explain xkcd - User contributions [en]

Talk:2975: Classical Periodic Table

2024-08-22T08:45:25Z

Darkwolf218:

I checked the Actinides and it looks like the criteria for "fire" is half-life < 1 day. [[User:SpriteGuard|SpriteGuard]] ([[User talk:SpriteGuard|talk]]) 18:11, 21 August 2024 (UTC)
:I would have found it funnier, if only on table-esthetic grounds, if all radioactive elements had been filed as Fire. (I'm a chemist.) [[Special:Contributions/198.41.242.175|198.41.242.175]] 07:58, 22 August 2024 (UTC)

notice how this periodic table predates the apartheid state of Israel. really makes you think, huh? [[Special:Contributions/172.70.85.153|172.70.85.153]] 19:43, 21 August 2024 (UTC)
:I don't see how this comic relates to the matter of Israel in any way. [[User:BunsenH|BunsenH]] ([[User talk:BunsenH|talk]]) 20:27, 21 August 2024 (UTC)
:Xir, this is a wiki that explains a web comic for nerds. [[Special:Contributions/172.71.150.128|172.71.150.128]] 04:52, 22 August 2024 (UTC)

The four classical Elements are still recognised by scientists; They just repurposed the word "element", and so have adopted "state" to describe this older classification - Solid, Liquid, Gas and Plasma exactly map to the classical 'elements'. I think we can forgive the medieval alchemical community for not recognising Bose-Einstein Condensate as their fifth element. [[Special:Contributions/172.68.64.149|172.68.64.149]] 21:05, 21 August 2024 (UTC)
:what about non-newtonian fluids? [[User:42.book.addict|42.book.addict]] ([[User talk:42.book.addict|talk]]) 22:17, 21 August 2024 (UTC)
::They're fluids... turns out. [[Special:Contributions/172.70.126.229|172.70.126.229]] 04:47, 22 August 2024 (UTC)
:If the 2016 movie "[https://en.wikipedia.org/wiki/Spectral Spectral]" is to be believed, then Bose–Einstein condensates maps to ghosts. [[Special:Contributions/172.68.0.167|172.68.0.167]] 23:26, 21 August 2024 (UTC)

He's done this comparison between 'classical' and 'modern' elements before... for example in comic #965. [[Special:Contributions/172.70.58.3|172.70.58.3]] 05:52, 22 August 2024 (UTC)

I did what I could for the Fire section earlier, and I've just gone back and added some relevant What-If context for both Mercury and Astatine. The latter is nasty stuff - lucky it can't really exist under standard temperature and pressure, or we'd all be screwed. [[User:Darkwolf218|Darkwolf218]] ([[User talk:Darkwolf218|talk]]) 08:45, 22 August 2024 (UTC)

2975: Classical Periodic Table

2024-08-22T07:42:32Z

Darkwolf218: Do not boat in mercury. It is discouraged by the great Overseers. Also all of the fire elements like to burn things, or would if they could exist in large enough quantities. (Looking at you, Astatine)

{{comic
| number = 2975
| date = August 21, 2024
| title = Classical Periodic Table
| image = classical_periodic_table_2x.png
| imagesize = 740x530px
| noexpand = true
| titletext = Personally I think mercury is more of a 'wet earth' hybrid element.
}}

==Explanation==
{{incomplete|Created by THE AVATAR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

An element is a basic atomic building block of the physical world. Ancient civilizations believed in a small number of broad elements. The most famous are the {{w|classical element|classical (Hellenistic) elements}} of earth, fire, air, water, and sometimes a fifth element such as "void", "ether", or "quintessence." The Chinese {{w|Wuxing (Chinese philosophy)|wuxing}} system was a bit different, dropping air and adding elements for wood and metal. Such elemental theories fell out of favor as alchemists and later scientists began to discover what we now recognize as the atomic model, and today 118 elements are recognized and organized into the {{w|Periodic Table of Elements}}.

