explain xkcd - User contributions [en]

3105: Interoperability

2025-06-21T07:52:52Z

Cochonou: US gauge -> Standard gauge

{{comic
| number = 3105
| date = June 20, 2025
| title = Interoperability
| image = interoperability_2x.png
| imagesize = 740x269px
| noexpand = true
| titletext = We're getting a lot of complaints from commuters who were routed onto a coaster, but the theme park patrons who spent hours stuck on an intercity line are also not happy.
}}

==Explanation==
{{incomplete|This page was created by a LOST ROLLER COASTER RIDER. Don't remove this notice too soon.}}

[[Black Hat]] gives a presentation regarding the existence of two standards: rail systems predominantly use the {{w|Standard-gauge railway|standard gauge}} of 143.5cm, and {{w|Rapid transit|subway systems}} and their cars are naturally built to match this standard. Meanwhile 'many' {{w|roller coaster}} tracks, and their cars, are said to use a 110cm gauge. The two standards are not compatible, without {{w|Dual gauge|some additional engineering}}; subway cars could not travel on roller coaster tracks, and vice versa, even assuming you solved {{w|List of steepest gradients on adhesion railways|other issues}}.

However, Black Hat has professed to make changes to roller coasters such that they now conform to the subway standard (i.e. 143.5cm gauge). This seemingly is Phase One of a plan, for which there is a further phase to come. No details of Phase Two are forthcoming. But, at face value, it may superficially allow subway cars to ride on roller coaster tracks ''and/or'' roller coaster cars to ride through subway systems, apparently in the name of {{w|interoperability}} and compatibility. Black Hat's plans to quietly connect the two, leading to various unexpected surprises.

[[Cueball]] and [[Hairbun]] are the apparently unwitting audience to Black Hat's presentation, and one of them (from off-panel) objects by stating that interoperability isn't ''necessarily'' a good thing, recognising where the plan is heading. Black Hat suggests that it would be fine as long as they listened to the destination announcement, which certainly confirms the above speculative continuation of the plan.

The title text confirms that ''both'' reapplications of railcars are being used. There are commuters who find themselves traveling upon a coaster; their exact problems are not stated, but they could range from merely not reaching their intended destination to suffering unexpectedly extreme {{w|g-force}}, if not both simultaneously.

Furthermore, those expecting to experience a theme park ride were probably ''expecting'' a short period of exciting g-forces, and expecting to return to at least within a short walk of where they initially boarded, but find themselves outside the theme park, spending hours on an intercity line and ''not'' moving much at all. (Noting that a subway line would also not usually be expected to travel between cities, unless serving a {{w|conurbation}}, but at least the interoperability of subway rail and wider rail systems ''might'' be expected, so long as the {{w|Third rail|appropriate infrastructure}} and track links can be made compatible.) Some part of this might be that the roller coaster cars will come to a stop (in the case of {{w|Physics of roller coasters#Energy|gravity coasters}}, where the cars aren't self-propelled), which may lead to the patrons being unable to leave the cars safely and will lead to the blockage of the route.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
: [A close-up shot of Black Hat from the shoulders up]
: Black Hat: Compatibility and interoperability are so important.

: [A zoom out reveals that Black Hat is standing in front of and pointing at a diagram showing a commuter subway car and a roller coaster car, and the tracks they both run on. Standing next to him are Cueball and Hairbun]
: Black Hat: For example, most subway rails are 143.5 cm apart. But many roller coasters use a narrower 110 cm gauge.

: [This panel shows only Black Hat]
: Black Hat: For the last few years, our company has been quietly retrofitting roller coasters to use 143.5 cm tracks.

: [Black Hat now has his fists raised]
: Black Hat: Soon, we can begin phase 2.
: Voice from off-panel: Maybe interoperability is actually bad.
: Black Hat: If you listen to the destination announcement while boarding, you'll be fine.
{{comic discussion}}<noinclude>
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring Black Hat]]
[[Category: Comics featuring Hairbun]]

2896: Crossword Constructors

2024-02-21T05:20:40Z

Cochonou: /* Explanation */ enta : "third-person singular past historic of enter" -> wrong, this is entra.

