explain xkcd - User contributions [en]

2275: Coronavirus Name

2022-05-04T01:22:19Z

172.70.179.20: Undo revision 234619 by X. K. C. D. (talk)

{{comic
| number = 2275
| date = March 2, 2020
| title = Coronavirus Name
| image = coronavirus_name.png
| titletext = It's important to keep the spider from touching your face.
}}

==Explanation==
This comic is the first comic in a long [[:Category:COVID-19|series of comics]] about the {{w|COVID-19 pandemic}}. For several weeks in a row, all comics were related to this pandemic.

This is thus [[Randall|Randall's]] first take on the COVID-19 pandemic. As of the publication date (March 2, 2020), the pandemic had infected more than 90,000 people, and had caused more than 3,000 deaths.

Coronavirus is a category of viruses named for their appearance, which is similar to a halo or crown, and includes four different viruses which can cause the common cold in humans. However, the virus itself is not called COVID-19, but is called {{w|severe acute respiratory syndrome coronavirus 2}} (SARS-CoV-2). So calling the virus or disease "coronavirus" is like calling a specific strain of flu ''The Influenza virus''. However, since the new coronavirus is so hyped in the media it has attracted so much attention, so the name "coronavirus" has become associated with COVID-19, making it difficult to discuss other types of coronaviruses later on.

As of March 2, 2020, COVID-19 in China has a 20% hospitalization rate and a 2% death rate by current estimates, compared to a [https://www.livescience.com/coronavirus-myths.html typical rate of around 0.1% for the flu in the US].

In this comic, researchers [[Ponytail]], [[Megan]] and [[Cueball]] are discussing that it is by now too late to try calling the disease its official name COVID-19, as the name coronavirus has stuck. [[Cueball]] reacts with dismay, since there are many other types of coronaviruses.

To illustrate that Cueball's complaint is excessively pedantic and inconsequential, Ponytail — rather than using a more real-world analogy — compares the coronavirus naming to a giant car-eating spider living on top of the skyscrapers of the town, which people similarly refer to generically as simply "The Spider," even though that is not the most technically-accurate name (it is technically a mutated ''{{w|Tigrosa annexa}}'' {{w|wolf spider}}). Everyone knows what you mean when you say "Coronavirus", as they do when you mention "The Spider".

The comic then goes on to poke fun at itself by treating Ponytail's example as a real concern, as [[Megan]] then asks if they should not also do something about the spider. But Ponytail and Cueball agree that they can only tackle one problem at a time, and coronavirus takes up all their time. Ponytail further notes that she simply began altering her route to circumvent the location where The Spider has taken up residence, as evidence that the Spider issue can be easily avoided, and is therefore not an immediate concern.

The title text references the health advice that people avoid touching their face with unwashed hands, in order to prevent infections that they picked up by touching things from entering their mucous membranes. (It's a lot easier for an infection to enter the body through the inside of your nose than your hands.) It is likewise quite important to keep the giant spider from touching your face, but for the dissimilar reason that it might bite and eat you.

Notably, the rename to COVID-19 did eventually catch on as the default description of the disease caused by "The Coronavirus" SARS-CoV2.

==Transcript==
:[Megan is carrying a box with biohazard symbols on it towards a desk where Ponytail (wearing safety glasses) is working on a laptop, across from Cueball (also wearing safety glasses) who is putting a test tube into a PCR machine. There's also a flask on the desk.]
:Ponytail: Feels like we missed the window for the "COVID-19" renaming. "Coronavirus" is just too catchy.
:Cueball: But it's not specific! There are a lot of coronaviruses.

:[In a frameless panel, Ponytail (still wearing safety glasses) is pointing at a screen or picture showing a modern city skyline with a large spider crawling across three of the high-rise buildings.]
:Ponytail: I think it's fine. It's like, you know the giant spider downtown that sits on the buildings and sometimes eats cars? I think ''technically'' it's a mutant ''T. annexa'' wolf spider, but everyone is just calling it "the spider" and we all know what they mean.

:[Back to the setting from the first panel. Megan is standing and Ponytail had turned towards her and Cueball has stepped back from the machine.]
:Megan: I've been meaning to ask, what's '''''with''''' that spider? Should we...do something?
:Ponytail: Honestly I've been too busy with the virus stuff to look into it-I just changed my commute to avoid Main St.
:Cueball: Yeah, that's fair. One thing at a time.

