iridum|eyes}} can produce notable differences of hue or shade.<br />
<br />
In {{w|C. S. Lewis}}' {{w|The Chronicles of Narnia}}, the {{w|Magical_creatures_in_The_Chronicles_of_Narnia#Centaurs|centaurs}} are described as eating two meals &mdash; a huge roast meal "to satisfy the man stomach," and a meal of grass, "to satisfy the horse stomach," making it take quite some time for them to eat every morning. Since the omnitaur also has herbivore and omnivore (as well as carnivore) parts, this could further support the supposition that it is an omnivore, and it may similarly need multiple stomachs for these multiple appetites. It is unclear how compatible the various diets of its components would be (not least because 'fish,' 'snake' and 'bird' are quite unspecific, and it's hard to know what a dragon would eat) but it would likely need several meals, taking even longer to eat than the Centaur (plus the bird beak may slow the process down quite a bit.) In any case, a chimera of both warm and cold-blooded organisms seems unlikely to be viable, even at the organ level, let alone with combined surface phenotypes. The Chimera monster in {{w|Dungeons and Dragons}} is a "vile combination of goat, lion, and dragon, and features the heads of all three."[https://www.dndbeyond.com/monsters/16823-chimera]<br />
<br />
While chimeras occur in fantasy fiction, they also occur in science fiction, for example as {{w|cyborg}}s. The famous ''{{w|The Restaurant at the End of the Universe}}'' sequel to Douglas Adams' ''The Hitchhiker's Guide to the Galaxy'', had a pig with the mind and vocal tract of a human so it could articulate how much it wanted to be eaten.<br />
<br />
=== Title text suppositions ===<br />
<br />
Since the example depicted seems to be only <sup>1</sup>/<sub>11</sub> human, the odds of two parents as mentioned in the title text having fully human offspring would simplistically appear to be (<sup>1</sup>/<sub>11</sub>)<sup>11</sup>, or one chance in 285 billion. In reality, each physical part could not be the result of an equal recombinant genetic contribution, because the eleven animal chromosomes vary widely in number and size. Moreover, chimeras composed of multiple animals do not have chimeric children, because even with multiple sets of reproductive organs, the {{w|germline}}s are not combined. <br />
Therefore, both omnitaur parents likely had human germlines and compatible reproductive organs. [https://journals.biologists.com/dev/article/148/12/dev195792/269139/The-road-to-generating-transplantable-organs-from Interspecies blastocyst complementation,] used to create human chimera organs and cell lines in other animals, is usually limited to combining two organisms into one whose offspring are not hybridized if they are even viable, and usually without human germlines or reproductive organs (or human central nervous systems, assuaging a major ethical concern.)<br />
<br />
==Transcript==<br />
:[A creature, the Omnitaur, is shown. It is a four legged animal divided into 11 segments, each segment is from a different animal. An arrow goes to each section from a label, most of the labels are above the animal, but the fourth and seventh segments labels are below the animal. The animal has a fish tail and cat like hind legs. The torso is divided into four segments, the first and last of these with scales, but only the last of these also with sharp scales at the top. The second torso segment is white and smooth, the third also white but with hair both above and below, those above merges with the sharp scales of the fourth torso segment. The front legs are horse like, the lower neck is from an animal with dark spots, the upper neck has rams horns, which goes over in the central part of a human head, with ears and hair (drawn like a real human, not like a xkcd stick figure) and finally the front of the face is a bird with its eyes and a beak shown. The labels are given here in the order of the segment of the animal from the back to the front (disregarding weather the label is written above or below the animal:]<br />
:Fish<br />
:Lion<br />
:Snake<br />
:Shark<br />
:Bull<br />
:Dragon<br />
:Horse<br />
:Leopard<br />
:Ram<br />
:Human<br />
:Bird<br />
<br />
:[Caption below the panel:]<br />
:The Omnitaur<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Animals]]<br />
[[Category:Biology]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2653:_Omnitaur&diff=2917942653: Omnitaur2022-08-02T17:00:25Z<p>172.70.214.95: /* Mythical phenotypical chimeras */ adjust heading</p>
<hr />
<div>{{comic<br />
| number = 2653<br />
| date = August 1, 2022<br />
| title = Omnitaur<br />
| image = omnitaur.png<br />
| titletext = "My parents were both omnitaurs, which is how I got interested in recombination," said the normal human.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by AN OMNITAUR ZYGOTE IN A FETUS'S BODY. Do NOT delete this tag too soon.}}<br />
Omnitaur is an {{w|anagram}} of {{w|minotaur}}, a mythical creature that was part man, part bull. "{{wiktionary|omni}}" is a prefix that means "all" that is, for instance, known from the word {{w|omnivore}}, meaning 'all eating' as compared to {{w|carnivore}} or {{w|herbivore}} — only eating meat or plant respectively. Given the combination of animals used to create the omnitaur, it could be expected that it was also an omnivore. "taur" usually means "bull", but besides "minotaur" it also appears in "{{w|centaur}}", another mythical creature which has the upper body of a human and the lower body and legs of a horse. Thus Randall is taking "taur" to mean any hybrid of different animals.<br />
<br />
An "omnitaur" would suggest that it would encompass all real and mythical creatures, or perhaps some random assortment of such. In this instance, it appears to be a hybrid, or {{w|Chimera (genetics)|genetic chimera}}, combined from eleven different creatures: {{w|fish}}, {{w|lion}}, {{w|snake}}, {{w|shark}}, {{w|bull}}, {{w|dragon}} (a mythical creature in its own right), {{w|horse}}, {{w|leopard}}, {{w|Sheep|ram}} (male sheep), {{w|human}} and {{w|bird}}. Chimerism is not as uncommon at the genetic level, for example humans have about 145 genes (out of around 30,000) originating from bacteria, other single-celled organisms, and viruses.[https://www.science.org/content/article/humans-may-harbor-more-100-genes-other-organisms] {{w|Mitochondria}}, the powerhouse of the cell, were originally chimeric bacteria {{w|symbiosis|symbionts}}. But chimeras of larger organisms are rare, usually involving fraternal twins whose {{w|zygote}}s or {{w|embryo}}s combined, as in {{w|conjoined twins}} but resulting in less distinct {{w|phenotype|phenotypical}} expression. Artificial human chimeras with viruses, mice, pigs, and monkeys have been the subject of ethics controversies in recent years.[https://www.theguardian.com/technology/2019/aug/11/the-five-chimeras-human-monkey-hybrid-genetic][https://jme.bmj.com/content/45/7/440.abstract]<br />
<br />
The title text is a comment by a human whose parents were both omnitaurs. It would be funny that such parents would not produce offspring that was still omnitaur. It suggests that this may be the result of {{w|genetic recombination}}, which is the exchange of genetic material between different organisms leading to production of offspring with combinations of traits that differ from those found in either parent. In this case, seemingly, they inherited ''only'' the human elements of each parent, yet sufficient to develop into a whole human with no missing or chimeric elements. Both omnitaur parents probably had human germlines and compatible reproductive organs<br />
<br />
===Phenotypical chimeras in folklore===<br />
<br />
In addition to the minotaur and centaur, many other potential inspirations can be found in mythology, like the {{w|manticore}}, with a body of a lion and human face; a {{w|griffin}}, with a lion's body and a eagle's head; a {{w|mermaid}}, with a lower body of a fish and upper body of a human; a {{w|Hippocampus (mythology)|hippocampus}}, with the upper body of a horse and a lower body of a fish; a {{w|qilin}}, with a body that resembles both a horse and a dragon; or the mythological {{w|chimera (mythology)|chimera}}, for which the genetic chimera is named, which has lion, snake, and goat body parts. Ultimately, there are {{w|List of hybrid creatures in folklore|lots of hybrid creatures in mythology}} with {{w|phenotype}}s combined from multiple animals. Usually, genetic hybridization produces much more smoothly blended phenotypes instead of dividing the body into large distinctly chimeric regions, although {{w|Mosaic (genetics)|mosaicism}} of fur, skin or {{w|Heterochromia iridum|eyes}} can produce notable differences of hue or shade.<br />
<br />
===Speculative implications===<br />
<br />
In {{w|C. S. Lewis}}' {{w|The Chronicles of Narnia}}, the {{w|Magical_creatures_in_The_Chronicles_of_Narnia#Centaurs|centaurs}} are described as eating two meals &mdash; a huge roast meal "to satisfy the man stomach," and a meal of grass, "to satisfy the horse stomach," making it take quite some time for them to eat every morning. Since the omnitaur also has herbivore and omnivore (as well as carnivore) parts, this could further support the supposition that it is an omnivore, and it may similarly need multiple stomachs for these multiple appetites. It is unclear how compatible the various diets of its components would be (not least because 'fish,' 'snake' and 'bird' are quite unspecific, and it's hard to know what a dragon would eat) but it would likely need several meals, taking even longer to eat than the Centaur (plus the bird beak may slow the process down quite a bit.) In any case, a chimera of both warm and cold-blooded organisms seems unlikely to be viable, even at the organ level, let alone with combined surface phenotypes. The Chimera monster in {{w|Dungeons and Dragons}} is a "vile combination of goat, lion, and dragon, and features the heads of all three."[https://www.dndbeyond.com/monsters/16823-chimera]<br />
<br />
While chimeras occur in fantasy fiction, they also occur in science fiction, for example as {{w|cyborg}}s. The famous ''{{w|The Restaurant at the End of the Universe}}'' sequel to Douglas Adams' ''The Hitchhiker's Guide to the Galaxy'', had a pig with the mind and vocal tract of a human so it could articulate how much it wanted to be eaten.<br />
<br />
==== Title text suppositions ====<br />
<br />
Since the example depicted seems to be only <sup>1</sup>/<sub>11</sub> human, the odds of two parents as mentioned in the title text having fully human offspring would simplistically appear to be (<sup>1</sup>/<sub>11</sub>)<sup>11</sup>, or one chance in 285 billion. In reality, each physical part could not be the result of an equal recombinant genetic contribution, because the eleven animal chromosomes vary widely in number and size. Moreover, chimeras composed of multiple animals do not have chimeric children, because even with multiple sets of reproductive organs, the {{w|germline}}s are not combined. <br />
Therefore, both omnitaur parents likely had human germlines and compatible reproductive organs. [https://journals.biologists.com/dev/article/148/12/dev195792/269139/The-road-to-generating-transplantable-organs-from Interspecies blastocyst complementation,] used to create human chimera organs and cell lines in other animals, is usually limited to combining two organisms into one whose offspring are not hybridized if they are even viable, and usually without human germlines or reproductive organs (or human central nervous systems, assuaging a major ethical concern.)<br />
<br />
==Transcript==<br />
:[A creature, the Omnitaur, is shown. It is a four legged animal divided into 11 segments, each segment is from a different animal. An arrow goes to each section from a label, most of the labels are above the animal, but the fourth and seventh segments labels are below the animal. The animal has a fish tail and cat like hind legs. The torso is divided into four segments, the first and last of these with scales, but only the last of these also with sharp scales at the top. The second torso segment is white and smooth, the third also white but with hair both above and below, those above merges with the sharp scales of the fourth torso segment. The front legs are horse like, the lower neck is from an animal with dark spots, the upper neck has rams horns, which goes over in the central part of a human head, with ears and hair (drawn like a real human, not like a xkcd stick figure) and finally the front of the face is a bird with its eyes and a beak shown. The labels are given here in the order of the segment of the animal from the back to the front (disregarding weather the label is written above or below the animal:]<br />
:Fish<br />
:Lion<br />
:Snake<br />
:Shark<br />
:Bull<br />
:Dragon<br />
:Horse<br />
:Leopard<br />
:Ram<br />
:Human<br />
:Bird<br />
<br />
:[Caption below the panel:]<br />
:The Omnitaur<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Animals]]<br />
[[Category:Biology]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2653:_Omnitaur&diff=2917932653: Omnitaur2022-08-02T16:59:01Z<p>172.70.214.95: /* Speculative implications */ D&D</p>
<hr />
<div>{{comic<br />
| number = 2653<br />
| date = August 1, 2022<br />
| title = Omnitaur<br />
| image = omnitaur.png<br />
| titletext = "My parents were both omnitaurs, which is how I got interested in recombination," said the normal human.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by AN OMNITAUR ZYGOTE IN A FETUS'S BODY. Do NOT delete this tag too soon.}}<br />
Omnitaur is an {{w|anagram}} of {{w|minotaur}}, a mythical creature that was part man, part bull. "{{wiktionary|omni}}" is a prefix that means "all" that is, for instance, known from the word {{w|omnivore}}, meaning 'all eating' as compared to {{w|carnivore}} or {{w|herbivore}} — only eating meat or plant respectively. Given the combination of animals used to create the omnitaur, it could be expected that it was also an omnivore. "taur" usually means "bull", but besides "minotaur" it also appears in "{{w|centaur}}", another mythical creature which has the upper body of a human and the lower body and legs of a horse. Thus Randall is taking "taur" to mean any hybrid of different animals.<br />
<br />
An "omnitaur" would suggest that it would encompass all real and mythical creatures, or perhaps some random assortment of such. In this instance, it appears to be a hybrid, or {{w|Chimera (genetics)|genetic chimera}}, combined from eleven different creatures: {{w|fish}}, {{w|lion}}, {{w|snake}}, {{w|shark}}, {{w|bull}}, {{w|dragon}} (a mythical creature in its own right), {{w|horse}}, {{w|leopard}}, {{w|Sheep|ram}} (male sheep), {{w|human}} and {{w|bird}}. Chimerism is not as uncommon at the genetic level, for example humans have about 145 genes (out of around 30,000) originating from bacteria, other single-celled organisms, and viruses.[https://www.science.org/content/article/humans-may-harbor-more-100-genes-other-organisms] {{w|Mitochondria}}, the powerhouse of the cell, were originally chimeric bacteria {{w|symbiosis|symbionts}}. But chimeras of larger organisms are rare, usually involving fraternal twins whose {{w|zygote}}s or {{w|embryo}}s combined, as in {{w|conjoined twins}} but resulting in less distinct {{w|phenotype|phenotypical}} expression. Artificial human chimeras with viruses, mice, pigs, and monkeys have been the subject of ethics controversies in recent years.[https://www.theguardian.com/technology/2019/aug/11/the-five-chimeras-human-monkey-hybrid-genetic][https://jme.bmj.com/content/45/7/440.abstract]<br />
<br />
The title text is a comment by a human whose parents were both omnitaurs. It would be funny that such parents would not produce offspring that was still omnitaur. It suggests that this may be the result of {{w|genetic recombination}}, which is the exchange of genetic material between different organisms leading to production of offspring with combinations of traits that differ from those found in either parent. In this case, seemingly, they inherited ''only'' the human elements of each parent, yet sufficient to develop into a whole human with no missing or chimeric elements. Both omnitaur parents probably had human germlines and compatible reproductive organs<br />
<br />
===Mythical phenotypical chimeras===<br />
<br />
In addition to the minotaur and centaur, many other potential inspirations can be found in mythology, like the {{w|manticore}}, with a body of a lion and human face; a {{w|griffin}}, with a lion's body and a eagle's head; a {{w|mermaid}}, with a lower body of a fish and upper body of a human; a {{w|Hippocampus (mythology)|hippocampus}}, with the upper body of a horse and a lower body of a fish; a {{w|qilin}}, with a body that resembles both a horse and a dragon; or the mythological {{w|chimera (mythology)|chimera}}, for which the genetic chimera is named, which has lion, snake, and goat body parts. Ultimately, there are {{w|List of hybrid creatures in folklore|lots of hybrid creatures in mythology}} with {{w|phenotype}}s combined from multiple animals. Usually, genetic hybridization produces much more smoothly blended phenotypes instead of dividing the body into large distinctly chimeric regions, although {{w|Mosaic (genetics)|mosaicism}} of fur, skin or {{w|Heterochromia iridum|eyes}} can produce notable differences of hue or shade.<br />
<br />
===Speculative implications===<br />
<br />
In {{w|C. S. Lewis}}' {{w|The Chronicles of Narnia}}, the {{w|Magical_creatures_in_The_Chronicles_of_Narnia#Centaurs|centaurs}} are described as eating two meals &mdash; a huge roast meal "to satisfy the man stomach," and a meal of grass, "to satisfy the horse stomach," making it take quite some time for them to eat every morning. Since the omnitaur also has herbivore and omnivore (as well as carnivore) parts, this could further support the supposition that it is an omnivore, and it may similarly need multiple stomachs for these multiple appetites. It is unclear how compatible the various diets of its components would be (not least because 'fish,' 'snake' and 'bird' are quite unspecific, and it's hard to know what a dragon would eat) but it would likely need several meals, taking even longer to eat than the Centaur (plus the bird beak may slow the process down quite a bit.) In any case, a chimera of both warm and cold-blooded organisms seems unlikely to be viable, even at the organ level, let alone with combined surface phenotypes. The Chimera monster in {{w|Dungeons and Dragons}} is a "vile combination of goat, lion, and dragon, and features the heads of all three."[https://www.dndbeyond.com/monsters/16823-chimera]<br />
<br />
While chimeras occur in fantasy fiction, they also occur in science fiction, for example as {{w|cyborg}}s. The famous ''{{w|The Restaurant at the End of the Universe}}'' sequel to Douglas Adams' ''The Hitchhiker's Guide to the Galaxy'', had a pig with the mind and vocal tract of a human so it could articulate how much it wanted to be eaten.<br />
<br />
==== Title text suppositions ====<br />
<br />
Since the example depicted seems to be only <sup>1</sup>/<sub>11</sub> human, the odds of two parents as mentioned in the title text having fully human offspring would simplistically appear to be (<sup>1</sup>/<sub>11</sub>)<sup>11</sup>, or one chance in 285 billion. In reality, each physical part could not be the result of an equal recombinant genetic contribution, because the eleven animal chromosomes vary widely in number and size. Moreover, chimeras composed of multiple animals do not have chimeric children, because even with multiple sets of reproductive organs, the {{w|germline}}s are not combined. <br />
Therefore, both omnitaur parents likely had human germlines and compatible reproductive organs. [https://journals.biologists.com/dev/article/148/12/dev195792/269139/The-road-to-generating-transplantable-organs-from Interspecies blastocyst complementation,] used to create human chimera organs and cell lines in other animals, is usually limited to combining two organisms into one whose offspring are not hybridized if they are even viable, and usually without human germlines or reproductive organs (or human central nervous systems, assuaging a major ethical concern.)<br />
<br />
==Transcript==<br />
:[A creature, the Omnitaur, is shown. It is a four legged animal divided into 11 segments, each segment is from a different animal. An arrow goes to each section from a label, most of the labels are above the animal, but the fourth and seventh segments labels are below the animal. The animal has a fish tail and cat like hind legs. The torso is divided into four segments, the first and last of these with scales, but only the last of these also with sharp scales at the top. The second torso segment is white and smooth, the third also white but with hair both above and below, those above merges with the sharp scales of the fourth torso segment. The front legs are horse like, the lower neck is from an animal with dark spots, the upper neck has rams horns, which goes over in the central part of a human head, with ears and hair (drawn like a real human, not like a xkcd stick figure) and finally the front of the face is a bird with its eyes and a beak shown. The labels are given here in the order of the segment of the animal from the back to the front (disregarding weather the label is written above or below the animal:]<br />
:Fish<br />
:Lion<br />
:Snake<br />
:Shark<br />
:Bull<br />
:Dragon<br />
:Horse<br />
:Leopard<br />
:Ram<br />
:Human<br />
:Bird<br />
<br />
:[Caption below the panel:]<br />
:The Omnitaur<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Animals]]<br />
[[Category:Biology]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2652:_Proxy_Variable&diff=291571Talk:2652: Proxy Variable2022-07-31T16:09:13Z<p>172.70.214.95: (?)</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
Maybe Randall is commenting on this recent article [https://www.nature.com/articles/s43588-022-00281-6 Nature Computational Science: Automated discovery of fundamental variables hidden in experimental data]?<br />
02:10, 30 July 2022 (UTC)<br />
suggested by a proxy editor<br />
<br />
Might be tangentially related to the alleged Alzheimer's disease drug Aduhelm, the anti-amyloid therapy, that did show some success in proxy variable (biomarker), but no success at all in curing the disease or its symptoms (no efficacy), but which got accepted with a huge amount of controversy by NDA (which disregarded its advisory committee’s recommendation against approving Aduhelm). --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 07:32, 30 July 2022 (UTC)<br />
: More relevantly, it came out recently that [https://www.dailykos.com/stories/2022/7/22/2111914/-Two-decades-of-Alzheimer-s-research-may-be-based-on-deliberate-fraud-that-has-cost-millions-of-lives|the last ~decade and a half of Alzheimer's drug research] is based on monitoring effects in mice on a specific biomarker that ''may not actually exist in humans'', and the initial study was potentially fraudulent. Seems like a damn topical proxy variable to me. [[Special:Contributions/162.158.166.249|162.158.166.249]] 00:56, 31 July 2022 (UTC)<br />
:"It’s not much of a stretch to suggest those amyloids are a primary cause of the associated memory loss and dementia," is the failed proxy hypothesis. [[Special:Contributions/172.69.33.163|172.69.33.163]] 02:47, 31 July 2022 (UTC)<br />
<br />
I removed this paragraph:<br />
:''Proxy variables are of interest to non-scientists as they provide a scientific way to indirectly monitor or improve the complex systems that affect their lives. For example, blood pressure is a causative factor for cardiovascular disease so it can be used as a proxy variable for healthy lifestyle. However, people need to remember that it isn't necessarily the proxy variable alone that is of concern. Atmospheric carbon dioxide is not the only gas released by humanity with global warming potential and other factors affect climate change; and it is not carbon dioxide but the impact of climate change that will cause major social, economic, cultural damage to the future of the planet. ''<br />
because I want to discuss it. The first sentence needs a source, the second and third sentences claim blood pressure is used by non-scientists as a proxy for living a healthy lifestyle, which I'm not sure about on multiple levels, and the fourth and fifth sentences seem like PR for fossil fuel companies. #notallgreenhousegases Nevertheless, I feel as if there are likely one or two good ideas hidden in it. [[Special:Contributions/172.70.206.95|172.70.206.95]] 16:01, 30 July 2022 (UTC)<br />
:I feel like the author doesn't know the work climate scientists go to to avoid using greenhouse gas concentration as a proxy for global warming (all the models of atmospheric water and its forms.) For blood pressure, it's easier to see what was attempted to be gotten at. [[Special:Contributions/172.70.211.90|172.70.211.90]] 16:37, 30 July 2022 (UTC)<br />
::Yes: the ones who dangerously simplify the climate change to "we must stop produce carbon dioxide" are not scientists but politicians. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 16:53, 30 July 2022 (UTC)<br />
:Definitely. We don't even KNOW all factors affecting climate change. Still, the link between rising carbon dioxide and temperature looks much more solid that the link between money spent on fighting climate change and levels of carbon dioxide. ... Wait, you didn't wanted to talk about climate did you? :-) (For record, I always though there are much better reasons to stop using fossil fuels than fighting global warming. Recently, for example, the energetic security from geopolitically problematic regions came under lot of attention.) -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 16:46, 30 July 2022 (UTC)<br />
::I want to talk about climate. Do you think we will be able to transition to carbon neutral and negative technologies in time to avoid the {{w|Jevons paradox}}? [[Special:Contributions/172.70.214.185|172.70.214.185]] 17:00, 30 July 2022 (UTC)<br />
:::The Jevons Paradox exists if the only forces affecting the consumption of a resource are supply and demand. If you're asking about carbon-neutral/negative technological process making sustainable technologies profitable faster than fossil fuel profits grow, then no, there's no hope even before the Jevons Paradox is considered. But if other options are considered, the Jevons Paradox doesn't really apply. (To take an extreme example: It doesn't matter how fuel-efficient internal combustion engines get, they'll never be the preferred choice if their manufacture is banned.) [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 18:14, 30 July 2022 (UTC)<br />
::Only carbon negative technology requires {{w|Carbon-burning_process|5×10^8 K or 50 keV and densities > 3×10^9 kg/m3}}. I think that in the moment we will be using THAT on industrial scale we would be quite desperate. Also, the amount of energy we will need is going to grow unless we reduce population a LOT (like, for example, if all ecological activists would do the carbon responsible thing and commit suicide). Also, more and more of that energy we will need will be specifically electrical energy. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:21, 30 July 2022 (UTC)<br />
:::We need to remove 38 gigatons per year, which is only 0.7 milligrams per square centimeter of ocean. Think of the mean depth of the ocean: that square centimeter is very tall. From that perspective, isn't this an easy biological solution? That's only 0.5 micrograms per minute, from the full depth of each square centimeter of ocean, right? [[Special:Contributions/172.70.214.43|172.70.214.43]] 20:47, 30 July 2022 (UTC)<br />
::::I'm not sure what is the "this" you talk about but it sounds you are only storing carbon, not removing it. BTW, one of best way to store carbon is to make more highways. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 23:07, 30 July 2022 (UTC)<br />
:::::Where on Earth would you ever want to build 38 gigatons of highways per year? By "this" I mean genetically modified {{w|phytoplankton}}; in particular modified by changes to {{w|carbonic anhydrase}} expression. [[Special:Contributions/172.70.214.81|172.70.214.81]] 23:13, 30 July 2022 (UTC) <br />
::::::Are there enough dissolved minerals in the ocean for that volume, assuming {{w|diatom}}s intended to sink to the seabed? [[Special:Contributions/172.70.211.134|172.70.211.134]] 09:35, 31 July 2022 (UTC)<br />
<br />
:Everyone thinks this is about pharmacology, and maybe it is. But I've been taking economics courses this semester, so that's what I think of. "We can't measure this factor directly, so we made up a formula that should let us calculate it (if we've measured all relevant factors correctly and all our other assumptions and theories are valid)" is a pretty common thing in that field. [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 18:14, 30 July 2022 (UTC)<br />
:: What's the best example, using GDP as a proxy for development? Or something current like using the money supply as a proxy for inflation? [[Special:Contributions/172.70.214.95|172.70.214.95]] 20:19, 30 July 2022 (UTC)<br />
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:This is the remainder from below, apparently objected to:<br />
::''Proxy variables are of interest to non-scientists as they provide a way to indirectly monitor or improve the complex systems that affect their lives. For example, people use local temperature as a rough experiential proxy for the severity of global warming. Economists might mistake GDP for productive or useful development, or mistake the size of the {{w|money supply}} for {{w|price inflation}}. While correlated, the causation implied by such assumptions is very much in doubt, because the GDP increase of demolishing a hospital might conflict with the widespread understanding of development, and while the money supply size is a cause of inflation, there are many other causes.''<br />
:But it's different from the original. Regardless of what my IP address may or may not suggest, I know the original objector to the earliest version does not object to this edited version, because that objector was and is me. However, I have not yet decided whether I think it should be in the explanation. I will let you know when it gets off the main page, like tomorrow, roughly in a day unless Monday morning continues its traditional trend of presenting unexpected immediate commitments. I have to run a long errand tomorrow so let's say Tuesdayish. <br />
:My initial impulse is to add another paragraph from the climate discussion above, and propose it for a subsection or collapse box. [[Special:Contributions/172.70.214.81|172.70.214.81]] 14:35, 31 July 2022 (UTC) <br />
::How about inserting: "The rate and conditions of {{w|carbonic anhydrase}} expression in genetically modified {{w|phytoplankton}}, such as {{w|diatom}}s intended to sink to the seabed, could be one of many partial proxies for carbon negative direct ocean removal. However, {{w|geoengineering}} success is difficult to measure, and harder to predict, because sometimes even small biological changes in one organism, like modulation of a gene, can have wide-ranging ecosystem effects."<br />
::Not sure where the paragraph break should be. If two paragraphs, try appending a subsection; if one, try the collapse box before the first title text paragraph. If people could contribute other interesting examples of proxies for carbon removal (I remember reading about a desalination process?) that would be awesome. [[Special:Contributions/172.70.214.43|172.70.214.43]] 14:53, 31 July 2022 (UTC)<br />
::: I'm not sure if you can use proportion of renewables, because of Jevons paradox. [[Special:Contributions/172.70.211.90|172.70.211.90]] 14:59, 31 July 2022 (UTC)<br />
::: Desalination doesn't really work here, but we could do {{w|Bacillus thuringiensis israelensis}} application rate as a proxy for {{w|mosquito abatement}} to carry the ecology theme. [[Special:Contributions/172.70.207.8|172.70.207.8]] 15:08, 31 July 2022 (UTC)<br />
