explain xkcd - User contributions [en]

2496: Mine Captcha

2021-07-30T16:34:14Z

172.70.114.172: Added visualization of the solution, with row/column labels as described in the text

{{comic
| number = 2496
| date = July 30, 2021
| title = Mine Captcha
| image = mine_captcha.png
| titletext = This data is actually going into improving our self-driving car project, so hurry up--it's almost at the minefield.
}}

==Explanation==
{{incomplete|Created by a LIVE MINEFIELD. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

This comic, like [[1897: Self Driving]], references the approach of using {{W|CAPTCHA}} inputs to solve problems, particularly those involving image classification, which are not solvable by computers, specifically {{W|reCAPTCHA}} v2's fallback puzzle which is based on identifying road features and vehicles. A reCAPTCHA version of this puzzle might ask a user to "check all squares containing a STOP SIGN."

The CAPTCHA in this comic, however, asks the user to "Click all the pictures of MINES" by, ironically, clicking on squares that do not show anything more than a gray square, with the understanding that some of those gray squares are hiding 'mines' in a {{w|Minesweeper (video game)|Minesweeper puzzle game}}, hence the title Mine Captcha.

Furthermore, the CAPTCHA in this comic asks the user to click on the squares containing mines themselves, which is the opposite of the traditional goal in Minesweeper, which is to click on all boxes where there are *no* mines, and solving the puzzle is usually (although not in this case) impossible without revealing the information in those squares without mines. So the CAPTCHA in this comic would be especially difficult for a user who is familiar with how to play Minesweeper, in addition to being difficult for a user who is familiar with the normal CAPTCHA image-selection puzzle. But would be impossible for anyone that have never heard of the game/know the rules.

A captcha (also spelled CAPTCHA) is a challenge designed to be solvable by humans, but not by computer programs. It is used to protect websites from automated software. For example, editing the explain xkcd wiki without being logged in requires the user to solve a Captcha.

The captcha depicted in this comic is similar in layout to one of the challenges of ''reCAPTCHA'', a captcha system developed by Google. It requires the user to click on several of 16 tiles laid out in a 4x4 grid. 6 of the 16 tiles has a colored number, in blue font for the three number ones, green for the single instance of two and red for the two number three. Each number used a different font style disregarding the color.

The comic combines this with the game of Minesweeper, a logic puzzle game where the player must uncover tiles in a grid by clicking on them. Some of the tiles contain "mines", clicking on those means immediate defeat. When uncovering a tile without a mine, it shows how many of the 8 adjacent tiles contain a mine.

This comic expects users click on the mines in a minesweeper puzzle to proceed with their task. As the goal in minesweeper is to click on boxes where there are NOT mines, the puzzle would be especially difficult for anyone used to playing minesweeper.

The comic shows a 4x4 grid with mostly grey squares, and a few tiles showing colored numbers. The setup and colors suggest a gaming board of the popular minesweeper game, with a few tiles uncovered. Numbers would then show the number of mines in adjacent squares. Given the current board configuration, one can deduce that there are four mines (in squares A2, B2, B3 and D3, where letters (numbers) mark columns (rows)). For example, there are two mines within the squares A2,B1,B2, as signified by the 2 in A1, but only one of those can be in B1 or B2 (because of the 1 in C1). Therefore, A2 has to be a mine. The title suggests this as a CAPTCHA, where proving to be human involves first recognizing this as a minesweeper simile, and then solving for those squares with mines.

<pre>
A B C D

1 2 . 1 .
2 * * 3 .
3 3 * . *
4 . 1 . 1
</pre>

Traditionally, the goal in minesweeper is to click on boxes where there are NOT mines, and solving the puzzle is usually (although not in this case) impossible without revealing the information in those squares, so the puzzle could easily trip up anyone used to playing minesweeper.

The title text is similar to [[1897: Self Driving]] where the CAPTCHA solver is asked to "answer quickly – [the] self-driving car is almost at the intersection". In this case the car is actually driving into this minefield and can only avoid the mines if the user solves this CAPTCHA fast enough. Where the first would be realistic, although very dangerous, this time it is of course just a continuation of that old joke. Even if the car drove into a mine field, there would be no way to have the given information.