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:COVID-19]]
[[Category:Science]]
[[Category:Spiders]]

1274: Open Letter

2022-05-04T01:22:03Z

172.70.179.20: Undo revision 232971 by X. K. C. D. (talk)

{{comic
| number = 1274
| date = October 7, 2013
| title = Open Letter
| image = open_letter.png
| titletext = Are you ok? Do you need help?
}}

==Explanation==
This comic is a reference to the {{w|United States federal government shutdown of 2013|US government shutdown in 2013}} that had been ongoing for a week and was still current as of the time of this comic. Under some circumstances, the United States Federal Government {{w|Government shutdown in the United States|can temporarily shut down}} pending budget legislation being passed by the United States Congress. These shutdowns are typically due to political disagreements between the President, the House of Representatives, and the Senate. Due to the shutdown, numerous government services and facilities are shut down, often resulting in many logistical issues for the public.

Over the years, various conspiracy theories have been proposed claiming that the United States Government is not controlled by publicly-elected officials, but rather by one or more organizations that secretly control the actions of the government (sometimes termed a {{w|Shadow government (conspiracy)|"shadow government"}}). In this strip, [[Randall]] writes a letter to the shadow government, telling them that the situation (having the country's government shut down) is embarrassing and asking them to fix the problem.

This comic also implicitly argues against the plausibility of the aforementioned conspiracy theories if one assumes that a shadow-controlled government would be more likely to operate with a singular purpose and therefore be less susceptible to paralyzing political disagreements. Randall previously alluded to this in the title text to [[1081|comic 1081]]: "Really, the comforting side in most conspiracy theory arguments is the one claiming that anyone who's in power has any plan at all." This is one of several comics in which Randall expresses dismay at how many intelligent people can fall for absurd conspiracy theories; see comics [[258]] and [[690]], among others.

The title text addresses the leadership of the shadow government in more colloquial terms, asking if they are suffering from personal problems that are impeding their ability to keep things under control. This is patronizing, and thus hilarious.

The message, as titled, is in the form of an "{{w|Open letter|Open Letter}}", being a directed and 'personal' message to a person or group of people which is nonetheless intended by the sender to be publicly aired (unlike a standard commentary or editorial, which is intended for public consumption, but addresses the concerned 'target' almost as an aside). In some cases this may be to ensure the correspondence is not kept confidential by the recipients and/or that the public as a whole are ''also'' indirectly addressed ('Cc'ed) in the correspondence, without having to compose a companion piece for that purpose. In this case, however, it may additionally be because the intended recipient(s) are not so easily identified for direct communication, and a public airing would ensure 'delivery' even without compromising the integrity of the message. Open Letters are often aired (or pre-copied, verbatim, from actual correspondence) in one or area or other of the public media, and while web-comics aren't ''necessarily'' the most publicised of forums, the xkcd readership almost certainly leads to covering both the 'named' recipients and the intended public view.