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::: I have questions about the phytoplankton stuff. Is it true that completely carbon negative sequestration could be accomplished with 0.5 micrograms per minute (carbon or carbonate) for each square centimeter of ocean? How can the innoculator be sure the strain is viable but not destructive? Are there any {{w|synthetic biology}} proposals for new carbonate diatoms? Can you guarantee sufficient sinking buoyancy from carbonates alone, or is silicon necessary for sequestration? Won't ocean bottom-feeders or e.g. whales just eat the phytoplankton and return it to the ocean and atmosphere when they die? (There could be worse carbon removal solutions than those providing extra whale food, but I fear keeping it unpalatable to bottom-feeders would require making it hazardous for other ocean life. What was the desalination ocean carbon removal proposal?) [[Special:Contributions/172.70.211.90|172.70.211.90]] 15:47, 31 July 2022 (UTC)<br />
<br />
;this dude keeps spamming<br />
<br />
Sorry for the mild crassness, especially as a new user, but some Nazi f*ck is vandalizing the page. May someone please ban them?{{unsigned ip|172.71.26.59|03:49, 30 July 2022}}<br />
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Nah, they're using multiple IPs. Someone could semi-protect it or something but there ain't any mods doing their job it seems.{{unsigned ip|172.70.147.47|03:55, 30 July 2022}}<br />
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Where are the mods, anyways?{{unsigned ip|172.71.82.65|03:59, 30 July 2022}}<br />
:You can't always count on volunteer authorities. Even us lowly IP address editors can revert vandalism. [[Special:Contributions/172.69.33.199|172.69.33.199]] 04:09, 30 July 2022 (UTC)<br />
::Yeah nah, we need it semi-protected {{unsigned ip|162.158.162.199|04:13, 30 July 2022}}<br />
::: Funny if that were the goal of the vandalism. [[Special:Contributions/172.70.206.95|172.70.206.95]] 16:03, 30 July 2022 (UTC)<br />
:::: One reason that I don't think it should be the go-to counter-vandalism approach being used. But not for me to say. Whilstsoever I'm capable of intervening ''at least'' as much as any vandal tries to, I support the mod actions (they are there, doing things, BTW).<br />
:::: Without actually tolerating the vandal, we easily outnumber the person concerned (and the very few other spammers/bots that sneak through the clearly effective existing speedbumps) and this means that such nuisance edits are heavily mitigated. If you see the damaged bits then you're either a regular or a very unlucky occasional visitor.<br />
:::: (This morning, I went to revert an ad-spam that I noted had been written over a page-redirect, to be told that someone else had just gotten there before me!)<br />
:::: I've been on far more abused online resources, both web (early days, long before CAPTCHA technology) and elsewhere (having seen how Usenet was both before and after The Eternal September) and the interference here is extraordinarily given the generally open nature of the submission process.<br />
:::: PS. Please do sign your posts ( with <code><nowiki>~~~~</nowiki></code> ), if only for the timestamp that makes the to and fro of conversations more understandable... [[Special:Contributions/162.158.34.221|162.158.34.221]] 19:01, 30 July 2022 (UTC)<br />
:The rant gets replaced within two minutes of each revert. Presumably it's done by bot. We need a mod to take action. [[Special:Contributions/172.70.130.217|172.70.130.217]] 05:15, 30 July 2022 (UTC)<br />
Article has been restored but some idiots keep spamming the page with random things. pls do something mods {{unsigned ip|172.70.147.47|03:59, 30 July 2022}}<br />
:it's not "some idiots" it's all one person using different ips. he posted the exact same covid rant several times. i think he's schizophrenic or something and just really wants to be heard --[[Special:Contributions/172.69.69.40|172.69.69.40]] 04:39, 30 July 2022 (UTC)<br />
::But why here? Like, this is such a weird place to try and be heard, I'm sure even Reddit posts would have more visibility than edits to a webcomic wiki. [[User:NErDysprosium|NErDysprosium]] ([[User talk:NErDysprosium|talk]]) 06:06, 30 July 2022 (UTC)<br />
::: Don't underestimate the importance of the can't-get-jokes demographic for PSYOP recruitment. The invasion of Panama might not even have occurred if it weren't for people distracted by cartoons. [[Special:Contributions/172.69.33.185|172.69.33.185]] 17:16, 30 July 2022 (UTC)<br />
:As one of the admin I can say that I only come here when I have time. Also I'm not as technically skilled as some of the others. But we all just do this as a hobby. At least we are now some active admins, after several years with none... I was just made admin recently. But I can see that both Theusa and Davidy22 has been active, and that Theusa has made some changes to his bot so it also can revert spam. Hope that helps. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:57, 31 July 2022 (UTC)<br />
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<br />
[https://www.explainxkcd.com/wiki/index.php?title=2652:_Proxy_Variable&diff=291433&oldid=291400 The protected version has much less text than the last non-vandalized version.] [[Special:Contributions/172.70.211.90|172.70.211.90]] 20:02, 30 July 2022 (UTC)<br />
: Re "The history of pharmaceutical research is largely a graveyard of failed proxy hypotheses." True, but someone should add that is the reason for experiment registration regulations. [[Special:Contributions/172.70.210.145|172.70.210.145]] 20:17, 30 July 2022 (UTC)<br />
:: I'm placing that version here, in hopes that it can be edited as a proxy for the protected version: [[Special:Contributions/172.69.33.229|172.69.33.229]] 20:28, 30 July 2022 (UTC)<br />
{{cot|Mostly approved (see above) non-vandalized version of the explanation, as further edited}}<br />
In this comic, [[Hairy]] is discussing use of a proxy variable with [[Cueball]]. In statistics, a {{w|proxy variable}} is used as a stand-in for one or more other variables that are difficult to measure. In order to be useful as such, proxy variables must be correlated with what they are intended to represent. For example, a drug might aim to reduce deaths from a slow-acting disease. But testing if it reduces deaths might take many years, so researchers might test for a proxy outcome instead, like whether it results in loss of bone density or damage to cells. Physicians use blood pressure as one of many proxies for cardiovascular health.<br />
<br />
Proxy variables are of interest to non-scientists as they provide a way to indirectly monitor or improve the complex systems that affect their lives. For example, people use local temperature as a rough experiential proxy for the severity of global warming. Economists might mistake GDP for productive or useful development, or mistake the size of the {{w|money supply}} for {{w|price inflation}}. While correlated, the causation implied by such assumptions is very much in doubt, because the GDP increase of demolishing a hospital might conflict with the widespread understanding of development, and while the money supply size is a cause of inflation, there are many other causes.<br />
<br />
Hairy is dismissing the question of whether they are studying the right variable as too expensive to answer. This is deeply ironic and thus satirical, because good {{w|experiment design}} requires sufficient attention to the robustness of all the involved parts of an experiment, even if the expense may be prohibitive. This comic might be referring to the recent discovery of [https://www.science.org/content/article/potential-fabrication-research-images-threatens-key-theory-alzheimers-disease nearly two decades] of fraudulent {{w|Alzheimer's disease}} research based on a mistaken proxy hypothesis.<br />
<br />
Choosing the wrong proxy variable might make the research misleading, irrelevant, or as the title text suggests, answer the wrong question. Separating correlation from {{w|Causality|causation}} is necessary when interpreting proxy variable results to make sure the question they answer is known. Mere correlation instead of {{w|Causal analysis|authentic causation}} yields weaker results. {{w|Exploratory causal analysis}} can assist with finding useful proxy variables, but is difficult for the layperson to interpret and can be misleading, because even if performed correctly, a {{w|combinatorial explosion}} of possible proxy variables can make traditional {{w|statistical significance}} analysis fail, requiring {{w|F-score}}s or similar measures. The history of pharmaceutical research is largely a graveyard of failed proxy hypotheses; that is one of the reasons for [https://clinicaltrials.gov/ct2/manage-recs/fdaaa experiment registration regulations.]<br />
<br />
The title text's notion of having an answer without knowing the actual question could also be be a reference to the classic comedy science fiction novel {{w|The Hitchhiker's Guide to the Galaxy|The Hitchhiker's Guide to the Galaxy}}, where in one scene Earth turns out to be a supercomputer built for the purpose of figuring out the question for the answer "42."<br />
{{cob}}<br />
:That such improvements are withheld from the main public view must feel like a victory for the vandal. Can autoconfimed users promote it? [[Special:Contributions/172.70.210.145|172.70.210.145]] 23:08, 30 July 2022 (UTC)<br />
::I have added the above except the "Proxy variables are of interest to non-scientists" part as there was someone explaining why this was removed above here. I will thus not be the one putting it back in.--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:57, 31 July 2022 (UTC) <br />
<br />
Is anyone going to comment that all of us IP editors are listed by our CDN proxy address? [[Special:Contributions/172.69.33.123|172.69.33.123]] 20:44, 30 July 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2652:_Proxy_Variable&diff=291487Talk:2652: Proxy Variable2022-07-30T20:20:06Z<p>172.70.214.95: Indent</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
Maybe Randall is commenting on this recent article [https://www.nature.com/articles/s43588-022-00281-6 Nature Computational Science: Automated discovery of fundamental variables hidden in experimental data]?<br />
02:10, 30 July 2022 (UTC)<br />
suggested by a proxy editor<br />
<br />
Might be tangentially related to the alleged Alzheimer's disease drug Aduhelm, the anti-amyloid therapy, that did show some success in proxy variable (biomarker), but no success at all in curing the disease or its symptoms (no efficacy), but which got accepted with a huge amount of controversy by NDA (which disregarded its advisory committee’s recommendation against approving Aduhelm). --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 07:32, 30 July 2022 (UTC)<br />
<br />
I removed this paragraph:<br />
:''Proxy variables are of interest to non-scientists as they provide a scientific way to indirectly monitor or improve the complex systems that affect their lives. For example, blood pressure is a causative factor for cardiovascular disease so it can be used as a proxy variable for healthy lifestyle. However, people need to remember that it isn't necessarily the proxy variable alone that is of concern. Atmospheric carbon dioxide is not the only gas released by humanity with global warming potential and other factors affect climate change; and it is not carbon dioxide but the impact of climate change that will cause major social, economic, cultural damage to the future of the planet. ''<br />
because I want to discuss it. The first sentence needs a source, the second and third sentences claim blood pressure is used by non-scientists as a proxy for living a healthy lifestyle, which I'm not sure about on multiple levels, and the fourth and fifth sentences seem like PR for fossil fuel companies. #notallgreenhousegases Nevertheless, I feel as if there are likely one or two good ideas hidden in it. [[Special:Contributions/172.70.206.95|172.70.206.95]] 16:01, 30 July 2022 (UTC)<br />
:I feel like the author doesn't know the work climate scientists go to to avoid using greenhouse gas concentration as a proxy for global warming (all the models of atmospheric water and its forms.) For blood pressure, it's easier to see what was attempted to be gotten at. [[Special:Contributions/172.70.211.90|172.70.211.90]] 16:37, 30 July 2022 (UTC)<br />
::Yes: the ones who dangerously simplify the climate change to "we must stop produce carbon dioxide" are not scientists but politicians. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 16:53, 30 July 2022 (UTC)<br />
:Definitely. We don't even KNOW all factors affecting climate change. Still, the link between rising carbon dioxide and temperature looks much more solid that the link between money spent on fighting climate change and levels of carbon dioxide. ... Wait, you didn't wanted to talk about climate did you? :-) (For record, I always though there are much better reasons to stop using fossil fuels than fighting global warming. Recently, for example, the energetic security from geopolitically problematic regions came under lot of attention.) -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 16:46, 30 July 2022 (UTC)<br />
::I want to talk about climate. Do you think we will be able to transition to carbon neutral and negative technologies in time to avoid the {{w|Jevons paradox}}? [[Special:Contributions/172.70.214.185|172.70.214.185]] 17:00, 30 July 2022 (UTC)<br />
:::The Jevons Paradox exists if the only forces affecting the consumption of a resource are supply and demand. If you're asking about carbon-neutral/negative technological process making sustainable technologies profitable faster than fossil fuel profits grow, then no, there's no hope even before the Jevons Paradox is considered. But if other options are considered, the Jevons Paradox doesn't really apply. (To take an extreme example: It doesn't matter how fuel-efficient internal combustion engines get, they'll never be the preferred choice if their manufacture is banned.) [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 18:14, 30 July 2022 (UTC)<br />
::Only carbon negative technology requires {{w|Carbon-burning_process|5×10^8 K or 50 keV) and densities (> 3×109 kg/m3)}}. I think that in the moment we will be using THAT on industrial scale we would be quite desperate. Also, the amount of energy we will need is going to grow unless we reduce population a LOT (like, for example, if all ecological activists would do the carbon responsible thing and commit suicide). Also, more and more of that energy we will need will be specifically electrical energy. -- [[Special:Contributions/141.101.96.232|141.101.96.232]] 20:19, 30 July 2022 (UTC)<br />
<br />
:Everyone thinks this is about pharmacology, and maybe it is. But I've been taking economics courses this semester, so that's what I think of. "We can't measure this factor directly, so we made up a formula that should let us calculate it (if we've measured all relevant factors correctly and all our other assumptions and theories are valid)" is a pretty common thing in that field. [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 18:14, 30 July 2022 (UTC)<br />
:: What's the best example, using GDP as a proxy for development? Or something current like using the money supply as a proxy for inflation? [[Special:Contributions/172.70.214.95|172.70.214.95]] 20:19, 30 July 2022 (UTC)<br />
<br />
== this dude keeps spamming ==<br />
<br />
Sorry for the mild crassness, especially as a new user, but some Nazi f*ck is vandalizing the page. May someone please ban them?{{unsigned ip|172.71.26.59|03:49, 30 July 2022}}<br />
<br />
Nah, they're using multiple IPs. Someone could semi-protect it or something but there ain't any mods doing their job it seems.{{unsigned ip|172.70.147.47|03:55, 30 July 2022}}<br />
<br />
Where are the mods, anyways?{{unsigned ip|172.71.82.65|03:59, 30 July 2022}}<br />
:You can't always count on volunteer authorities. Even us lowly IP address editors can revert vandalism. [[Special:Contributions/172.69.33.199|172.69.33.199]] 04:09, 30 July 2022 (UTC)<br />
::Yeah nah, we need it semi-protected {{unsigned ip|162.158.162.199|04:13, 30 July 2022}}<br />
::: Funny if that were the goal of the vandalism. [[Special:Contributions/172.70.206.95|172.70.206.95]] 16:03, 30 July 2022 (UTC)<br />
:::: One reason that I don't think it should be the go-to counter-vandalism approach being used. But not for me to say. Whilstsoever I'm capable of intervening ''at least'' as much as any vandal tries to, I support the mod actions (they are there, doing things, BTW).<br />
:::: Without actually tolerating the vandal, we easily outnumber the person concerned (and the very few other spammers/bots that sneak through the clearly effective existing speedbumps) and this means that such nuisance edits are heavily mitigated. If you see the damaged bits then you're either a regular or a very unlucky occasional visitor.<br />
:::: (This morning, I went to revert an ad-spam that I noted had been written over a page-redirect, to be told that someone else had just gotten there before me!)<br />
:::: I've been on far more abused online resources, both web (early days, long before CAPTCHA technology) and elsewhere (having seen how Usenet was both before and after The Eternal September) and the interference here is extraordinarily given the generally open nature of the submission process.<br />
:::: PS. Please do sign your posts ( with <code><nowiki>~~~~</nowiki></code> ), if only for the timestamp that makes the to and fro of conversations more understandable... [[Special:Contributions/162.158.34.221|162.158.34.221]] 19:01, 30 July 2022 (UTC)<br />
<br />
:The rant gets replaced within two minutes of each revert. Presumably it's done by bot. We need a mod to take action. [[Special:Contributions/172.70.130.217|172.70.130.217]] 05:15, 30 July 2022 (UTC)<br />
Article has been restored but some idiots keep spamming the page with random things. pls do something mods {{unsigned ip|172.70.147.47|03:59, 30 July 2022}}<br />
:it's not "some idiots" it's all one person using different ips. he posted the exact same covid rant several times. i think he's schizophrenic or something and just really wants to be heard --[[Special:Contributions/172.69.69.40|172.69.69.40]] 04:39, 30 July 2022 (UTC)<br />
::But why here? Like, this is such a weird place to try and be heard, I'm sure even Reddit posts would have more visibility than edits to a webcomic wiki. [[User:NErDysprosium|NErDysprosium]] ([[User talk:NErDysprosium|talk]]) 06:06, 30 July 2022 (UTC)<br />
::: Don't underestimate the importance of the can't-get-jokes demographic for PSYOP recruitment. The invasion of Panama might not even have occurred if it weren't for people distracted by cartoons. [[Special:Contributions/172.69.33.185|172.69.33.185]] 17:16, 30 July 2022 (UTC)<br />
<br />
[https://www.explainxkcd.com/wiki/index.php?title=2652:_Proxy_Variable&diff=291433&oldid=291400 The protected version has much less text than the last non-vandalized version.] [[Special:Contributions/172.70.211.90|172.70.211.90]] 20:02, 30 July 2022 (UTC)<br />
: Re "The history of pharmaceutical research is largely a graveyard of failed proxy hypotheses." True, but someone should add that is the reason for experiment registration regulations. [[Special:Contributions/172.70.210.145|172.70.210.145]] 20:17, 30 July 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2652:_Proxy_Variable&diff=291485Talk:2652: Proxy Variable2022-07-30T20:19:34Z<p>172.70.214.95: Reply</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
Maybe Randall is commenting on this recent article [https://www.nature.com/articles/s43588-022-00281-6 Nature Computational Science: Automated discovery of fundamental variables hidden in experimental data]?<br />
02:10, 30 July 2022 (UTC)<br />
suggested by a proxy editor<br />
<br />
Might be tangentially related to the alleged Alzheimer's disease drug Aduhelm, the anti-amyloid therapy, that did show some success in proxy variable (biomarker), but no success at all in curing the disease or its symptoms (no efficacy), but which got accepted with a huge amount of controversy by NDA (which disregarded its advisory committee’s recommendation against approving Aduhelm). --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 07:32, 30 July 2022 (UTC)<br />
<br />
I removed this paragraph:<br />
:''Proxy variables are of interest to non-scientists as they provide a scientific way to indirectly monitor or improve the complex systems that affect their lives. For example, blood pressure is a causative factor for cardiovascular disease so it can be used as a proxy variable for healthy lifestyle. However, people need to remember that it isn't necessarily the proxy variable alone that is of concern. Atmospheric carbon dioxide is not the only gas released by humanity with global warming potential and other factors affect climate change; and it is not carbon dioxide but the impact of climate change that will cause major social, economic, cultural damage to the future of the planet. ''<br />
because I want to discuss it. The first sentence needs a source, the second and third sentences claim blood pressure is used by non-scientists as a proxy for living a healthy lifestyle, which I'm not sure about on multiple levels, and the fourth and fifth sentences seem like PR for fossil fuel companies. #notallgreenhousegases Nevertheless, I feel as if there are likely one or two good ideas hidden in it. [[Special:Contributions/172.70.206.95|172.70.206.95]] 16:01, 30 July 2022 (UTC)<br />
:I feel like the author doesn't know the work climate scientists go to to avoid using greenhouse gas concentration as a proxy for global warming (all the models of atmospheric water and its forms.) For blood pressure, it's easier to see what was attempted to be gotten at. [[Special:Contributions/172.70.211.90|172.70.211.90]] 16:37, 30 July 2022 (UTC)<br />
::Yes: the ones who dangerously simplify the climate change to "we must stop produce carbon dioxide" are not scientists but politicians. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 16:53, 30 July 2022 (UTC)<br />
:Definitely. We don't even KNOW all factors affecting climate change. Still, the link between rising carbon dioxide and temperature looks much more solid that the link between money spent on fighting climate change and levels of carbon dioxide. ... Wait, you didn't wanted to talk about climate did you? :-) (For record, I always though there are much better reasons to stop using fossil fuels than fighting global warming. Recently, for example, the energetic security from geopolitically problematic regions came under lot of attention.) -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 16:46, 30 July 2022 (UTC)<br />
::I want to talk about climate. Do you think we will be able to transition to carbon neutral and negative technologies in time to avoid the {{w|Jevons paradox}}? [[Special:Contributions/172.70.214.185|172.70.214.185]] 17:00, 30 July 2022 (UTC)<br />
:::The Jevons Paradox exists if the only forces affecting the consumption of a resource are supply and demand. If you're asking about carbon-neutral/negative technological process making sustainable technologies profitable faster than fossil fuel profits grow, then no, there's no hope even before the Jevons Paradox is considered. But if other options are considered, the Jevons Paradox doesn't really apply. (To take an extreme example: It doesn't matter how fuel-efficient internal combustion engines get, they'll never be the preferred choice if their manufacture is banned.) [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 18:14, 30 July 2022 (UTC)<br />
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:Everyone thinks this is about pharmacology, and maybe it is. But I've been taking economics courses this semester, so that's what I think of. "We can't measure this factor directly, so we made up a formula that should let us calculate it (if we've measured all relevant factors correctly and all our other assumptions and theories are valid)" is a pretty common thing in that field. [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 18:14, 30 July 2022 (UTC)<br />
: What's the best example, using GDP as a proxy for development? Or something current like using the money supply as a proxy for inflation? [[Special:Contributions/172.70.214.95|172.70.214.95]] 20:19, 30 July 2022 (UTC)<br />
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== this dude keeps spamming ==<br />
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Sorry for the mild crassness, especially as a new user, but some Nazi f*ck is vandalizing the page. May someone please ban them?{{unsigned ip|172.71.26.59|03:49, 30 July 2022}}<br />
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Nah, they're using multiple IPs. Someone could semi-protect it or something but there ain't any mods doing their job it seems.{{unsigned ip|172.70.147.47|03:55, 30 July 2022}}<br />
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Where are the mods, anyways?{{unsigned ip|172.71.82.65|03:59, 30 July 2022}}<br />
:You can't always count on volunteer authorities. Even us lowly IP address editors can revert vandalism. [[Special:Contributions/172.69.33.199|172.69.33.199]] 04:09, 30 July 2022 (UTC)<br />
::Yeah nah, we need it semi-protected {{unsigned ip|162.158.162.199|04:13, 30 July 2022}}<br />
::: Funny if that were the goal of the vandalism. [[Special:Contributions/172.70.206.95|172.70.206.95]] 16:03, 30 July 2022 (UTC)<br />
:::: One reason that I don't think it should be the go-to counter-vandalism approach being used. But not for me to say. Whilstsoever I'm capable of intervening ''at least'' as much as any vandal tries to, I support the mod actions (they are there, doing things, BTW).<br />
:::: Without actually tolerating the vandal, we easily outnumber the person concerned (and the very few other spammers/bots that sneak through the clearly effective existing speedbumps) and this means that such nuisance edits are heavily mitigated. If you see the damaged bits then you're either a regular or a very unlucky occasional visitor.<br />
:::: (This morning, I went to revert an ad-spam that I noted had been written over a page-redirect, to be told that someone else had just gotten there before me!)<br />
:::: I've been on far more abused online resources, both web (early days, long before CAPTCHA technology) and elsewhere (having seen how Usenet was both before and after The Eternal September) and the interference here is extraordinarily given the generally open nature of the submission process.<br />
:::: PS. Please do sign your posts ( with <code><nowiki>~~~~</nowiki></code> ), if only for the timestamp that makes the to and fro of conversations more understandable... [[Special:Contributions/162.158.34.221|162.158.34.221]] 19:01, 30 July 2022 (UTC)<br />
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:The rant gets replaced within two minutes of each revert. Presumably it's done by bot. We need a mod to take action. [[Special:Contributions/172.70.130.217|172.70.130.217]] 05:15, 30 July 2022 (UTC)<br />
Article has been restored but some idiots keep spamming the page with random things. pls do something mods {{unsigned ip|172.70.147.47|03:59, 30 July 2022}}<br />
:it's not "some idiots" it's all one person using different ips. he posted the exact same covid rant several times. i think he's schizophrenic or something and just really wants to be heard --[[Special:Contributions/172.69.69.40|172.69.69.40]] 04:39, 30 July 2022 (UTC)<br />
::But why here? Like, this is such a weird place to try and be heard, I'm sure even Reddit posts would have more visibility than edits to a webcomic wiki. [[User:NErDysprosium|NErDysprosium]] ([[User talk:NErDysprosium|talk]]) 06:06, 30 July 2022 (UTC)<br />
::: Don't underestimate the importance of the can't-get-jokes demographic for PSYOP recruitment. The invasion of Panama might not even have occurred if it weren't for people distracted by cartoons. [[Special:Contributions/172.69.33.185|172.69.33.185]] 17:16, 30 July 2022 (UTC)<br />
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[https://www.explainxkcd.com/wiki/index.php?title=2652:_Proxy_Variable&diff=291433&oldid=291400 The protected version has much less text than the last non-vandalized version.] [[Special:Contributions/172.70.211.90|172.70.211.90]] 20:02, 30 July 2022 (UTC)<br />
: Re "The history of pharmaceutical research is largely a graveyard of failed proxy hypotheses." True, but someone should add that is the reason for experiment registration regulations. [[Special:Contributions/172.70.210.145|172.70.210.145]] 20:17, 30 July 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2207:_Math_Work&diff=291116Talk:2207: Math Work2022-07-30T00:24:14Z<p>172.70.214.95: Reply</p>
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This makes me think of my profession (software engineer) - Normie: "Oh wow, that looks complicated!" Me: wires two pre-existing libraries together and calls it a day [[User:Baldrickk|Baldrickk]] ([[User talk:Baldrickk|talk]]) 09:39, 26 September 2019 (UTC)<br />
<br />
;Image of Blackboard<br />
I was looking at the blackboard and was wondering if there were any Easter eggs on it.<br />
Here is the result of my badly cropped photoshopping skills.<br />
[https://drive.google.com/open?id=1kGCrQehNGksE2cSK1WvTJcgdwaZ5cdWe]<br />
idk if it would help to sharpen the image.<br />
--[[User:DarkAndromeda31|DarkAndromeda31]] ([[User talk:DarkAndromeda31|talk]]) 01:25, 26 September 2019 (UTC)<br />
:The only thing that really jumps out at me are the wedges, as portions of pie charts where radius also controls area, evoking the {{w|climate stabilization wedge}} game [https://cmi.princeton.edu/wedges/game from Princeton] where the total area of the disk needing to be mitigated is something like 38 gigatons of atmospheric carbon, and the various mitigation solutions have angles representing potential and radius indicating uptake, the proportion of which represents gigatons mitigated as the wedge area. We can offer that game as an example of a bivariate optimization problem which might not have to be manually solved by anyone, if we assume that the local market for [https://drive.google.com/file/d/1ritJrcDKyXNe4Kp2dHBWiFuyBEHvn_81/view surplus potable water, carbon-neutral liquid transportation fuel, and carbon-negative composite lumber for centuries-to-millenia scale sequestration along with wood timber displacement for reforestation] represents locally satisfiable economic demand for N shipping containers of [https://x.company/projects/foghorn Project Foghorn] [https://www.docdroid.net/WlkWabq/ioc-part-1-prototype-article-in-press.pdf plants] and M shipping containers of [https://www.docdroid.net/SRxC3bd/power-to-gas-efficiency.pdf power-to-gas upgrades for natural gas] power plants. That's an example of how a locally market-driven system can solve a bivariate optimization without anyone doing the actual math work in a spreadsheet or otherwise. The economic solution is not necessarily optimal, because even [https://twitter.com/jsalsman/status/1118030378747351040 as powerful as the free market can be,] it isn't necessarily going to find the bivariate optimums for every point on the planet (although it will likely converge asymptotically in some sense) and defectors such as fossil fuel producers are interested in delaying the optimum solution. <br />
:Is that nontangential enough? [[Special:Contributions/172.68.143.18|172.68.143.18]] 20:49, 26 September 2019 (UTC)<br />
::Yes that was far out :-) I'm sure there is nothing interesting hidden in the image. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:36, 27 September 2019 (UTC)<br />
:::Compare the graph at [https://www.wolframalpha.com/input/?i=World+natural+gas+production] with that at [https://www.wolframalpha.com/input/?i=World+wind+power+production]. When will the latter overtake the former? [[Special:Contributions/172.68.142.221|172.68.142.221]] 19:19, 27 September 2019 (UTC)<br />
::::Soon one may hope, but that has nothing to do with the drawings on the blackboard...? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 21:07, 27 September 2019 (UTC)<br />
:::::"Soon" lacks mathematical precision. How do you feel about {{w|distributed constraint optimization}}? [[Special:Contributions/172.68.142.83|172.68.142.83]] 22:56, 27 September 2019 (UTC)<br />
:::::P.S. I would also point out that this comic appeared during the [https://globalclimatestrike.net/ Global Climate Strike] so I stand by my interpretation of the wedges. [[Special:Contributions/162.158.255.136|162.158.255.136]] 19:11, 3 October 2019 (UTC)<br />
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Does [https://www.wolframalpha.com/ Wolfram Alpha] constitute such a problem solver? Cause both Randall and this site has used it on several occasions. But I have not ever really used such things, and do not know if Wolfram can be used as Cueball thinks about in the comic. But if it could, it could be worth mentioning as a method sometimes used by Randall. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:43, 27 September 2019 (UTC)<br />
