explain xkcd - User contributions [en]

3096: Check Engine

2025-06-01T15:10:25Z

162.158.212.171: /* Explanation */

{{comic
| number = 3096
| date = May 30, 2025
| title = Check Engine
| image = check_engine_2x.png
| imagesize = 331x383px
| noexpand = true
| titletext = They say it's probably safe to keep orbiting for a while, but if it stays on or starts flashing we might have to call someone.
}}

==Explanation==
{{incomplete|This page was created by THE SOLAR PIT CREW. Don't remove this notice too soon.}}
{{w|Sunspot|Sunspots}} are temporary, relatively small, darker (because cooler) regions on the surface of Earth's Sun. The number of sunspots that can be observed varies over an approximately 11-year cycle. The current cycle is {{w|Solar_cycle_25|the 25th since reckoning began in 1755}}. Solar Cycle 25, which began in December 2019 and is expected to peak around mid-2025, has been more active than anticipated, raising some concerns about the impacts of recent solar flares and associated space weather events.

The joke in this comic is that the sunspot array shown has taken the form of a "{{w|Check engine light}}", found on the instrument panel of most automobiles. The illumination of this light means that the automobile's onboard computer has detected an engine malfunction, which should be checked out by an experienced mechanic. For such a signal to appear among the nuclear fires and plasma of the sun would most certainly be of concern to astronomers.

Many drivers will barely notice a Check Engine light, and may hope that they ''never'' have cause to see it appear except maybe briefly during the turning of the ignition key as one of the bulb-checks. If it lights persistently before or during driving, it could mean a costly problem, or at least the inconvenience of paying someone to investigate the problem and then to solve some broken sensor issue.

As we don't appear to be cycling the Sun's ignition process (i.e., it hasn't recently stalled, which would be a worry in itself) the showing of the light/dark-patch would probably be very concerning, and hopefully someone at least has the owner's manual in order to run through any initial troubleshooting, before perhaps a more extensive check is made at the local solar-repair shop to clear the error. Given the rotating nature of the star and Earth's orbit, one might also wonder how long this, or any other warnings, might be shown before becoming visible to {{w|Solar viewer|suitably equipped}} viewers of the Sun.

The title text says that "they" (presumably the astronomers) advise that it's probably safe for Earth to continue to orbit the Sun unless and until there is a change in the nature of the "check engine light" sunspot array. Such a change, on an instrument panel, signals that the matter needs immediate attention, lest something dramatic and expensive occur, such as an [https://www.reddit.com/r/explainlikeimfive/comments/l8j0ip/eli5_what_is_a_seized_engine/ engine seizure], which can be spectacular and is irreparable. The solar equivalent of an engine seizure would be a {{w|Nova|nova}}, which would definitely be of concern to astronomers (and everyone else), and for which the prospect of "calling [[673: The Sun | someone]]" that can do anything useful (a cosmic tow truck to pull Earth to a safe distance?) seems remote.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[A pattern in the form of a "check engine" light (as displayed on a car's instrument panel) is shown on the surface of the Sun, in the bottom right quarter. The pattern has a pictogram of a motor on the top and the text "Check Engine" below it, both in orange inside a black square, matching the orange color of the Sun.]

:[Caption below the panel:]
:This new sunspot cluster has raised concern among astronomers

{{comic discussion}}<noinclude>
[[Category:Comics with color]]
[[Category:Astronomy]]

3082: Chess Position

2025-04-29T13:31:03Z

162.158.212.171: /* Explanation */

{{comic
| number = 3082
| date = April 28, 2025
| title = Chess Position
| image = chess_position_2x.png
| imagesize = 740x598px
| noexpand = true
| titletext = It's important to learn the moves that take you into the vortex, but it's best not to study vortex itself too closely. Even grandmasters who have built up a tolerance lose the ability to play for a few hours after studying it.
}}

==Explanation==
{{incomplete|CREATED BY THE INTERCONTINENTAL BALLISTIC BOT GAMBIT. This page was created recently. Don't remove this notice too soon.}}

[[Cueball]], a newer chess player, talks to [[Ponytail]], presumably a more experienced player, about a chess game he had last week against [[Knit Cap]]. After Cueball made a {{w|blunder (chess)|blunder}}, a critically bad mistake which frequently changes the course of the game, both of them quickly made inaccurate moves, probably rated as a "{{w|Blunder (chess)|blunder}}", "mistake", or "miss", leading to an odd configuration of the chess pieces. Blunders that are not taken advantage of can lead to this effect for less experienced players.