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

[A "CAPTCHA" box.]

To proceed, click<br>all the pictures of<br>MINES

[A 4 by 4 ''Minesweeper'' field, with some cells revealed with numbers. Each number is drawn in a different font/style.]

<pre>
2 . 1 .
. . 3 .
3 . . .
. 1 . 1
</pre>

{{comic discussion}}

[[Category:CAPTCHA]]

Talk:2492: Commonly Mispronounced Equations

2021-07-22T21:04:38Z

172.70.114.172:

This comic is obviously a take on the generation Z style of writing words without vowels so that they fit on T-Shirts, text messages or to avoid censorship, like "BRLN", "O RLY", "PIX PLZ". Some of the people from that generation are now established scientist, leading their respective fields forward. Obviously this is how they refer to common equations. [[Special:Contributions/162.158.92.29|162.158.92.29]] 13:10, 22 July 2021 (UTC)

I think the wave equation is wrong based on units, but it's been a while. The wave speed ought to be squared. Of course, ''c'' could be a squared speed, but it's usually not. [[Special:Contributions/172.70.34.164|172.70.34.164]] 01:22, 22 July 2021 (UTC)

:I agree, normally it's written as C squared... The equations in order are 1: Gravitational Attraction, 2: Einstein's Mass / Energy Conversion, 3: Pythagorean Theorem (triangle side relations), 4: Area of a Circle, 5: Entropy equation, 6: Ideal Gas Law, 7: Euler's Identity, 8: Newtons Second law, 9: Wave equation, 10: The derivative of a function f, and, 11: The Quadratic Equation... I don't understand the linguistic rules being applied to the names, but they seem to be visual as much as anything [[Special:Contributions/108.162.237.66|108.162.237.66]] 02:04, 22 July 2021 (UTC)
::You should turn that into a table in the explanation. We can have a column where we try to come up with the pronunciation rule. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 04:10, 22 July 2021 (UTC)

The equation for the thing I have as what it was made by is
L
=
i
ψ
¯
γ
μ
∂
μ
ψ
−
e
ψ
¯
γ
μ
(
A
μ
+
B
μ
)
ψ
−
m
ψ
¯
ψ
1
4
F
μ
ν
F
μ
ν
.
{\displaystyle {\mathcal {L}}=i{\bar {\psi }}\gamma ^{\mu }\partial _{\mu }\psi -e{\bar {\psi }}\gamma ^{\mu }(A_{\mu }+B_{\mu })\psi -m{\bar {\psi }}\psi -{\frac {1}{4}}F_{\mu \nu }F^{\mu \nu }.}

when copy-pasted from Wikipedia. {{w|Quantum electrodynamics#Equations_of_motion|here is the link:}} [https://en.m.wikipedia.org/wiki/Quantum_electrodynamics#Equations_of_motion These are both the links.]
For archival, this is the thing: LAGRONJ EYSIBARYMOODMOOSIOYLERSIBRYMOOAMOOBAMOOSIMASIBRSIQORTFAHMOOVYFAHMOOVY.
[[User:4D4850|4D4850]] ([[User talk:4D4850|talk]]) 02:22, 22 July 2021 (UTC)

My friends and I actually pretty often say "PəV-nert" for the ideal gas law. First syllable is kind of vowel-less, sort of a schwa if anything. But also stressed? Didn't know you could stress a schwa but, guess I did.
[[Special:Contributions/172.70.130.160|172.70.130.160]] 02:36, 22 July 2021 (UTC)
:My teachers always pronounced it PIV-nert. [[Special:Contributions/172.69.62.20|172.69.62.20]] 18:38, 22 July 2021 (UTC)

I think this is the XKCD that has made me laugh the most, out of all 2492.
:I'd say it might be the one that made me laugh the most, out of all {{LATESTCOMIC}}. I won't, because it didn't, but I could. --[[User:4D4850|4D4850]] ([[User talk:4D4850|talk]]) 03:23, 22 July 2021 (UTC)