{{comic
| number = 2896
| date = February 19, 2024
| title = Crossword Constructors
| image = crossword_constructors_2x.png
| imagesize = 285x388px
| noexpand = true
| titletext = Also, we would really appreciate it if you could prominently refer to it as an 'eHit'.
}}

==Explanation==
{{incomplete|Created by a THREE-LETTER WORD THAT STARTS WITH B - Add meanings of words given, if any. Also check whether any of these words are albums or songs already. Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic is inspired by a common situation when people try to make {{w|Crossword#American-style crosswords|US-style quick crossword}} puzzles (where the grid is [[media:CrosswordUSA.svg|almost completely filled]] with words). Here, [[Cueball]], [[Hairbun]], and [[White Hat]] are {{w|crossword puzzle}} constructors, but some of the words they would like to use would result in awkward sequences of letters which are not English words or familiar names, such as "aete", "eni", etc. However, they have an idea to write a letter to persuade prominent singers ({{w|Taylor Swift}}, {{w|Ed Sheeran}}, {{w|Nicki Minaj}}, {{w|Ariana Grande}} and {{w|The Weeknd}}) to choose these awkward sequences of letters as titles of their future albums, thereby letting Cueball, Hairbun, and White Hat write clues about those albums and use those letter sequences as answers.

The particular sequences of letters that are selected are notable for their exclusive usage of the {{w|Letter frequency|most common English letters}}. They also all begin and end with a vowel. These are two features that are common in "crosswordese", i.e., words which appear significantly more often in crosswords than in reality. Examples of crosswordese that are actually used include the words "{{w|OREO}}", "{{w|Épée|EPEE}}", and "{{w|Yoko Ono|ONO}}".

The title text lists another sequence of awkward letters, "eHit". Here, Cueball, Hairbun, and White Hat ask these singers to refer their hits (popular songs) as "eHit"s, adding the "e" for electronic such as in e-mail and e-dating. This is also a reference to common crossword entries like "E-TAIL" or "E-MAG" which are often criticized for using the prefix "E" to create words that no one really uses.

===Possible unintended meanings of words===
*aete: {{w|Apple_event#Object_Model|AppleEvent Terminology Extension}}
*eni: {{w|Eni|Eni S.p.A.}}, Italian multinational energy company; the name of an {{W|Eniola_Aluko|England footballer}}
*oreta: ''{{w|Oreta}}'', moth genus in family {{w|Drepanidae}}
*aroe: {{w|Aroe}} may refer to: The Aru Islands Regency, islands in eastern Indonesia; Aroe, an alternative name for Aroi, Patras, in western Greece
*oine: {{w|Kusumoto Ine}}, also known as O-Ine, Japanese physician
*aen: {{w|AEN}} may refer to: Acute esophageal necrosis, a rare esophageal disorder; and more
*aerae: ''[[wikt:aerae|aerae]]'' (Latin noun) genitive/dative singular and nominative plural of ''[[wikt:aera#Latin|aera]]'' (era)

''{{w|Enta da Stage}}'' is the debut album by American East Coast hip hop group Black Moon. 
''öine'' means nocturnal/nightly in Estonian, and features in the titles of a number of albums by artists from that country.

The above words and definitions would be considered too obscure for use in most American crossword puzzles, as puzzle editors normally prefer answers to be at least somewhat familiar to the general public, even if the answers wind up being clued obscurely.

