explain xkcd - User contributions [en]

3242: Aperiodic Table

2026-05-06T23:00:00Z

2001:1998:3500:42D:0:0:0:B4: /* Explanation */ punctuation

{{comic
| number = 3242
| date = May 6, 2026
| title = Aperiodic Table
| image = aperiodic_table_2x.png
| imagesize = 740x464px
| noexpand = true
| titletext = Scientists occasionally invent alternative periodic table layouts, which is usually a sign that they don't have enough enrichment in their enclosures.
}}

==Explanation==
{{incomplete|This page was created APERIODICALLY. Don't remove this notice too soon.}}
The {{w|Periodic Table of the Elements}} is a diagram often used to show the properties of the elements that make up the world. Its structure represents several properties of the elements- for example, all elements in a single column will have similar chemical properties, and the elements increase in size when reading it left-to-right and top-to-bottom (like a book).

Randall spoofs this concept by creating a similar, but useless, diagram. The original table is "periodic" because it has consistent, repeating patterns that are represented by the horizontal position of the elements. Randall's table is "aperiodic", meaning it has no consistent, repeating patterns. Instead, it is just a line in order by {{w|atomic number}}. To fit in the same space as a normal periodic table, the sequence snakes back and forth and down the page in a space-filling manner. The diagram is not actually helpful, since it contains next-to-no information other than the atomic number of each element, plus faint colouring on each box to show its category, though due to the dull colours that is also quite inconvenient to use, and it depicts this information in an unnecessarily unhelpful and hard-to-read format.

Chemistry and the periodic table is a periodic theme on xkcd, with there being many comics featuring humorous variations and "fixes" of it, such as [[2639: Periodic Table Changes]] and [[2975: Classical Periodic Table]].

The title text might be a reference to [[3052: Archive Request]], or maybe some real attempts at inventing actual 'non-grid' linear versions of the periodic table, such as the {{w|File:Elementspiral_(polyatomic).svg|'periodic snail'}} that was created by {{w|Otto Theodor Benfey}}.

Thallium’s symbol is incorrectly given as Ti in this comic; its actual symbol is Tl.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

The Aperiodic Table of the Elements

[Rectangles showing the atomic symbols and atomic numbers from H 1 through Og 118 are arranged in a serpentine chain. The color of each rectangle matches the the pattern of a standard periodic table. For example, the noble elements all have a red background.]

{{comic discussion}}<noinclude>

3241: Horizontal Stabilizers

2026-05-06T22:57:00Z

2001:1998:3500:42D:0:0:0:B4: /* Explanation */ Spelling corrections

{{comic
| number = 3241
| date = May 5, 2026
| title = Horizontal Stabilizers
| image = horizontal_stabilizers_2x.png
| imagesize = 436x341px
| noexpand = true
| titletext = It started as a mistake that everyone was afraid to admit to, and then it stuck because removing it 'looks silly.'.
}}

==Explanation==
{{incomplete|This page was created HORIZONTALLY, so just make it BIGGER. Don't remove this notice too soon.}}

A {{w|Stabilizer (aircraft)#Horizontal stabilizers|horizontal stabilizer}} (also often described as a {{w|tailplane}}) is part of an aircraft which typically provides extra longitudinal balance, with the tailplane maintaining balance and control of the aircraft. Although some alternate types of airframe work without them (e.g. by making use of more complex main wing control surfaces), most (and the most common) aircraft use {{w|Tailplane#Tailplane types|some version or other}} of a tailplane. The structure of aircraft varies based on what they {{What If|30|have to do}}.

This comic claims that horizontal stabilizers are a mistake in the design process, and not at all necessary. The original construction of some particular plane only had small wings and the mere stub of fusalage to which they were attached, but neither wings nor body were big enough to be useful. Rather than spending time and resources rebuilding from scratch, they just added more fuselage, with much bigger wings, and continued to use the original insufficient fuselage and 'wings' in the manner of a tailplane.

The title text takes this even further, stating that people deliberately ignored the superfluousness of this new part, and later, whenever they decided to remove the feature (perhaps to save weight, or just 'complexity') people were already so used to them being there that it "looked silly", so they put them back on to satisfy expectations. This may be referencing the use of 'spoilers' on everyday passenger cars, which are often included purely for cosmetic reasons, because it makes the vehicle look 'fast' or 'sporty' while having little or no effect in producing the desired downforce (for extreme cornering or acceleration), and may instead just add drag to the car to make it ultimately ''slower'' in a straight line speed-test.