===Addressees===
{| class="wikitable"
|-
! Addressee !! Brief Description
|-
| {{w|Freemasonry|The Freemasons}}|| Fraternity claiming the legacy of medieval stonemasons. Some of the {{w|Founding Fathers of the United States}} were members of the organization. Organised in local groups, the so-called ''Lodges''.
|-
| {{w|Illuminati}} || Secret society formed in Bavaria to further the ideas of {{w|enlightenment}}. Although officially banned in 1785, many conspiracy theorists believe the organisation might have survived and is still secretly exerting influence.
|-
| {{w|Scientology}} || A church founded by science-fiction writer {{w|L. Ron Hubbard}}. Often criticised for alleged {{w|brainwashing}} of its members and accused of hiding commercial interests behind religious claims.
|-
| {{w|FEMA}} || Agency of the United States Department of Homeland Security, that has been granted extensive authorisations in cases of emergency and is therefore believed to act as an entity independent of governmental control. Conspiracy theorists also claim that FEMA has been building concentration camps to silence conspiracy theorists.
|-
| {{w|New_World_Order|The New World Order}} || Not a secret organisation itself, but rather the concept of establishing a totalitarian system controlled by an elitist group in this list.
|-
| {{w|Federal_Reserve|The Federal Reserve}} || Central state bank system of the United States, therefore to some degree able to control the monetary circulation of the {{w|US Dollar}}.
|-
| {{w|Citigroup}} || One of the four biggest American financial service corporations. Considered by the {{w|Financial Stability Board}} to be a {{w|Too big to fail|"systemically important financial institution"}}.
|-
| {{w|Halliburton}} || International corporation offering technical services, especially in the field of oil and gas production. Also a major supplier for the {{w|US military}}. Halliburton was in the headlines for unethical business practices and connections to the former US Vice President {{w|Dick Cheney}}.
|-
| {{w|Google}} || Corporation offering Internet services, most notably the {{w|Google Search|Google search engine}}. Known for collecting massive amounts of data about its users in order to sell personalised advertisement. The idea of secret plans of Google has been mentioned in comic [[792]].
|-
| {{w|Holy See|The Vatican}} || Central government of the {{w|Catholic Church}} and residence of the {{w|pope}}. Historically important not only as a religious authority, but also as a {{w|Papal States|secular political power}}.
|-
| {{w|Bilderberg_Group|Bilderburg (correctly: ''Bilderberg'')}} || Annual conference of important politicians, bankers, directors of major corporations and other {{w|List of Bilderberg participants|people of influence}}, therefore considered the quintessential elitist meeting.
|-
| {{w|Walmart}} || American retail corporation, best known for the eponymous chain of warehouse stores. As of January 2013, Walmart is the world's largest public corporation by revenue.
|-
| {{w|Rothschild_family|The Rothschilds}} || Family of Jewish financiers that was later elevated into European nobility. Believed to exercise influence through considerable wealth. The subject of conspiracy theories since the mid-19th century, when they amassed the largest fortune in world history.
|-
| {{w|Knights Templar}} || Originally a medieval Christian military order of considerable influence, the Knights Templar were inspiration for many successive (secret) organisations that are sometimes believed to undermine governmental authorities. There is also an {{w|Knights Templar (Freemasonry)|eponymous order}} affiliated with Freemasonry. It may also be a reference to the ''{{w|Assassin's Creed|Assassins Creed}}'' video game series, in which several historical figures are claimed to have been Templars.
|-
| {{w|High Frequency Active Auroral Research Program#Conspiracy theories|HAARP}} || Ionospheric research project of the US military. Believed by some conspiracy theorists to conceal attempts to control the weather and trigger catastrophes.
|-
| {{w|United Nations|The UN}} || Large intergovernmental organization; most countries (193) in the world are members, with Palestine and the Vatican having observer status at the UN. It has little direct power unless its member states choose to cooperate.
|-
| {{w|Skull and Bones|Skull & Bones}} || A secret society at the {{w|Yale University}} that has many influential American politicians amongst its members, including former Presidents {{w|George H. W. Bush}} and {{w|George W. Bush}}, as well as former Secretary of State {{w|John Kerry}}.
|-
| {{w|Bohemian Grove}} || Campground of the private {{w|Bohemian Club}} in San Francisco, known for hosting an annual encampment of club members and selected guests who are among the most powerful men in the world.
|-
| {{w|Political activities of the Koch brothers|The Koch Brothers}} || Owners of the second-largest private company in the USA, known for supporting libertarian and conservative political causes.
|-
| {{w|George_Soros|George Soros}} || Business magnate and investor, known for supporting liberal political causes.
|-
| {{w|The Trilateral Commission}} || {{W|Think tank}} and associated meeting, emphasizing cooperation between North America, Western Europe, and Japan; founded by {{w|David Rockefeller}}
|-
| {{w|Sovereign Military Order of Malta|The Knights of Malta}} || Religious order that was once a sovereign state; contemporary {{w|Malta|Republic of Malta}} is not controlled by this order. Its exact status now is debated; it considers itself a "sovereign subject of international law" and has observer status at the United Nations.
|-
| {{w|Council on Foreign Relations|The CFR}} || Acronym for the {{w|Council on Foreign Relations|Council on Foreign Relations}}. Foreign policy think tank in the United States
|-
| {{w|ExxonMobil|Exxon Mobil}} || Major petroleum corporation; third largest company in the world, by revenue
|-
| {{w|Zionism|The Zionists}} || Political movement favouring the creation of a Jewish homeland, a goal achieved with the creation of the state of {{w|Israel}}. In a conspiracy-theory context, it references the belief that wealthy and powerful Jews (such as the above-referenced Rothschilds) control political and social institutions, as presented e.g. in the (fake) {{w|Protocols of Zion}}.
|-
| {{w|Vril#Vril society|The Vril Society}} || The "Vril" are a hidden subterranean race from the novel ''Vril, the Power of the Coming Race'' by {{w|Edward_Bulwer-Lytton|Edward Bulwer-Lytton}}. The novel allegedly inspired a "Vril Society" in Nazi Germany; however, there is no real evidence that the society existed, much less that it had the influence sometimes ascribed to it.
|-
| {{w|Reptilian humanoid|The Lizard People}} || Secret snake-men, similar to the aliens from ''{{w|V (franchise)|V}}''. This is probably a reference to the conspiracy theories of {{w|David Icke}}, which include the idea that an ancient race of god-like, shapeshifting Lizards have interbred with humans, and that these half-bloods now secretly control the world.
|-
| and everyone else who secretly controls the {{w|Federal government of the United States|US Government}} || Note the implicit notion that so many different groups each have control, which makes no sense.
|}