===Uses in mainstream crossword puzzles===
Some of these words have appeared in the New York Times crossword, albeit only in the pre-1992 era (that is, before the current editor Will Shortz began his tenure).
*aroe: Clued as an variant spelling for the {{w|Aru Islands Regency}}, and also as part of the phrase "and be thou like unto a roe" from the King James Bible.
*aen: Clued as an abbreviation for the ''{{w|Aeneid}}'' or as an abbreviation for the Latin word ''aeneus'' meaning "of bronze" or "of copper"

==Transcript==
:[Cueball is sitting in an office chair at a table and typing on his laptop, with small movement lines above his hands indicating typing. White Hat and Hairbun are standing behind him and looking at what he writes. The text he writes can be seen above them. The list of words at the end are written in two columns with four words in each. Here below, the second column of words is written below the first:]
:Dear Ms. Swift, Mr. Sheeran, Ms. Minaj, Ms. Grande, and Mr. Weeknd,
:We are a group of crossword puzzle constructors, and we would like to suggest some titles for your future albums:
:*Aete
:*Eni
:*Oreta
:*Aroe
:*Oine
:*Aen
:*Enta
:*Aerae

{{comic discussion}}

[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Hairbun]]
[[Category:Comics featuring Cueball]]
[[Category:Language]]
[[Category:Music]]
[[Category:Comics featuring real people]]

Talk:2821: Path Minimization

2023-08-29T11:54:41Z

Cochonou:

Judging from the angle of the arms, I do not believe that the swimmer is in distress. In fact I think the swimmer is just a future projection of Cueball, not a separate person.

:I agree that the swimmer does not appear to be in distress, although the title text suggests that it is probably a separate person.
:
:My personal interpretation is that the situation is "meeting a friend at the beach to get ice cream". Options are either a) meet the friend first and then swim back to get ice cream or b) get ice cream first and take it out to eat together in the water. [[Special:Contributions/172.70.86.54|172.70.86.54]] 04:02, 29 August 2023 (UTC)
:: Or the more sensible walk to the water's edge and wait for your friend to swim in to meet you... [[Special:Contributions/172.70.85.29|172.70.85.29]] 08:43, 29 August 2023 (UTC)
:I agree as well, I changed it to "possibly in distress". [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 04:43, 29 August 2023 (UTC)
::I changed it further. Still admits the possibility, but less possibly than "possibly" hints at. (It is, nonetheless, a (mostly!) typical "you ''need'' to get here, minimising <some form of time/distance/energy/endurance resource>, what is the optimal strategy" tbing that lifesaving courses might include to train you in such considerations. [[Special:Contributions/172.71.242.82|172.71.242.82]] 09:01, 29 August 2023 (UTC)

Technically, the path that minimizes swimming passed a nearby boat rental stand. (by the way, I didn't write the unsigned paragraph above this one) [[Special:Contributions/172.69.247.40|172.69.247.40]] 03:05, 29 August 2023 (UTC)

When I first saw the comic, I thought cueball was suspended on a tether in the air above the water, and the ice cream stand was floating. I didn't realize it was a beach until I read this explanation. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 04:41, 29 August 2023 (UTC)

The ice cream path reminds me of the [[2407|bread-first search]] (similar punchline). [[Special:Contributions/172.71.182.158|172.71.182.158]] 06:55, 29 August 2023 (UTC)

Noting, in passing, that an almost "flosbury flop"-like path could have been shown, too. A gentle curve, bending to hit the shore somewhere between shortest-time and shortest-swim, that would allow maximum run-up to dive ''into'' the water at the right angle to then power straight towards the target with the original running impetus turned straight into initial swimming speed, with no sharp turns involved. (Also, an 'Aquaman' line, perhaps exactly complimentary to the land-favouring 'bent-leg' routes, minimising/reducing land in favour of water.) [[Special:Contributions/172.71.242.82|172.71.242.82]]

This was one of my first edits in this wiki, so I hope I didn't do anything wrong. I think this comic clearly references Feynman's Lifeguard problem (there is an almost identical diagram in his QED book) and the Ice-cream vendor problem. I wrote a couple of paragraphs explaining this, but they were promptly deleted by the next editor. Did I do something wrong? I think the explanation is incomplete without those references. [[User:Prallax|Prallax]] ([[User talk:Prallax|talk]]) 10:08, 29 August 2023 (UTC)
: Seeing the history, this is probably just an edit conflict, you should insert your contribution again. [[User:Cochonou|Cochonou]] ([[User talk:Cochonou|talk]]) 11:54, 29 August 2023 (UTC)