:[https://www.wolframalpha.com/input/?i=x%2By%3D10%2C+x-y%3D4&lk=3] is the first bivariate system of equations example. [[Special:Contributions/172.69.22.134|172.69.22.134]] 17:51, 27 September 2019 (UTC)<br />
::Is that then a yes to my question? ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 21:07, 27 September 2019 (UTC)<br />
:::Do you think it's more worthwhile to include a general discussion of avoiding the work of solving for two unknowns than the climate wedges? Why do you suggest that the wedges aren't the only distinctive elements on the blackboard? [[Special:Contributions/172.68.142.83|172.68.142.83]] 22:58, 27 September 2019 (UTC)<br />
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I only just now noticed that Randall always puts the crossbars on the I in the word "I" and not otherwise. Looking back, he has nearly always done this, even since the first few comics. That's quite a principled yet subtle stance on letterforms. (There are some exceptions, however, such as comic #87, and a period that goes at least from comic #128 to comic #180. I wonder if it would be too typography-nerdy to put them all in a category.) [[Special:Contributions/198.41.231.85|198.41.231.85]] 14:47, 27 September 2019 (UTC)<br />
: Those "crossbars" would be serifs, whereas he normally uses a sans serif font. A sans serif would be quicker/easier to write by hand, but he probably realized early on (perhaps subconsciously) that an I by itself without serifs looks too much like a random line or a numeral 1 so he treats the solo I like a special letter, with serifs. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 15:16, 27 September 2019 (UTC)<br />
::Yes so not something for a category! But funny detail. I have no idea where to put this? Maybe in some part of the format of xkcd? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 21:07, 27 September 2019 (UTC)<br />
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Thank you, person who sees beauty in grammar (Jkrstrt). I thought something looked off when I said "often site the beauty they see" but I didn't catch it until you sighted the error and made it cite instead. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 15:10, 27 September 2019 (UTC)<br />
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We need something about the [https://trends.google.com/trends/explore?date=all&q=%22they%20did%20the%20math%22 2014 popularity spike of the phrase "They did the math"] with a link to e.g. r/theydidthemath. And ask the Hashtag Research Studies group to figure out the cause of that spike. [[Special:Contributions/172.68.189.19|172.68.189.19]] 15:29, 29 September 2019 (UTC)<br />
:This has got to be [https://imgur.com/gallery/qpWueVf somehow related to xkcd.] But how? [[Special:Contributions/172.68.189.19|172.68.189.19]] 20:42, 29 September 2019 (UTC)<br />
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In other olds, [https://books.google.com/ngrams/graph?content=they+did+the+math&case_insensitive=on&year_start=1980&year_end=2008&corpus=15&smoothing=3&share=&direct_url=t4%3B%2Cthey%20did%20the%20math%3B%2Cc0%3B%2Cs0%3B%3Bthey%20did%20the%20math%3B%2Cc0%3B%3BThey%20did%20the%20math%3B%2Cc0 Google Books says it started in 1988] but won't show me the 1988 book in question. I'm going to work on the drone fishing now. [[Special:Contributions/162.158.255.136|162.158.255.136]] 05:31, 30 September 2019 (UTC)<br />
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== Deletions ==<br />
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I feel that [https://www.explainxkcd.com/wiki/index.php?title=2207:_Math_Work&diff=182511&oldid=180894 these deletions] were done without sufficient discussion of the rationales for the material given above, leaving the explanation shorter than that of almost all if not all other comics. Whatever you think of the climate change distributed optimization example, there were no objections to the well-documented "they did the math" popularity surge or to the academic references deleted. [[Special:Contributions/172.69.22.68|172.69.22.68]] 01:16, 22 November 2019 (UTC)<br />
:How was that even related to the content of the comic? --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:14, 22 November 2019 (UTC)<br />
::Which? The two wedges involving an optimization problem in two variables on Climate Strike Week (a strike being an intentional avoidance of work), or the phrase "They did the math" in relation to "Math work"? <br />
::I intend to replace the deleted material. [[Special:Contributions/172.69.22.68|172.69.22.68]] 05:26, 3 December 2019 (UTC)<br />
:::Why? please explain how it is relevant/related to the comic or helps in understanding it. The comic is about math being complicated and incomprehensible from outside, while from the inside it is just as complicated when you understand it. The comic does not contain the words "the math" nor does the pie chart or the wedge give any indication of being about anything specific. It is just as likely something about Pizza. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:24, 3 December 2019 (UTC)<br />
::::I have, in detail, above. I have asked famed Bloomberg columnist and fellow economics science communication enthusiast Noah Smith to mediate this dispute. Will you accept him as mediator? [[Special:Contributions/172.68.143.24|172.68.143.24]] 12:06, 8 December 2019 (UTC)<br />
:::::First a personal note: As it seems like we are discussing here, I'd appreciate if you'd create an account here, so that I can link your comments to a single commenter, instead of a changing cloudfare IP adresses. To the topic: I do not deny that a wedge can represent an optimization problem. It can also represent other things. As far as visible from the comic, Cueball could be calculating how much Pizza he has left. Even if it is about an optimization problem, there is no indication in the comic to link this to human-made climate change, apart from the apperance of the comic in climate strike week. If it was a reference to that point, it'd be very (!) subtle. How do you think some spark in the search for some term in 2014, which has a one-word-overlap (and math is the topic of the comic...) with the comic is relevant again? I, again, do not doubt the correctnes of the statements, but only their relevance/connection with this comic. Last but not least: Any registered (and therefore "unique", even though it's easy to register multiple accounts...) commenter may join this discussion, to reach consensus (by the way, I was not even the one deleting it actually). I have never heard of that famed person, nor do I care about his column in some magazine and his enthusiasm about communication. (If he should ever read this, I'd like to repeat myself: I have never heard of him, so it is not meant to disrispect him. He might be a nice guy and very qualified in whatever he writes his column about. He might also be famous to people he is relevant for.) --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:29, 9 December 2019 (UTC)<br />
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===An aside to That Guy===<br />
( Hi Kynde, if you read this, I was already rewriting it as a subsection to make it not look like the original issue, then got Edit Conflicted by your plea not to edit your Talk Page unnecessarily. So pasting it all here, instead, plus this comment. :-p ) <br />
No, I'm [https://www.explainxkcd.com/wiki/index.php?title=2207:_Math_Work&diff=291019&oldid=282989 this guy.] [[Special:Contributions/172.70.211.88|172.70.211.88]] 15:52, 28 July 2022 (UTC)<br />
:Hello, That Guy. (BTW, I'm also none of the above conversationalists, Kynde...) That change you linked... I just reverted it. It was fixed (devandalised) already in a state that was after the removal of the Incomplete tag and I couldn't work out ''why'' you considered it needing reverting. Yes, a lot of restored stuff (now unrestored), but I couldn't quite work out which (pre-vandalism) version you even reverted to, and surely there were various useful culling edits ("no, we don't need to say that, it's irrelevent", etc) that you were negating.<br />
:Or at least that was my almost knee-jerk response (almost, because I went back through the crapcrapcrap stuff and beyond trying to find where you were coming from, so I spent some time on thinking about it before I did it).<br />
:I offer it up to review by the wider community, or back to yourself (or give Kynde a shot, if they aren't busy). Maybe some old bits could be reintegrated, but I couldn't see which on a semi-cursory glance. So, given you have provided a handle on you, expanding upon the woefully short edit-summary space, to more fully explain any confusion (of mine, or yours, or just in general). Ok? [[Special:Contributions/172.70.91.128|172.70.91.128]] 16:43, 28 July 2022 (UTC)<br />
::Are you saying you removed vandalism with the revert? Which parts do you think are crap stuff? Do you not see how it is all directly related to the drawing on the board? I should have removed the incomplete tag, but I think I'll try the appended section idea to appease objectors with a compromise. [[Special:Contributions/172.69.33.185|172.69.33.185]] 05:15, 29 July 2022 (UTC)<br />
:::Simply put, your initial effort looked indistinguishable from an opportunity to sneak in creative vandalism. I couldn't even easily confirm you were reverting and not creating from scratch, and we've had some "whole unrelated paragraphs with random external links in" spam recently, although at least there were only wikilinks (IIRC) so it wasn't entirely that.<br />
:::I spent ten minutes or so trawling the history (in and out of various version differences) and didn't have time to do more so I played it safe (reverted to the ''actual'' last good version) with the best explanatory message I could fit in the Summary, and then saw you'd posted here.<br />
:::Then saw (clearly before reading here) you'd reverted my revert, and I was still doubtful but used the longer Summary space (multi-version revert doesn't use up character-limit with details) to express my doubts... I had decided I'd not revert again (keeping below 3RR) if you tried exactly the same again, having said all that I wished for the benefit of other editors to consider, but you didn't force me to even consider it - and, for that, much thanks.<br />
:::Yes, if you find historic bits (whole or multiple paragraphs, even) that you think should be restored then a copypasta would be best. It shows consideration above that of (seemingly) choosing a whole past version and reverting out who-knows-how-much intermediate editing without even reading it and seeing the Incomplete Tag has reappeared. Then they can be (re)assessed on their own merit, unspoilt by the stupid inclusion of signs of wholesale-reversion.<br />
:::But I'm not the main (or only) gatekeeper here, just a random IP who is perhaps a bit over-cautious and occasionally conservative (ironic, given you were trying to 'conserve' the bits you ressurected). I have no authority, I just tried to do what seems to be best. YMMV, as it may for others. And I probably would (and will) do the same again for another instance (on a different article, or that one after significant 'good' new changes) with the same criteria, if I'm around at the right time to do so. But I won't revert anything that might be sensible.<br />
:::And so that's my long-winded answer to cover the many questions you possibly have and many more questions you almost certainly do not have. :P [[Special:Contributions/172.70.86.34|172.70.86.34]] 09:29, 29 July 2022 (UTC)<br />
::::No problemo! What do you think of the subsectioned version? [[Special:Contributions/172.69.33.229|172.69.33.229]] 22:35, 29 July 2022 (UTC)<br />
:::::Honestly, it may now be a more profound explanation, but far less elegant and beautifully succint as without the diversion. I'm sure it could be less wordy (and the gods know that I'm no stranger to verbosity, myself) whilst being at least as usefully informative. But I'm not eager to dive in and try to perform the verbal surgery that I have a feeling is necessary, nor do I retain any desire to revert.<br />
:::::So it's not up to me, and down to the whims of other (future?) editors. ;) [[Special:Contributions/172.70.91.80|172.70.91.80]] 00:12, 30 July 2022 (UTC)<br />
::::::As is always expected. [[Special:Contributions/172.70.214.95|172.70.214.95]] 00:24, 30 July 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2651:_Air_Gap&diff=291050Talk:2651: Air Gap2022-07-29T03:24:30Z<p>172.70.214.95: Reply</p>
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Worth noting that this is a large and inefficient version of an [https://en.wikipedia.org/wiki/Opto-isolator opto-isolator] [[Special:Contributions/108.162.221.79|108.162.221.79]] 05:37, 28 July 2022 (UTC)<br />
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: Incandescent light bulb (assuming it the lamp does not use LED in the shape of light bulb) is not only less efficient than diode, but also much slower to warm up and cool down - it usually is much more sensitive to rapid switching, and has shorter life counted in the number of on/off cycles. --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 07:45, 28 July 2022 (UTC)<br />
:: There’s not even any indication that the bulb is shaped like an incandescent bulb. Only that the front of the light (either fixture or bulb) is a convex curve. For all we know that could be a lens or diffuser in front of a flat LED. Whoever wrote that needs to go back and walk, because the claim that an incandescent bulb is depicted is quite simply false.[[Special:Contributions/172.71.142.89|172.71.142.89]] 10:35, 28 July 2022 (UTC)<br />
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: I don't think it's less or more efficient than an opto-isolator, it essentially ''is'' just an opto-isolator. But an opto-isolator isn't supposed to be energy efficient to begin with; it's only designed to transmit data between circuits, not power. So the output side only needs to generate enough voltage/current to change the state of a transistor, and the input side only needs to generate enough light for the output side to do that. The voltages and currents involved aren't comparable to power circuits. --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 08:14, 28 July 2022 (UTC)<br />
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: By the way, wikipedia links can be written like this: <code><nowiki>[[wikipedia:opto-isolator|]]</nowiki></code> result: [[wikipedia:opto-isolator|opto-isolator]] (the final <code>|</code> automatically gets expanded to the article title without the <code>wikipedia:</code> prefix). --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 08:26, 28 July 2022 (UTC)<br />
::Or more often here on ExplainXkcd, <code><nowiki>{{w|article}}</nowiki></code> or <code><nowiki>{{w|article|anchor text}}</nowiki></code>. [[Special:Contributions/172.70.206.213|172.70.206.213]] 08:35, 28 July 2022 (UTC)<br />
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::: Yes, thanks :) although there is a tiiiiiny advantage to the direct link without the template (the way I said), <code><nowiki>[[wikipedia:Pipe (computing)|]]</nowiki></code> becomes [[wikipedia:Pipe (computing)|Pipe]] whereas <code><nowiki>{{w|Pipe (computing)}}</nowiki></code> becomes {{w|Pipe (computing)}}. The pipe trick strips out the disambiguation parts of the title according to [[Wikipedia:Help:Pipe trick|some rules]]. --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 12:30, 28 July 2022 (UTC)<br />
:::: Why not <code><nowiki>{{w|Pipe (computing)|pipe}}</nowiki></code>? [[Special:Contributions/172.70.214.95|172.70.214.95]] 15:18, 28 July 2022 (UTC)<br />
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It is missing that air-gapping the power supply would protect your home from voltage surges in the power network caused by lightning strikes. Depending where the lightning hits the power network, there may be no fuses protecting your home or single fuses may fail to protect you. --[[Special:Contributions/172.70.246.115|172.70.246.115]] 07:57, 28 July 2022 (UTC)<br />
:That is true. But the suggestion that this might have anything to do with general energy security (as is currently very prominent in the explanation) is entirely unconvincing to me.<br />
::I also originally thought this was the main joke, until seeing the title text about bit rate. Certainly it's worth mentioning, even if this isn't the main joke, since it would actually work, with a wide enough gap, ideally with a vacuum in between.<br />
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Incandescent light bulbs convert most of their energy to infrared light. There are solar cells that work in this infrared spectrum, so this might not be all that inefficient as stated. This should in fact be a lot more efficient than any LED+visible spectrum based panel, as incandescent bulbs are very efficient in converting electricity into infrared light, much more than LEDs most likely will ever be.<br />
The (mostly) omnidirectionality of the light source might be an even bigger loss, as most of the light (however efficient) does not even reach the panel.<br />
And regarding sending data over this construct: As soon as there's a 0V state (which will be the case as soon as the transmission starts, due to some form of manchester coding, regardless of it being a 0 or 1 bit) the PC behind the solar panel would not only have a data transmission problem :)<br />
(With incandescent bulb, that is. A LED 0V might be short enough for capacitors in the PC's power supply to buffer it, if it is only at 50%(+PSU conversion loss) load max, as manchester coded signals per definition have a duty cycle of 50% to keep the DC bias at 0V)<br />
[[Special:Contributions/172.68.51.204|172.68.51.204]] 08:26, 28 July 2022 (UTC)<br />
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What is the highest wattage commercial opto-isolator, and how can I get one mounted from the ceiling in my bedroom? [[Special:Contributions/172.70.207.8|172.70.207.8]] 14:10, 28 July 2022 (UTC)<br />
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I wonder if it's worth noting the significant understatement within the title text, where it says "the bitrate does drop a little" in contrast to the severe and drastic drop in bitrate that would actually occur, especially in light of today's typical Internet speeds. It might not be worth mentioning, but it struck me as a humorous understatement of the true impact. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:25, 28 July 2022 (UTC)<br />
:We don't know if the light bulb is incandescent or LED, so we can't describe the bandwidth drop other than in very general terms. [[Special:Contributions/172.70.211.88|172.70.211.88]] 15:34, 28 July 2022 (UTC)<br />
<br />
I'm almost tempted to suggest that this should be an (honourary) addition to the Cursed Connectors comic-collection. [[Special:Contributions/172.71.94.187|172.71.94.187]] 14:56, 28 July 2022 (UTC)<br />
<br />
Yes, solar panels can transform electrical into electromagnetic signals. It is more on the side of the incandescent bulb that the capability to receive and forward these signals is missing. My source: https://www.youtube.com/watch?v=TGUteH93xNo<br />
[[User:Torge|Torge]] ([[User talk:Torge|talk]]) 15:11, 28 July 2022 (UTC)<br />
<br />
Nobody caught on that powerline networking is about sending data through powerlines? or that a crude opto-isolation setup could effectively scrub it? Where my networking geeks at? I am disappoint [[Special:Contributions/172.69.71.51|172.69.71.51]] 15:19, 28 July 2022 (UTC)<br />
<br />
An electrical engineer here: perhaps we should mention that the box pictured after the solar panel must be an inverter? The lightbulb/solar panel pair will be acting as a rectifier, putting out purely positive voltage, and to get back to AC to run appliances on there would need to be an inverter.<br />
[[Special:Contributions/172.69.62.49|172.69.62.49]] 01:10, 29 July 2022 (UTC)<br />
:Can you please help out with the argument about rectifier efficiency at [[2642]]? [[Special:Contributions/172.70.214.95|172.70.214.95]] 03:24, 29 July 2022 (UTC)<br />
<br />
Most of the bulbs in my house (before compact flourescent and LED) were 75 Watt or 100 Watt. 50 Watt would be a very dim bulb.</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2651:_Air_Gap&diff=291011Talk:2651: Air Gap2022-07-28T15:18:23Z<p>172.70.214.95: Alternative</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
Worth noting that this is a large and inefficient version of an [https://en.wikipedia.org/wiki/Opto-isolator opto-isolator] [[Special:Contributions/108.162.221.79|108.162.221.79]] 05:37, 28 July 2022 (UTC)<br />
<br />
: Incandescent light bulb (assuming it the lamp does not use LED in the shape of light bulb) is not only less efficient than diode, but also much slower to warm up and cool down - it usually is much more sensitive to rapid switching, and has shorter life counted in the number of on/off cycles. --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 07:45, 28 July 2022 (UTC)<br />
:: There’s not even any indication that the bulb is shaped like an incandescent bulb. Only that the front of the light (either fixture or bulb) is a convex curve. For all we know that could be a lens or diffuser in front of a flat LED. Whoever wrote that needs to go back and walk, because the claim that an incandescent bulb is depicted is quite simply false.[[Special:Contributions/172.71.142.89|172.71.142.89]] 10:35, 28 July 2022 (UTC)<br />
<br />
: I don't think it's less or more efficient than an opto-isolator, it essentially ''is'' just an opto-isolator. But an opto-isolator isn't supposed to be energy efficient to begin with; it's only designed to transmit data between circuits, not power. So the output side only needs to generate enough voltage/current to change the state of a transistor, and the input side only needs to generate enough light for the output side to do that. The voltages and currents involved aren't comparable to power circuits. --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 08:14, 28 July 2022 (UTC)<br />
<br />
: By the way, wikipedia links can be written like this: <code><nowiki>[[wikipedia:opto-isolator|]]</nowiki></code> result: [[wikipedia:opto-isolator|opto-isolator]] (the final <code>|</code> automatically gets expanded to the article title without the <code>wikipedia:</code> prefix). --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 08:26, 28 July 2022 (UTC)<br />
::Or more often here on ExplainXkcd, <code><nowiki>{{w|article}}</nowiki></code> or <code><nowiki>{{w|article|anchor text}}</nowiki></code>. [[Special:Contributions/172.70.206.213|172.70.206.213]] 08:35, 28 July 2022 (UTC)<br />
<br />
::: Yes, thanks :) although there is a tiiiiiny advantage to the direct link without the template (the way I said), <code><nowiki>[[wikipedia:Pipe (computing)|]]</nowiki></code> becomes [[wikipedia:Pipe (computing)|Pipe]] whereas <code><nowiki>{{w|Pipe (computing)}}</nowiki></code> becomes {{w|Pipe (computing)}}. The pipe trick strips out the disambiguation parts of the title according to [[Wikipedia:Help:Pipe trick|some rules]]. --[[User:NeatNit|NeatNit]] ([[User talk:NeatNit|talk]]) 12:30, 28 July 2022 (UTC)<br />
:::: Why not <code><nowiki>{{w|Pipe (computing)|pipe}}</nowiki></code>? [[Special:Contributions/172.70.214.95|172.70.214.95]] 15:18, 28 July 2022 (UTC)<br />
<br />
It is missing that air-gapping the power supply would protect your home from voltage surges in the power network caused by lightning strikes. Depending where the lightning hits the power network, there may be no fuses protecting your home or single fuses may fail to protect you. --[[Special:Contributions/172.70.246.115|172.70.246.115]] 07:57, 28 July 2022 (UTC)<br />
:That is true. But the suggestion that this might have anything to do with general energy security (as is currently very prominent in the explanation) is entirely unconvincing to me.<br />
<br />
Incandescent light bulbs convert most of their energy to infrared light. There are solar cells that work in this infrared spectrum, so this might not be all that inefficient as stated. This should in fact be a lot more efficient than any LED+visible spectrum based panel, as incandescent bulbs are very efficient in converting electricity into infrared light, much more than LEDs most likely will ever be.<br />
The (mostly) omnidirectionality of the light source might be an even bigger loss, as most of the light (however efficient) does not even reach the panel.<br />
And regarding sending data over this construct: As soon as there's a 0V state (which will be the case as soon as the transmission starts, due to some form of manchester coding, regardless of it being a 0 or 1 bit) the PC behind the solar panel would not only have a data transmission problem :)<br />
(With incandescent bulb, that is. A LED 0V might be short enough for capacitors in the PC's power supply to buffer it, if it is only at 50%(+PSU conversion loss) load max, as manchester coded signals per definition have a duty cycle of 50% to keep the DC bias at 0V)<br />
[[Special:Contributions/172.68.51.204|172.68.51.204]] 08:26, 28 July 2022 (UTC)<br />
<br />
What is the highest wattage commercial opto-isolator, and how can I get one mounted from the ceiling in my bedroom? [[Special:Contributions/172.70.207.8|172.70.207.8]] 14:10, 28 July 2022 (UTC)<br />
<br />
I wonder if it's worth noting the significant understatement within the title text, where it says "the bitrate does drop a little" in contrast to the severe and drastic drop in bitrate that would actually occur, especially in light of today's typical Internet speeds. It might not be worth mentioning, but it struck me as a humorous understatement of the true impact. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 14:25, 28 July 2022 (UTC)<br />
<br />
I'm almost tempted to suggest that this should be an (honourary) addition to the Cursed Connectors comic-collection. [[Special:Contributions/172.71.94.187|172.71.94.187]] 14:56, 28 July 2022 (UTC)<br />
<br />
Yes, solar panels can transform electrical into electromagnetic signals. It is more on the side of the incandescent bulb that the capability to receive and forward these signals is missing. My source: https://www.youtube.com/watch?v=TGUteH93xNo<br />
[[User:Torge|Torge]] ([[User talk:Torge|talk]]) 15:11, 28 July 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=User:SqueakSquawk4&diff=290924User:SqueakSquawk42022-07-27T19:18:00Z<p>172.70.214.95: Wikilink</p>
<hr />
<div><noinclude>I have done a bunch of things! I wrote most of explanation for [[2527]], and created (Badly) the page for [[2616]]. I think I screwed that last one up though. I will add more later.<br />
<br />
----<br />
<br />
Hello people! You are probably looking for how I calculated the yield of a baloon made of helium-2. Well you're in luck!<br />
<br />
Calculation time! (Sorry). </noinclude>Helium-2 has a {{w|half-life}} of {{w|Isotopes_of_helium#List_of_isotopes|roughly 10<sup>-9</sup> seconds, or one nanosecond}}, and a mean life of [https://www.omnicalculator.com/chemistry/half-life roughly 1.44 nanoseconds.] For context, light travels at [https://www.google.com/search?q=1+speed+of+light+to+cm%2Fnanosecond roughly 30 cm per nanosecond.] This means that on a human scale the energy is released all at once, and we only have to calculate total energy released, and not worry about time taken.<br />
<br />
Helium-2 decays through 99.99% {{w|proton emission}}. For simplicity's sake, we'll call that 100%. Helium-2 is formed from two hydrogen-1s, and 1.25 megaelectron-volts, or as {{w|Isotopes_of_helium#Helium-2_(diproton)|an equation,}} [[2614: 2|<table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:7pt; text-size-adjust: none;"><tr><td>1</td></tr><tr><td>1</td></tr></table>]]H + [[2614: 2|<table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:7pt; text-size-adjust: none;"><tr><td>1</td></tr><tr><td>1</td></tr></table>]]H + 1.25 {{w|MeV}} = [[2614: 2|<table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:7pt; text-size-adjust: none;"><tr><td>2</td></tr><tr><td>2</td></tr></table>]]He. It therefore follows that decay from a helium-2 atom to two hydrogen-1 atoms would release 1.25 MeV,{{cn}} per the {{w|conservation law}}s of energy and mass.<br />
<br />
A moderately-sized balloon [https://www.balloonartonline.com/balloons-sizes-and-types-2/ might have a diameter of 12 inches.] Some calculations give this a volume of roughly 14.83 liters (assuming a spherical balloon.) If the balloon is at 1 atmosphere of pressure at 25 degrees Celsius, then [https://www.omnicalculator.com/chemistry/molar-mass-of-gas there would be 0.6058 mol] in the balloon, mean that there is 0.6058 * 6.022×10<sup>23</sup> atoms, or [https://www.convertunits.com/from/mol/to/atoms 364,800,000,000,000,000,000,000 atoms.]<br />
<br />
To recap, a helium-2 atom decaying results in 1.25 MeV of energy, and there are roughly 364.821 sextillion atoms in a balloon. <br />
<br />
Every atom will create 1.25 MeV of energy, and therefore 364.821 sextillion atoms will create [https://www.google.com/search?client=firefox-b-d&q=364%2C821%2C332%2C070%2C000%2C040%2C000%2C000*1.25 364.821*1.25 sextillion, or 456 sextillion MeV.] Interestingly, this is equal to {{w|Names of large numbers|456 nonillion electron volts}}, or {{w|Metric prefix|4.56 megayottaelectron-volts}}.<br />
<br />
456 sextillion megaelectron-volts is also equal to [https://www.google.com/search?q=456000000000000000000000+MeV+to+Megajoules roughly 73,100 megajoules,] or [https://www.google.com/search?q=73100+Megajoules+to+Tons+of+TNT 17.4 tons of TNT equivalent.]<noinclude><br />
<br />
This is rather big. but not massively so. The smallest nuclear bomb, the {{w|W54}}, had a yield of between 10 and 1000 {{w|TNT equivalent|tons of TNT}}. The largest conventional bomb, the {{w|GBU-43/B MOAB}}, has a yield of roughly 11 tons. The {{w|M67 grenade}} uses 180 grams of {{w|Composition B|TNT-RDX mixture}}. So while the Helium-2 baloon bomb would be larger than all conventional bombs, it would still be smaller than most nukes.<br />
<br />
----<br />
<br />
I have a discussion page now!<br />
<br />
</noinclude><!-- remove all these tags after subst:ing. ~~~~ --></div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2649:_Physics_Cost-Saving_Tips&diff=2908892649: Physics Cost-Saving Tips2022-07-27T06:26:14Z<p>172.70.214.95: /* Table of tips */ #notallobjects</p>
<hr />
<div>{{comic<br />
| number = 2649<br />
| date = July 22, 2022<br />
| title = Physics Cost-Saving Tips<br />
| image = physics_cost_saving_tips.png<br />
| titletext = I got banned from the county fair for handing out Helium-2 balloons. Apparently the instant massive plasma explosions violated some local ordinance or something.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FAUX VECTOR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
This is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time with a series of Physics Cost-Saving Tips. It also continues the previous [[2648: Chemicals]] comic's jocular theme of tricks to supposedly save money based on misinterpretations of science. <br />
<br />
It suggests four ways to reduce costs or provide something for free for physicists to save money on their research. For instance getting free electrons from a conductor or replacing regular {{w|helium}} with {{w|Isotopes_of_helium#Helium-2_(diproton)|helium 2}}. None of these would provide any real advantages even when possible to implement, and could even be very dangerous, see below in the [[#Table of tips|table]]. Obtaining money from physics experiments was also described in [[2007: Brookhaven RHIC]].<br />
<br />
In the title text, Randall claims to have been banned from the county fair for handing out helium-2 balloons because of the instant massive explosions caused by its radioactive decay (that helium-2 decays fast is mentioned in the comic, with a joke suggestion to use it quickly). He jokes that the balloons violated a local ordinance. {{w|Gas balloon|Helium balloons}} are often given out at county fairs and similar events, but they are filled with {{w|helium-4}} and therefore inert (a very small part will be {{w|Helium-3}}, 2 ppm). A balloon filled with helium-2 is a practical impossibility because of its nanosecond half-life. Assuming a 12-inch diameter balloon at 1 atmosphere of pressure, the balloon-bomb would have a yield of roughly 17 {{w|TNT equivalent|tons of TNT equivalent}}.<br />