==Transcript==
:[The picture shows a letter.]
:October 7th 2013
:To: The Freemasons, the Illuminati, Scientology, FEMA, the New World Order, the Federal Reserve, Citigroup, Halliburton, Google, the Vatican, Bilderburg, Walmart, the Rothschilds, the Knights Templar, HAARP, the UN, Skull & Bones, Bohemian Grove, the Koch Brothers, George Soros, the Trilateral Commision, the Knights of Malta, the CFR, Exxon Mobil, the Zionists, the Vril Society, the Lizard People, and everyone else who secretly controls the US government
:Can you please get your shit together?
:This is embarrassing.
:Sincerely,
:A Concerned Citizen

{{comic discussion}}
[[Category:Politics]]
[[Category:Conspiracy theory]]

188: Reload

2022-05-04T01:21:36Z

172.70.179.20: Undo revision 233948 by X. K. C. D. (talk)

{{comic
| number = 188
| date = November 24, 2006
| title = Reload
| image = reload.png
| titletext = And watch out for that guy from comic #53.
}}

==Explanation==
This comic refers to the common method for reloading your ammunition in arcade game type shooters, also known as "rail shooters." The player is typically given a {{w|Light gun}}, and the player characters typically have unlimited magazines of ammunition; to load a new magazine, the player would aim his light gun away from the screen and pull the trigger.

The title text tells you to watch out for the guy from comic [[53: Hobby]], which shows a man who randomly pops up to the police when they are performing a drug raid. This refers to the random figures that pop out at many games; if they are not a valid target and you shoot them, you will lose points.

==Transcript==
:[Four soldiers are preparing to enter a battlefield; their leader addresses them.]
:Leader: Okay men, we're going in. Stay low, keep behind cover, and if you run out of ammunition, shoot outside the battlefield to reload.

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Video games]]

231: Cat Proximity

2022-05-04T01:21:10Z

172.70.179.20: Undo revision 233378 by X. K. C. D. (talk)

{{comic
| number =231
| date =March 5, 2007
| title =Cat Proximity
| image =cat_proximity.png
| titletext =Yes you are! And you're sitting there! Hi, kitty!
}}

==Explanation==
This comic refers to the use of "{{w|baby talk}}" when speaking to pets, especially {{w|cats}}. A person's voice becomes {{w|falsetto}} and {{Wiktionary|cooing}}, vocabulary becomes simplified, and phrases are repeated, such as "Here, kitty, kitty, kitty."

The chart shows that a person's apparent intelligence decreases, and that the {{Wiktionary|inanity}} (i.e. uselessness or emptiness) of their statements increases, the closer they get to a cat.
Most people act like this when they're playing with cats or trying to call them over to them.
Thankfully, being close to a cat doesn't actually cause any decrease of intelligence in normal circumstances; the graph technically refers to ''demonstrated'' intelligence rather than actual IQ levels.{{Citation needed}}

The title text continues [[Cueball|Cueball's]] obvious statement (and thus inane/useless point made) from below the graph.