2776: Crystal Ball

2023-05-21T11:51:03Z

Cochonou: /* Explanation */ Correcting the main problems with the article

{{comic
| number = 2776
| date = May 15, 2023
| title = Crystal Ball
| image = crystal_ball_2x.png
| imagesize = 257x336px
| noexpand = true
| titletext = They often use ball lenses to collect light at the ends of optical fibers, so when you look stuff up on the internet you're actually scrying through a crystal ball.
}}

==Explanation==
{{incomplete|Created by AN INSUFFICIENT UNDERSTANDING OF THE PHYSICS PRINCIPLES BEHIND REFRACTION AND WHY LIGHT MIGHT ONLY HAVE A ONE-WAY SPEED- Elaborate on the title-text. Do NOT delete this tag too soon.}}

In optics, {{w|spherical aberration }} is an image imperfection that occurs due to the increased refraction of light rays that occurs when rays strike a spherical lens near its edge, in comparison with those that strike nearer the center. The origin lies within the fact, that reflection/ refraction on a spherical surface is not perfectly focused on a single point, in contrast to paraboloid reflective surfaces, that have a single focus point. From the perspective of a viewer, this causes the image to appear blurry.

The comic makes the joke that, since a {{w|crystal ball}} is a sphere, anyone trying to use one for {{w|scrying}} or seeing the future would have to deal with this issue as well; the wizard is telling Cueball that he can only make out the parts of his future which are near the center, as the rest are distorted. Spherical aberration is specifically a property of refracted light, and since the crystal ball is presumably not showing an image originating from the other side of the ball (unless it is a {{w|3-sphere|hypersphere}} additionally extending itself though a time-like dimension), the image should not be distorted by both entering and leaving the sphere, perhaps only in the manner of a hemispherical lens (for which the internally formed holographic image-source perhaps could be properly anamorphically adjusted to exit in all directions a coherent manner). However, traditional scrying may have actually relied on spherical aberration, to allow unexpected shapes to emerge from subtleties such as surrounding flickering candles, that the seer may have used to amplify intuition and visions.
The comic also incorrectly implies that spherical aberration only affects the edges of the image, possibly confusing it with {{w|distortion (optics)}}. In reality, spherical aberration affects the full field of view.

The comic is also making use of the vague meaning of something being "hard to see". One would expect that this would mean that Cueball's future is vague or mysterious, as is often the case in many fantasy novels. But in this case, the wizard is telling Cueball that his future is ''literally'' hard to see due to the spherical aberration.

The title text observes a real-world action that could [[1475: Technically|technically]] be described as "scrying through a crystal ball", that being the usage of the internet. Information over the internet is often transmitted via light sent through {{w|fiber-optic cables}}, which is sometimes collected using ball lenses.[https://www.edmundoptics.com/knowledge-center/application-notes/optics/understanding-ball-lenses/] Due to the similarity between ball lenses and crystal balls, Randall argues that this is technically scrying through a crystal ball because you're receiving information from elsewhere (searching for something) and receiving it by way of a crystal ball (through the ball lenses). This is flawed as any lenses at the end of a fiber optic cable are to assist a detector in decoding potentially billions of light flashes per second into computer signals as opposed to actually allowing a human to view the contents of the internet with their eyes.

==Transcript==
:[A wizard with with a pointed hat, long hair and a large beard is sitting on a chair at the left side of a table. He is holding a crystal ball with both hands while he is looking into it. The ball has a reflection on the side towards Cueball who is sitting on a chair at the opposite side of the table with his hands in his lap.]
:Wizard: Your future is hard to see.
:Wizard: I can make out some hazy details in the center, but the off-axis components are particularly unclear.