{{cot|[[User:SqueakSquawk4|Calculations]]}}<br />
{{User:SqueakSquawk4}} <!-- SqueakSquawk4 prefers this not be subst:ed --><br />
{{cob}}<br />
The smallest nuclear bomb, the {{w|W54}}, had a yield of between 10 and 1,000 tons of TNT. The largest conventional bomb, the {{w|GBU-43/B MOAB}}, has a yield of roughly 11 tons. The {{w|2020 Beirut explosion}} was roughly equivalent to 500 tons. So, while the helium-2 balloon bomb would be larger than all conventional bombs, it would still be smaller than most nukes. Handing out what are effectively small atomic bombs at a county fair would not go down well with any surviving local authorities, so merely being banned is a very mild punishment. Criminal charges such as mass murder and terrorism would be more likely if it weren't for the absurd impossibility of the scenario.<br />
<br />
===Table of tips===<br />
{| class="wikitable"<br />
|-<br />
! scope="col" |Cost-Saving Tip<br />
! scope="col" |Explanation<br />
|-<br />
|Try replacing regular vectors with pseudovectors whenever possible<br />
|[[File:Torque animation.gif|frame|right|Relationship of pseudovectors {{w|torque}} ('''τ''') and {{w|angular momentum}} ('''L''') to "regular" Euclidian vectors {{w|Position (vector)|position}} ('''r'''), {{w|force}} ('''F'''), and linear {{w|momentum}} ('''p''') in an oscillatory rotating system. Not shown is the {{w|centripetal force}} of the spoke's {{w|Tension (physics)|tension}}, a Euclidian vector towards the axle proportional to linear momentum, converting it to angular momentum.]]<br />
<br />
The prefix "pseudo-" refers to an inauthentic variation of something. Fakes are usually cheaper than their original brand-name product, while often working just as well, so the comic implies a {{w|pseudovector}} could be a less expensive substitute for a regular vector. On the contrary, pseudovectors, or axial vectors, are distinct from regular {{w|Euclidean vector}}s, the former usually being involved with rotation or physical effects that share properties with rotation, similar to the relationship between angles and lengths. Pseudovectors are formed from the {{w|cross product}}s of Euclidean vectors, in three dimensions, and while similar to Euclidean vectors, there is no physical meaning to their specific direction, only their magnitude and portions of their position. For example, {{w|angular momentum}} is described by a pseudovector, labeled '''L''' in the comic, {{w|Normal (geometry)|normal}} to the {{w|plane of rotation}}, originating from the center of rotation, with magnitude equal to the angular velocity of rotation '''ω''' multiplied by the {{w|moment of inertia}} '''I'''. (The comic's diagram is drawn according to very uncommon {{w|Right-hand rule#Coordinates|left-handed coordinates}} instead of the standard {{w|right-hand rule}}. Randall is right-handed.[https://www.youtube.com/watch?v=j1tcyEo2tQk&t=28s])<br />
|-<br />
|A square wave can be broken down into an infinite supply of valuable sine waves<br />
|{{w|Fourier analysis}} can decompose any periodic function into a series of {{w|sine wave}}s. A {{w|square wave}} can thereby be represented as the sum of an infinite series of sine waves. However, the sine waves are not removed or separated individually, so such a {{w|Fourier transform}} does not produce a "supply" of sine waves for practical use in any tasks other than analysis, and as abstract mathematical objects exempt from the laws of supply and demand, their value is similarly limited.<br />
|-<br />
|Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
|Chemical elements are identified by the number of protons in each atomic nucleus, equal to the number of electrons in their shell (unless the atom is ionized), which dictates most of their chemical behavior. {{w|Isotopes}} are variants of the element with different numbers of neutrons in the nucleus, among which chemical behavior is usually nearly identical. The comic suggests that the neutrons don't serve any useful purpose, so, in theory, if purchasing an element by weight, and its isotopes have the same price per unit weight, then you can save money by buying isotopes with no neutrons at all. In reality, the cost per unit weight for material containing a larger concentration of normally rare isotopes, such as {{w|heavy water}} or {{w|enriched uranium}}, is much higher than the cost of material containing isotopes in their ordinary proportions. (An exception is {{w|depleted uranium}}, which costs less than regular uranium because it is a byproduct of the production of enriched uranium.) In addition, a certain range of neutron quantity is needed to keep atoms stable, as atoms with too many or too few neutrons will decay more quickly than the common isotopes. The image shown is helium-2, an {{w|Isotopes of helium|isotope of helium}} which has a half-life of less than a nanosecond. It decays into two ionized hydrogen atoms, releasing a large amount of energy—hence the explosions mentioned in the title text.<br />
|-<br />
|Conductors are a great source of free electrons (may carry charges)<br />
|{{w|Charge carrier|Free}} {{w|electron}}s are electrons that are not tightly bound to specific atoms so they can move freely, such as in {{w|conduction band}}s of the {{w|metallic bond}}s throughout the iron ingot depicted in the comic. Randall interprets "free" in a different sense, meaning no cost. The charges free electrons carry are electric, not monetary as implied by the pun. Ordinary matter usually contains electrons, but although the {{w|dielectric}} layer of a {{w|capacitor}} can collect electrons, it is not easy to store pure electrons, as they repel each other. When a {{w|Solution (chemistry)|solution}} has free electrons, it becomes {{w|alkaline}} and corrosive. Randall has [https://what-if.xkcd.com/140/ explained the problems] with collecting a large number of electrons before.<br />
|}<br />
<br />
==Transcript==<br />
:[The comic shows four rows each with a drawing and an explanation text belonging to each drawing. They alternate between having the drawing on the left and the right side. Above the first row is a large header:]<br />
:<big>Physics Cost-Saving Tips</big><br />
<br />
:[The first row has a drawing of a diagramatical spinning disc, at an angle. It is identified with an 'I', with a dotted axial arrow labelled 'L' and a rotational movement labelled 'ω' (small omega). <br />
:I<br />
:L<br />
:ω<br />
<br />
:[To the right of the diagram is this text:]<br />
:Try replacing regular vectors with pseudovectors whenever possible<br />
<br />
:[The second row shows a square wave with three maxima between four minima. Below the central maxima and the two nearby minima are five arrows pointing down (two bending left two right one straight down). Each arrow points to one of five sine waves below the square wave, in three rows, with different wavelengths. The one with the shortest wavelength is the top left, then the wavelength becomes longer for the one to the right and even longer for each of the next two, in the next row with the final very long wave with longest wavelength at the bottom, with the straight down arrow pointing to that. The long waves at the bottom has the same frequency as the square wave.]<br />
<br />
:[To the left of the waves is this text:]<br />
:A square wave can be broken down into an infinite supply of valuable sine waves<br />
<br />
:[The third row shows two atomic models. The left containing two protons (white with a "+" sign), two neutrons (black) and orbited by two electrons (white with a "-" sign, small outlines, dotted orbits/movement lines). The right model is drawn similarly but without the black neutrons.]<br />
:+ +<br />
:- -<br />
:+ +<br />
:- -<br />
<br />
:[The atoms have labels below and there is an extra message for the second model:]<br />
:<sup>4</sup>He<br />
:<sup>2</sup>He<br />
:<small>(Decays fast- use quickly)</small><br />
<br />
:[To the right of the models is this text:]<br />
:Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
<br />
:[The fourth row shows a flat rectangular bar, drawn in perspective with a scattering of four small circles with "-" sign inside them and ten lines looking like parts of circles, all on the top face towards the far end.]<br />
:- - - - <br />
<br />
:[A bending arrow goes from a label above the bar and points to one of the circles. And on the forward-facing side of the bar there is a label.]<br />
:Arrow: Free electrons<br />
:Label: Iron<br />
<br />
:[To the left of the bar is this text:]<br />
:Conductors are a great source of free electrons<br />
:(May carry charges)<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Tips]]<br />
[[Category:Physics]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2650:_Deepfakes&diff=290828Talk:2650: Deepfakes2022-07-26T06:48:25Z<p>172.70.214.95: No joke?</p>
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<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Is it worth mentioning that this comic is merely sincere discussion, without (please correct me if I'm wrong) any sort of a joke or irony? The closest it gets is hyperbole in the title text. I know it's not unique in this respect, but it does seem to be different than other such comics because it seems like it might have a joke, given the obscurity of the Ea-nasir reference. If our job is truly to explain, should we let people coming here to figure out the humor know there isn't any? [[Special:Contributions/172.70.214.95|172.70.214.95]] 06:48, 26 July 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2650:_Deepfakes&diff=2908272650: Deepfakes2022-07-26T06:43:17Z<p>172.70.214.95: /* Explanation */ traditional to link characters</p>
<hr />
<div>{{comic<br />
| number = 2650<br />
| date = July 25, 2022<br />
| title = Deepfakes<br />
| image = deepfakes.png<br />
| titletext = If so great a deductive mind as Arthur Conan Doyle can be fooled by the Cottingley Deepfakes, what chance do we mortals have? Soon our very reality will be dictated by the whims of Frances (9) and Elsie (16).<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a DEEPFAKE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
A {{w|deepfake}} is an altered video, designed to deceive by replacing a person in a video. [[White Hat]] believes that this technology will make it difficult to trust videos. However, [[Cueball]] responds by saying that "fakes" have always existed, in photos (either through {{w|photoshopping|alterations by software such as Adobe Photoshop}}, or deliberately staging fakes images, e.g. the {{w|Loch Ness Monster}}) and even moreso by people simply lying. White Hat comes around to Cueball's position and says that even the written word is prone to deception and lying.<br />
<br />
Scientific studies of deepfakes have produced surprising results, suggesting that they are more likely to increase uncertainty than persuade,[https://journals.sagepub.com/doi/full/10.1177/2056305120903408] that their increased prevalence could inoculate the public against {{w|disinformation}},[https://dspace.cuni.cz/handle/20.500.11956/150489] and that they are more likely to be shared because of their humorousness than persuasiveness.[http://essay.utwente.nl/91654/] Other studies have found that deepfakes are persuasive, especially among those who are unfamiliar with them.[https://www.liebertpub.com/doi/abs/10.1089/cyber.2020.0174][https://www.osti.gov/biblio/1780812]<br />
<br />
The {{w|complaint tablet to Ea-nasir}} is an ancient clay tablet, in which a customer complains to a merchant, Ea-nasir, about his copper ingots. Cueball's last statement says that perhaps this complaint could've been a lie to begin with, and there was nothing wrong with Ea-nasir's wares.<br />
<br />
The title text references the {{w|Cottingley Fairies}}, a series of photographs of "fairies" by two children, Elsie Wright and Frances Griffiths, who were 16 and 9, respectively. The photographs received widespread attention when Sir {{w|Arthur Conan Doyle}}, the author of the Sherlock Holmes series, used the photos as proof of paranormal phenomena in a 1920 magazine article. In 1983, Elsie and Frances confessed that the photos had been faked.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:[White Hat and Cueball walking to the right]<br />
:White Hat: Thanks to deepfakes, soon we won't know what's real anymore. Video will become meaningless.<br />
<br />
:[White Hat and Cueball continuing to walk to the right]<br />
:Cueball: I dunno.<br />
:Cueball: We've had Photoshop for decades and staged photos for centuries.<br />
:Cueball: It hasn't made photos meaningless.<br />
<br />
:[Zoom in on Cueball]<br />
:Cueball: The bottleneck for fake stuff isn't technical. The bottleneck is willingness to lie.<br />
:Cueball: "People lying" is a very old problem.<br />
:Cueball: It's a known exploit.<br />
<br />
:[Zoom back out on White Hat and Cueball who have stopped. White Hat has a hand on his chin. Cueball has his hands to the side.]<br />
:White Hat: I guess technically we've been able to make ''text'' deepfakes for 5,000 years.<br />
:Cueball: Maybe Ea-nasir's copper ingots were actually fine!<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring White Hat]]<br />
[[Category:Comics featuring real people]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=664:_Academia_vs._Business&diff=290566664: Academia vs. Business2022-07-24T19:59:37Z<p>172.70.214.95: Undo revision 290564 by Davidy22 the tranny killer (talk)</p>
<hr />
<div>{{comic<br />
| number = 664<br />
| date = November 18, 2009<br />
| title = Academia vs. Business<br />
| image = academia_vs_business.png<br />
| titletext = Some engineer out there has solved P=NP and it's locked up in an electric eggbeater calibration routine. For every 0x5f375a86 we learn about, there are thousands we never see.<br />
}}<br />
<br />
== Explanation ==<br />
[[Cueball]] has solved some tricky and very important problem in computer science, related to {{w|queueing theory}}.<br />
<br />
The comic splits into two timelines. Showing the brilliant computer code he'd written to somebody who actually knows computer code allows the academic to see the programmer's true brilliance and get him much-earned plaudits from the academic community.<br />
<br />
In the alternate timeline – implied to be what ''actually'' happens – the boss, not possessing that knowledge, simply sees the results and not the means Cueball used to attain them. He then gives Cueball another assignment. This, sadly, is the usual course of events in bureaucracy, which only seems to care about your results, not how you came about them. To drive in the point, the boss asks Cueball to do something as simple as setting up email on the office phones, a stark contrast to the skill and creativity Cueball would have needed to write his code in the first panel.<br />
<br />
The references in the title text are to the {{w|P versus NP problem}}, a famous unsolved problem in computer science, and the "magical constant" (0x5f375a86) used in finding the {{w|fast inverse square root}}, i.e. solving y=1/√x as fast as possible through a program – no-one knows quite who came up with this very useful bit of code (Now believed to be devised by Greg Walsh at Ardent Computer in consultation with Cleve Moler, the creator of MATLAB. see wikipedia), but it was discovered hiding in the graphics code of the video game {{w|Quake III Arena}}. Note that the actual constant used in the Quake III source code is 0x5f375'''9df''', but the constant in the title text works also, and is actually slightly more accurate as shown in this paper: [http://www.lomont.org/Math/Papers/2003/InvSqrt.pdf Fast inverse square root by CHRIS LOMONT (Purdue university, 2003)].<br />
<br />
The title text may be a reference to {{w|Stephen Jay Gould}}'s quotation: “I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops.” originally about how great minds are suppressed due to racism and their genius go unknown, but could be interpreted as general exploitation by the commercial world.<br />
<br />
==Transcript==<br />
:[Cueball sits at a desk in front of a computer, leaning back in his chair with both hands down to his side. There are cans on the desk and more crushed ones on the floor.]<br />
:Cueball: I just wrote the most beautiful code of my life.<br />
<br />
:[Zoom in on Cueball and top half of desk.]<br />
:Cueball: They casually handed me an impossible problem. In 48 hours and 200 lines, I ''solved'' it.<br />
<br />
:[Curved lines with arrows divide the comic into two possible end panels, labeled "Academia" and "Business."]<br />
<br />
:Academia:<br />
:Professor: My god... this will mean a half-dozen papers, a thesis or two, and a paragraph in every textbook on queuing theory!<br />
<br />
:Business:<br />
:Boss: You got the program to stop jamming up? Great. While you're fixing stuff, can you get Outlook to sync with our new phones?<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Programming]]<br />
[[Category:Multiple Cueballs]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2649:_Physics_Cost-Saving_Tips&diff=2905652649: Physics Cost-Saving Tips2022-07-24T19:59:13Z<p>172.70.214.95: Undo revision 290563 by Davidy22 the tranny killer (talk)</p>
<hr />
<div>{{comic<br />
| number = 2649<br />
| date = July 22, 2022<br />
| title = Physics Cost-Saving Tips<br />
| image = physics_cost_saving_tips.png<br />
| titletext = I got banned from the county fair for handing out Helium-2 balloons. Apparently the instant massive plasma explosions violated some local ordinance or something.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FAUX VECTOR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time to reduce costs or provide something for free for physicists to save money on their research. None of these would provide any real advantages even when possible to implement. It continues the previous [[2648: Chemicals]] comic's jocular theme of tricks to supposedly save money based on misinterpretations of science. Obtaining money from physics experiments was also described in [[2007: Brookhaven RHIC]].<br />
<br />
{| class="wikitable"<br />
|-<br />
! scope="col" |Cost-Saving Tip<br />
! scope="col" |Explanation<br />
|-<br />
|Try replacing regular vectors with pseudovectors whenever possible<br />
|[[File:Torque animation.gif|frame|right|Relationship of pseudovectors {{w|torque}} ('''τ''') and {{w|angular momentum}} ('''L''') to "regular" Euclidian vectors {{w|Position (vector)|position}} ('''r'''), {{w|force}} ('''F'''), and linear {{w|momentum}} ('''p''') in an oscillatory rotating system. Not shown is the {{w|centripetal force}} of the spoke's {{w|Tension (physics)|tension}}, a Euclidian vector towards the axle proportional to linear momentum, converting it to angular momentum.]]<br />
<br />
The prefix "pseudo-" refers to an inauthentic variation of something. Fakes are usually cheaper than their original brand-name product, while often working just as well, so the comic implies a {{w|pseudovector}} could be a less expensive substitute for a regular vector. On the contrary, pseudovectors, or axial vectors, are distinct from regular {{w|Euclidean vector}}s, the former usually being involved with rotation or physical effects that share properties with rotation, similar to the relationship between angles and lengths. Pseudovectors are formed from the {{w|cross product}}s of Euclidean vectors, in three dimensions, and while similar to Euclidean vectors, there is no physical meaning to their specific direction, only their magnitude and portions of their position. For example, {{w|angular momentum}} is described by a pseudovector, labeled '''L''' in the comic, {{w|Normal (geometry)|normal}} to the {{w|plane of rotation}}, originating from the center of rotation, with magnitude equal to the angular velocity of rotation '''ω''' multiplied by the {{w|moment of inertia}} '''I'''. (The comic's diagram is drawn according to very uncommon {{w|Right-hand rule#Coordinates|left-handed coordinates}} instead of the standard {{w|right-hand rule}}. Randall is right-handed.[https://www.youtube.com/watch?v=j1tcyEo2tQk&t=28s])<br />
|-<br />
|A square wave can be broken down into an infinite supply of valuable sine waves<br />
|{{w|Fourier analysis}} can decompose any periodic function into a series of {{w|sine wave}}s. A {{w|square wave}} can thereby be represented as the sum of an infinite series of sine waves. However, the sine waves are not removed or separated individually, so such a {{w|Fourier transform}} does not produce a "supply" of sine waves for practical use in any tasks other than analysis, and as abstract mathematical objects exempt from the laws of supply and demand, their value is similarly limited.<br />
|-<br />
|Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
|Chemical elements are identified by the number of protons in each atomic nucleus, equal to the number of electrons in their shell (unless the atom is ionized), which dictates most of their chemical behavior. {{w|Isotopes}} are variants of the element with different numbers of neutrons in the nucleus, among which chemical behavior is usually nearly identical. The comic suggests that the neutrons don't serve any useful purpose, so, in theory, if purchasing an element by weight, and its isotopes have the same price per unit weight, then you can save money by buying isotopes with no neutrons at all. In reality, the cost per unit weight for material containing a larger concentration of normally rare isotopes, such as {{w|heavy water}} or {{w|enriched uranium}}, is much higher than the cost of material containing isotopes in their ordinary proportions. (An exception is {{w|depleted uranium}}, which costs less than regular uranium because it is a byproduct of the production of enriched uranium.) In addition, a certain range of neutron quantity is needed to keep atoms stable, as atoms with too many or too few neutrons will decay more quickly than the common isotopes. The image shown is helium-2, an {{w|Isotopes of helium|isotope of helium}} which has a half-life of less than a nanosecond. It decays into two ionized hydrogen atoms, releasing a large amount of energy—hence the explosions mentioned in the title text.<br />
|-<br />
|Conductors are a great source of free electrons (may carry charges)<br />
|{{w|Charge carrier|Free}} {{w|electron}}s are electrons that are not tightly bound to specific atoms so they can move freely, such as in {{w|conduction band}}s of the {{w|metallic bond}}s throughout the iron ingot depicted in the comic. Randall interprets "free" in a different sense, meaning no cost. The charges free electrons carry are electric, not monetary as implied by the pun.<br />
|}<br />
<br />
In the title text, Randall claims to have been banned from the county fair for handing out helium-2 balloons because of the instant massive explosions caused by its radioactive decay. He jokes they violated a local ordinance. Helium balloons are often given out at county fairs and similar events, but they are filled with helium-4 and therefore inert. A balloon filled with helium-2 is a practical impossibility because of its sub-nanosecond half-life. Assuming a 12-inch diameter balloon at 1 atmosphere of pressure, the balloon-bomb would have a yield of roughly 18 {{w|TNT equivalent|tons of TNT equivalent}}.<br />
<br />
{{cot|[[User:SqueakSquawk4|Calcuations]]}}<br />
{{User:SqueakSquawk4}} <!-- want to subst: this if it's okay with SqueakSquawk4 --><br />
{{cob}}<br />
<br />
The smallest nuclear bomb, the {{w|W54}}, had a yield of between 10 and 1,000 tons of TNT. The largest conventional bomb, the {{w|GBU-43/B MOAB}}, has a yield of roughly 11 tons. The {{w|2020 Beirut explosion}} was roughly equivalent to 500 tons of TNT.[https://link.springer.com/article/10.1007/s00193-021-00992-1] So, while the helium-2 balloon bomb would be larger than all conventional bombs, it would still be smaller than most nukes. Handing out what are effectively small atomic bombs at a county fair would not go down well with any surviving local authorities, so merely being banned is a very mild punishment. Criminal charges such as mass murder and terrorism would be more likely if it weren't for the absurd impossibility of the scenario.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Title]<br />
:Physics Cost-Saving Tips<br />
<br />
:[A diagramatical spinning disc, at an angle]<br />
:[It is identified with an 'I', with a dotted axial arrow labelled 'L' and a rotational movement labelled 'ω' (small omega)]<br />
:[It sits on the left, and to the right of this is text...]<br />
:Try replacing regular vectors with pseudovectors whenever possible<br />
<br />
:[A square wave with three maxima (between four minima), and arrows pointing down into a collection of five sine waves of different wavelengths]<br />
:[One of the waves having the same frequency as the square wave and the rest of them are of shorter lengths with more peaks and troughs]<br />
:[It sits on the right, and to the left of this is text...]<br />
:A square wave can be broken down into an infinite supply of valuable sine waves<br />
<br />
:[Two atomic models]<br />
:[The left containing two protons (white with a "+" sign), two neutrons (black) and orbited by two electrons (small outlines, dotted orbits/movement lines), labelled below with the text of superscript atomic weight and element symbol]<br />
:<sup>4</sup>He<br />
:[The right model has just the two protons and the two electrons, labelled below with the text of an atomic weight and elemental symbol, and some subtext within brackets]<br />
:<sup>2</sup>He<br />
:(Decays fast - use quickly)<br />
:[Both models sit on the left of the comic, and to the right is text...]<br />
:Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
<br />
:[A flat rectangular bar, drawn in perspective with a scattering of dots/small circles on the top face and on the forward-facing one the label]<br />
:Iron<br />
:[An arrow points to the dots, from the text...]<br />
:Free electrons<br />
:[It sits to the right, and there is text to the left...]<br />
:Conductors are a great source of free electrons<br />
:(May carry charges)<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Tips]]<br />
[[Category:Physics]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2649:_Physics_Cost-Saving_Tips&diff=2905022649: Physics Cost-Saving Tips2022-07-24T14:54:06Z<p>172.70.214.95: /* Explanation */ spelling, replace incomparable dinky grenade with an event many probably remember from news and viral vids</p>
<hr />
<div>{{comic<br />
| number = 2649<br />
| date = July 22, 2022<br />
| title = Physics Cost-Saving Tips<br />
| image = physics_cost_saving_tips.png<br />
| titletext = I got banned from the county fair for handing out Helium-2 balloons. Apparently the instant massive plasma explosions violated some local ordinance or something.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FAUX VECTOR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time to reduce costs or provide something for free for physicists to save money on their research. None of these would provide any real advantages even when possible to implement. It continues the previous [[2648: Chemicals]] comic's jocular theme of tricks to supposedly save money based on misinterpretations of science. Obtaining money from physics experiments was also described in [[2007: Brookhaven RHIC]].<br />
<br />
{| class="wikitable"<br />
|-<br />
! scope="col" |Cost-Saving Tip<br />
! scope="col" |Explanation<br />
|-<br />
|Try replacing regular vectors with pseudovectors whenever possible<br />
|[[File:Torque animation.gif|frame|right|Relationship of pseudovectors {{w|torque}} ('''τ''') and {{w|angular momentum}} ('''L''') to "regular" Euclidian vectors {{w|Position (vector)|position}} ('''r'''), {{w|force}} ('''F'''), and linear {{w|momentum}} ('''p''') in an oscillatory rotating system. Not shown is the {{w|centripetal force}} of the spoke's {{w|Tension (physics)|tension}}, a Euclidian vector towards the axle proportional to linear momentum, converting it to angular momentum.]]<br />
<br />
The prefix "pseudo-" refers to an inauthentic variation of something. Fakes are usually cheaper than their original brand-name product, while often working just as well, so the comic implies a {{w|pseudovector}} could be a less expensive substitute for a regular vector. On the contrary, pseudovectors, or axial vectors, are distinct from regular {{w|Euclidean vector}}s, the former usually being involved with rotation or physical effects that share properties with rotation, similar to the relationship between angles and lengths. Pseudovectors are formed from the {{w|cross product}}s of Euclidean vectors, in three dimensions, and while similar to Euclidean vectors, there is no physical meaning to their specific direction, only their magnitude and portions of their position. For example, {{w|angular momentum}} is described by a pseudovector, labeled '''L''' in the comic, {{w|Normal (geometry)|normal}} to the {{w|plane of rotation}}, originating from the center of rotation, with magnitude equal to the angular velocity of rotation '''ω''' multiplied by the {{w|moment of inertia}} '''I'''. (The comic's diagram is drawn according to very uncommon {{w|Right-hand rule#Coordinates|left-handed coordinates}} instead of the standard {{w|right-hand rule}}. Randall is right-handed.[https://www.youtube.com/watch?v=j1tcyEo2tQk&t=28s])<br />
|-<br />
|A square wave can be broken down into an infinite supply of valuable sine waves<br />
|{{w|Fourier analysis}} can decompose any periodic function into a series of {{w|sine wave}}s. A {{w|square wave}} can thereby be represented as the sum of an infinite series of sine waves. However, the sine waves are not removed or separated individually, so such a {{w|Fourier transform}} does not produce a "supply" of sine waves for practical use in any tasks other than analysis, and as abstract mathematical objects exempt from the laws of supply and demand, their value is similarly limited.<br />
|-<br />
|Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
|Chemical elements are identified by the number of protons in each atomic nucleus, equal to the number of electrons in their shell (unless the atom is ionized), which dictates most of their chemical behavior. {{w|Isotopes}} are variants of the element with different numbers of neutrons in the nucleus, among which chemical behavior is usually nearly identical. The comic suggests that the neutrons don't serve any useful purpose, so, in theory, if purchasing an element by weight, and its isotopes have the same price per unit weight, then you can save money by buying isotopes with no neutrons at all. In reality, the cost per unit weight for material containing a larger concentration of normally rare isotopes, such as {{w|heavy water}} or {{w|enriched uranium}}, is much higher than the cost of material containing isotopes in their ordinary proportions. (An exception is {{w|depleted uranium}}, which costs less than regular uranium because it is a byproduct of the production of enriched uranium.) In addition, a certain range of neutron quantity is needed to keep atoms stable, as atoms with too many or too few neutrons will decay more quickly than the common isotopes. The image shown is helium-2, an {{w|Isotopes of helium|isotope of helium}} which has a half-life of less than a nanosecond. It decays into two ionized hydrogen atoms, releasing a large amount of energy—hence the explosions mentioned in the title text.<br />
|-<br />
|Conductors are a great source of free electrons (may carry charges)<br />
|{{w|Charge carrier|Free}} {{w|electron}}s are electrons that are not tightly bound to specific atoms so they can move freely, such as in {{w|conduction band}}s of the {{w|metallic bond}}s throughout the iron ingot depicted in the comic. Randall interprets "free" in a different sense, meaning no cost. The charges free electrons carry are electric, not monetary as implied by the pun.<br />
|}<br />
<br />
In the title text, Randall claims to have been banned from the county fair for handing out helium-2 balloons because of the instant massive explosions caused by its radioactive decay. He jokes they violated a local ordinance. Helium balloons are often given out at county fairs and similar events, but they are filled with helium-4 and therefore inert. A balloon filled with helium-2 is a practical impossibility because of its sub-nanosecond half-life. Assuming a 12-inch diameter balloon at 1 atmosphere of pressure, the balloon-bomb would have a yield of roughly 18 {{w|TNT equivalent|tons of TNT equivalent}}.<br />
<br />
{{cot|[[User:SqueakSquawk4|Calcuations]]}}<br />
{{User:SqueakSquawk4}} <!-- want to subst: this if it's okay with SqueakSquawk4 --><br />