Here, Randall has taken a modern periodic table and color-coded the modern elements with the four classical elements. Gaseous elements such as hydrogen are colored blue for "air." Bromine and mercury, the two elements that remain liquid at room temperature and pressure, are colored dark blue for "water." Radioactive elements along the bottom of the table whose isotopes have only extremely short half-lives are red for "fire," with the rest of the chart filled in brown for "earth." The "earth" region includes many elements which are radioactive but whose half-lives are greater than 1 day. Elements appear to be grouped how they would appear in their elemental form, not as a chemical compound — for example, real water is made of Oxygen and Hydrogen (H2O), but elemental Hydrogen (H2) and elemental Oxygen (O2) alone are both gasses and thus grouped as "air."

The title text says that mercury should be classified as "wet earth". While it's a liquid, it has a very high surface tension so even large drops will stick together and may seem almost like a gel. Additionally, as evidenced by a {{w|Pseudoscience|very trustworthy source}}[https://what-if.xkcd.com/50/], mercury is functionally a solid for many fluid purposes, including boating.
===Table Sections===
{| class=wikitable
! scope="col" | Section in Randall’s Table
! scope="col" | Periodic table groups
! scope="col" | Elements contained
! scope="col" | Explanation
|-
| Air || All noble gases and most reactive nonmetals || Hydrogen, Nitrogen, Oxygen, Fluorine, Neon, Helium, Chlorine, Argon, Krypton, Xenon, Radon || These elements are a gas at room temperature, so they are grouped into "Air".
|-
| Water || One metal and one nonmetal || Bromine, Mercury || These elements are liquid at room temperature, so they are grouped into “Water”.
|-
| Fire || One alkali metal and many synthetic metals || Astatine, Francium, Californium, Einsteinium, Rutherfordium, Dubnium, Seaborgium, Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium, Copernicium, Oganesson, Nihonium, Flerovium, Moscovium, Livermorium, Tennessine || These are all highly radioactive metals with a half-life less than one day and a tendency to violently decompose at standard temperature and pressure, hence they are classified as "Fire". Any unshielded exposure to them tends to include severe burns, be they radiation or otherwise.
|-
| Earth || Most metals and metalloids || All other elements || Most of the periodic table consists of solid metals and metalloids which collectively make up most of the "Earth" and the life-forms living on it.
|}

This comic is similar to [[2913: Periodic Table Regions]], which also groups elements using unconventional methods.

The classical elements have been a topic of previous comics, such as [[965: Elements]]

==Triva==

* In Randall's first What-If book, it is explained that a 1-liter (sides of roughly 10 cm / 3.19 inches) cube of Astatine, which cannot exist under standard conditions, would "immediately turn into a column of superheated gas" which would destroy roughly a city block.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Header:]
:Classical Periodic Table

:[A diagram in the shape of the periodic table of elements is split into labeled colored regions. Each region is labeled with a large letter over a word in smaller letters.]

:[The regions and colors are as follows:]
:* A: Air: light blue: Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, and the noble gases.
:* W: Water: dark blue: Bromine and Mercury.
:* F: Fire: red-orange: Astatine, Francium, and everything from Mendelevium onwards (radioactive).
:* E: Earth: brown: everything else, covers majority of the diagram.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Chemistry]]
[[Category:Periodic table]]

2975: Classical Periodic Table

2024-08-21T19:01:10Z

Darkwolf218:

{{comic
| number = 2975
| date = August 21, 2024
| title = Classical Periodic Table
| image = classical_periodic_table_2x.png
| imagesize = 740x530px
| noexpand = true
| titletext = Personally I think mercury is more of a 'wet earth' hybrid element.
}}

==Explanation==
{{incomplete|Created by THE AVATAR - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

An element is a basic atomic building block of the physical world. Ancient civilizations believed in a small number of broad elements. The most famous are the {{w|classical element|classical (Hellenistic) elements}} of earth, fire, air, water, and sometimes a fifth element such as "void", "ether", or "quintessence." The Chinese {{w|Wuxing (Chinese philosophy)|wuxing}} system was a bit different, dropping air and adding elements for wood and metal. Such elemental theories fell out of favor as alchemists and later scientists began to discover what we now recognize as the atomic model, and today 118 elements are recognized and organized into the {{w|Periodic Table of Elements}}.