There are some {{w|tailless aircraft}}, often designed as such precisely to minimize the latent drag from the tailplane surfaces (another possible reason being to create a {{w|Radar cross section|more 'stealthy' aircraft}}), and many people do consider them unusual-looking. Some aircraft, including the original {{w|Wright Flyer}}, have the horizontal stabilizers in the front rather than the tail section due to design assumptions made at the time (later superseded by the 'normal' and typically more stable configuration), with some more modern planes again using {{w|Canard (aeronautics)|canard}} 'forward control surfaces' instead of (or {{w|three-surface aircraft|in addition to}}) the rear-mounted ones using a more modern understanding of the active aerodynamic needs of a plane in flight.

The comic does not address the need for any {{w|vertical stabilizer}} and rudder, often integrated in some way with the (horizontal) tailplane or at least being rooted in the same section of fuselage. (Some may describe the {{w|empennage|whole assembly}} of horizontal and vertical rear surfaces (both static and actuated) as the "tailplane", due to it being all together in the same place.) The comic's original 'stabilizer only' plane ''also'' lacked any such vertical control surfaces. By the same logic, of course, a true 'tailless' aircraft like a Flying Wing ''can'' also fly without a tailfin-like structure, usually controlling its yaw through differential power and/or drag across its two remaining wings. Although 'half-tail' airframes exist that still use one ''or'' the other of horizontal and vertical control surfaces, where the main wing controls the other, and there are also tail designs that integrate both control and stabilization functions into {{w|V-tail|the same hybrid tail-structure}}.

At some point before the scene in the factory and the conversation about the airplane in flight, the evolving design seems to have gained the vertical stabiliser as well, for unstated in-comic reasons perhaps just as superfluous as that for which it has retained the horizontal version. But, then again, as well as gaining more fuselage (which may necessarily have completed the stated design expectation of it being 'bigger', by increasing its potential cargo capacity) it has also managed to gain such useful features as a cockpit/nosecone ''and also engines'', the ultimate superfluity of which is far less likely to (even reluctantly) justify.

==Trivia==
*This is a rare [[:Category:Tuesday comics|Tuesday comic]]. There was no [[:Category:Monday comics|Monday comic]] this week. However, the archive states the publication date as 2026-5-4 (the previous Monday), so the comic was likely intended to be a Monday comic.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}

:[Cueball and Ponytail are standing, looking up at an airplane in the sky. Cueball is pointing at the airplane.]
:Cueball: What's with the little wings on the tails of the airplanes? Do they really need them?
:Ponytail: They're horizontal stabilizers. They serve a crucial aerodynamic role.

:[Hairy, another Cueball, and Megan are standing in a room, with Hairy on the left of a small fuselage segment with small wings attached to the sides of it, while Cueball and Megan are standing on the right of it. Hairy has his arms raised. There is a caption in a box at the top of the panel.]
:Caption: Previously, at the airplane factory...
:Hairy: These wings you made are way too small! The plane is supposed to be much bigger!
:Other Cueball: Sorry! We'll start over.
:Hairy: No, there's no time. Just make it longer and put the bigger wings on the new section.

{{comic discussion}}<noinclude>
[[Category:Aviation]]
[[Category:Multiple Cueballs]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Megan]]

3239: Simple Machines

2026-04-29T23:21:31Z

2001:1998:3500:42D:0:0:0:B4: /* Explanation */

{{comic
| number = 3239
| date = April 29, 2026
| title = Simple Machines
| image = simple_machines_2x.png
| imagesize = 250x255px
| noexpand = true
| titletext = It's hard to decide which simple machine system to invest in. DeWalt makes a great lever and inclined plane, but I hear Milwaukee's wheel-and-axles are really good.
}}