{{cob}}<br />
<br />
The smallest nuclear bomb, the {{w|W54}}, had a yield of between 10 and 1000 {{w|TNT equivalent|tons of TNT equivalent}}. The largest conventional bomb, the {{w|GBU-43/B MOAB}}, has a yield of roughly 11 tons. The {{w|2020 Beirut explosion}} was roughly equivalent to 500 tons of TNT.[https://link.springer.com/article/10.1007/s00193-021-00992-1] So, while the helium-2 balloon bomb would be larger than all conventional bombs, it would still be smaller than most nukes. Handing out what are effectively small atomic bombs at a county fair would not go down well with any surviving local authorities, so merely being banned is a very mild punishment. Criminal charges such as mass murder and terrorism would be more likely if it weren't for the absurd impossibility of the scenario.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Title]<br />
:Physics Cost-Saving Tips<br />
<br />
:[A diagramatical spinning disc, at an angle]<br />
:[It is identified with an 'I', with a dotted axial arrow labelled 'L' and a rotational movement labelled 'ω' (small omega)]<br />
:[It sits on the left, and to the right of this is text...]<br />
:Try replacing regular vectors with pseudovectors whenever possible<br />
<br />
:[A square wave with three maxima (between four minima), and arrows pointing down into a collection of five sine waves of different wavelengths]<br />
:[One of the waves having the same frequency as the square wave and the rest of them are of shorter lengths with more peaks and troughs]<br />
:[It sits on the right, and to the left of this is text...]<br />
:A square wave can be broken down into an infinite supply of valuable sine waves<br />
<br />
:[Two atomic models]<br />
:[The left containing two protons (white with a "+" sign), two neutrons (black) and orbited by two electrons (small outlines, dotted orbits/movement lines), labelled below with the text of superscript atomic weight and element symbol]<br />
:<sup>4</sup>He<br />
:[The right model has just the two protons and the two electrons, labelled below with the text of an atomic weight and elemental symbol, and some subtext within brackets]<br />
:<sup>2</sup>He<br />
:(Decays fast - use quickly)<br />
:[Both models sit on the left of the comic, and to the right is text...]<br />
:Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
<br />
:[A flat rectangular bar, drawn in perspective with a scattering of dots/small circles on the top face and on the forward-facing one the label]<br />
:Iron<br />
:[An arrow points to the dots, from the text...]<br />
:Free electrons<br />
:[It sits to the right, and there is text to the left...]<br />
:Conductors are a great source of free electrons<br />
:(May carry charges)<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Tips]]<br />
[[Category:Physics]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2649:_Physics_Cost-Saving_Tips&diff=2904442649: Physics Cost-Saving Tips2022-07-24T07:16:58Z<p>172.70.214.95: /* Explanation */ spurious comma</p>
<hr />
<div>{{comic<br />
| number = 2649<br />
| date = July 22, 2022<br />
| title = Physics Cost-Saving Tips<br />
| image = physics_cost_saving_tips.png<br />
| titletext = I got banned from the county fair for handing out Helium-2 balloons. Apparently the instant massive plasma explosions violated some local ordinance or something.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FAUX VECTOR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time to reduce costs or provide something for free for physicists to save money on their research. None of them would provide any real advantages, even when possible to implement. It continues the previous [[2648: Chemicals]] comic's jocular theme of tricks to supposedly save money based on misinterpretations of science. Saving money from science experiments was also described in [[2007: Brookhaven RHIC]].<br />
<br />
{| class="wikitable"<br />
|-<br />
! scope="col" |Cost-Saving Tip<br />
! scope="col" |Explanation<br />
|-<br />
|Try replacing regular vectors with pseudovectors whenever possible<br />
|[[File:Torque animation.gif|frame|right|Relationship of Euclidian vectors {{w|force}} ('''F'''), {{w|momentum}} ('''p'''), and {{w|Position (vector)|position}} ('''r''') to pseudovectors {{w|angular momentum}} ('''L''') and {{w|torque}} ('''τ''') in an oscillatory rotating system.]]<br />
<br />
The prefix "pseudo-" refers to an inauthentic variation of something. Fakes are usually cheaper than their original brand-name product, while often working just as well, so the comic implies a {{w|pseudovector}} could be a less expensive substitute for a regular vector. On the contrary, pseudovectors, or axial vectors, are distinct alternatives to regular {{w|Euclidean vector}}s, the former usually being involved with rotation or physical effects that share properties with rotation, similar to the relationship between angles and lengths. Pseudovectors are formed from the {{w|cross product}}s of Euclidean vectors, in three dimensions, and while similar to Euclidean vectors, there is no physical meaning to their specific direction, only their magnitude and portions of their position. For example, {{w|angular momentum}} is described by a pseudovector, labeled '''L''' in the comic, {{w|Normal (geometry)|normal}} to the {{w|plane of rotation}}, originating from the center of rotation, with magnitude proportional to the angular velocity of rotation '''ω''' multiplied by '''I''', the {{w|moment of inertia}}. (For some reason, the comic's diagram is drawn according to very uncommon {{w|Right-hand rule#Coordinates|left-handed coordinates}} instead of the standard {{w|right-hand rule}}. Randall is right-handed.[https://www.youtube.com/watch?v=j1tcyEo2tQk&t=28s])<br />
|-<br />
|A square wave can be broken down into an infinite supply of valuable sine waves<br />
|{{w|Fourier analysis}} can decompose any periodic function into a series of {{w|sine wave}}s. A {{w|square wave}} can thereby be represented as the sum of an infinite series of sine waves. However, the sine waves are not removed or separated individually, so such a {{w|Fourier transform}} does not produce a "supply" of sine waves for practical use in any tasks other than analysis, and as abstract mathematical objects exempt from the laws of supply and demand, their value is similarly limited.<br />
|-<br />
|Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
|Chemical elements are identified by the number of protons in each atomic nucleus, equal to the number of electrons in their shell (unless the atom is ionized), which dictates most of their chemical behavior. {{w|Isotopes}} are variants of the element with different numbers of neutrons in the nucleus, among which chemical behavior is usually nearly identical. The comic suggests that the neutrons don't serve any useful purpose, so, in theory, if purchasing an element by weight, and its isotopes have the same price per unit weight, then you can save money by buying isotopes with no neutrons at all. In reality, the cost per unit weight for material containing a larger concentration of normally rare isotopes, such as {{w|heavy water}} or {{w|enriched uranium}}, is much higher than the cost of material containing isotopes in their ordinary proportions. (An exception is {{w|depleted uranium}}, which costs less than regular uranium because it is a byproduct of the production of enriched uranium.) In addition, a certain range of neutron quantity is needed to keep atoms stable, as atoms with too many or too few neutrons will decay more quickly than the common isotopes. The image shown is helium-2, an {{w|Isotopes of helium|isotope of helium}} which has a half-life of less than a nanosecond. It decays into two protons, releasing a large amount of energy—hence the explosion mentioned in the title text.<br />
|-<br />
|Conductors are a great source of free electrons (may carry charges)<br />
|{{w|Charge carrier|Free}} {{w|electron}}s are electrons that are not tightly bound to specific atoms so they can move freely, such as in {{w|conduction band}}s of the {{w|metallic bond}}s throughout the iron ingot depicted in the comic. Randall interprets "free" in a different sense, meaning no cost. The charges free electrons carry are electric, not monetary as implied by the pun.<br />
|}<br />
<br />
In the title text [[Randall]] claims to have been banned from the county fair for handing out helium-2 balloons, presumably because of the massive explosions caused by its immediate radioactive decay. He jokes that this, "violated some local ordinance or something." Helium balloons are often given out at county fairs and similar events, but they are filled with helium-4, and therefore inert. If a balloon was filled with helium-2, the results would be instantly explosive, comparable to 2,000 kg of {{w|TNT}}. Handing out what are effectively atomic bombs at a county fair would not go down well with any surviving local authorities, so merely being banned is a very mild punishment. Criminal charges such as mass murder and terrorism would be more likely, if it weren't for the sub-nanosecond fuse length rendering the scenario absurdly impossible. For comparison, the {{w|AIR-2 Genie}} nuclear air-to-ground rocket was equivalent to 1.5 kilotons of TNT, {{w|Little Boy|the bomb dropped on Hiroshima}} was about 15 kilotons, and the {{w|2020 Beirut explosion}} was equivalent to between 0.3 and 1.1 kilotons.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Title]<br />
:Physics Cost-Saving Tips<br />
<br />
:[A diagramatical spinning disc, at an angle]<br />
:[It is identified with an 'I', with a dotted axial arrow labelled 'L' and a rotational movement labelled 'ω' (small omega)]<br />
:[It sits on the left, and to the right of this is text...]<br />
:Try replacing regular vectors with pseudovectors whenever possible<br />
<br />
:[A square wave with three maxima (between four minima), and arrows pointing down into a collection of five sine waves of different wavelengths]<br />
:[One of the waves having the same frequency as the square wave and the rest of them are of shorter lengths with more peaks and troughs]<br />
:[It sits on the right, and to the left of this is text...]<br />
:A square wave can be broken down into an infinite supply of valuable sine waves<br />
<br />
:[Two atomic models]<br />
:[The left containing two protons (white with a "+" sign), two neutrons (black) and orbited by two electrons (small outlines, dotted orbits/movement lines), labelled below with the text of superscript atomic weight and element symbol]<br />
:<sup>4</sup>He<br />
:[The right model has just the two protons and the two electrons, labelled below with the text of an atomic weight and elemental symbol, and some subtext within brackets]<br />
:<sup>2</sup>He<br />
:(Decays fast - use quickly)<br />
:[Both models sit on the left of the comic, and to the right is text...]<br />
:Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
<br />
:[A flat rectangular bar, drawn in perspective with a scattering of dots/small circles on the top face and on the forward-facing one the label]<br />
:Iron<br />
:[An arrow points to the dots, from the text...]<br />
:Free electrons<br />
:[It sits to the right, and there is text to the left...]<br />
:Conductors are a great source of free electrons<br />
:(May carry charges)<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Tips]]<br />
[[Category:Physics]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2649:_Physics_Cost-Saving_Tips&diff=2902782649: Physics Cost-Saving Tips2022-07-23T07:20:46Z<p>172.70.214.95: /* Explanation */ Euclidean vector is a more common name</p>
<hr />
<div>{{comic<br />
| number = 2649<br />
| date = July 22, 2022<br />
| title = Physics Cost-Saving Tips<br />
| image = physics_cost_saving_tips.png<br />
| titletext = I got banned from the county fair for handing out Helium-2 balloons. Apparently the instant massive plasma explosions violated some local ordinance or something.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FAUX VECTOR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic continues the previous [[2648: Chemicals]] comic's jocular theme of tricks to supposedly save money based on misinterpretations of science. Here is a list of "cost-saving tips" which would seem to reduce a cost or provide something for free, allowing physicists to save money in their research.<br />
<br />
* The prefix "pseudo-" refers to an inauthentic variation of something. Fakes are usually cheaper than their original brand-name product, while often working just as well, so the comic implies a {{w|pseudovector}} could be a less expensive substitute for a regular vector. On the contrary, pseudovectors, or axial vectors, are distinct alternatives to regular {{w|Euclidean vector}}s, the former usually being involved with rotation or physical effects that share properties with rotation, similar to the relationship between angles and lengths. Pseudovectors are formed from the {{w|cross product}}s of Euclidean vectors, and while similar to Euclidean vectors, there is no physical meaning to their specific direction, only their magnitude and portions of their position. For example, {{w|angular velocity}} is described by a pseudovector (labeled 'L' in the comic) {{w|Normal (geometry)|normal}} to the {{w|plane of rotation}}, originating from the center of rotation, with magnitude proportional to the velocity ('ω') of rotation. <br />
<br />
* {{w|Fourier analysis}} can decompose any periodic function into a series of {{w|sine wave}}s. A {{w|square wave}} can thereby be represented as the sum of an infinite series of sine waves. However, the sine waves are not removed or separated individually, so such a {{w|Fourier transform}} does not produce a "supply" of sine waves for practical use in any tasks other than analysis, and as abstract mathematical objects exempt from the laws of supply and demand, their value is similarly limited.<br />
<br />
* Chemical elements are identified by the number of protons in each atomic nucleus, equal to the number of electrons in their shell (unless the atom is ionized), which dictates most of their chemical behavior. {{w|Isotopes}} are variants of the element with different numbers of neutrons in the nucleus, among which chemical behavior is usually nearly identical. The comic suggests that the neutrons don't serve any useful purpose, so, in theory, if purchasing an element by weight, and its isotopes have the same price per unit weight, then you can save money by buying isotopes with no neutrons at all. In reality, the cost per unit weight for material containing a larger concentration of normally rare isotopes, such as {{w|heavy water}} or {{w|enriched uranium}}, is much higher than the cost of material containing isotopes in their ordinary proportions. (An exception is {{w|depleted uranium}}, which costs less than regular uranium because it is a waste product from the production of enriched uranium.) In addition, a certain range of neutron quantity is needed to keep atoms stable, as atoms with too many or too few neutrons will decay more quickly than the common isotopes. <br />
<br />
: The image shown is helium-2, an {{w|Isotopes of helium|isotope of helium}} which has a half-life of less than a nanosecond. It decays into two protons, releasing a large amount of energy—hence the explosion mentioned in the title text. Helium balloons are often given out at county fairs and other similar events, but they are filled with helium-4, and therefore inert. If a balloon was filled with helium-2, as the title text suggests, the results would be immediately explosive, comparable to 2,000 kg of {{w|TNT}}. Handing out what are effectively bombs at a county fair would not go down well with local authorities, and therefore being banned from the fair is a very mild punishment. Criminal charges such as mass murder and terrorism would be more likely, if it weren't for the sub-nanosecond fuse length rendering the scenario absurdly impossible.<br />
<br />
* {{w|Charge carrier|Free}} {{w|electron}}s are electrons that are not tightly bound to specific atoms so they can move freely, such as in {{w|conduction band}}s of the {{w|metallic bond}}s throughout the iron ingot depicted in the comic. Randall interprets "free" in a different sense, meaning no cost. The charges free electrons carry are electric, not monetary as implied by this pun.<br />
<br />
Saving money from science experiments like this was also mentioned in [[2007: Brookhaven RHIC]].<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Title]<br />
:Physics Cost-Saving Tips<br />
<br />
:[A diagramatical spinning disc, at an angle]<br />
:[It is identified with an 'I', with a dotted axial arrow labelled 'L' and a rotational movement labelled 'ω' (small omega)]<br />
:[It sits on the left, and to the right of this is text...]<br />
:Try replacing regular vectors with pseudovectors whenever possible<br />
<br />
:[A square wave with three maxima (between four minima), and arrows pointing down into a collection of five sine waves of different wavelengths]<br />
:[One of the waves having the same frequency as the square wave and the rest of them are of shorter lengths with more peaks and troughs]<br />
:[It sits on the right, and to the left of this is text...]<br />
:A square wave can be broken down into an infinite supply of valuable sine waves<br />
<br />
:[Two atomic models]<br />
:[The left containing two protons (white with a "+" sign), two neutrons (black) and orbited by two electrons (small outlines, dotted orbits/movement lines), labelled below with the text of superscript atomic weight and element symbol]<br />
:<sup>4</sup>He<br />
:[The right model has just the two protons and the two electrons, labelled below with the text of an atomic weight and elemental symbol, and some subtext within brackets]<br />
:<sup>2</sup>He<br />
:(Decays fast - use quickly)<br />
:[Both models sit on the left of the comic, and to the right is text...]<br />
:Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
<br />
:[A flat rectangular bar, drawn in perspective with a scattering of dots/small circles on the top face and on the forward-facing one the label]<br />
:Iron<br />
:[An arrow points to the dots, from the text...]<br />
:Free electrons<br />
:[It sits to the right, and there is text to the left...]<br />
:Conductors are a great source of free electrons<br />
:(May carry charges)<br />
<br />
{{comic discussion}}<br />
[[Category:Tips]]<br />
[[Category:Physics]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2649:_Physics_Cost-Saving_Tips&diff=2902772649: Physics Cost-Saving Tips2022-07-23T07:17:30Z<p>172.70.214.95: /* Explanation */ prevent cat-apostrophe</p>
<hr />
<div>{{comic<br />
| number = 2649<br />
| date = July 22, 2022<br />
| title = Physics Cost-Saving Tips<br />
| image = physics_cost_saving_tips.png<br />
| titletext = I got banned from the county fair for handing out Helium-2 balloons. Apparently the instant massive plasma explosions violated some local ordinance or something.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FAUX VECTOR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic continues the previous [[2648: Chemicals]] comic's jocular theme of tricks to supposedly save money based on misinterpretations of science. Here is a list of "cost-saving tips" which would seem to reduce a cost or provide something for free, allowing physicists to save money in their research.<br />
<br />
* The prefix "pseudo-" refers to an inauthentic variation of something. Fakes are usually cheaper than their original brand-name product, while often working just as well, so the comic implies a {{w|pseudovector}} could be a less expensive substitute for a regular vector. On the contrary, pseudovectors, or axial vectors, are distinct alternatives to regular polar vectors, the former usually being involved with rotation or physical effects that share properties with rotation, similar to the relationship between angles and lengths. Pseudovectors are formed from the {{w|cross product}}s of polar vectors, and while similar to polar vectors, there is no physical meaning to their specific direction, only their magnitude and portions of their position. For example, {{w|angular velocity}} is described by a pseudovector (labeled 'L' in the comic) {{w|Normal (geometry)|normal}} to the {{w|plane of rotation}}, originating from the center of rotation, with magnitude proportional to the velocity ('ω') of rotation. <br />
<br />
* {{w|Fourier analysis}} can decompose any periodic function into a series of {{w|sine wave}}s. A {{w|square wave}} can thereby be represented as the sum of an infinite series of sine waves. However, the sine waves are not removed or separated individually, so such a {{w|Fourier transform}} does not produce a "supply" of sine waves for practical use in any tasks other than analysis, and as abstract mathematical objects exempt from the laws of supply and demand, their value is similarly limited.<br />
<br />
* Chemical elements are identified by the number of protons in each atomic nucleus, equal to the number of electrons in their shell (unless the atom is ionized), which dictates most of their chemical behavior. {{w|Isotopes}} are variants of the element with different numbers of neutrons in the nucleus, among which chemical behavior is usually nearly identical. The comic suggests that the neutrons don't serve any useful purpose, so, in theory, if purchasing an element by weight, and its isotopes have the same price per unit weight, then you can save money by buying isotopes with no neutrons at all. In reality, the cost per unit weight for material containing a larger concentration of normally rare isotopes, such as {{w|heavy water}} or {{w|enriched uranium}}, is much higher than the cost of material containing isotopes in their ordinary proportions. (An exception is {{w|depleted uranium}}, which costs less than regular uranium because it is a waste product from the production of enriched uranium.) In addition, a certain range of neutron quantity is needed to keep atoms stable, as atoms with too many or too few neutrons will decay more quickly than the common isotopes. <br />
<br />
: The image shown is helium-2, an {{w|Isotopes of helium|isotope of helium}} which has a half-life of less than a nanosecond. It decays into two protons, releasing a large amount of energy—hence the explosion mentioned in the title text. Helium balloons are often given out at county fairs and other similar events, but they are filled with helium-4, and therefore inert. If a balloon was filled with helium-2, as the title text suggests, the results would be immediately explosive, comparable to 2,000 kg of {{w|TNT}}. Handing out what are effectively bombs at a county fair would not go down well with local authorities, and therefore being banned from the fair is a very mild punishment. Criminal charges such as mass murder and terrorism would be more likely, if it weren't for the sub-nanosecond fuse length rendering the scenario absurdly impossible.<br />
<br />
* {{w|Charge carrier|Free}} {{w|electron}}s are electrons that are not tightly bound to specific atoms so they can move freely, such as in {{w|conduction band}}s of the {{w|metallic bond}}s throughout the iron ingot depicted in the comic. Randall interprets "free" in a different sense, meaning no cost. The charges free electrons carry are electric, not monetary as implied by this pun.<br />
<br />
Saving money from science experiments like this was also mentioned in [[2007: Brookhaven RHIC]].<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Title]<br />
:Physics Cost-Saving Tips<br />
<br />
:[A diagramatical spinning disc, at an angle]<br />
:[It is identified with an 'I', with a dotted axial arrow labelled 'L' and a rotational movement labelled 'ω' (small omega)]<br />
:[It sits on the left, and to the right of this is text...]<br />
:Try replacing regular vectors with pseudovectors whenever possible<br />
<br />
:[A square wave with three maxima (between four minima), and arrows pointing down into a collection of five sine waves of different wavelengths]<br />
:[One of the waves having the same frequency as the square wave and the rest of them are of shorter lengths with more peaks and troughs]<br />
:[It sits on the right, and to the left of this is text...]<br />
:A square wave can be broken down into an infinite supply of valuable sine waves<br />
<br />
:[Two atomic models]<br />
:[The left containing two protons (white with a "+" sign), two neutrons (black) and orbited by two electrons (small outlines, dotted orbits/movement lines), labelled below with the text of superscript atomic weight and element symbol]<br />
:<sup>4</sup>He<br />
:[The right model has just the two protons and the two electrons, labelled below with the text of an atomic weight and elemental symbol, and some subtext within brackets]<br />
:<sup>2</sup>He<br />
:(Decays fast - use quickly)<br />
:[Both models sit on the left of the comic, and to the right is text...]<br />
:Cut waste by buying lighter isotopes that don't have any dead-weight neutrons<br />
<br />
:[A flat rectangular bar, drawn in perspective with a scattering of dots/small circles on the top face and on the forward-facing one the label]<br />
:Iron<br />
:[An arrow points to the dots, from the text...]<br />
:Free electrons<br />
:[It sits to the right, and there is text to the left...]<br />
:Conductors are a great source of free electrons<br />
:(May carry charges)<br />
<br />
{{comic discussion}}<br />
[[Category:Tips]]<br />
[[Category:Physics]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2648:_Chemicals&diff=2899772648: Chemicals2022-07-22T18:07:46Z<p>172.70.214.95: /* Explanation */ comma</p>
<hr />
<div>{{comic<br />
| number = 2648<br />
| date = July 20, 2022<br />
| title = Chemicals<br />
| image = chemicals.png<br />
| titletext = It's hard to believe, but lots of kids these days ONLY know how to buy prepackaged molecules.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by BIG ISOMER - Please change this comment when editing this page. Do NOT delete this tag too soon. This page has been subject to _extensive_ vandalism and misediting, and for a time editors were unable to contribute content, which has been lost. Anything you can do to review it and make it better is welcome.}}<br />
<br />
In this comic, [[Megan]] mentions to [[Cueball]] that their company spends a lot on chemicals for which you can find formulas online. She suggests assembling chemicals from atoms "bought in bulk," holding a sheet of paper with the {{w|empirical formula}} C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub>, which designates [https://pubchem.ncbi.nlm.nih.gov/#query=C6H5NO2 hundreds of compounds] including {{w|nitrobenzene}}, {{w|niacin}}, {{w|isonicotinic acid}}, and {{w|picolinic acid}}, followed by their component elements listed with quantities and prices. The ambiguity of chemical formulae is one of the jokes in the comic.<br />
<br />
While many expensive chemicals are composed of inexpensive and easily available elements, "assembling" those elements into specific molecules is rarely as simple as Megan implies. That work is the primary purpose of the global chemical industry. In-house {{w|chemical synthesis}} is usually not cost effective, because end users have limited time and are generally unable to leverage the {{w|economies of scale}} inherent in bulk manufacturing by specialist industrial firms.[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2880393/] However, we don't know whether Megan and Cueball work in a laboratory, factory, or some other industrial setting. If they need chemicals in bulk, or only very small quantities, synthesizing them might be cost effective. In any case, producing chemicals from their constituent elements or {{w|Precursor (chemistry)|precursor compound}}s is difficult and time-consuming, usually requires expensive equipment, and is often fraught with peril. It's conceivable that this could change as biotechnology, artificial intelligence, and nanotechnology develop, but it is a far fetch given the relative ease of synthesizing chemicals from other chemicals.[https://www.youtube.com/watch?v=5QwW2owNWgc] {{w|Nitrobenzene}}, one of the C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub> compounds, is an excellent example because it is explosive and extremely toxic, and its synthesis is highly exothermic, making it one of the most dangerous syntheses in the chemical industry.[https://www.icheme.org/media/10339/xiii-paper-36.pdf] Such issues answer Cueball's question as to why more places don't manufacture their own compounds from atoms. Usually chemicals are derived from precursor chemicals instead of constituent elements. Megan seems to be imagining synthesis as a much simpler process without reactivity, energy release, or hazardous intermediate substances. The characters' naivety also gives rise to the humor of the comic.<br />
<br />
"Big Molecule" is an [[2130: Industry Nicknames|industry nickname like Big Oil or Big Pharma]], amusing in its own right, and conceivably implying that the chemical industry is conspiring to prevent end users from synthesizing their own compounds. Big Oil and Big Pharma are real industrial nicknames, referring to large industries run by a relatively small number of massive and hugely profitable companies. These companies are sufficiently wealthy and influential that they exert significant control over the marketplace, and even over government policy. Consequently, many consumers believing that their influence allows them to price products unfairly and prevent competition. "Big Molecule," on the other hand, is not a common term. It could be used to refer to the global chemical industry, but that industry is neither seen as being excessively powerful, nor does it impact consumers as visibly, and so doesn't merit a similar nickname.<br />
<br />
Megan is holding a note listing how many of the four types of atoms she needs to build one molecule of the compound she wants to assemble. The paper seems to list prices for buying 6 carbon, 5 hydrogen, 1 nitrogen and 2 oxygen atoms, although the units aren't specified and the very small prices are illegible. At the bottom is a sum showing she needs 14 total, again with an illegible price. She is suggesting buying atoms in bulk, which should be even cheaper than buying them individually. However, this is another layer of humor, as you can neither buy individual atoms or get a price for them, showing her lack of understanding of chemistry. An actual {{w|bill of materials}} for a chemical compound synthesis from constituent elements alone would list the elements converting their number of atoms to {{w|Mole (unit)|mole}}s, then [https://www.omnicalculator.com/chemistry/mole to mass] for solids and some fluids or to volume at the available pressure for other fluids, and then to the purchase price, which usually needs to be rounded up to match the next largest size available from suppliers. Plus, {{w|reagent}}s necessary for the synthesis such as {{w|catalyst}}s and {{w|enzyme}}s often cost more than the constituents, but are sometimes recoverable for reuse, which may require even more reagents.<br />
<br />
The title text refers to the fact that older people often complain that "kids these days" don't know how to do things that seemed fundamental to past generations. Randall may have expressed that he dislikes other statements like these in [[2165: Millennials|previous comics]]. It may also refer to the decline of home {{w|chemistry set}}s popular from the late 1700s through the early 1980s that encouraged kids to experiment with basic chemical reactions like generating esters or polymers, or the even older decline in home manufacture of gunpowder as was common in the 1800s. Chemical engineering was more widely practiced during the development of plastics, but far fewer people understand how they are made today. Similarly with automobiles, domesticated crops, and many other technologies that progressed through a period of popular attention but became siloed into industries, corporations, governments, or branches of academia. This is happening now with some software, circuitry, and other technologies, where fewer people know how to build and troubleshoot complex devices and systems. Technology users thus lose their ability to build and repair machines and modify their tools themselves, having to rely on paid services instead. Similar to the makerspace movement, community chemical labs have occasionally been cropping up, where people work together to perform citizen science, including occasional chemical synthesis, by sharing community resources; however, biohacking and structural manufacturing are far more common.{{citation needed}}<br />