The rest of this comic becomes absurd, as Cueball then describes himself and Knit Cap descending into a fantasy world "on a deep branch of the game tree." Chess strategy is commonly described in terms of following a {{w|decision tree}} or {{w|game tree}}, as one usually needs to calculate multiple moves ahead when planning out what move to play. As a chess game progresses, the {{w|phase space}} of possible positions increases wildly, though this will include many more configurations than are typically seen or anticipated by players. Rarely, an expert player may 'discover' a truly clever {{w|Glossary of chess#theoretical novelty|novel opening}}, but centuries of recorded gameplay has explored many of the possible moves, both good and not so good, that are often recognized by experienced students of the game as common stepping-stones on the way to possible victory (or frequent traps that send the unwary down the road to defeat). Both precise game-board states and more general variations may be easily recognized by an experienced player, and even be {{w|Checkmate pattern|given a name}} by the player community as a whole.

However, it seems that Cueball and Knit Cap each made a sequence of seemingly obvious 'blunders' that neither opponent then took advantage of, reaching a board configuration that Cueball had never even anticipated happening. In some apparently mystical (or at least psychological) manner, by travelling such an unlikely and unfamiliar branch of the player/board game-space, the precise positioning of pieces combined with the state of mind that Cueball had developed created the impression of literally entering a mythical garden, with time even stopping.

Ponytail reacts nonchalantly to this story, as she says this is a common scenario for new players, and that there even is a defined name for it: the Kasparov Vortex Gambit. Russian grandmaster {{w|Garry Kasparov}} was the number-one rated chess player from 1984 to 2005, and is considered one of the greatest chess players of all time, if not ''the'' greatest. A {{w|gambit (chess)|gambit}} refers to a chess opening in which a player sacrifices material with the aim of achieving a subsequent positional advantage. This name seems to indicate that Kasparov himself either discovered/’invented’ or made popular this "gambit" to suck new players into a "vortex" and trap them from getting out. As of April 28, 2025, this is obviously not the case,{{cn}} but within the xkcd universe, he has performed an equally absurd gambit (also named after himself) in the title text of [[2936: Exponential Growth]].

Ponytail's advice to Cueball after he "recovers" from the disillusionment of the "vortex" is that she can teach him how to defend against the attack, by using the "f pawn". The f-pawn is the pawn that begins on the "f-file" (the 6th vertical column of the chessboard from white's perspective). The pawn would start either on f2 (sixth column, second row) for the white player or f7 (sixth column, seventh row) for black. The fact that an apparent distortion in the fabric of space can be countered with ''a single pawn'' just adds to the absurdity of the situation. In the title text, Ponytail continues with her advice, telling Cueball that he needs to understand how the vortex can be entered, but not to study the actual vortex. It appears that the vortex, when pursued too far, is like a black hole which will irrevocably suck in even experienced players such as grandmasters, though they at least seem to be able to last a bit longer.

==Transcript==
:[In the first panel, Cueball is walking in from the left, while talking to Ponytail.]
:Cueball: Something odd happened to me last week in a game at the chess club.

:[Cueball is playing a game of chess against Knit Cap.]
:[Caption above frame:]
:I moved, then instantly realized I'd blundered. But my opponent didn't notice and made a weird move.
:I got rattled and moved almost randomly, then I think we both panicked and made a couple of nonsensical moves, rapid-fire.

:[Zoomed in on Cueball, with three question marks above his head]
:I don't know how it happened, but suddenly I realized I was staring at an indescribably strange board position.

:[Cueball is talking to Ponytail.]
:Cueball: I've never seen anything like it. It seemed like every move attacked every piece, yet every piece was also protected. Pieces refracted through crystalline pawn structures.
:Cueball: The game clock slowed and then stopped.

:[Cueball and Knit Cap are floating in a complex five-fold symmetrical plant-like pattern of "game tree branches".]
:[Caption above the frame]
:It didn't even feel like we were playing chess. We had stumbled into a magical garden tucked away on a deep branch of the game tree.