Here, Randall has taken a modern periodic table and color-coded the modern elements with the four classical elements. Gaseous elements such as hydrogen are colored blue for "air." Bromine and mercury, the two elements that remain liquid at room temperature and pressure, are colored dark blue for "water." Radioactive elements along the bottom of the table whose isotopes have only extremely short half-lives are red for "fire," with the rest of the chart filled in brown for "earth." The "earth" region includes many elements which are radioactive but whose half-lives aren't extremely short; it isn't clear what the cut-off is.

The title text says that mercury should be classified as "wet earth". While it's a liquid, it has a very high surface tension so even large drops will stick together and may seem almost like a gel.

===Table Sections===
{| class=wikitable
! scope="col" | Section
! scope="col" | Real table
! scope="col" | Elements contained
! scope="col" | Explanation
|-
| Air || All noble gases and most reactive nonmetals || Hydrogen, Nitrogen, Oxygen, Fluorine, Neon, Helium, Chlorine, Argon, Krypton, Xenon, Radon || These elements are a gas at room temperature, so they are grouped into "Air".
|-
| Water || One metal and one nonmetal || Bromine, Mercury || These elements are liquid at room temperature, so they are grouped into “Water”.
|-
| Fire || One alkali metal and many synthetic metals || || These are all highly radioactive metals with a half-life less than one day and a tendency to violently decompose at standard temperature and pressure, hence they are classified as "Fire".
|}

This comic is similar to [[2913: Periodic Table Regions]], which also groups elements using unconventional methods.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[Title text: Classical Periodic Table]

[A diagram in the shape of the periodic table of elements is split into labeled colored regions. Each region is labeled with a large letter over a word in smaller letters.]

[The regions and colors are as follows:
* A: Air: light blue: the first element and the upper-right of the main body, which includes noble gases, halogens and some non-metals.
* W: Water: dark blue: two separated cells in the main body.
* F: Fire: red-orange: the bottom stripe of both the main body and the separated section.
* E: Earth: brown: everything else, the majority of the diagram.
]

{{comic discussion}}

2929: Good and Bad Ideas

2024-05-07T07:28:23Z

Darkwolf218: Updating boxes.

{{comic
| number = 2929
| date = May 6, 2024
| title = Good and Bad Ideas
| image = good_and_bad_ideas_2x.png
| imagesize = 595x522px
| noexpand = true
| titletext = While it seemed like a fun prank at the time, I realize my prank fire extinguishers full of leaded gasoline were a mistake.
}}

==Explanation==
{{incomplete|Created by a BLOOD FOR THE BLOOD GOD- Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This is a scatter plot comparing how good an idea sounds to how good the idea actually is. For example, leaded gasoline sounds like a good idea due to the anti-knocking effects, but is actually a bad idea due to lead toxicity. Fake prank fire extinguishers however sound bad and are bad as they can result in a dangerous situation in an emergency. Putting mold on infections sounds like a bad idea, but this could be referring to Penicillin, an antibiotic.

The title text combines leaded gasoline and a fake prank fire extinguisher into something that is worse than either. Not only is the fire extinguisher fake, it also releases flammable material onto the fire, and there is the additional lead toxicity.