<br />
This comic may have been prompted by recent news that [https://english.elpais.com/science-tech/2022-07-15/for-the-first-time-in-history-we-can-modify-atomic-bonds-in-a-single-molecule.html scientists have found a way to assemble and change atoms in individual molecules] by modifying their bonds.<br />
<br />
==Transcript==<br />
:[Megan and Cueball standing next to each other. Megan has her palms raised.]<br />
:Megan: You know how our company spends a lot on expensive chemicals?<br />
:Cueball: Yeah?<br />
<br />
:[Zoom in on Megan who is holding piece of paper up in one hand. The paper has a large chemical formula at the top. Below is a list of the atoms needed, with amount and a price tag in dollars but with unreadable amount. There is a sum total at the bottom beneath a line.]<br />
:Megan: Well, I just learned you can look up all of the formulas online!<br />
:Megan: We can just buy the atoms in bulk and assemble them here! <br />
:Paper:<br />
::<big>C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub></big><br />
::Carbon 6 $...<br />
::Hydrogen 5 $...<br />
::Nitrogen 1 $...<br />
::<u>Oxygen 2 $...</u><br />
::Total 14 $...<br />
<br />
:[Cueball is now on the left of Megan as she is walking past him to the right holding her arms outstretched with her palms up.]<br />
:Cueball: I wonder why more places don't do that.<br />
:Megan: People have no idea they're getting ripped off by Big Molecule!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2648:_Chemicals&diff=2899512648: Chemicals2022-07-22T14:53:44Z<p>172.70.214.95: /* Explanation */ copyedit and further explain paragraph about Megan's note</p>
<hr />
<div>{{comic<br />
| number = 2648<br />
| date = July 20, 2022<br />
| title = Chemicals<br />
| image = chemicals.png<br />
| titletext = It's hard to believe, but lots of kids these days ONLY know how to buy prepackaged molecules.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by BIG ISOMER - Please change this comment when editing this page. Do NOT delete this tag too soon. This page has been subject to _extensive_ vandalism and misediting, and for a time editors were unable to contribute content, which has been lost. Anything you can do to review it and make it better is welcome.}}<br />
<br />
In this comic, [[Megan]] mentions to [[Cueball]] that their company spends a lot on chemicals for which you can find formulas online. She suggests assembling chemicals from atoms "bought in bulk," holding a sheet of paper with the {{w|empirical formula}} C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub>, which designates [https://pubchem.ncbi.nlm.nih.gov/#query=C6H5NO2 hundreds of compounds] including {{w|nitrobenzene}}, {{w|niacin}}, {{w|isonicotinic acid}}, and {{w|picolinic acid}}, followed by their component elements listed with prices. The ambiguity of chemical formulae is one of the jokes in the comic.<br />
<br />
While many expensive chemicals are composed of inexpensive and easily available elements, "assembling" those elements into specific molecules is rarely as simple as Megan implies. That work is the primary purpose of the global chemical industry. In-house {{w|chemical synthesis}} is usually not cost effective, because end users have limited time and are generally unable to leverage the {{w|economies of scale}} inherent in bulk manufacturing by specialist industrial firms.[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2880393/] However, we don't know whether Megan and Cueball work in a laboratory, factory, or some other industrial setting. If they need chemicals in bulk, or only very small quantities, synthesizing them might be cost effective. In any case, producing chemicals from their constituent elements or {{w|Precursor (chemistry)|precursor compound}}s is difficult and time-consuming, usually requires expensive equipment, and is often fraught with peril.[https://www.youtube.com/watch?v=5QwW2owNWgc] {{w|Nitrobenzene}}, one of the C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub> compounds, is an excellent example because it is explosive and extremely toxic, and its synthesis is highly exothermic, making it one of the most dangerous syntheses in the chemical industry.[https://www.icheme.org/media/10339/xiii-paper-36.pdf] Such issues answer Cueball's question as to why more places don't manufacture their own compounds from atoms. Usually chemicals are derived from precursor chemicals instead of constituent elements. Megan seems to be imagining synthesis as a much simpler process without reactivity, energy release, or hazardous intermediate substances. The characters' naivety also gives rise to the humor of the comic.<br />
<br />
"Big Molecule" is an [[2130: Industry Nicknames|industry nickname like Big Oil or Big Pharma]], amusing in its own right, and conceivably implying that the chemical industry is conspiring to prevent end users from synthesizing their own compounds. Big Oil and Big Pharma are real industrial nicknames; with "Big Pharma", huge corporations invest in research and then charge immensely high prices for medicines. This became more notable when the coronavirus vaccine was released, with media and commerce being focused on large pharmaceutical manufacturers rather than community labs, where community labs could possibly have distributed vaccines directly to their surrounding communities, and recruited from these communities to aid manufacturing, if supported by their governments and economies. Comparatively, "Big Molecule" is fictitious.<br />
<br />
Megan is holding a note listing how many of the four types of atoms she needs to build one molecule of the compound she wants to assemble. The paper seems to list prices for buying 6 carbon, 5 hydrogen, 1 nitrogen and 2 oxygen atoms, although the units aren't specified and the very small prices are illegible. At the bottom is a sum showing needs 14 total, again with an illegible price. She is suggesting buying atoms in bulk, which should be even cheaper than buying them individually. However, this is another layer of humor, as you can neither buy individual atoms or get a price for them, showing her lack of understanding of chemistry. An actual {{w|bill of materials}} for a chemical compound synthesis from constituent elements alone would list the elements converting their number of atoms to {{w|Mole (unit)|mole}}s, then [https://www.omnicalculator.com/chemistry/mole to mass,] and then to purchase price.<br />
<br />
The title text refers to the fact that older people often complain that "kids these days" don't know how to do things that seemed fundamental to past generations. Randall may have expressed that he dislikes other statements like these in [[2165: Millennials|previous comics]]. It may also refer to the decline of home {{w|chemistry set}}s popular from the late 1700s through the early 1980s that encouraged kids to experiment with basic chemical reactions like generating esters or polymers, or the even older decline in home manufacture of gunpowder as was common in the 1800s. Chemical engineering was more widely practiced during the development of plastics, but far fewer people understand how they are made today. Similarly with automobiles, domesticated crops, and many other technologies that progressed through a period of popular attention but became siloed into industries, corporations, governments, or branches of academia. This is happening now with some software, circuitry, and other technologies, where fewer people know how to build and troubleshoot complex devices and systems. Technology users thus lose their ability to build and repair machines and modify their tools themselves, having to rely on paid services instead. Similar to the makerspace movement, community chemical labs have been cropping up, where people work together to perform chemical synthesis and other chemistry acts by sharing community resources.{{citation needed}}<br />
<br />
This comic may have been prompted by recent news that [https://english.elpais.com/science-tech/2022-07-15/for-the-first-time-in-history-we-can-modify-atomic-bonds-in-a-single-molecule.html scientists have found a way to assemble and change atoms in individual molecules] by modifying their bonds.<br />
<br />
==Transcript==<br />
:[Megan and Cueball standing next to each other. Megan has her palms raised.]<br />
:Megan: You know how our company spends a lot on expensive chemicals?<br />
:Cueball: Yeah?<br />
<br />
:[Zoom in on Megan who is holding piece of paper up in one hand. The paper has a large chemical formula at the top. Below is a list of the atoms needed, with amount and a price tag in dollars but with unreadable amount. There is a sum total at the bottom beneath a line.]<br />
:Megan: Well, I just learned you can look up all of the formulas online!<br />
:Megan: We can just buy the atoms in bulk and assemble them here! <br />
:Paper:<br />
::<big>C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub></big><br />
::Carbon 6 $...<br />
::Hydrogen 5 $...<br />
::Nitrogen 1 $...<br />
::<u>Oxygen 2 $...</u><br />
::Total 14 $...<br />
<br />
:[Cueball is now on the left of Megan as she is walking past him to the right holding her arms outstretched with her palms up.]<br />
:Cueball: I wonder why more places don't do that.<br />
:Megan: People have no idea they're getting ripped off by Big Molecule!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Chemistry]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=823:_Guest_Week:_David_Troupes_(Buttercup_Festival)&diff=289244823: Guest Week: David Troupes (Buttercup Festival)2022-07-20T17:48:01Z<p>172.70.214.95: Undo revision 289223 by 108.162.246.206 (talk)</p>
<hr />
<div>{{comic<br />
| number = 823<br />
| date = November 23, 2010<br />
| title = Guest Week: David Troupes (Buttercup Festival)<br />
| image = guest_week_david_troupes_buttercup_festival.png<br />
| titletext = Guest comic by David Troupes of Buttercup Festival, who is living in that lovely tree outside your window.<br />
}}<br />
<br />
==Explanation==<br />
This comic is a commentary on relationships. [[Megan]] is perfectly happy sitting on the moon (which is impossible){{Citation needed}} with [[Cueball]], the person she loves. Cueball, however, has his experience ruined when he notices a former bully of his passing by below. After hitting the bully with a rock that he shoots from the moon with his {{w|slingshot}}, he can share in Megan's happiness. (This is practically impossible as well. To start, the rock would most likely fall back down unless Cueball could throw it at escape velocity, but the precision required for such a throw would be extreme, and he would need to account for the movement of the Earth and Moon, as well as the Earth's rotation. Even if accounting for all of that, it would very likely disintegrate in Earth's atmosphere.)<br />
<br />
[http://www.buttercupfestival.com/ David Troupes] is the author of the webcomic {{w|Buttercup Festival}}.<br />
<br />
''Guest Week'' was a series of five comics written by five other comic authors. They were released over five consecutive days (Monday-Friday); not over the usual Monday/Wednesday/Friday schedule.<br><br />
The five comics are:<br />
*[[822: Guest Week: Jeph Jacques (Questionable Content)]]<br />
*[[823: Guest Week: David Troupes (Buttercup Festival)]]<br />
*[[824: Guest Week: Bill Amend (FoxTrot)]]<br />
*[[825: Guest Week: Jeffrey Rowland (Overcompensating)]]<br />
*[[826: Guest Week: Zach Weiner (SMBC)]]<br />
<br />
==Transcript==<br />
:[Megan and Cueball are leaning against each other, sitting on top of a giant moon in a black, star dotted sky. Trees are visible on the bottom of the panel.]<br />
<br />
:[The scene broadens.]<br />
:Megan: I've never been so happy. I—<br />
:Cueball: Hold on—that guy used to dump my notebooks in high school. Give me a moment. Try to keep the moon steady.<br />
<br />
:[A rock hits a Cueball on the ground on the back of the head.]<br />
<br />
:[The guy falls and clutches the back of his head.]<br />
<br />
:[Back to the moon again, where Cueball is leaning his head against Megan while holding a slingshot.]<br />
:Cueball: I've never been so happy.<br />
<br />
{{comic discussion}}<br />
[[Category:Guest Week]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Multiple Cueballs]]<br />
[[Category:Romance]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2647:_Capri_Suns&diff=2892402647: Capri Suns2022-07-20T17:46:55Z<p>172.70.214.95: Undo revision 289232 by 108.162.246.206 (talk)</p>
<hr />
<div>{{comic<br />
| number = 2647<br />
| date = July 18, 2022<br />
| title = Capri Suns<br />
| image = capri_suns.png<br />
| titletext = [As security is dragging me away] "Come on, at least I didn't make the mistake in the other direction!"<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SPECIAL OPERATIVE TRYING TO HANDLE A DISGUSTED NURSE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
[[Cueball]] has been impersonating a doctor at a hospital. But his attempt to fool the staff (including [[Megan]] and [[:Category:Doctor Ponytail|Doctor Ponytail]]) fails when he mistakes a saline bag for a Capri Sun juice drink.<br />
<br />
{{w|Capri Sun}} is a fruit juice concentrate beverage that comes in soft rectangular mylar bags with a small seal near the top, to be pierced with an included straw so as to sip the drink. {{w|Saline (medicine)|Saline}} bags, used in hospitals and other medical settings, are also soft and rectangular, with an {{w|Intravenous therapy#Medical uses|intravenous}} (I.V.) drip connection about the same size as such straws, and usually contain a 0.9% sodium chloride (table salt) solution in sterile water so they are salty enough to be {{w|Tonicity#Isotonicity|isotonic}} with blood. Capri Sun is mostly sugar water, and only 0.00008% salt,[https://www.aqua-calc.com/calculate/food-volume-to-weight/substance/capri-blank-sun-coma-and-blank-fruit-blank-juice-blank-drink] so it tastes sweet instead.<br />
<br />
Almost everyone would be very unlikely to accidentally mistake saline bags for Capri Sun, especially a medical doctor.{{citation needed}} Cueball begins to realize that his attempt to impersonate a doctor has derailed when the hospital staff notice that he made such an absurdly unlikely and therefore humorous error.<br />
<br />
The title text makes it clear that Cueball is being removed from the hospital by security personnel. While they are dragging him out, he tries to point out that drinking saline is better than putting Capri Sun into a patient's I.V. drip, as it would endanger the patient,[https://www.bbc.com/news/world-asia-china-47623816] arguing that this mitigates the severity of his transgression. The guards apprehending him are unlikely to be persuaded, as impersonating hospital staff is a serious offense with dangerous risks and severe consequences. In California, the unlicensed practice of medicine can result in a maximum $10,000 fine, up to three years in prison, or both.[https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=BPC&sectionNum=2052.]<br />
<br />
The comic arguably continues [[451: Impostor]] and [[699: Trimester]].<br />
<br />
==Transcript==<br />
:[Cueball, wearing a lab coat, is drinking out of a straw inserted into an IV drip bag that is labelled "saline" (on the 2x image; it is rendered unreadable on the standard resolution version, just like the rest of the label's squiggles). Cueball is surrounded by hospital staff. To the left is Megan with a white hat, she is holding a clipboard, with a paper with unreadable text. To his right is Dr. Ponytail holding a rolled up paper under one arm and to the right of her a man with a similar hat as Megan. They are all looking at Cueball.]<br />
:Cueball: You know, these Capri Suns are good, but they're ''really'' salty.<br />
<br />
:[Caption below the panel:]<br />
:I think the hospital may be starting to realize that I'm not actually a doctor.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Doctor Ponytail]]<br />
[[Category:Characters with hats]]<br />
[[Category:Medicine]]<br />
[[Category:Food]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2647:_Capri_Suns&diff=2891582647: Capri Suns2022-07-20T15:05:51Z<p>172.70.214.95: /* Explanation */ a little more precise</p>
<hr />
<div>{{comic<br />
| number = 2647<br />
| date = July 18, 2022<br />
| title = Capri Suns<br />
| image = capri_suns.png<br />
| titletext = [As security is dragging me away] "Come on, at least I didn't make the mistake in the other direction!"<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SPECIAL OPERATIVE TRYING TO HANDLE A DISGUSTED NURSE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
[[Cueball]] has been impersonating a doctor at a hospital. But his attempt to fool the staff (including [[Megan]] and [[:Category:Doctor Ponytail|Doctor Ponytail]]) fails when he mistakes a saline bag for a Capri Sun juice drink.<br />
<br />
{{w|Capri Sun}} is a fruit juice concentrate beverage that comes in soft rectangular mylar bags with a small seal near the top, to be pierced with an included straw so as to sip the drink. {{w|Saline (medicine)|Saline}} bags, used in hospitals and other medical settings, are also soft and rectangular, with an {{w|Intravenous therapy#Medical uses|intravenous}} (I.V.) drip connection about the same size as such straws, and usually contain a 0.9% sodium chloride (table salt) solution in sterile water so they are salty enough to be {{w|Tonicity#Isotonicity|isotonic}} with blood. Capri Sun is mostly sugar water, and only 0.00008% salt,[https://www.aqua-calc.com/calculate/food-volume-to-weight/substance/capri-blank-sun-coma-and-blank-fruit-blank-juice-blank-drink] so it tastes sweet instead.<br />
<br />
Almost everyone would be very unlikely to accidentally mistake saline bags for Capri Sun, especially a medical doctor.{{citation needed}} Cueball begins to realize that his attempt to impersonate a doctor has derailed when the hospital staff notice that he made such an absurdly unlikely and therefore humorous error.<br />
<br />
The title text makes it clear that Cueball is being removed from the hospital by security personnel. While they are dragging him out, he tries to point out that drinking saline is better than putting Capri Sun into a patient's I.V. drip, as it would endanger the patient,[https://www.bbc.com/news/world-asia-china-47623816] arguing that this mitigates the severity of his transgression. The guards apprehending him are unlikely to be persuaded, as impersonating hospital staff is a serious offense with dangerous risks and severe consequences. In California, the unlicensed practice of medicine can result in a maximum $10,000 fine, up to three years in prison, or both.[https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=BPC&sectionNum=2052.]<br />
<br />
The comic arguably continues [[451: Impostor]] and [[699: Trimester]].<br />
<br />
==Transcript==<br />
:[Cueball, wearing a lab coat, is drinking out of a straw inserted into an IV drip bag that is labelled "saline" (on the 2x image; it is rendered unreadable on the standard resolution version, just like the rest of the label's squiggles). Cueball is surrounded by hospital staff. To the left is Megan with a white hat, she is holding a clipboard, with a paper with unreadable text. To his right is Dr. Ponytail holding a rolled up paper under one arm and to the right of her a man with a similar hat as Megan. They are all looking at Cueball.]<br />
:Cueball: You know, these Capri Suns are good, but they're ''really'' salty.<br />
<br />
:[Caption below the panel:]<br />
:I think the hospital may be starting to realize that I'm not actually a doctor.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Doctor Ponytail]]<br />
[[Category:Characters with hats]]<br />
[[Category:Medicine]]<br />
[[Category:Food]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2647:_Capri_Suns&diff=2890562647: Capri Suns2022-07-19T09:35:52Z<p>172.70.214.95: /* Explanation */ not sure we can say anything stronger than endanger, but it need not be qualified</p>
<hr />
<div>{{comic<br />
| number = 2647<br />
| date = July 18, 2022<br />
| title = Capri Suns<br />
| image = capri_suns.png<br />
| titletext = [As security is dragging me away] "Come on, at least I didn't make the mistake in the other direction!"<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a DISGUSTED NURSE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Capri Sun}}, a German juice concentrate drink, is a soft, flat, rectangular bag with a foil-sealed port you pierce with a straw and sip the juice. In hospitals, saline bags are also soft, flat, rectangular bags with the end of an IV drip connection tube sticking out. {{w|Saline (medicine)}} solutions are usually about 0.90% sodium chloride (table salt), so would taste fairly salty compared to a Capri Sun, which is mostly just sugar water. For comparison, assuming the fluid in a Capri Sun pouch weighs about 6.5625 oz, based on [https://www.aqua-calc.com/calculate/food-volume-to-weight/substance/capri-blank-sun-coma-and-blank-fruit-blank-juice-blank-drink this site] giving 8.75 oz for a cup, the typical Capri Sun is about 0.00008% salt by weight. <br />
<br />
The title text is pointing out that mistakenly drinking saline ''out'' of the bag like a Capri Sun is better than a Capri Sun being put ''into'' a patient's body, similar to a saline IV drip, as that would endanger the recipient.[https://www.bbc.com/news/world-asia-china-47623816] The speaker appears to be using this as a justification for their actions, since their incompetence was, while inexcusable, at least not actually deadly to anyone. The security mentioned in the title text are likely not impressed by this, as hospitals are places where the act of pretending to be a doctor has the potential for many dangerous outcomes.<br />
<br />
The comic arguably functions as a continuation of [[451: Impostor]] and [[699: Trimester]].<br />
<br />
==Transcript==<br />
{{incomplete transcript|Created by SOMEONE W.H.O. IS NOT A DOCTOR - Do NOT delete this tag too soon.}}<br />
:[Cueball, wearing a lab coat, is drinking out of a straw inserted into an IV drip bag that is labelled "saline". The figure is surrounded by doctors and hospital staff who appear to include Ponytail and Megan, all of whom are looking at Cueball.]<br />
:Cueball: You know, these Capri Suns are good, but they're ''really'' salty.<br />
<br />
:[Caption below panel:]<br />
:I think the hospital may be starting to realize that I'm not actually a doctor.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Multiple Cueballs]]<br />
[[Category:Doctor Ponytail]]<br />
[[Category:Medicine]]<br />
[[Category:Food]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=Talk:2647:_Capri_Suns&diff=289055Talk:2647: Capri Suns2022-07-19T09:33:47Z<p>172.70.214.95: /* IV sucrose solutions aren't that bad */ reply to self</p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
The title text could also be referring to a catheter. I'm not sure which is funnier, but one is certainly grosser. [[Special:Contributions/172.70.85.115|172.70.85.115]] 18:15, 18 July 2022 (UTC)<br />
<br />
That is defenitely a urine collection bag from the end of a catheter. The colour would make it doubly "mistakable" for a Capri-Sun with primary flavour/colour being orange. And urine (when collected and undiluted) is usually orange in colour. [[Special:Contributions/172.69.156.215|172.69.156.215]] 18:38, 18 July 2022 (UTC)<br />
:Actually, Capri Sun drinks are generally completely colorless{{citation needed}}, since the pouches are opaque and the liquid is therefore never really seen, so there's no need for artificial coloring to be added (which is the only reason other similar drinks have a color to them). [[User:Dansiman|Dansiman]] ([[User talk:Dansiman|talk]]) 21:27, 18 July 2022 (UTC)<br />
:: Depends on the flavor, because they have actual fruit juice. The drinks with cherry juice, for example, are red, and deeper than the drinks with orange juice are orange/yellow, because of the strength of pigment in the juices. [[Special:Contributions/172.70.206.213|172.70.206.213]] 01:41, 19 July 2022 (UTC)<br />
<br />
I feel like these are more likely saline bags, given that 1) they've got a substantial amount of text on them, more consistent with saline bags' photos (https://www.google.com/search?q=saline+bag&tbm=isch) than with urine bags, which generally are blank. The tiny label text on the bag also seems to read saline -- would it be all right to change this to the preferred interpretation? [[User:Lorea|Lorea]] ([[User talk:Lorea|talk]]) 18:56, 18 July 2022 (UTC)<br />
:In the larger version, the text clearly says "Saline" [[Special:Contributions/172.71.30.123|172.71.30.123]] 21:38, 18 July 2022 (UTC)<br />
::Zooming in on the larger version the text clearly says "saline". I've updated the transcript to reflect that. I've also cleaned up the explanation to incorporate that update.[[User:The Cat Lady|-- The Cat Lady]] ([[User talk:The Cat Lady|talk]]) 00:12, 19 July 2022 (UTC)<br />
<br />
Yeah, it's definitely an IV bag, not a urine bag. I would say to change it back. [[Special:Contributions/172.70.214.185|172.70.214.185]] 19:01, 18 July 2022 (UTC)<br />
<br />
All I can say is "thank goodness for explainXKCD" otherwise I had no idea as Capri Sun isn't a thing in many countries [[Special:Contributions/172.69.62.49|172.69.62.49]] 23:19, 18 July 2022 (UTC)<br />
<br />
There was I thinking it was blood<br />
[[Special:Contributions/172.70.91.78|172.70.91.78]] 07:34, 19 July 2022 (UTC)<br />
<br />
; IV sucrose solutions aren't that bad <br />
<br />
Regarding whether IV Capri Sun is potentially dangerous, please see [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1998290/] which discusses IV injection of 100 ml of 50% sucrose solution as a theraputic, and [https://journals.physiology.org/doi/epdf/10.1152/ajplegacy.1935.112.1.97] which states sucrose is quickly cleared by the kidneys. The other simple sugars aren't going to hurt. Citric acid is "a common ingredient used in [injected] pharmaceutical formulations."[https://pubmed.ncbi.nlm.nih.gov/33888605/]. What's in Capri Sun which could cause IV toxicity? Its ingredients are, per [https://www.caprisun.com/product/capri-sun-juice-drink/capri-sun-tropical-punch-flavored-juice-drink-blend-10-ct-box-6-fl-oz-pouches-00087684001028#id_pdpNutritionContainer], "WATER; SUGAR; APPLE JUICE CONCENTRATE; CITRIC ACID; GRAPE, PINEAPPLE AND CHERRY JUICE CONCENTRATES; NATURAL FLAVOR; MUSHROOM EXTRACT." It's pasteurized.<br />
<br />
I'm trying to find some quantification of the level at which undigested fruit juices are harmful when injected. They can cause temporary loss of liver and kidney function along with clotting resulting in pulmonary embolism, but it's not clear at what concentrations they become dangerous, and I can't find good sources. [[Special:Contributions/172.69.34.32|172.69.34.32]] 09:27, 19 July 2022 (UTC)<br />
<br />
: https://www.bbc.com/news/world-asia-china-47623816 will have to do for now. [[Special:Contributions/172.70.214.95|172.70.214.95]] 09:33, 19 July 2022 (UTC)</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2647:_Capri_Suns&diff=2890542647: Capri Suns2022-07-19T09:32:59Z<p>172.70.214.95: /* Explanation */ https://www.bbc.com/news/world-asia-china-47623816 will do for now</p>
<hr />
<div>{{comic<br />
| number = 2647<br />
| date = July 18, 2022<br />
| title = Capri Suns<br />
| image = capri_suns.png<br />
| titletext = [As security is dragging me away] "Come on, at least I didn't make the mistake in the other direction!"<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a DISGUSTED NURSE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Capri Sun}}, a German juice concentrate drink, is a soft, flat, rectangular bag with a foil-sealed port you pierce with a straw and sip the juice. In hospitals, saline bags are also soft, flat, rectangular bags with the end of an IV drip connection tube sticking out. {{w|Saline (medicine)}} solutions are usually about 0.90% sodium chloride (table salt), so would taste fairly salty compared to a Capri Sun, which is mostly just sugar water. For comparison, assuming the fluid in a Capri Sun pouch weighs about 6.5625 oz, based on [https://www.aqua-calc.com/calculate/food-volume-to-weight/substance/capri-blank-sun-coma-and-blank-fruit-blank-juice-blank-drink this site] giving 8.75 oz for a cup, the typical Capri Sun is about 0.00008% salt by weight. <br />
<br />
The title text is pointing out that mistakenly drinking saline ''out'' of the bag like a Capri Sun is better than a Capri Sun being put ''into'' a patient's body, similar to a saline IV drip, as this would likely seriously endanger, if not kill, the recipient.[https://www.bbc.com/news/world-asia-china-47623816] The speaker appears to be using this as a justification for their actions, since their incompetence was, while inexcusable, at least not actually deadly to anyone. The security mentioned in the title text are likely not impressed by this, as hospitals are places where the act of pretending to be a doctor has the potential for many dangerous outcomes.<br />
<br />
The comic arguably functions as a continuation of [[451: Impostor]] and [[699: Trimester]].<br />
<br />
==Transcript==<br />
{{incomplete transcript|Created by SOMEONE W.H.O. IS NOT A DOCTOR - Do NOT delete this tag too soon.}}<br />
:[Cueball, wearing a lab coat, is drinking out of a straw inserted into an IV drip bag that is labelled "saline". The figure is surrounded by doctors and hospital staff who appear to include Ponytail and Megan, all of whom are looking at Cueball.]<br />
:Cueball: You know, these Capri Suns are good, but they're ''really'' salty.<br />
<br />
:[Caption below panel:]<br />
:I think the hospital may be starting to realize that I'm not actually a doctor.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Ponytail]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Multiple Cueballs]]<br />
[[Category:Doctor Ponytail]]<br />
[[Category:Medicine]]<br />
[[Category:Food]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2646:_Minkowski_Space&diff=2890452646: Minkowski Space2022-07-19T01:49:41Z<p>172.70.214.95: /* Explanation */ this is not actually an implication because jumping to Minkowski space isn't doing anything</p>
<hr />
<div>{{comic<br />
| number = 2646<br />
| date = July 15, 2022<br />
| title = Minkowski Space<br />
| image = minkowski_space.png<br />
| titletext = My liege, we were able to follow the ship into Minkowski space, but now they've jumped to Hilbert space and they could honestly be anywhere.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by A RELATIVISTIC QUANTUM STATE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
In science fiction, {{w|faster than light travel}}, an impossibility in our universe, is often portrayed by having spaceships enter (or "jump") into some different realm, termed "hyperspace" or similar {{w|technobabble}}, where superluminal travel can occur prior returning to the ordinary universe. In this comic, a spaceship is being chased by an enemy ship. The crew attempt to escape by jumping into {{w|Minkowski space}} which is actually just conventional 3-D space together with time combined into a mathematical object called a {{w|manifold}} used in {{w|special relativity}}. Because Minkowski space is merely a representation of real physical {{w|spacetime}}, "jumping" into it is meaningless and offers no benefit for escaping pursuit, providing the humor of the comic's absurdist joke.<br />
<br />
The visual depiction of the spaceships skewed diagonally is based on the graphical {{w|Minkowski diagram}} representation of objects in Minkowski space, where the {{w|world line}} of matter is bounded inside its diagonal {{w|light cone}}. <br />
<br />
The mention of distance depending on the observer's frame of reference refers to distances changing when measured in different {{w|inertial frame of reference|inertial frames of reference}}, a concept called the {{w|relativity of simultaneity}}. Here are [https://www.youtube.com/watch?v=asW78vToNLQ some videos] intended [https://www.youtube.com/watch?v=Xrqj88zQZJg to explain] that concept. The skewing depicted changes the distance between the spaceships in such a way that the tip of the pursuer comes closer to the pursued spaceship, but their centers move further apart. So the question of whether they have come closer is indeterminate for the reader of the comic. <br />
<br />