In [[1535: Words for Pets]], [[Randall]] again mentions how people often talk strangely to their pets.

==Transcript==
:[A graph with the x-axis labeled, and the scale indicated from left to right:]
:Far
:Human proximity to cat
:Near
:[Two curves are drawn and labeled, first the one starting on top, which then veers downwards and crosses the other as that curve veers upwards.]
:Intelligence
:Inanity of statements

:[Below the graph, Cueball is seen standing at three distances from a cat that is drawn to the far right. The two first Cueballs are just standing, one below far, the other in the middle, and the last is standing close to the cat (below near) with his hands up, and he is speaking.]
:Cueball: You're a kitty!

==Trivia==
*This comic is available as a signed print in the [https://store.xkcd.com/products/signed-prints xkcd store].

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Cats]]
[[Category:Line graphs]]
[[Category:Comics with xkcd store products]]

1458: Small Moon

2022-05-04T00:59:09Z

172.70.179.20: Undo revision 234988 by X. K. C. D. (talk)

{{comic
| number = 1458
| date = December 10, 2014
| title = Small Moon
| image = small_moon.png
| titletext = GENERAL JAN DODONNA: An analysis of the plans provided by Princess Leia has reinvigorated the arguments of the 'artificial moonlet' and 'rogue planet-station' camps. I fear this question is fracturing the Rebellion.
}}

==Explanation==
The comic depicts a [https://www.youtube.com/watch?v=EVekNsgUqn4 classic scene] from {{w|Star Wars Episode IV}}, in which the heroes trail a {{w|TIE fighter}} to the never-before-seen {{w|Death Star}}: a super-weapon the size of a small moon capable of demolishing entire planets. In the original scene and the comic, {{w|Luke Skywalker}} misidentifies a body as a natural satellite, and {{w|Obi-Wan Kenobi|Obi-Wan 'Ben' Kenobi}} ominously corrects him.

The comic's version diverges at this point, as the dialogue devolves into a rather bitter argument over the semantics of size classifications, alluding to scientific discussions on whether {{w|Pluto}} should be classified as a {{w|planet}} or as a {{w|dwarf planet}}. The argument goes on for hours, which in the original plot would suggest one of two situations:
*The Death Star apparently never caught them, and {{w|Princess Leia}} was never rescued (but Ben survived).
*The argument was picked up after escaping the Death Star, and now Leia is joining in.

The argument is confused as to whether they're talking about size or about natural vs artificial objects. In terms of size, the Death Star is much larger (70 km radius) than dozens of {{w|List of natural satellites|full-fledged moons}} in our solar system. One of the smallest moons found so far in the solar system is {{w|S/2009 S 1}}, which is about 400 meters in diameter and orbits Saturn. But we don't generally speak of the tiny rocks in the rings of Saturn as moons, so there is some distinction there, which may include the orbit of the object [http://www.exploratorium.edu/saturn/moon.html]. There is also the distinction between natural moons and spacecraft, which seems to be ignored in the final panel.

The title text makes reference to a later scene in the film when Rebel pilots are being briefed on the planned attack on the Death Star. Those who analysed the plans for the Death Star run into the same discussion picture, and end up arguing about the classification of the Death Star, dividing those involved into the 'artificial moonlet' camp and the 'rogue planet-station' camp, thus deunifying the rebellion. If events are otherwise the same from the movie, this is also happening at threat of their destruction, and thus a crippling of the Rebellion.

The timing of the comic may be related to the {{w|New Horizons}} mission to {{w|Pluto}}. The spacecraft awoke from hibernation 4 days earlier, on December 6, 2014, to start the encounter phase with Pluto.

==Transcript==
:[Millennium Falcon follows a Tie Fighter towards an unidentified orb in the distance.]
:Luke Skywalker: He's heading for that small moon.
:Ben Kenobi: That's no moon - it's a space station.

:Luke Skywalker: It's too big to be a space station.
:Ben Kenobi: But it's too '''''small''''' to be a moon.