{| class="wikitable"
|-
! Idea !! What it means !! How good it sounds !! How good it actually is !! Explanation
|-
|Leaded Gasoline||Adding tetraethyl lead to gasoline to increase performance||++||---||Lead is toxic. Burning the leaded gasoline in an engine releases the lead in the air. This is bad.
|-
|Bloodletting||Releasing "bad blood" from the veins||---||---||You need your blood.{{Citation needed}}
|-
|Asbestos||Mineral which does not burn and is good isolation||+++||---||Asbestos was used extensively. Sadly the microscopic fibers which make up asbestos greatly increase the risk of cancer when inhaled.
|-
|Extension cords with prongs on both ends||allows easy connection between 2 female connectors||0 (neutral)||---||Prongs on both ends would make it easier to plug the extension cord in on either side. But once plugged into an outlet, the other end becomes a serious shock hazard.
|-
|Stair Kayaking||||--||---|| Stair kayaking is a stunt where a person positions a kayak at the top of a flight of stairs and then, using their paddle to push off, rides the kayak down the stairs. This poses significant risks of injury or death, as well as being very bad for the kayak, which is designed to ride on water, not concrete.
|-
|Fake prank fire extinguishers||||---||---|| The idea of placing fake fire extinguishers as a prank, presumably so that a person who thinks they are grabbing a real fire extinguisher will instead find a decoy, sounds very dangerous and potentially life-threatening for many people, and it would, in fact, be highly dangerous. In the United States, (and presumably most countries), this would also be a felony in most, if not all, jurisdictions. An example of a similar situation, although not intended as a prank, can be found here[https://twitter.com/ThatSamWinkler/status/1657154071051239424]
|-
|Always saying what you think||||||||
|-
|Replying to spammers||||||||
|-
|Solar cars||||||||
|-
|Heelies||||||||
|-
|Prequels||||||||
|-
|Transition Lenses||||||||
|-
|Cutting pizza in squares||||||||
|-
|{{w|Project Orion (nuclear propulsion)|Project Orion}}||Study by the U.S. government looking into nuclear pulse propulsion for spacecraft.||---||-||Repeated nuclear explosions in order to move sounds bad for both the spacecraft and everything else, especially with a ground launch. But there are ways to address a lot of the concerns, so it isn't as bad as it sounds. Project Orion's theorized specific impulse and thrust would also be far higher than anything chemical rockets can accomplish. The efficiency of Project Orion is extremely low, however.
|-
|Soup||||0 (neutral)||0 (neutral)||
|-
|Combo washer dryers||||||||
|-
|Cutting sandwiches diagonally||||||||
|-
|Diverging diamond interchanges||||||||
|-
|Toasting sandwiches||||||||
|-
|Crumple zones||||||||
|-
|Sliced bread||Bread, sliced by the baker before packaging for sale||+++||++||It's far more convenient for making sandwiches or toast, but unfortunately presliced bread will go stale faster and some applications may be better off thicker or thinner than the slices provided.
|-
|Pizza||Flat, though usually leavened, bread with tomato sauce, cheese, and often vegetables or preserved meats||++||++||Pizza is a widely popular dish throughout much of the world, uncontroversial except {{w|Pineapple|certain toppings.}}
|-
|Eating citrus fruit while at sea||||0 (neutral)||+++||The vitamin C present in citrus fruits prevents one from contracting {{w|Scurvy|scurvy}}.
|-
|Putting mold on infections||Seemingly a reference to ancient practice of pressing moldy bread against infected wounds||---||++||While this sounds like a good way to get a fungal infection, with the correct mold this is a primitive antibiotic, and led to the discovery of penicillin.
|-
|Wheels on luggage||Some luggage bags have small wheels inset on their frame and a carrying handle.||+++||+++||A relatively simple fitting for rigid or semi-rigid luggage that substantially eases its transport through air and seaport terminals.
|-
|Heat pumps||Refrigeration (or air conditioning) technology operated in reverse to heat an area instead.||++||+++||Because refrigeration is a very efficient way to move heat (as long as the cold side's temperature is high enough) this is often far more energetically efficient than directly heating a space. Reversible heat pumps also exist which can take care of both temperature needs in some climates.
|-
|Laser eye surgery||Surgical techniques using lasers for precision cutting in the eyeball.||-||+++||This technology has substantially improved the eyesight of millions of people worldwide by allowing treatment of eye problems otherwise only corrected by lenses, or entirely untreatable.
|-
|Fecal transplants||||||||
|-
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