The title text is a status report from someone in the pursuing spaceship to their leader (whom they call "my {{w|Homage (feudal)|liege}}.") Following the spaceship to Minkowski space was not a problem, but the pursued ship subsequently jumped to Hilbert space and could now be anywhere. Hiding in {{w|Hilbert space}} is much easier because Hilbert spaces (of which there are many very different varieties, unlike Minkowski space) can have an infinite number of dimensions, and are thus much more complicated than four-dimensional Minkowski spacetime. However, Hilbert space is a mathematical construct used to describe objects such as functions of various parameters and complexity, not physical spatiotemporal reality, so it would be very unusual for a physical object to be represented in Hilbert space. Quantum states can be represented as vectors in Hilbert spaces, so it might relate to the {{w|uncertainty principle}} concerning how the escaped spaceship could be anywhere.<br />
<br />
As in the [[2577:_Sea_Chase|Sea Chase]] comic, there was also more than one type of space to jump to here.<br />
<br />
==Transcript==<br />
:[A spaceship is being pursued by another spaceship. Both ships have a black part in the front representing a window. They are the same size but different designs. The pursued spaceship to the right has two engines below and a big engine behind. The pursuing spaceship to the left has a V-shaped rear end, and what seems like two weapons on either side pointing forward. At least two persons inside the pursued spaceship are talking to each other, and their text comes out from two starburst on top and bottom of the spaceship.]<br />
:Voice 1: The enemy ship is right behind us! <br />
:Voice 2: Prepare to jump to Minkowski space on my mark.<br />
<br />
:[Same setting, with star burst above only. The sound coming from the pursued spaceship is written inside a burst of small lines below the spaceship. Voice 2, by context, is the same as in panel 1.]<br />
:Voice 2: Three... two... one... ''mark!''<br />
:Click<br />
<br />
:[Both spaceship are tilted upwards and becomes distorted so they become longer and thinner.]<br />
<br />
:[The tilting increases and the distortion is now so pronounced that the spaceships are almost unrecognizable, almost just lines with structure. The distance between the tip of the pursuing spaceship and the pursued becomes shorter in the last two panels, but the distance between their center parts becomes larger. Up to three distinct voices are shown, here, which may include those seen in Panel 1 but with no clear relation.]<br />
:Voice 3: Are they still getting closer?<br />
:Voice 4: I can't tell.<br />
:Voice 5: I think it depends on your frame of reference.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Space]]<br />
[[Category:Math]]<br />
[[Category:Physics]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2644:_fMRI_Billboard&diff=2886382644: fMRI Billboard2022-07-12T04:13:06Z<p>172.70.214.95: /* Explanation */ next paragraph</p>
<hr />
<div>{{comic<br />
| number = 2644<br />
| date = July 11, 2022<br />
| title = fMRI Billboard<br />
| image = fmri_billboard.png<br />
| titletext = [other side] If the first word of an instruction you're given starts with the same letter as your crush's name, for that step imagine the experimenter is your crush.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by YOUR SCARIEST MEMORY - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Functional magnetic resonance imaging}}, or fMRI, is a method of {{w|4DCT|four-dimensional computed tomography}} able to record animated images of animal brain activity by detecting changes associated with blood flow. fMRI experiments are often criticized because they have low {{w|statistical power}} and can easily be confounded by experiment subject error in following instructions, among many other variables.<br />
<br />
This comic shows a billboard erected by a neuroscience department located near one of their rivals whom they wish to discredit by sabotaging their subjects' compliance with experiment instructions by suggesting behaviors which would likely produce unexpected results.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[A giant, building-sized billboard rises over what appears to be a college campus. It reads:]<br />
: ⚠ Student fMRI volunteers ⚠<br />
: Remember, when you're in the scanner, if you see a slide that's similar to one they already showed you, think as hard as you can about your scariest memory.<br />
<br />
[Caption below the panel:] A rival neuroscience department keeps trying to sabotage our experiments.<br />
{{comic discussion}}<br />
[[Category: Science]]<br />
[[Category: Psychology]]<br />
[[Category: Biology]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2644:_fMRI_Billboard&diff=2886372644: fMRI Billboard2022-07-12T04:08:29Z<p>172.70.214.95: /* Explanation */ start</p>
<hr />
<div>{{comic<br />
| number = 2644<br />
| date = July 11, 2022<br />
| title = fMRI Billboard<br />
| image = fmri_billboard.png<br />
| titletext = [other side] If the first word of an instruction you're given starts with the same letter as your crush's name, for that step imagine the experimenter is your crush.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by YOUR SCARIEST MEMORY - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Functional magnetic resonance imaging}}, or fMRI, is a method of {{w|4DCT|four-dimensional computed tomography}} able to record animated images of animal brain activity by detecting changes associated with blood flow. fMRI experiments are often criticized because they have low {{w|statistical power}} and can easily be confounded by experiment subject error in following instructions, among many other variables.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
[A giant, building-sized billboard rises over what appears to be a college campus. It reads:]<br />
: ⚠ Student fMRI volunteers ⚠<br />
: Remember, when you're in the scanner, if you see a slide that's similar to one they already showed you, think as hard as you can about your scariest memory.<br />
<br />
[Caption below the panel:] A rival neuroscience department keeps trying to sabotage our experiments.<br />
{{comic discussion}}<br />
[[Category: Science]]<br />
[[Category: Psychology]]<br />
[[Category: Biology]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2643:_Cosmologist_Gift&diff=2885712643: Cosmologist Gift2022-07-11T01:23:15Z<p>172.70.214.95: /* Explanation */ better term for this</p>
<hr />
<div>{{comic<br />
| number = 2643<br />
| date = July 8, 2022<br />
| title = Cosmologist Gift<br />
| image = cosmologist_gift.png<br />
| titletext = These neutrinos were freshly produced by a local source just 8 minutes ago<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a MUON ON SALE, PACKAGED IN A BOX THAT A CAT MIGHT OR MIGHT NOT HAVE DIED IN- Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic shows a box labeled to indicate that it contains 30,000 fresh {{w|neutrino}}s and four zeptograms of {{w|dark matter}}. The box is intended as an inexpensive gift for a {{w|cosmologist}}. The gift giver didn't put those things in the box—both are simply passing through it, so the "gift" consists of exactly what was in the empty space it occupies. While the caption suggests this would be a good gift for a cosmologist, what they or anyone else would do with such a box is uncertain.<br />
<br />
There are about a billion neutrinos per cubic meter throughout space, produced during the {{w|Big Bang}}.[https://physics.mit.edu/news/journal/physicsatmit_14_conrad/] However, the flux of "freshly produced" {{w|solar neutrino}}s at Earth is around 7&times;10<sup>10</sup>/cm<sup>2</sup>/s, yielding about 2.3 million per cubic meter, implying the box is around 13 liters, about 80% of the volume of a typical {{w|breadbox}}.<br />
<br />
Four zeptograms is a minuscule mass, equal to four sextillionths of a gram, the mass of about 200 carbon-12 atoms or around 20 to 23 {{w|amino acid}}s. There is an estimated 0.011 to 0.016 {{w|solar mass}}es of dark matter per cubic {{w|parsec}} local to the solar system,[https://iopscience.iop.org/article/10.1088/1361-6633/ac24e7/meta] or about 900 zeptograms per cubic meter, suggesting the box is closer to 4 liters. This discrepancy could imply Randall agrees with cosmologists who believe dark matter is partially composed of {{w|primordial black hole}}s,[https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.121301][https://www.sciencedirect.com/science/article/abs/pii/S2212686418301250?via%3Dihub][https://news.yale.edu/2021/12/16/black-holes-and-dark-matter-are-they-one-and-same][https://iopscience.iop.org/article/10.3847/2041-8205/823/2/L25][https://iopscience.iop.org/article/10.1088/1475-7516/2010/04/023] instead of being comprised entirely of ubiquitous subatomic particles. A billion neutrinos have a mass of only about 2×10<sup>-12</sup> zeptograms, at about 0.1 {{w|electron volt}}s each.<br />
<br />
The "local source" mentioned in the title text is a joke about the commercial value of fresh, locally produced items, but the comic means the Sun. It takes solar neutrinos slightly more than 8 minutes to reach Earth once they're emitted, roughly the same time as photons take to make the trip. (This doesn't include the time -- [https://en.wikipedia.org/wiki/Radiative_zone approximately 170,000 years] over many [https://news.stanford.edu/pr/97/971219neutrino.html 28 day neutrino cycles] -- that energy takes to get from the core to where photons are emitted at the Sun's surface.) However, as the neutrinos are not similarly slowed down inside the Sun and have been travelling at more than 99.999% of the speed of light, they will have aged by less than two seconds,[https://www.omnicalculator.com/physics/time-dilation] and so are technically even fresher than indicated.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[A picture of a box with writing on one side, saying as follows:]<br />
<br />
:30,000 neutrinos<br />
:<small>Freshly produced</small><br />
:Plus 4 zeptograms of dark matter<br />
<br />
:[Caption below the panel]: <br />
:Cosmologists are easy to shop for because you can just get them a box.<br />
<br />
{{comic discussion}}<br />
[[Category:Astronomy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2643:_Cosmologist_Gift&diff=2885702643: Cosmologist Gift2022-07-11T01:22:12Z<p>172.70.214.95: /* Explanation */ better context</p>
<hr />
<div>{{comic<br />
| number = 2643<br />
| date = July 8, 2022<br />
| title = Cosmologist Gift<br />
| image = cosmologist_gift.png<br />
| titletext = These neutrinos were freshly produced by a local source just 8 minutes ago<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a MUON ON SALE, PACKAGED IN A BOX THAT A CAT MIGHT OR MIGHT NOT HAVE DIED IN- Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic shows a box labeled to indicate that it contains 30,000 fresh {{w|neutrino}}s and four zeptograms of {{w|dark matter}}. The box is intended as an inexpensive gift for a {{w|cosmologist}}. The gift giver didn't put those things in the box—both are simply passing through it, so the "gift" consists of exactly what was in the empty space it occupies. While the caption suggests this would be a good gift for a cosmologist, what they or anyone else would do with such a box is uncertain.<br />
<br />
There are about a billion neutrinos per cubic meter throughout space, produced during the {{w|Big Bang}}.[https://physics.mit.edu/news/journal/physicsatmit_14_conrad/] However, the flux of "freshly produced" {{w|solar neutrino}}s at Earth is around 7&times;10<sup>10</sup>/cm<sup>2</sup>/s, yielding about 2.3 million per cubic meter, implying the box is around 13 liters, about 80% of the volume of a typical {{w|breadbox}}.<br />
<br />
Four zeptograms is a minuscule mass, equal to four sextillionths of a gram, the mass of about 200 carbon-12 atoms or around 20 to 23 {{w|amino acid}}s. There is an estimated 0.011 to 0.016 {{w|solar mass}}es of dark matter per cubic {{w|parsec}} local to the solar system,[https://iopscience.iop.org/article/10.1088/1361-6633/ac24e7/meta] or about 900 zeptograms per cubic meter, suggesting the box is closer to 4 liters. This discrepancy could imply Randall agrees with cosmologists who believe dark matter is partially composed of {{w|primordial black hole}}s,[https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.121301][https://www.sciencedirect.com/science/article/abs/pii/S2212686418301250?via%3Dihub][https://news.yale.edu/2021/12/16/black-holes-and-dark-matter-are-they-one-and-same][https://iopscience.iop.org/article/10.3847/2041-8205/823/2/L25][https://iopscience.iop.org/article/10.1088/1475-7516/2010/04/023] instead of being comprised entirely of ubiquitous subatomic particles. A billion neutrinos have a mass of only about 2×10<sup>-12</sup> zeptograms, at about 0.1 {{w|electron volt}}s each.<br />
<br />
The "local source" mentioned in the title text is a joke about the commercial value of fresh, locally produced items, but the comic means the Sun. It takes solar neutrinos slightly more than 8 minutes to reach Earth once they're emitted, roughly the same time as photons take to make the trip. (This doesn't include the time -- [https://en.wikipedia.org/wiki/Radiative_zone approximately 170,000 years] over many [https://news.stanford.edu/pr/97/971219neutrino.html 28 day neutrino cycles] -- that energy takes to get from the core to where photons are emitted at the Sun's surface.) However, as the neutrinos are not similarly slowed down inside the Sun and have been travelling at more than 99.999% of the speed of light, they will have aged by less than two seconds,[https://www.omnicalculator.com/physics/time-dilation] and so are technically even fresher than stated.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[A picture of a box with writing on one side, saying as follows:]<br />
<br />
:30,000 neutrinos<br />
:<small>Freshly produced</small><br />
:Plus 4 zeptograms of dark matter<br />
<br />
:[Caption below the panel]: <br />
:Cosmologists are easy to shop for because you can just get them a box.<br />
<br />
{{comic discussion}}<br />
[[Category:Astronomy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2643:_Cosmologist_Gift&diff=2885692643: Cosmologist Gift2022-07-11T01:21:18Z<p>172.70.214.95: /* Explanation */ explain in more detail</p>
<hr />
<div>{{comic<br />
| number = 2643<br />
| date = July 8, 2022<br />
| title = Cosmologist Gift<br />
| image = cosmologist_gift.png<br />
| titletext = These neutrinos were freshly produced by a local source just 8 minutes ago<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a MUON ON SALE, PACKAGED IN A BOX THAT A CAT MIGHT OR MIGHT NOT HAVE DIED IN- Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic shows a box labeled to indicate that it contains 30,000 fresh {{w|neutrino}}s and four zeptograms of {{w|dark matter}}. The box is intended as an inexpensive gift for a {{w|cosmologist}}. The gift giver didn't put those things in the box—both are simply passing through it, so the "gift" consists of exactly what was in the empty space it occupies. While the caption suggests this would be a good gift for a cosmologist, what they or anyone else would do with such a box is uncertain.<br />
<br />
There are about a billion neutrinos per cubic meter throughout space, produced during the {{w|Big Bang}}.[https://physics.mit.edu/news/journal/physicsatmit_14_conrad/] However, the flux of "freshly produced" {{w|solar neutrino}}s at Earth is around 7&times;10<sup>10</sup>/cm<sup>2</sup>/s, yielding about 2.3 million per cubic meter, implying the box is around 13 liters, about 80% of the volume of a typical {{w|breadbox}}.<br />
<br />
Four zeptograms is a minuscule mass, equal to four sextillionths of a gram, the mass of about 200 carbon-12 atoms or around 20 to 23 {{w|amino acid}}s. There is an estimated 0.011 to 0.016 {{w|solar mass}}es of dark matter per cubic {{w|parsec}} local to the solar system,[https://iopscience.iop.org/article/10.1088/1361-6633/ac24e7/meta] or about 900 zeptograms per cubic meter, suggesting the box is closer to 4 liters. This discrepancy could imply Randall agrees with cosmologists who believe dark matter is partially composed of {{w|primordial black hole}}s,[https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.121301][https://www.sciencedirect.com/science/article/abs/pii/S2212686418301250?via%3Dihub][https://news.yale.edu/2021/12/16/black-holes-and-dark-matter-are-they-one-and-same][https://iopscience.iop.org/article/10.3847/2041-8205/823/2/L25][https://iopscience.iop.org/article/10.1088/1475-7516/2010/04/023] instead of being comprised entirely of ubiquitous subatomic particles. A billion neutrinos have a mass of only about 2×10<sup>-12</sup> zeptograms, at about 0.1 {{w|electron volt}}s each.<br />
<br />
The "local source" mentioned in the title text is a joke about the commercial value of fresh, locally produced items, but the comic means the Sun. It takes solar neutrinos slightly more than 8 minutes to reach Earth once they're emitted, roughly the same time as photons take to make the trip. (This doesn't include the time -- [https://en.wikipedia.org/wiki/Radiative_zone approximately 170,000 years] over many [https://news.stanford.edu/pr/97/971219neutrino.html 28 day neutrino cycles] -- that energy takes to get from the core to where photons are emitted at the Sun's surface.) However, as the neutrinos are not similarly slowed down inside the Sun and have been travelling at more than 99.999% of the speed of light, they will have aged by less than two seconds,[https://www.omnicalculator.com/physics/time-dilation] and so are technically even fresher.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[A picture of a box with writing on one side, saying as follows:]<br />
<br />
:30,000 neutrinos<br />
:<small>Freshly produced</small><br />
:Plus 4 zeptograms of dark matter<br />
<br />
:[Caption below the panel]: <br />
:Cosmologists are easy to shop for because you can just get them a box.<br />
<br />
{{comic discussion}}<br />
[[Category:Astronomy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2641:_Mouse_Turbines&diff=2882022641: Mouse Turbines2022-07-04T21:51:51Z<p>172.70.214.95: /* Explanation */ another extra comma</p>
<hr />
<div>{{comic<br />
| number = 2641<br />
| date = July 4, 2022<br />
| title = Mouse Turbines<br />
| image = mouse_turbines.png<br />
| titletext = It's sad seeing those videos of turbine blade being torn apart in high winds, but it's the only way they can disperse their seeds.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a RENEWABLE ENERGY RODENT - Elaborate on the title text. Do NOT delete this tag too soon.}}<br />
<br />
[[Beret Guy]] and [[Megan]] are walking in summer, where Beret Guy expresses his appreciation for the weather typical of a summer day. He also mentions "field mice's wind turbines", which Megan initially assumes to be referring to dandelions (similar to the wordplay that Beret Guy utilized in [[1322: Winter]]). However, Beret Guy turns out to be speaking literally, as he picks up what is in fact a tiny {{w|wind turbine}} and blows into it. This causes the blades of the turbine to spin very rapidly, generating a lot of power for the structure it is connected to, thus causing the field mice to cheer in excitement.<br />
<br />
Sadly, the efficiency of wind turbines is proportional to their size,[https://www.energy.gov/eere/articles/wind-turbines-bigger-better] a limitation not shared by other forms of renewable energy such as {{w|solar panel}}s and {{w|pico hydro}}. According to [https://www.omnicalculator.com/ecology/wind-turbine this calculator], a 10 centimeter radius wind turbine powered by a 5.7 meter/second breath[https://www.sciencedirect.com/science/article/pii/S2215098616300830] would produce one watt at just 26% efficiency.<br />
<br />
Further frustrating mice using wind power, {{w|Wind gradient|windspeed increases logarithmically with height}} above ground. Windspeed is published as its value 10 meters above ground, where it is 1.5 times faster than at ground level.[https://www.nooutage.com/wind.htm] In the U.S., where Randall lives, average year-round windspeed is about 15 km/h,[https://sciencing.com/average-daily-wind-speed-24011.html], or about 2.8 m/s at ground level, yielding only 0.1 watt for such turbines. However, a typical mouse weighs 25 grams,[https://web.jhu.edu/animalcare/procedures/mouse.html] compared to about 81 kilograms for humans,[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3408371/] so presumably mice electricity needs would be about 0.003% of people. The average U.S. residential customer uses about 1,242 watts of electricity,[https://www.electricchoice.com/blog/electricity-on-average-do-homes/] 0.003% of which is 0.04 watts. Therefore, a single such turbine might be able to serve a family of two mice, assuming they have sufficient {{w|home energy storage}} batteries.<br />
<br />
The title text claims wind turbines reproduce by dispersing their blades, in the manner of dandelion {{w|seed dispersal}}.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Megan and Beret Guy are walking on grass.]<br />
:Beret Guy: Ahh, summer!<br />
:Beret Guy: The clouds are big, the bugs are zooming,<br />
<br />
:[Beret Guy stops walking. There are tiny structures on the grass in front of him.]<br />
:Beret Guy: and the field mice have put up their little wind turbines.<br />
<br />
:[Beret Guy picks up one of the turbines. Under the turbine there is a wire attached to the ground.]<br />
:Megan (off-panel): You mean dandelions?<br />
:Beret Guy: No.<br />
<br />
:[Beret Guy holds the turbine in front of him.]<br />
:Beret Guy: Make a wish!<br />
<br />
:[Beret Guy blows into the turbine blades and makes them spin. The wire transfers electricity towards the ground.]<br />
:''Puff''<br />
:⚡ ⚡ ⚡ ⚡<br />
:Voice below the ground: Yaaay!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Beret Guy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2641:_Mouse_Turbines&diff=2882012641: Mouse Turbines2022-07-04T21:50:56Z<p>172.70.214.95: /* Explanation */ extra comma</p>
<hr />
<div>{{comic<br />
| number = 2641<br />
| date = July 4, 2022<br />
| title = Mouse Turbines<br />
| image = mouse_turbines.png<br />
| titletext = It's sad seeing those videos of turbine blade being torn apart in high winds, but it's the only way they can disperse their seeds.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a RENEWABLE ENERGY RODENT - Elaborate on the title text. Do NOT delete this tag too soon.}}<br />
<br />
[[Beret Guy]] and [[Megan]] are walking in summer, where Beret Guy expresses his appreciation for the weather typical of a summer day. He also mentions "field mice's wind turbines", which Megan initially assumes to be referring to dandelions (similar to the wordplay that Beret Guy utilized in [[1322: Winter]]). However, Beret Guy turns out to be speaking literally, as he picks up what is in fact a tiny {{w|wind turbine}} and blows into it. This causes the blades of the turbine to spin very rapidly, generating a lot of power for the structure it is connected to, thus causing the field mice to cheer in excitement.<br />
<br />
Sadly, the efficiency of wind turbines is proportional to their size,[https://www.energy.gov/eere/articles/wind-turbines-bigger-better] a limitation not shared by other forms of renewable energy such as {{w|solar panel}}s and {{w|pico hydro}}. According to [https://www.omnicalculator.com/ecology/wind-turbine this calculator], a 10 centimeter radius wind turbine powered by a 5.7 meter/second breath[https://www.sciencedirect.com/science/article/pii/S2215098616300830] would produce one watt at just 26% efficiency.<br />
<br />
Further frustrating mice using wind power, {{w|Wind gradient|windspeed increases logarithmically with height}} above ground. Windspeed is published as its value 10 meters above ground, where it is 1.5 times faster than at ground level.[https://www.nooutage.com/wind.htm] In the U.S., where Randall lives, average year-round windspeed is about 15 km/h,[https://sciencing.com/average-daily-wind-speed-24011.html], or about 2.8 m/s at ground level, yielding only 0.1 watt for such turbines. However, a typical mouse weighs 25 grams,[https://web.jhu.edu/animalcare/procedures/mouse.html] compared to about 81 kilograms for humans,[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3408371/] so presumably mice electricity needs would be about 0.003% of people. The average U.S. residential customer uses about 1,242 watts of electricity,[https://www.electricchoice.com/blog/electricity-on-average-do-homes/], 0.003% of which is 0.04 watts. Therefore, a single such turbine might be able to serve a family of two mice, assuming they have sufficient {{w|home energy storage}} batteries.<br />
<br />
The title text claims wind turbines reproduce by dispersing their blades, in the manner of dandelion {{w|seed dispersal}}.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Megan and Beret Guy are walking on grass.]<br />
:Beret Guy: Ahh, summer!<br />
:Beret Guy: The clouds are big, the bugs are zooming,<br />
<br />
:[Beret Guy stops walking. There are tiny structures on the grass in front of him.]<br />
:Beret Guy: and the field mice have put up their little wind turbines.<br />
<br />
:[Beret Guy picks up one of the turbines. Under the turbine there is a wire attached to the ground.]<br />
:Megan (off-panel): You mean dandelions?<br />
:Beret Guy: No.<br />
<br />
:[Beret Guy holds the turbine in front of him.]<br />
:Beret Guy: Make a wish!<br />
<br />
:[Beret Guy blows into the turbine blades and makes them spin. The wire transfers electricity towards the ground.]<br />
:''Puff''<br />
:⚡ ⚡ ⚡ ⚡<br />
:Voice below the ground: Yaaay!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Beret Guy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2641:_Mouse_Turbines&diff=2882002641: Mouse Turbines2022-07-04T21:50:02Z<p>172.70.214.95: /* Explanation */ calculations</p>
<hr />
<div>{{comic<br />
| number = 2641<br />
| date = July 4, 2022<br />
| title = Mouse Turbines<br />
| image = mouse_turbines.png<br />
| titletext = It's sad seeing those videos of turbine blade being torn apart in high winds, but it's the only way they can disperse their seeds.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a RENEWABLE ENERGY RODENT - Elaborate on the title text. Do NOT delete this tag too soon.}}<br />
<br />
[[Beret Guy]] and [[Megan]] are walking in summer, where Beret Guy expresses his appreciation for the weather typical of a summer day. He also mentions "field mice's wind turbines", which Megan initially assumes to be referring to dandelions (similar to the wordplay that Beret Guy utilized in [[1322: Winter]]). However, Beret Guy turns out to be speaking literally, as he picks up what is in fact a tiny {{w|wind turbine}} and blows into it. This causes the blades of the turbine to spin very rapidly, generating a lot of power for the structure it is connected to, thus causing the field mice to cheer in excitement.<br />
<br />
Sadly, the efficiency of wind turbines is proportional to their size,[https://www.energy.gov/eere/articles/wind-turbines-bigger-better] a limitation not shared by other forms of renewable energy such as {{w|solar panel}}s and {{w|pico hydro}}. According to [https://www.omnicalculator.com/ecology/wind-turbine this calculator], a 10 centimeter radius wind turbine powered by a 5.7 meter/second breath[https://www.sciencedirect.com/science/article/pii/S2215098616300830] would produce one watt at just 26% efficiency.<br />
<br />
Further frustrating mice using wind power, {{w|Wind gradient|windspeed increases logarithmically with height}} above ground. Windspeed is published as its value 10 meters above ground, where it is 1.5 times faster than at ground level.[https://www.nooutage.com/wind.htm] In the U.S., where Randall lives, average year-round windspeed is about 15 km/h,[https://sciencing.com/average-daily-wind-speed-24011.html], or about 2.8 m/s at ground level, yielding only 0.1 watt for such turbines. However, a typical mouse weighs 25 grams,[https://web.jhu.edu/animalcare/procedures/mouse.html] compared to about 81 kilograms for humans,[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3408371/], so presumably mice electricity needs would be about 0.003% of people. The average U.S. residential customer uses about 1,242 watts of electricity,[https://www.electricchoice.com/blog/electricity-on-average-do-homes/], 0.003% of which is 0.04 watts. Therefore, a single such turbine might be able to serve a family of two mice, assuming they have sufficient {{w|home energy storage}} batteries.<br />
<br />
The title text claims wind turbines reproduce by dispersing their blades, in the manner of dandelion {{w|seed dispersal}}.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:[Megan and Beret Guy are walking on grass.]<br />
:Beret Guy: Ahh, summer!<br />
:Beret Guy: The clouds are big, the bugs are zooming,<br />
<br />
:[Beret Guy stops walking. There are tiny structures on the grass in front of him.]<br />
:Beret Guy: and the field mice have put up their little wind turbines.<br />
<br />
:[Beret Guy picks up one of the turbines. Under the turbine there is a wire attached to the ground.]<br />
:Megan (off-panel): You mean dandelions?<br />
:Beret Guy: No.<br />
<br />
:[Beret Guy holds the turbine in front of him.]<br />
:Beret Guy: Make a wish!<br />
<br />
:[Beret Guy blows into the turbine blades and makes them spin. The wire transfers electricity towards the ground.]<br />
:''Puff''<br />
:⚡ ⚡ ⚡ ⚡<br />
:Voice below the ground: Yaaay!<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Comics featuring Beret Guy]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2638:_Extended_NFPA_Hazard_Diamond&diff=2880912638: Extended NFPA Hazard Diamond2022-07-02T21:34:07Z<p>172.70.214.95: /* Explanation */ terms</p>
<hr />
<div>{{comic<br />
| number = 2638<br />
| date = June 27, 2022<br />
| title = Extended NFPA Hazard Diamond<br />
| image = extended_nfpa_hazard_diamond.png<br />
| titletext = With most labs, the hushed horror stories are about something like dimethylmercury or prions, but occasionally you'll get a weird lab where it's about the soda machine or the drop ceiling.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SUBSTANCE WORTH $500 IN STREET VALUE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic depicts an extension of the National Fire Protection Association's {{w|NFPA 704|NFPA 704 Standard System for the Identification of the Hazards of Materials for Emergency Response}} "fire diamond" emblematic insignia used to warn about the properties of hazardous substances inside a building, vehicle, room, cabinet, or container that are important during an emergency or accident, such as a fire, earthquake, spill or leak, bringing the diamond from 2x2 squares to 3x3 by adding five variously useful and humorous squares along the bottom edges.<br />
<br />
The numbers in a normal NFPA 704 diamond do not specify values of substances' properties, but rather broad categories designating characteristics of the substances of greatest interest to {{w|first responders}} and hazardous materials cleanup crews. Randall's expanded diamond breaks with this convention, with several squares (Lilac, Orange, and Black) denoting absolute values, and one square (Green) denoting an economic value. This could very easily lead to documentation update headaches if these values were ever to change, doubly so since the Lilac square is linked to political outcomes.<br />
<br />
{| class="wikitable"<br />
|+ Squares and explanations<br />
|-<br />
! Square !! Color !! Comic text !! Explanation<br />
|-<br />
!colspan=5| Real NFPA 704 diamond [http://www.ilpi.com/msds/ref/nfpa.html square and number meanings]<br />
|-<br />
| Top || Red || Flammability (0) || Denotes flammability. 0 indicates "materials that will not burn."<br />
|-<br />
| Top Left || Blue || Health Hazard (4) || Denotes the danger that the substance(s) pose to living beings in ways other than flammability and reactivity. 4 indicates that "Very short exposure could cause death or serious residual injury even though prompt medical attention was given."<br />
|-<br />
| Top Right || Yellow || Instability (2) || Denotes how stable the substance(s) are when exposed to water, heat, shock, air, or other substances. 2 indicates that "Normally unstable and will readily undergo violent decomposition but does not detonate. Also: may react violently with water or may form potentially explosive mixtures with water."<br />
|-<br />
| Center || White || (Special Hazard) || The standard's "Special Notice" field may contain a symbol denoting additional information about the substance(s), e.g., '''OX''' for {{w|oxidizer}}s, '''SA''' for simple {{w|asphyxiant}} gases such as nitrogen and helium, and <s>'''W'''</s> for substances which react dangerously with water.<br />