:[Three hours pass]

:Ben Kenobi: Fine! What if we agree it's not a moon, but we make a new category called "Dwarf Moon"?
:Luke Skywalker: And what's the cutoff, asshole?! Is this '''''ship''''' a dwarf moon now?
:Ben Kenobi: Screw you.

{{comic discussion}}

[[Category:Space]]
[[Category:Star Wars]]

2614: 2

2022-05-04T00:42:19Z

172.70.179.20:

<div style="display: none">crap</div><noinclude>:''This page refers to the comic named "2". For comic #2, see [[2: Petit Trees (sketch)]].''</noinclude>
{{notice|'''WARNING:''' The vast majority of the pages of ExplainXKCD are currently vandalized. {{#expr: {{LATESTCOMIC}} - {{PAGESINCAT:All comics|R}}}} out of {{LATESTCOMIC}} ({{#expr: 100 - ({{PAGESINCAT:All comics|R}} / {{LATESTCOMIC}} * 100 round 0)}}%) are vandalized, leaving only {{PAGESINCAT:All comics|R}} ({{#expr: ({{PAGESINCAT:All comics|R}} / {{LATESTCOMIC}} * 100 round 0)}}%). ''Users:'' You can help combat this! Click "Random page" and undo/revert the vandalism in the page history. Every bit of help counts! (Admins, are you there?)}}
{{comic
| number = 2614
| date = May 2, 2022
| title = 2
| image = 2.png
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.
}}

==Explanation==
{{incomplete|Created by A VERY JEALOUS NUMBER ₃½ⁿ₇₇₇ⅥⅣ₆⁸⁴⁴½⅔⅜ↆ↉↉∂, WHO DEMANDS TO HAVE THEIR OWN WEBCOMIC NEXT - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}

This demonstrates the different ways in which the number 2 can be typeset in various scientific fields. Whilst these typefaces are used with any number, using the number 2 in this instance provides a clear illustration of where adding numbers can signify either a feature of a concept (such as the number of electrons in an atom) or a mathematical operation on it (such as raising a value to it's second power).