I tried to transcribe these pronunciations into IPA, because reading them like this is kind of ambiguous. I probably got a bunch of stuff wrong though.
fəˈdʒæmɚ |
ˈɛmkɑˌtu |
ætˈbutkut |
ˈæpɚˌtu |
həˈsplɒgpi |
ˈpævnɚt |
ˈaɪpɪn |
ˈfimɑ |
dut kəˈduks |
ˈfækslɪmˌoʊ ˈfæksəˌfɒx |
zəˈbɔbə fækˈtoʊɑ |
ˌɛpsɪˈhutəˌmu ˈdupsɪˌkwɔrps

Why is it a soft G in the gravity equation? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 04:10, 22 July 2021 (UTC)
:I believe it's a reference to the "gif" pronunciation debate. "Fuh-gam-er" is the obvious pronunciation, Randal is facetiously asserting "Fuh-jam-er" is correct.--[[Special:Contributions/108.162.250.130|108.162.250.130]] 05:00, 22 July 2021 (UTC)
:I think it might be because the English letter "G" is pronounced "Gee" (i.e. "Jee"), which made its way into the pronunciation here.[[User:BenjaminTheBenevolent|BenjaminTheBenevolent]] ([[User talk:BenjaminTheBenevolent|talk]]) 10:27, 22 July 2021 (UTC)

The most similar time when equations are actually 'pronounced' a bit like this is the "soh cah toa" mnemonic for the trigonometric identities - should this be in the explanation? (the comic made at least me think that might be the original inspiration) [[Special:Contributions/141.101.99.204|141.101.99.204]] 06:42, 22 July 2021 (UTC)

:The circle area might be meant to read out like "upper two", referencing the square. I can't see the same for any of the others though. / [[Special:Contributions/162.158.183.157|162.158.183.157]] 06:52, 22 July 2021 (UTC)

:Mneumonics are supposed to make it easier to remember the equations; this collection would actually make it more challenging to remember these. Mind you, as a math tutor, my first thought was that these were attempts at mnemonics that missed the mark, '''badly'''. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 15:04, 22 July 2021 (UTC)

I see nobody has attempted the Transcript yet. (Also I'm wondering how to 'properly' pronounce P-One V-One Over T-One Equals P-Two V-Two Over T-Two.) [[Special:Contributions/162.158.155.157|162.158.155.157]] 10:41, 22 July 2021 (UTC)
:I started a transcript. --[[User:4D4850|4D4850]] ([[User talk:4D4850|talk]]) 16:54, 22 July 2021 (UTC)

Sorry to come in as an amateur, but I think the equation pronounced Ha-SPLOG-pee is actually the equation for Shannon diversity. [[Special:Contributions/162.158.126.134|162.158.126.134]] 11:58, 22 July 2021 (UTC)
: In my opinion, most of the contributions here are from people pretending to know more than they do. Edit away. Be bold. [[Special:Contributions/172.70.114.172|172.70.114.172]] 21:04, 22 July 2021 (UTC)

The Pythagorean Theorem one made me think of the AT-AT debate for Star Wars
:The wave equation reminded me of Jimmy Durante's Ink A Dinka Doo: https://www.youtube.com/watch?v=EWqi9eWwXvk I think I'm dating myself (no one else will). [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 16:55, 22 July 2021 (UTC)

I don't think it's clear if the provided pronunciations are the ''Correct'' ones or the common ''mispronunciations''

2490: Pre-Pandemic Ketchup

2021-07-17T06:06:47Z

172.70.114.172:

{{comic
| number = 2490
| date = July 16, 2021
| title = Pre-Pandemic Ketchup
| image = pre_pandemic_ketchup.png
| titletext = I wonder what year I'll discard the last weird food item that I bought online in early 2020.
}}

==Explanation==
{{incomplete|Created by POST-PANDEMIC MUSTARD. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
This comic is part of a [[:Category:COVID-19|series of comics]] on the {{w|COVID-19 pandemic|2020 pandemic}} of {{w|coronavirus}} {{w|severe acute respiratory syndrome coronavirus 2|SARS-CoV-2}}, which causes {{w|COVID-19}}.