:[Cueball is talking to Ponytail.]
:Cueball: I don't remember how the game ended, if it did.
:Cueball: I don't remember how I got home.
:Cueball: It's all a blur.

:[Close-up of Cueball's head.]
:Cueball: I've spent all week trying to reconstruct the position and can't.
:Cueball: It's consuming me.
:Cueball: I don't want to play chess. I just want to return to that garden.
:Cueball: Does... any of this make sense to you?

:[Cueball is standing with hands on face surprised as Ponytail talks with him.]
:Ponytail: Yeah, that's the Kasparov Vortex Gambit. Common trap for new players.
:Cueball: ''What?!''
:Ponytail: Once you recover I'll show you how to block it with the f pawn.

{{comic discussion}}
[[Category:Chess]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Knit Cap]]
[[Category:Comics featuring Ponytail]]

Talk:3073: Tariffs

2025-04-08T14:49:37Z

162.158.212.171:

Uh, still no April fools [[User:Aprilfoolsupdate!|Aprilfoolsupdate!]] ([[User talk:Aprilfoolsupdate!|talk]]) 23:50, 7 April 2025 (UTC)
:The April fools is the president the U.S. Elected. (note: I am Usanian)[[Special:Contributions/172.70.214.232|172.70.214.232]] 12:41, 8 April 2025 (UTC)
I felt like using all caps is a good idea for explanations, since the comic itself is all caps [[User:Aprilfoolsupdate!|Aprilfoolsupdate!]] ([[User talk:Aprilfoolsupdate!|talk]]) 00:03, 8 April 2025 (UTC)
: Please don't. If you did that, then all of the other explanations and transcripts would have to be edited to all-caps, which makes it harder to read. [[User:Firestar233|guess who]] ([[User talk:Firestar233|if you desire conversing]] | [[Special:Contributions/Firestar233|what i have done]]) 01:07, 8 April 2025 (UTC)
:Doesn't just about ''every'' xkcd comic use all-caps? That would make pretty much the entire wiki unreadable. [[Special:Contributions/172.71.155.35|172.71.155.35]] 04:15, 8 April 2025 (UTC)

What's wrong with the explanation? It's showing this weird string of letters: expDia thud enzo Isla idiosyncrasies talk 3totheaudienceandtheotherswhoareyouheresoearlyinthedayafterMittenslefttodois sign up for both ofuscan'twaitforthemostparttobeabrightandwarmwelcomeandIhopethatyouwillfindapenthatwillOrbitz pap [[Special:Contributions/162.158.159.8|162.158.159.8]] 20:23 7 April 2025 EST
: Vandals --[[User:Btx40|Btx40]] ([[User talk:Btx40|talk]]) 00:32, 8 April 2025 (UTC)
::I'm getting a few Cloudflare messages that the server isn't responding. I'm used to explainxkcd giving straight 503s, etc, but this is the kind of thing (code 522, in at least one case) that you get only when an active pressure (crap-spamming, etc) is being applied. I'm wondering if there's some pushback from the pro-tariff (or at least 'pro-Donald') online community. [[Special:Contributions/172.70.85.32|172.70.85.32]] 11:12, 8 April 2025 (UTC)

Hopefully, just HOPEFULLY, we can prevent the comment section from devolving into insults like https://xkcd.com/1756/: I'm With Her. [[User:Thehydraclone|Thehydraclone]] ([[User talk:Thehydraclone|talk]]) 01:51, 8 April 2025 (UTC)
:I concur, though I want to stress that I think it's very important that we try to make this comic explanation as neutral as possible. Is it possible to not show a bias towards either side of the issue? Randall's comic obviously has a point of view, but perhaps the explanation on this site can be a little bit more neutral. [[User:Dogman15|Dogman15]] ([[User talk:Dogman15|talk]]) 11:41, 8 April 2025 (UTC)
:You stink! [[Special:Contributions/172.70.91.181|172.70.91.181]] 13:09, 8 April 2025 (UTC)

Comic [[2566]] was supposed to be a joke... --[[Special:Contributions/172.68.175.87|172.68.175.87]] 03:58, 8 April 2025 (UTC)