{{comic discussion}}
[[Category:Charts]]

2908: Moon Armor Index

2024-03-19T05:11:59Z

Darkwolf218:

{{comic
| number = 2908
| date = March 18, 2024
| title = Moon Armor Index
| image = moon_armor_index_2x.png
| imagesize = 740x390px
| noexpand = true
| titletext = Astronomers are a little unsure of the applicability of this index, but NASA's Planetary Protection Officer is all in favor.
}}

==Explanation==
{{incomplete|Created by a MOON ARMOR SAMURAI BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Randall]] hypothesizes a situation in which each planet's moons were converted into protective armor to coat their respective planets. For example, the {{w|Moon}} would coat {{w|Earth}} in a 43 kilometer layer if it were molded into protective armor for the planet. It is unknown how the moons would be converted into armor, but with current technology, this would be highly impractical, if not impossible.{{citation needed}} It is also unclear how planets such as Jupiter, Saturn, Uranus, and Neptune, which are gas giants and thus have no solid surface, would sustain such a layer of armor, nor is it immediately evident what threat might necessitate such drastic measures. Mars' moons, being small compared to Mars, would make a thinner layer over Mars. Jupiter, being very big compared to its moons, would also have a small layer of "moon" on it. This is similar for Saturn, Uranus and Neptune. Pluto, having a moon (Charon) of a comparable size to its planet, would have a layer thicker than Earth's.

The title text states that astronomers are confused about the idea of protective armor made from moons, but NASA's Planetary Protection Officer, who is responsible for keeping other celestial bodies away from Earth's contamination, is apparently strongly in favor of this idea.

{| class="wikitable"
|-
! Planet/<br>dwarf planet !! Area (km²) || Moons || Volume (km³) || Moon shield thickness 
|-
| {{w|Earth}} || 5.1007*10^8 || {{w|Moon|1}} || 21.96*10^9 || 43 km (27 mi)
|-
| {{w|Mars}} || 1.4437*10^8 || {{w|Moons of Mars|2}} || {{w|Phobos (moon)
|(5695±32)}}+{{w|Deimos (moon)|(1033±19)}} || 5 cm (2 in)
|-
| {{w|Jupiter}} || 6.1469*10^10 || {{w|Moons of Jupiter|95}}
|-
| {{w|Saturn}} || 4.27*10^10 || {{w|Moons of Saturn|146}}
|-
| {{w|Uranus}} || 8.1156*10^9 || {{w|Moons of Uranus|28}}
|-
| {{w|Neptune}} || 7.6187*10^9 || {{w|Moons of Neptune|16}}
|-
| {{w|Pluto}} || 1.7744*10^7 || {{w|Moons of Pluto|5}}
|-
| {{w|120347 Salacia|Salacia}} || || {{w|Actaea (moon)|1}}
|-
| {{w|Haumea}} || 8.14*10^6 || {{w|Moons of Haumea|2}}
|-
| {{w|50000 Quaoar|Quaoar}} || 3.78*10^6 || {{w|Weywot|1}}
|-
| {{w|225088 Gonggong|Gonggong}} || || {{w|Xiangliu (moon)|1}}
|-
| {{w|Eris (dwarf planet)|Eris}} || (1.70±0.02)*10^7 || {{w|Dysnomia (moon)|1}}
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[Text above diagram:]
:Moon armor index:
:How thick the shells around various worlds would be if their moon(s) were converted into protective armor
:≈Total moon volume/Planet surface area

:[Vertical bars showing "moon armor" thicknesses for the Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Salacia, Haumea, Quaoar, Gonggong and Eris. Earth's bar has a label named "43 km thick" and is compared to the height of Mt Everest. The zoom in to the Mars' bar has a thickness label of 2" and is compared to a rover wheel over it. Pluto's bar has a label named "(Mostly Charon)".]

{{comic discussion}}

[[Category:Astronomy]]
[[Category:Bar charts]]