==Explanation==
{{incomplete|This page was recently purchased from DeWalt, and we're still reading the manual. Don't remove this notice too soon.}}
There are a lot of simple tools used to give a {{w|mechanical advantage}} in various things. The 6 most common ones are called {{w|simple machines}}: a {{w|lever}}, {{w|wheel and axle}}, {{w|pulley}}, {{w|inclined plane}}, {{w|wedge}} and {{w|Screw (simple machine)|screw}}. Additionally, there are all-in-one tools that are made with multiple features, such as classic {{w|Swiss Army Knife}} that combines various different forms of blade (which in part act as levers and/or wedges, depending upon use) along with some non-bladed tools (such as the corkscrew, which naturally embodies the same forces as the 'simple screw' itself). This comic combines both ideas, suggesting the existence of an all-in-one instrument with all six simple tools. The tool shown merges them by mounting multiple components (no longer being quite so a 'simple' machine), some of them with multiple purposes depending upon application. For example the lever and the inclined plane are both present via the same core rod.

Having one of these "all-in-one" devices does not mean it does everything you can do with different combinations — the choice of components and how they interact (or don't get in each others' way) is important for the function of a particular device.

There are obvious drawbacks to having this 'all-in-one' tool. The tools all have varying uses, some very different from one other, and you would find it unlikely to find many devices in need of all the tools together in a spot. So such a tool would be largely useless compared to its singular variants. As well as that, the tools come in many different sizes as well, meaning unless it has special adjustable sizes (which could well be impossible, to account for all the different sizes){{Citation needed}} the tool would be unlikely to be the right size to fit many features! As well as that, though [[Randall]] claims he can stop buying simple tools thanks to his all-in-one, in reality you often need more than one of the various tools for projects- particularly screws, of which there can be hundreds in a single project. So a thoroughly useless innovation.

The title text is a joke about what brands to choose. {{w|Milwaukee Tool}} and {{w|DeWalt}} are two common tool companies. The text points out that as both companies have advantages in certain simple tools, then deciding which to use for an all-in-one tool would be difficult. This is also likely a reference to the problem of choosing which tool company to use. As for battery powered tools, the batteries are not usually interchangeable, so once you buy a few tools from one company, you are stuck using only that company, as you already have "spare" batteries for all of the tools.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}[A rod with a square cross-section is shown sloping from top-left to bottom-right. At the bottom-right, it has a wedge tip. At the top-left, it is threaded and has a long nut on it. The nut has an eyelet where a rope is connected. The rope travels taut around a wheel on an axle connected near the wedge-end and then lies loose with a hook on the free end.]

[Caption below comic:]
I can finally stop buying simple machines now that I got an all-in-one tool with all six of them.

{{comic discussion}}<noinclude>

3231: Lightning

2026-04-10T22:42:57Z

2001:1998:3500:42D:0:0:0:B4: /* Explanation */

{{comic
| number = 3231
| date = April 10, 2026
| title = Lightning
| image = lightning_2x.png
| imagesize = 328x364px
| noexpand = true
| titletext = Maybe you should wear one too? I guess I'm taller than you, so as long as I have one we're fine.
}}

==Explanation==
{{incomplete|This page was created by a GROUNDED BOT. Don't remove this notice too soon.}}

An {{w|anti-static wrist strap}} is a device worn by people working with sensitive electronic devices. The strap is connected to a "ground", so that if there's any static charge built up it will discharge there rather than being transmitted to the device, which may otherwise damage it.

{{w|Lightning}} is a release of static electricity that occurs when there's a large charge difference between a cloud and the Earth or between two clouds. In the comic, [[Cueball]] has [[649|once again]] confused how anti-static devices work -- rather than protecting a device from static in the person, he thinks it will protect the person from static in the lightning. In fact, wearing a strap that conducts electricity will make it ''more'' likely that he will be struck by lightning, and the strap is far too small to protect him from the electricity in the lightning strike.

He may think that the anti-static device works like a {{w|lightning rod}}, attracting the lighting and diverting it away from his body. This is corroborated by the title text, in which he thinks that [[Ponytail]] should be safe because he's taller than she is, and lightning tends to be attracted to the highest conductor in its vicinity (e.g., lightning rods that are above the roof of the building they're protecting). While this is true, it ignores the fact that he's made himself more likely to be struck, and potentially severely hurt or killed, by a lightning strike.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[Lightning overhead. Cueball and Ponytail are standing on a hill at night.]

:[In the sky, by the lightning:]
:BOOOOM

:[Cueball:]

:Don't worry, I'm wearing an anti-static wrist strap

{{comic discussion}}<noinclude>