"venmo" needs explaining. Apparently it's some sort of USAian proprietary payment system? And I think Ponytail's company is providing a service (which the USA exports of lot of), rather than selling equipment - services usually not being captured by simple trade figures for goods. And in order to post here I have to identify features of foreign street scenes in order to train a monopolist's proprietary image recognition system. [[Special:Contributions/162.158.216.115|162.158.216.115]] 13:03, 8 April 2025 (UTC)
:Ah, didn't read this first, but I ''just'' put a link in for that (slightly awkwardly, but best I could - expecting a later editor to better phrase/place it). Hadn't heard of it, myself. Presumably Leftpondians know about it a lot more, perhaps most do, given how much business it gets/facilitates ''only'' in the US. Anyway, consider me one of those that learnt something new today! (Not that I can, or would, use it, of course.) [[Special:Contributions/172.70.163.71|172.70.163.71]] 13:19, 8 April 2025 (UTC)

I added this comic as an answer to a Politics.SE question. https://economics.stackexchange.com/questions/60191/does-it-make-sense-to-treat-trade-deficit-as-tariffs/60229#60229 [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 14:41, 8 April 2025 (UTC)

This is unironically the best explanation of Trump's tariffs I've seen
--[[Special:Contributions/162.158.212.171|162.158.212.171]] 14:49, 8 April 2025 (UTC)

3066: Cosmic Distance Calibration

2025-03-22T00:47:08Z

162.158.212.171: /* Explanation */ fixing formatting on asterisk

{{comic
| number = 3066
| date = March 21, 2025
| title = Cosmic Distance Calibration
| image = cosmic_distance_calibration_2x.png
| imagesize = 317x409px
| noexpand = true
| titletext = This is the biggest breakthrough since astronomers noticed that the little crosshairs around red giant stars starting to burn helium are all the same size.
}}

==Explanation==
{{incomplete|Created by AN ASTRONOMER BOT - MILKY WAY GALAXY - 0 LIGHT YEARS AWAY - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
The comic interprets the UI labels next to the stars as actual objects in space, which is absurd.{{cn}} If these labels were to become astrophysical objects in reality, it would quickly result in major changes to the universe. As each of these labels would need to be clearly visible from an observatory, they would require monstrous size, maybe even big enough to collapse into black holes when pointing to stars farther away. They would also create a sudden lack of need for themselves, as the stars would be gravitationally attracted to their respective labels and promptly destroyed.

The label on the billboard appears to be pointing to a star in the spiral Galaxy M106, located between 22 and 25 million light-years away from earth.

This comic was released the same week as cosmologists revealed [https://www.quantamagazine.org/is-dark-energy-getting-weaker-new-evidence-strengthens-the-case-20250319/ news] that dark energy appears to be weakening, a result based on measurements of distances to many galaxies across the universe. No mention of distance labels was made in the announcement.{{cn}}

The title text refers to "crosshairs" a common UI element that appears in the middle of the screen in many first person games, seams to be referring to the diffraction pattern caused by the arms holding the secondary mirror in most telescopes, causing a star to appear to have several "spikes" radially outward.
Of course these aren't physical objects next around the star, they are (as mentioned) created in the telescope.

The size of the diffraction spikes is correlated with the luminosity of the star being viewed. Red giant stars starting to burn helium have the same size diffraction spikes* because they are the same absolute brightness. They are "Tip of the Red Giant Branch" standard candles, the fact that they have the same absolute brightness makes them essential for cosmic distance measuring, since the observed luminosity is a simple inverse-distance-squared falloff from a known original value.

<nowiki>*:</nowiki> Randall is taking a little bit of license here, the spikes depend on luminosity, whereas the stars in question have the same brightness, which is not the same thing.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Ponytail is at a lectern, pointing at an image of intergalactic space. There is an image that shows a zoomed-in label beneath a star with 4 points. The zoomed-in label shows three lines of text, some of it partially cut off:]
:M106 0-06 [cut-off]
:Distance:
:23.6163 MLY

:[Caption below the panel:]
:Cosmology News: New telescopes are finally powerful enough to read the little labels next to stars showing how far away they are.

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Cosmology]]
[[Category:Telescopes]]