The dotted box represents any character (presumably a letter or bigram of letters). All the other notation consists only of the digit 2, in various fashions with occasional additional punctuation, and labelled as to what the 'purpose' might normally be of any particular element(s) as indicated, with respect to the general term, in the following fashions:
;Regular Math
:Precedes the term. "2x" indicates two times the value of ''x'' in normal {{w|algebra|algebraic}} use that should be familiar for many people. {{Citation needed}}
;Physics
:A preceding superscript. "2H" would indicate the particular {{w|isotope}} of Hydrogen with the atomic weight of two, i.e. deuterium, which is most often encountered when working with the atomic level of matter where the total number of neutrons and protons in the atom is important. It can also represent tetration, which is iterated exponentiation.
;Chemical Physics
:A preceding subscript, "2He" indicates the atomic number of an atom, which is the number of protons it contains, and thus a guide to the number of electrons its unionised form usually has and hence meaningful in its potential chemical interactions with other atoms. This should be invariant for any particular named element, but is usually given simultaneously with the presuperscripted mass number where it can be indicative of the applicable nuclear physics. {{w|Chemical Physics}} is a subdiscipline of physics and chemistry and **must never** be confused with {{w|Physical Chemistry}}. It can also represent pentation, which is iterated tetration.
;Regular Math or Footnotes
:A trailing superscript is typical of a {{w|Exponentiation|power value}}, in this case "x²" would be ''x'' multiplied by a second copy of itself, and a fairly typical mathematical standard.
:Additionally, superscripted numbers are one common way to mark words in a line of text in a way to refer to a {{w|Note (typography)|footnote}}, typically placed at the bottom of the page, with additional information that would not be appropriate or easily comprehendable to edit into the main text itself. The ambiguity between footnotes and exponents was used in [[1184: Circumference Formula]]
;Chemistry
:A trailing subscript is used in chemistry to indicate a multiple of the element (or group of elements, in brackets) in a {{w|chemical formula}}. "H2O" indicates two hydrogen atoms bond with a single oxygen atom in a molecule of water.
;Matrices! ("2,2")
:Extending the trailing subscript with a comma-separated value usually indicates a multidimensional array (e.g. establishing a 2-by-2 square of numbers, or this particular position in such an array), which is in the realms of {{w|Matrix (mathematics)|matrix mathematics}}. This is a little bit beyond 'everyday algebra' for many people, as seemingly indicated by the exclamation of the mere mention of matrices!
;The Physicists Are At It Again ("2;2")
:This label encompasses a mark that turns the prior comma into a semicolon, as part of the trailing subscript. This is a common notation for the {{w|Covariant derivative}} of a tensor field, which is commonly used in the mathematics of general relativity.
;Either High School Math Function or Incomprehensible Group Theory
:The number 2 in parentheses that follow a term would normally be the argument to a {{w|Function (mathematics)|function}}, e.g. "f(2)", which means that you should take the value (in this case 2) and find the result if manipulated by the predefined function ''f''. It is generally taught as part of algebraic mathematics already described, i.e. at {{w|Secondary school|High School}}.
:In {{w|group theory}}, however, the number 2 in parentheses could indicate a cyclic subgroup or ideal generated by two or a special case of cycle notation for elements of symmetry groups used to mean an element that keeps 2 fixed. This may be somewhat beyond high-school level.{{citation needed}}
;Oh no. Whatever this is, it's cursed.
:A symbol centered underneath another symbol is normally reserved for doing summations, where the big symbol is Σ, or some other operation applied to a sequence of numbers.
:It does not make sense to have a single number there, as indicated in the alt text. As with [[2529: Unsolved Math Problems|other things]] in Randall's comic universe, the explanation for this particular anomaly is that it is 'Cursed'. The usage mentioned in the alt text is an operation (Σ, summation) over a variable usually indicated by a letter such as i, where the operation is performed over all values of the variable, i.e. you Σ the argument over all values of i. In the "2" case, the alt text says you "you 2 the argument over all values of 2", i.e. the Σ operation has been replaced by the "2" operation and the i variable has been replaced by the "2" variable. 2 is usually not an operation, though the definition of 2 under {{w|Church_encoding#Church_numerals|church encoding}} is a function that takes in and produces functions. However, 2 is not a variable (and definitely not both at the same time).
:: Things being cursed is a common trope within recent XKCD comics which have mentioned items including [[2332:_Cursed_Chair|Cursed chairs]] and [[Category:Cursed_Connectors]]. This notation is one of the few occasions where the supernatural have demonstrable implications on science and mathematics for those foolhardy enough to use it.

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

:[An apparent generalisation of a scientific expression consisting of a dotted rectangular 'box' outline, left empty, and various commonly-themed symbology around it:]

:[as normal text, to the left of all the rest:] 2
:[superscript to the immediate left of the box:] 2
:[subscript also to the immediate left of the box:] 2
:[superscript to the immediate right of the box:] 2
:[subscript also to the immediate right of the box:] 2;2 [i.e. separated by a semicolon]
:[as normal text, to the right of almost all the rest:] (2) [i.e. enclosed in standard parentheses]
:[smaller subscript, centered immediately beneath the 2 within the parentheses:] 2

:[Further details are drawn in grey tone, around or near various of the elements of the expression:]
;[Captions above the numbers]
:[with an arrow pointing to the leftmost 2:] Regular Math
:[with an arrow pointing to the leftwards superscript 2:] Physics
:[with an arrow pointing to the rightwards superscript 2:] Regular math or footnotes
:[with an arrow pointing to the parenthetical 2 at the right:] Either high school math functions or incomprehensible group theory

;[Captions below the numbers]
:[with an arrow pointing to the leftwards subscript 2:] Chemical Physics
:[with an arrow pointing to just the rightwards subscript 2:] Chemistry
:[with an arrow pointing to a distorted grey ring snaking around only the comma of the semicolon and the following 2 of the rightmost subscript:] Matrices!
:[with an arrow pointing to a larger grey ring that passes fully around the whole semicolon and final 2 of the rightmost subscript:] The physicists are at it again
:[with an arrow pointing to the small 2 placed below the parenthetical 2:] Oh no. Whatever this is, it's cursed.