:[Caption below the panel:]
:Wizards never did figure out how to fix spherical aberration.

{{comic discussion}}

[[Category:Characters with hats]]
[[Category:Comics featuring Cueball]]
[[Category:Physics]]
[[Category:Internet]]

Talk:2562: Formatting Meeting

2022-01-01T17:32:36Z

Cochonou:

I downloaded and ran theusaf's bot from its website to make this page. Not sure how to give page creation permission to [[User:Baffo32RunningTheusafBOT]]. When you run the bot you notice that Theusaf's username is "the usa f". [[Special:Contributions/172.70.110.45|172.70.110.45]] 16:02, 31 December 2021 (UTC)

shouldn't it be ISO, not iso? actually, the whole title text is lowercase-d when I feel like it shouldn't be [[Special:Contributions/172.70.35.70|172.70.35.70]] 16:59, 31 December 2021 (UTC)Bumpf
: you're probably right. as a geek, one uses lowercase 'iso' all the time in computer date code where it is usually lowercase. e.g. i type `date --iso=seconds` every day into my linux terminal; it outputs 8601 format. [[Special:Contributions/172.70.114.167|172.70.114.167]] 19:23, 31 December 2021 (UTC)

Speaking as a European, we'd often read 2/3/22 as "2nd March 2022" (same order as the numbers), not "March 2, 2022", though obviously we'd understand both expressions. Also, the suggestion that the thousands/decimal punctuation is reversed in the EU is wrong, as this does not apply to all countries of the EU. For example, Ireland uses the same as the US (and the same as the UK, though that is no longer part of the EU and might eventually give up decimalisation altogether on account of fractions being more wholesome...) [[User:Rotan|Rotan]] ([[User talk:Rotan|talk]]) 18:47, 31 December 2021 (UTC)
:You mean the 12-times-tables, that I was thoroughly taught when I was young, might (literally) gain currency once more? That'll be interesting! [[Special:Contributions/172.70.85.73|172.70.85.73]] 16:42, 1 January 2022 (UTC)

Another comic which references ISO-8601 is: https://xkcd.com/1179/ [[User:Rps|Rps]] ([[User talk:Rps|talk]]) 21:27, 31 December 2021 (UTC)

It's been more than 20 years since in 'casual' date writing I started prefering "D/Mmm/YYYY" format (today is 31/Dec/2021, for me right now, tomorrow is 1/Jan/2022) when I had a totally free hand. A combination of indicating to US colleagues in my multinational company of that time that I wasn't writing trying to write Jan/1/2022 (not that it would matter in that particular case!) and doing my bit to support the upcoming Y2K-compatability issues that other people were gradually getting to know about. Though for coded dates, YYYYMMDD[.hh[mm[ss[...]]]] always worked best for me. It numerically sorts (it will even when YYYY eventually becomes YYYYY!) and can be given arbitrary sub-day specification - at least until float-rounding errors start to creep in. [[Special:Contributions/172.70.90.43|172.70.90.43]] 22:25, 31 December 2021 (UTC)

Around year 2000 there was short time when people were writing the years properly. Afterwards, the laziness won again and people started using just two digits again ... sigh ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 01:19, 1 January 2022 (UTC)

Is localization spelled localisation in countries that use English? [[User:Boatster|Boatster]] ([[User talk:Boatster|talk]]) 01:59, 1 January 2022 (UTC)
:It is. Obviously that excludes the US and any other past colonials who picked up the wrong habit along the way. ;) [[Special:Contributions/172.70.86.22|172.70.86.22]] 02:18, 1 January 2022 (UTC)

:Actually, the -ise/-ize distinction only came in in UK English quite recently and some UK publishers still use -ize endings. I was told both endings were OK at school in the UK in the sixties.[[Special:Contributions/172.70.86.68|172.70.86.68]] 09:46, 1 January 2022 (UTC)