Just like [[2474: First Time Since Early 2020]], [[Randall]] compares the pre-pandemic life and the post-pandemic life in this comic. Life has changed dramatically due to the COVID-19 pandemic and the subsequent lockdowns and restrictions by governments around the world.

In this comic, [[Cueball]] bought a bottle of ketchup before the pandemic and they have not bought that kind of ketchup since, possibly due to supply chain disruptions or that brand not being available to order online. It may be a reference to the shortage of ketchup packets caused by an increase in takeout orders and restaurants replacing the ketchup bottle on the table with single serving units. Cueball is now cleaning out his cupboard, perhaps as a form of "pandemic spring cleaning" to make way for the future, and considers throwing it away. An offscreen character encourages him to toss it, because ketchup has a shelf life of approximately one year, and a bottle of ketchup from March 2020 has probably gone bad by July 2021.

In the title text, [[Cueball]] (or possibly [[Randall]]) is wondering in which year he would discard the last weird food item that he bought online in early 2020. If he's going for the [[Expiration Date High Score]] to beat 24.3, he should probably wait until 2035 or so.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is standing in a kitchen, looking at bottle of ketchup, and talking to a person off-screen. There is an cupboard above him and a counter next to him with a soda can, a can of food and a jar of mayonnaise. ]
:Cueball: Oh wow, pre-pandemic ketchup!
:Cueball: We haven't bought this kind since before.
:Cueball: I'm gonna toss it.
:(off-screen): Eww, yes.

:[Caption below the panel:]
:Spring 2020 forms a weird dividing line in my kitchen.

{{comic discussion}}
[[Category:COVID-19]]
[[Category:Comics featuring Cueball]]
[[Category:Food]]

2482: Indoor Socializing

2021-06-30T10:21:48Z

172.70.114.172: I don't know the nature of this quip for sure, but this common usage is in line with past comics.

{{comic
| number = 2482
| date = June 28, 2021
| title = Indoor Socializing
| image = indoor_socializing.png
| titletext = The problem with learning about biology is that everyone you meet is it.
}}

==Explanation==
{{incomplete|Created by a RESPIRATORY DROPLET. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
[[Cueball]] is meeting [[White Hat]], who is probably not in the same household. White Hat asks how Cueball is, which is normal small talk, but Cueball responds by expressing his awareness that they're inhaling one another's "gross lung air", an awareness that could be heightened after months of studying covid-19. Cueball then repeats a common joke regarding how impossible it is to connect with people when our conversation norms discourage honest communication, switching to a more socially acceptable "fine".

"Gross" here may be a pun on the term {{w|gross anatomy}} (i.e. anatomy at the macroscopic level) and "gross" as a synonym for "disgusting."

A recurring theme in XKCD is characters expressing an uncomfortable awareness of realities that most people tend to ignore, particularly for experts in a particular field (examples include [[2057: Internal Monologues]], [[913: Core]], [[203: Hallucinations]], and [[1839: Doctor Visit]]). In this strip, likely as a result of being primed by awareness of the {{w|COVID-19 pandemic}}, Cueball finds it difficult to be in the same building with other people without being aware of the fact that they're breathing the same air, meaning that particles of biological material are being freely exchanged. In an earlier era, such concerns might have been dismissed as being extreme, but the pandemic has demonstrated that there's very real reason to be concerned. Even if everyone involved is vaccinated, that doesn't entirely remove the risk, nor does it protect against other diseases, which can spread in similar ways.

The title text reinforces the idea that knowing more about any subject increases the likelihood that you'll become disturbed by some constant and basic reality of life. In this case, studying biology tends to be disturbing, since the field involves in depth knowledge of our own bodies, as well as all other organisms we encounter, and which makes one uncomfortably aware of all the risks and flaws basic to being alive.

==Transcript==
:[White Hat and Cueball are having a conversation.]
:White Hat: How are you?
:Cueball: Excruciatingly aware of how much of each other's gross lung air we're breathing.
:Cueball: I mean, fine! How are you?

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Social interactions]]
[[Category:Biology]]