|-<br />
!colspan=5| After this point, all squares are made up by Randall.<br />
|-<br />
| Center Left || Green || Number of digits in the street value ($/gram) (2) || Describes the order of magnitude of the price (in USD) of one gram of the substance when sold illegally and informally. This is done on a logarithmic scale, with a '1' selling for $9/gram or less, a '2' selling for $99/gram, and so on. As such this is the first of several squares where the number may presumably go to 5 or above (which is not allowed on the original Blue/Red/Yellow squares, as they do not denote strict numerical values). That said it's not immediately clear how substances which command <$1/gram would be handled.<br />
<br />
Randall's example substance apparently sells for tens of dollars per gram (which would be similar to most common illicit drugs).<br />
|-<br />
| Center Right || Dark Purple || How much of a hassle it is to dispose of (4) || While many things can be thrown in the trash with no additional procedures, substances that merit an NFPA 704 square often require additional procedures to avoid significant danger, damage to the environment, or hefty dumping fines. Biohazards that may carry diseases are often disposed of in special containers, and nuclear materials are notoriously difficult to safely dispose of. This square would be at least theoretically useful, though not as much as the actual disposal guidelines.<br />
<br />
If the numbering here follows the scheme of the real categories, Randall's example substance is about as hard to dispose of as it gets. This matches the substance's rating of 4 for Blue and 2 for Yellow. Presumably it requires highly specialized handling or processing, and may also very bulky or awkward to store.<br />
|-<br />
| Bottom Left || Lilac || Number of federal agencies who want to know if you have any (3) || In many countries, including Randall's home country, the USA, the government has agencies dedicated to controlling or limiting the use of regulated substances, due to their use as drugs, weapons, harm to the environment, etc. While any given substance might be of interest to one agency, something that is both an environmental hazard and a chemical weapon component could interest, for example, the {{w|EPA}}, {{w|Chemical Safety Board}} and the FBI Counter-terrorism Division.<br />
|-<br />
| Bottom Right || Orange || How many times you have to scrub your hands after touching it before they stop smelling weird (1) || While the real NFPA 704 chart describes properties ranging from unsafe to potentially deadly, this square describes a minor but very real inconvenience. Some things are harder to wash off your hands than others, and, given that most people don't often work with dangerous substances {{Citation Needed}}, this would be a more common, but less relevant, concern for many people.<br />
<br />
In this case, the substance, or its residue, seems to be fairly easy to wash off. This is seemingly incongruous with its ratings in the Blue and Black squares (see below), though it's possible that this substance simply doesn't have a strong odor.<br />
|-<br />
| Bottom || Black || Number of times it's caused one of those terrifying lab accidents that chemists tell scary stories about late at night (2) || This square might show how concerned and careful someone should be in handling the substance in question, especially if the number is more than one. However, it would be dependent not just on how inherently dangerous the substance is, but also on how commonly it occurs in labs. It's also vague as to what kind of accidents it has been involved in and what precautions therefore need to be taken. It could, for example, have caused some terrifying reaction, destroying things around it, or it could be very large and unwieldy and liable to crush people if handled improperly.<br />
<br />
In this case, it seems the substance has caused two such accidents, presumably on account of its high health risk of 4 in the Blue square, and may also be linked to its hazardous disposal score of 4 in the Purple square.<br />
|}<br />
<br />
The title text (which references "scary stories" of the Black square) refers to {{w|dimethylmercury}} and {{w|prions}}. Dimethylmercury, C<sub>2</sub>H<sub>6</sub>Hg, is an organic form of mercury with an NFPA score of 4-4-3 (contact can be fatal, will burn below 73° F (22 °C), will combust if put under pressure). In 1997, an American chemist, {{w|Karen Wetterhahn}}, died 298 days after a few drops of C<sub>2</sub>H<sub>6</sub>Hg on her latex gloves were absorbed into her hand through the gloves, causing fatal mercury poisoning. Despite her having followed all safety protocols of the time, it was not then understood that the chemical was so toxic, nor that latex was so permeable to it. Prions are misfolded proteins that are responsible for a number of neurodegenerative diseases, including {{w|mad cow disease}} and {{w|chronic wasting disease}} in non-human animals and {{w|Creutzfeldt-Jakob disease}} in humans. These would indeed be the kind of substances that would scare those working with them in their labs; if an accident occurred, the results could be calamitous. See for example the case of [https://arstechnica.com/science/2021/07/second-lab-worker-with-deadly-prion-disease-prompts-research-pause-in-france/ Émilie Jaumain], a lab technician who died after accidentally coming into contact with prions in mouse tissue.<br />
<br />
But a few labs have apparently had accidents involving a soda machine or {{w|dropped ceiling}}. The latter may be a reference to {{w|1978 smallpox outbreak in the United Kingdom|the death of Janet Parker}}: One inquiry found that she was infected with {{w|smallpox}} when a sample traveled upward from a lab on the floor below hers; however, other investigations have challenged that finding. There are occasional instances of vending machines causing injury or death, usually caused by people trying to shake or tilt the machines to get product out and having the machine tip and fall on them. On average, [https://www.cpsc.gov/Newsroom/News-Releases/1996/CPSC-Soda-Vending-Machine-Industry-Labeling-Campaign-Warns-Of-Deaths-And-Injuries a couple of Americans per year] are killed in this way. Reagents obtained in this way tend to have more impurities than those usually used in labs, but are relatively safe to shake.<br />
<br />
The only easily identifiable substance which could likely meet the specific insignia numbers shown in the comic is {{w|thionyl chloride}} (SOCl<sub>2</sub>), a chlorinating reagent and solvent regulated as a chemical weapons precursor and sometimes used in the production of methamphetamine, which would also be represented with the '''<s>W</s>''' symbol inside the white square, indicating reactivity with water. However, it's known to have a very strong odor, so a single hand scrubbing might be insufficient to remove it.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:Know your extended NFPA hazard diamond:<br />
<br />
:[The diamond is divided into 3x3 squares.]<br />
:Flammability: 0 (top, red)<br />
:Health hazard: 4 (top-left, blue)<br />
:Instability/reactivity: 2 (top-right, yellow)<br />
:Number of digits in the street value ($/gram): 2 (left, green)<br />
:(Special hazard) (center, white)<br />
:How much of a hassle it is to dispose of: 4 (right, purple)<br />
:Number of federal agencies who want to know if you have any: 3 (bottom-left, pink)<br />
:How many times you have to scrub your hands after touching it before they stop smelling weird: 1 (bottom-right, orange)<br />
:Number of times it's caused one of those terrifying lab accidents that chemists tell scary stories about late at night: 2 (bottom, black)<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Science]]<br />
[[Category:Chemistry]]<br />
[[Category:Comics with color]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2638:_Extended_NFPA_Hazard_Diamond&diff=2880902638: Extended NFPA Hazard Diamond2022-07-02T21:33:05Z<p>172.70.214.95: /* Explanation */ mention odor</p>
<hr />
<div>{{comic<br />
| number = 2638<br />
| date = June 27, 2022<br />
| title = Extended NFPA Hazard Diamond<br />
| image = extended_nfpa_hazard_diamond.png<br />
| titletext = With most labs, the hushed horror stories are about something like dimethylmercury or prions, but occasionally you'll get a weird lab where it's about the soda machine or the drop ceiling.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SUBSTANCE WORTH $500 IN STREET VALUE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic depicts an extension of the National Fire Protection Association's {{w|NFPA 704|NFPA 704 Standard System for the Identification of the Hazards of Materials for Emergency Response}} "fire diamond" emblematic insignia used to warn about the properties of hazardous substances inside a building, vehicle, room, cabinet, or container that are important during an emergency or accident, such as a fire, earthquake, spill or leak, bringing the diamond from 2x2 squares to 3x3 by adding five variously useful and humorous squares along the bottom edges.<br />
<br />
The numbers in a normal NFPA 704 diamond do not specify values of substances' properties, but rather broad categories designating characteristics of the substances of greatest interest to {{w|first responders}} and hazardous materials cleanup crews. Randall's expanded diamond breaks with this convention, with several squares (Lilac, Orange, and Black) denoting absolute values, and one square (Green) denoting an economic value. This could very easily lead to documentation update headaches if these values were ever to change, doubly so since the Lilac square is linked to political outcomes.<br />
<br />
{| class="wikitable"<br />
|+ Squares and explanations<br />
|-<br />
! Square !! Color !! Comic text !! Explanation<br />
|-<br />
!colspan=5| Real NFPA 704 diamond [http://www.ilpi.com/msds/ref/nfpa.html square and number meanings]<br />
|-<br />
| Top || Red || Flammability (0) || Denotes flammability. 0 indicates "materials that will not burn."<br />
|-<br />
| Top Left || Blue || Health Hazard (4) || Denotes the danger that the substance(s) pose to living beings in ways other than flammability and reactivity. 4 indicates that "Very short exposure could cause death or serious residual injury even though prompt medical attention was given."<br />
|-<br />
| Top Right || Yellow || Instability (2) || Denotes how stable the substance(s) are when exposed to water, heat, shock, air, or other substances. 2 indicates that "Normally unstable and will readily undergo violent decomposition but does not detonate. Also: may react violently with water or may form potentially explosive mixtures with water."<br />
|-<br />
| Center || White || (Special Hazard) || The standard's "Special Notice" field may contain a symbol denoting additional information about the substance(s), e.g., '''OX''' for {{w|oxidizer}}s, '''SA''' for simple {{w|asphyxiant}} gases such as nitrogen and helium, and <s>'''W'''</s> for substances which react dangerously with water.<br />
|-<br />
!colspan=5| After this point, all squares are made up by Randall.<br />
|-<br />
| Center Left || Green || Number of digits in the street value ($/gram) (2) || Describes the order of magnitude of the price (in USD) of one gram of the substance when sold illegally and informally. This is done on a logarithmic scale, with a '1' selling for $9/gram or less, a '2' selling for $99/gram, and so on. As such this is the first of several squares where the number may presumably go to 5 or above (which is not allowed on the original Blue/Red/Yellow squares, as they do not denote strict numerical values). That said it's not immediately clear how substances which command <$1/gram would be handled.<br />
<br />
Randall's example substance apparently sells for tens of dollars per gram (which would be similar to most common illicit drugs).<br />
|-<br />
| Center Right || Dark Purple || How much of a hassle it is to dispose of (4) || While many things can be thrown in the trash with no additional procedures, substances that merit an NFPA 704 square often require additional procedures to avoid significant danger, damage to the environment, or hefty dumping fines. Biohazards that may carry diseases are often disposed of in special containers, and nuclear materials are notoriously difficult to safely dispose of. This square would be at least theoretically useful, though not as much as the actual disposal guidelines.<br />
<br />
If the numbering here follows the scheme of the real categories, Randall's example substance is about as hard to dispose of as it gets. This matches the substance's rating of 4 for Blue and 2 for Yellow. Presumably it requires highly specialized handling or processing, and may also very bulky or awkward to store.<br />
|-<br />
| Bottom Left || Lilac || Number of federal agencies who want to know if you have any (3) || In many countries, including Randall's home country, the USA, the government has agencies dedicated to controlling or limiting the use of regulated substances, due to their use as drugs, weapons, harm to the environment, etc. While any given substance might be of interest to one agency, something that is both an environmental hazard and a chemical weapon component could interest, for example, the {{w|EPA}}, {{w|Chemical Safety Board}} and the FBI Counter-terrorism Division.<br />
|-<br />
| Bottom Right || Orange || How many times you have to scrub your hands after touching it before they stop smelling weird (1) || While the real NFPA 704 chart describes properties ranging from unsafe to potentially deadly, this square describes a minor but very real inconvenience. Some things are harder to wash off your hands than others, and, given that most people don't often work with dangerous substances {{Citation Needed}}, this would be a more common, but less relevant, concern for many people.<br />
<br />
In this case, the substance, or its residue, seems to be fairly easy to wash off. This is seemingly incongruous with its ratings in the Blue and Black squares (see below), though it's possible that this substance simply doesn't have a strong odor.<br />
|-<br />
| Bottom || Black || Number of times it's caused one of those terrifying lab accidents that chemists tell scary stories about late at night (2) || This square might show how concerned and careful someone should be in handling the substance in question, especially if the number is more than one. However, it would be dependent not just on how inherently dangerous the substance is, but also on how commonly it occurs in labs. It's also vague as to what kind of accidents it has been involved in and what precautions therefore need to be taken. It could, for example, have caused some terrifying reaction, destroying things around it, or it could be very large and unwieldy and liable to crush people if handled improperly.<br />
<br />
In this case, it seems the substance has caused two such accidents, presumably on account of its high health risk of 4 in the Blue square, and may also be linked to its hazardous disposal score of 4 in the Purple square.<br />
|}<br />
<br />
The title text (which references "scary stories" of the Black square) refers to {{w|dimethylmercury}} and {{w|prions}}. Dimethylmercury, C<sub>2</sub>H<sub>6</sub>Hg, is an organic form of mercury with an NFPA score of 4-4-3 (contact can be fatal, will burn below 73° F (22 °C), will combust if put under pressure). In 1997, an American chemist, {{w|Karen Wetterhahn}}, died 298 days after a few drops of C<sub>2</sub>H<sub>6</sub>Hg on her latex gloves were absorbed into her hand through the gloves, causing fatal mercury poisoning. Despite her having followed all safety protocols of the time, it was not then understood that the chemical was so toxic, nor that latex was so permeable to it. Prions are misfolded proteins that are responsible for a number of neurodegenerative diseases, including {{w|mad cow disease}} and {{w|chronic wasting disease}} in non-human animals and {{w|Creutzfeldt-Jakob disease}} in humans. These would indeed be the kind of substances that would scare those working with them in their labs; if an accident occurred, the results could be calamitous. See for example the case of [https://arstechnica.com/science/2021/07/second-lab-worker-with-deadly-prion-disease-prompts-research-pause-in-france/ Émilie Jaumain], a lab technician who died after accidentally coming into contact with prions in mouse tissue.<br />
<br />
But a few labs have apparently had accidents involving a soda machine or {{w|dropped ceiling}}. The latter may be a reference to {{w|1978 smallpox outbreak in the United Kingdom|the death of Janet Parker}}: One inquiry found that she was infected with {{w|smallpox}} when a sample traveled upward from a lab on the floor below hers; however, other investigations have challenged that finding. There are occasional instances of vending machines causing injury or death, usually caused by people trying to shake or tilt the machines to get product out and having the machine tip and fall on them. On average, [https://www.cpsc.gov/Newsroom/News-Releases/1996/CPSC-Soda-Vending-Machine-Industry-Labeling-Campaign-Warns-Of-Deaths-And-Injuries a couple of Americans per year] are killed in this way. Reagents obtained in this way tend to have more impurities than those usually used in labs, but are relatively safe to shake.<br />
<br />
The only easily identifiable substance which could likely meet the specific insignia numbers shown in the comic is {{w|thionyl chloride}} (SOCl<sub>2</sub>), a chlorinating reagent and solvent regulated as a chemical weapons precursor and sometimes used in the production of methamphetamine, which would also be represented with the '''<s>W</s>''' symbol inside the white square, indicating reactivity with water. However, it is known to have a very strong odor, so a single hand-washing might be insufficient to remove it.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:Know your extended NFPA hazard diamond:<br />
<br />
:[The diamond is divided into 3x3 squares.]<br />
:Flammability: 0 (top, red)<br />
:Health hazard: 4 (top-left, blue)<br />
:Instability/reactivity: 2 (top-right, yellow)<br />
:Number of digits in the street value ($/gram): 2 (left, green)<br />
:(Special hazard) (center, white)<br />
:How much of a hassle it is to dispose of: 4 (right, purple)<br />
:Number of federal agencies who want to know if you have any: 3 (bottom-left, pink)<br />
:How many times you have to scrub your hands after touching it before they stop smelling weird: 1 (bottom-right, orange)<br />
:Number of times it's caused one of those terrifying lab accidents that chemists tell scary stories about late at night: 2 (bottom, black)<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Science]]<br />
[[Category:Chemistry]]<br />
[[Category:Comics with color]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2638:_Extended_NFPA_Hazard_Diamond&diff=2880332638: Extended NFPA Hazard Diamond2022-07-02T03:31:03Z<p>172.70.214.95: Revert: "Special Hazards" is the official standard name of the white square; see http://www.ilpi.com/msds/ref/nfpa.html</p>
<hr />
<div>{{comic<br />
| number = 2638<br />
| date = June 27, 2022<br />
| title = Extended NFPA Hazard Diamond<br />
| image = extended_nfpa_hazard_diamond.png<br />
| titletext = With most labs, the hushed horror stories are about something like dimethylmercury or prions, but occasionally you'll get a weird lab where it's about the soda machine or the drop ceiling.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a SUBSTANCE WORTH $500 IN STREET VALUE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
This comic depicts an extension of the {{w|NFPA 704}} "fire diamond" emblematic insignia used to warn about the properties of hazardous substances inside a building, vehicle, room, cabinet, or container that are important during an emergency or accident, such as a fire, earthquake, spill or leak, bringing the diamond from 2x2 squares to 3x3 by adding five variously useful and humorous squares along the bottom edges.<br />
<br />
The numbers in a normal NFPA 704 diamond do not specify values of substances' properties, but rather broad categories designating characteristics of the substances of greatest interest to first responders and hazardous materials cleanup crews. Randall's expanded diamond breaks with this convention, with several squares (Lilac, Orange, and Black) denoting absolute values, and one square (Green) denoting an economic value. This could very easily lead to documentation update headaches if these values were ever to change, doubly so since the Lilac square is linked to political outcomes.<br />
<br />
{| class="wikitable"<br />
|+ Squares and explanations<br />
|-<br />
! Square !! Color !! Comic text !! Explanation<br />
|-<br />
!colspan=5| Real NFPA 704 diamond [http://www.ilpi.com/msds/ref/nfpa.html square and number meanings]<br />
|-<br />
| Top || Red || Flammability (0) || Denotes flammability. 0 indicates "materials that will not burn."<br />
|-<br />
| Top Left || Blue || Health Hazard (4) || Denotes the danger that the substance(s) pose to living beings in ways other than flammability and reactivity. 4 indicates that "Very short exposure could cause death or serious residual injury even though prompt medical attention was given."<br />
|-<br />
| Top Right || Yellow || Instability (2) || Denotes how stable the substance(s) are when exposed to water, heat, shock, air, or other substances. 2 indicates that "Normally unstable and will readily undergo violent decomposition but does not detonate. Also: may react violently with water or may form potentially explosive mixtures with water."<br />
|-<br />
| Center || White || (Special Hazard) || Contains a symbol with additional information about the substance(s), e.g., '''OX''' for {{w|oxidizer}}s, '''SA''' for simple {{w|asphyxiant}}s such as nitrogen and helium, and <s>'''W'''</s> for substances which react dangerously with water.<br />
|-<br />
!colspan=5| After this point, all squares are made up by Randall.<br />
|-<br />
| Center Left || Green || Number of digits in the street value ($/gram) (2) || Describes the order of magnitude of the price (in USD) of one gram of the substance when sold illegally and informally. This is done on a logarithmic scale, with a '1' selling for $9/gram or less, a '2' selling for $99/gram, and so on. As such this is the first of several squares where the number may presumably go to 5 or above (which is not allowed on the original Blue/Red/Yellow squares, as they do not denote strict numerical values). That said it's not immediately clear how substances which command <$1/gram would be handled.<br />
<br />
Randall's example substance apparently sells for tens of dollars per gram (which would be similar to most common illicit drugs).<br />
|-<br />
| Center Right || Dark Purple || How much of a hassle it is to dispose of (4) || While many things can be thrown in the trash with no additional procedures, substances that merit an NFPA 704 square often require additional procedures to avoid significant danger, damage to the environment, or hefty dumping fines. Biohazards that may carry diseases are often disposed of in special containers, and nuclear materials are notoriously difficult to safely dispose of. This square would be at least theoretically useful, though not as much as the actual disposal guidelines.<br />
<br />
If the numbering here follows the scheme of the real categories, Randall's example substance is about as hard to dispose of as it gets. This matches the substance's rating of 4 for Blue and 2 for Yellow. Presumably it requires highly specialized handling or processing, and may also very bulky or awkward to store.<br />
|-<br />
| Bottom Left || Lilac || Number of federal agencies who want to know if you have any (3) || In many countries, including Randall's home country, the USA, the government has agencies dedicated to controlling or limiting the use of regulated substances, due to their use as drugs, weapons, harm to the environment, etc. While any given substance might be of interest to one agency, something that is both an environmental hazard and a chemical weapon component could interest, for example, the {{w|EPA}}, {{w|Chemical Safety Board}} and the FBI Counter-terrorism Division.<br />
|-<br />
| Bottom Right || Orange || How many times you have to scrub your hands after touching it before they stop smelling weird (1) || While the real NFPA 704 chart describes properties ranging from unsafe to potentially deadly, this square describes a minor but very real inconvenience. Some things are harder to wash off your hands than others, and, given that most people don't often work with dangerous substances {{Citation Needed}}, this would be a more common, but less relevant, concern for many people.<br />
<br />
In this case, the substance, or its residue, seems to be fairly easy to wash off. This is seemingly incongruous with its ratings in the Blue and Black squares (see below).<br />
|-<br />
| Bottom || Black || Number of times it's caused one of those terrifying lab accidents that chemists tell scary stories about late at night (2) || This square might show how concerned and careful someone should be in handling the substance in question, especially if the number is more than one. However, it would be dependent not just on how inherently dangerous the substance is, but also on how commonly it occurs in labs. It's also vague as to what kind of accidents it has been involved in and what precautions therefore need to be taken. It could, for example, have caused some terrifying reaction, destroying things around it, or it could be very large and unwieldy and liable to crush people if handled improperly.<br />
<br />
In this case, it seems the substance has caused two such accidents, presumably on account of its high health risk of 4 in the Blue square, and may also be linked to its hazardous disposal score of 4 in the Purple square.<br />
|}<br />
<br />
The title text (which references "scary stories" of the Black square) refers to {{w|dimethylmercury}} and {{w|prions}}. Dimethylmercury, C<sub>2</sub>H<sub>6</sub>Hg, is an organic form of mercury with an NFPA score of 4-4-3 (contact can be fatal, will burn below 73° F (22 °C), will combust if put under pressure). In 1997, an American chemist, {{w|Karen Wetterhahn}}, died 298 days after a few drops of C<sub>2</sub>H<sub>6</sub>Hg on her latex gloves were absorbed into her hand through the gloves, causing fatal mercury poisoning. Despite her having followed all safety protocols of the time, it was not then understood that the chemical was so toxic, nor that latex was so permeable to it. Prions are misfolded proteins that are responsible for a number of neurodegenerative diseases, including {{w|mad cow disease}} and {{w|chronic wasting disease}} in non-human animals and {{w|Creutzfeldt-Jakob disease}} in humans. These would indeed be the kind of substances that would scare those working with them in their labs; if an accident occurred, the results could be calamitous. See for example the case of [https://arstechnica.com/science/2021/07/second-lab-worker-with-deadly-prion-disease-prompts-research-pause-in-france/ Émilie Jaumain], a lab technician who died after accidentally coming into contact with prions in mouse tissue.<br />
<br />
But a few labs have apparently had accidents involving a soda machine or {{w|dropped ceiling}}. The latter may be a reference to {{w|1978 smallpox outbreak in the United Kingdom|the death of Janet Parker}}: One inquiry found that she was infected with {{w|smallpox}} when a sample traveled upward from a lab on the floor below hers; however, other investigations have challenged that finding. There are occasional instances of vending machines causing injury or death, usually caused by people trying to shake or tilt the machines to get product out and having the machine tip and fall on them. On average, [https://www.cpsc.gov/Newsroom/News-Releases/1996/CPSC-Soda-Vending-Machine-Industry-Labeling-Campaign-Warns-Of-Deaths-And-Injuries a couple of Americans per year] are killed in this way. Reagents obtained in this way tend to have more impurities than those usually used in labs, but are relatively safe to shake.<br />
<br />
The only easily identifiable substance which could likely meet the specific insignia numbers shown in the comic is {{w|thionyl chloride}} (SOCl<sub>2</sub>), a chlorinating reagent and solvent regulated as a chemical weapons precursor and sometimes used in the production of methamphetamine, which would also be represented with the '''<s>W</s>''' symbol inside the white square, indicating reactivity with water.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:Know your extended NFPA hazard diamond:<br />
<br />
:[The diamond is divided into 3x3 squares.]<br />
:Flammability: 0 (top, red)<br />
:Health hazard: 4 (top-left, blue)<br />
:Instability/reactivity: 2 (top-right, yellow)<br />
:Number of digits in the street value ($/gram): 2 (left, green)<br />
:(Special hazard) (center, white)<br />
:How much of a hassle it is to dispose of: 4 (right, purple)<br />
:Number of federal agencies who want to know if you have any: 3 (bottom-left, pink)<br />
:How many times you have to scrub your hands after touching it before they stop smelling weird: 1 (bottom-right, orange)<br />
:Number of times it's caused one of those terrifying lab accidents that chemists tell scary stories about late at night: 2 (bottom, black)<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Science]]<br />
[[Category:Chemistry]]<br />
[[Category:Comics with color]]</div>172.70.214.95https://www.explainxkcd.com/wiki/index.php?title=2640:_The_Universe_by_Scientific_Field&diff=2880222640: The Universe by Scientific Field2022-07-02T01:48:05Z<p>172.70.214.95: /* Explanation */ copyedit</p>
<hr />
<div>{{comic<br />
| number = 2640<br />
| date = July 1, 2022<br />
| title = The Universe by Scientific Field<br />
| image = the_universe_by_scientific_field.png<br />
| titletext = The math and philosophy people also claim everything, but the astronomers argue that the stuff they study really only comprises a small number of paper surfaces.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by the UNIVERSE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
{{w|Astronomy}} is the study of outer space and celestial phenomena. This comic makes a joke that most of the "universe" falls under the study of astronomy. Which makes sense because the "universe" is so vast and large and is not studied by other fields of science.<br />
<br />
The volume of the observable universe is 3.566×10<sup>80</sup> cubic meters. The volume of Earth is 1.08321×10<sup>21</sup> cubic meters.<br />
<br />
1.08321×10<sup>21</sup> m<sup>3</sup> &divide; 3.566×10<sup>80</sup> m<sup>3</sup> × 100% ≈ 3×10<sup>-58</sup>%, which is scientific notation for the second of the two percentages, the first being its difference from 100%.<br />
<br />
The title text says that mathematicians and philosophers claim that what they study also represents everything. But astronomers counter this by saying that they just study things that are written down, and this comprises just tiny amounts of "paper" on the Earth. This claim by mathematicians also appears in [[435: Purity]]. <br />
<br />
The adjacent fields of optics, physics, chemistry, mathematics, and geometry underpin almost all aspects of astronomy other than nomenclature, so the comic may be seen as biased by proponents of those disciplines. Other objections may include the fact that almost everyone's subjective life experiences are overwhelmingly more involved with matters best described by fields other than astronomy, even in the case of professional astronomers (who often complain about how little time they can allocate to making actual astronomical observations.) Furthermore, the information provided by astronomical observations of light, subatomic particles, and gravity's effects represents only a tiny fraction of the scientific properties of the extraterrestrial substances in the volume of space that astronomers study.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
:The Universe by Scientific Field<br />
<br />
:[A pie chart is shown.]<br />
:Astronomy<br />
:99.9999999999999999999999999999999999999999999999999999999997%<br />
:Other<br />
:0.0000000000000000000000000000000000000000000000000000000003%<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Pie charts]]<br />
[[Category:Science]]<br />
[[Category:Astronomy]]<br />
[[Category:Math]]<br />
[[Category:Philosophy]]</div>172.70.214.95