::I treat the Oxford Spelling with the respect I give the Oxford Comma. None. (My own '70s education drummed that into me, and it's not going to change easily.) [[Special:Contributions/172.70.90.71|172.70.90.71]] 11:56, 1 January 2022 (UTC)

Anyone who doesn't use ISO-8601 dates should be shot on sight. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 10:24, 1 January 2022 (UTC)

I got the impression that slashes as separators mark us-notation and dashes EU notation. [[Special:Contributions/162.158.88.139|162.158.88.139]] 11:36, 1 January 2022 (UTC)
:The UK complicated this notation (don't we always!). We typically use 'European' ordering (or maybe they use ours?) but also slashes (whichever side of the Atlantic that started). This makes it not so easy to just assume dd-mm-yyyy and mm/dd/yyyy differentiate by separator used. Not sure how to rewrite "In Europe, the usual order is day/month/year - although the slash is rarely used as the separator" in light of this. Are we 'rare' in Europe, or no longer to be considered that at all and therefore not even discussed? [[Special:Contributions/172.70.85.73|172.70.85.73]] 16:38, 1 January 2022 (UTC)
::We use the same notations as you in France (and it's very rare when our two countries do the same thing), so I'm not sure the "rarely used as a separator" is correct. [[User:Cochonou|Cochonou]] ([[User talk:Cochonou|talk]]) 17:32, 1 January 2022 (UTC)

The discussion of currency seems way too much for something that isn't actually part of the comic. I believe it would be better in trivia, if part of the article at all. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 13:36, 1 January 2022 (UTC)
-- concur with that. Its also annoying as on the east of the atlantic, I'd be writing 10^5 as 100,000 not 100.000

2409: Steepen the Curve

2021-01-09T19:52:33Z

Cochonou: The number of vaccinated people does not follow an exponential law

{{comic
| number = 2409
| date = January 8, 2021
| title = Steepen the Curve
| image = steepen_the_curve.png
| titletext = 1. Flatten the curve. 2. Steepen the curve. 3. Hang out.
}}

==Explanation==
{{incomplete|Created by a STEEPENED FLATTENED CURVE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.

In early 2020, the COVID-19 pandemic rapidly became the main public concern. All kinds of political, civic and personal efforts were put towards doing things that would cause the 'curve' (the graph of cumulative deaths, or deaths per period) to flatten and not rise as rapidly as it was feared it would do, unchecked. The graphic drawn in black depicts this statistic — though it is not clear (without proper units or values on either axis) if this is a cumulative one or the initial 'rate' graph for before initial lockdowns started to reduce the initial trajectory for a time.

In 2021, the same issues exist (with second or even third 'waves' of resurgence affecting some populations) but now we have a handful of vaccines available. The red overlay intends to update the 'original' graphic to portray the curve of vaccines provided (again, it could easily be either cumulative or rate-wise). This year, the line remains the same but the year, the thing labelled as being represented and the hoped-for outcome are changed accordingly.

Note that, in both cases, there would be an upper limit on the cumulative value, but the ceiling must be well beyond the upper (and timewise) limits of this graph. If this is a rate-graph, it would show a peak and subsequent decline at the same point in time where a cumulative graph would show an inflection in its gradient, but neither are visible here.

Additionally, the analogy between the number of deaths and the number of vaccinated people could be considered as questionable, as the number of deaths in the initial stages of a pandemic is expected to follow an exponential law, whereas the same cannot be said for the number of vaccinated people.

==Transcript==
:[Line graph shown with a rising curve drawn in black. There is an underlined label above and another label below the graph. The Y-axis line is ending in an arrowhead and also has a label. All this is in black. But the last number in the upper label as well as one word in each of the other two labels, have been crossed out in red and then another number or word has been written behind or beneath in red.]
:[Caption above the graph:]
:202<s>0</s> 1

:[Y-Axis:]
:COVID <s>Deaths</s> Vaccinations

:[Caption below the graph:]
:<s>Flatten</s> Steepen The Curve

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Line graphs]]
[[Category:COVID-19]]