{{comic discussion}}
[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Comics featuring Cursed Items]]

2614: 2

2022-05-04T00:41:39Z

172.70.179.20:

<div style="display: none">crap</div><noinclude>:''This page refers to the comic named "2". For comic #2, see [[2: Petit Trees (sketch)]].''</noinclude>
{{notice|'''WARNING:''' The vast majority () of the pages of ExplainXKCD are currently vandalized. {{#expr: {{LATESTCOMIC}} - {{PAGESINCAT:All comics|R}}}} out of {{LATESTCOMIC}} ({{#expr: 100 - ({{PAGESINCAT:All comics|R}} / {{LATESTCOMIC}} * 100 round 0)}}%) are vandalized, leaving only {{PAGESINCAT:All comics|R}} ({{#expr: ({{PAGESINCAT:All comics|R}} / {{LATESTCOMIC}} * 100 round 0)}}%). ''Users:'' You can help combat this! Click "Random page" and undo/revert the vandalism in the page history. Every bit of help counts! (Admins, are you there?)}}
{{comic
| number = 2614
| date = May 2, 2022
| title = 2
| image = 2.png
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.
}}

==Explanation==
{{incomplete|Created by A VERY JEALOUS NUMBER ₃½ⁿ₇₇₇ⅥⅣ₆⁸⁴⁴½⅔⅜ↆ↉↉∂, WHO DEMANDS TO HAVE THEIR OWN WEBCOMIC NEXT - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}

This demonstrates the different ways in which the number 2 can be typeset in various scientific fields. Whilst these typefaces are used with any number, using the number 2 in this instance provides a clear illustration of where adding numbers can signify either a feature of a concept (such as the number of electrons in an atom) or a mathematical operation on it (such as raising a value to it's second power).

The dotted box represents any character (presumably a letter or bigram of letters). All the other notation consists only of the digit 2, in various fashions with occasional additional punctuation, and labelled as to what the 'purpose' might normally be of any particular element(s) as indicated, with respect to the general term, in the following fashions:
;Regular Math
:Precedes the term. "2x" indicates two times the value of ''x'' in normal {{w|algebra|algebraic}} use that should be familiar for many people. {{Citation needed}}
;Physics
:A preceding superscript. "2H" would indicate the particular {{w|isotope}} of Hydrogen with the atomic weight of two, i.e. deuterium, which is most often encountered when working with the atomic level of matter where the total number of neutrons and protons in the atom is important. It can also represent tetration, which is iterated exponentiation.
;Chemical Physics
:A preceding subscript, "2He" indicates the atomic number of an atom, which is the number of protons it contains, and thus a guide to the number of electrons its unionised form usually has and hence meaningful in its potential chemical interactions with other atoms. This should be invariant for any particular named element, but is usually given simultaneously with the presuperscripted mass number where it can be indicative of the applicable nuclear physics. {{w|Chemical Physics}} is a subdiscipline of physics and chemistry and **must never** be confused with {{w|Physical Chemistry}}. It can also represent pentation, which is iterated tetration.
;Regular Math or Footnotes
:A trailing superscript is typical of a {{w|Exponentiation|power value}}, in this case "x²" would be ''x'' multiplied by a second copy of itself, and a fairly typical mathematical standard.
:Additionally, superscripted numbers are one common way to mark words in a line of text in a way to refer to a {{w|Note (typography)|footnote}}, typically placed at the bottom of the page, with additional information that would not be appropriate or easily comprehendable to edit into the main text itself. The ambiguity between footnotes and exponents was used in [[1184: Circumference Formula]]
;Chemistry
:A trailing subscript is used in chemistry to indicate a multiple of the element (or group of elements, in brackets) in a {{w|chemical formula}}. "H2O" indicates two hydrogen atoms bond with a single oxygen atom in a molecule of water.
;Matrices! ("2,2")
:Extending the trailing subscript with a comma-separated value usually indicates a multidimensional array (e.g. establishing a 2-by-2 square of numbers, or this particular position in such an array), which is in the realms of {{w|Matrix (mathematics)|matrix mathematics}}. This is a little bit beyond 'everyday algebra' for many people, as seemingly indicated by the exclamation of the mere mention of matrices!
;The Physicists Are At It Again ("2;2")
:This label encompasses a mark that turns the prior comma into a semicolon, as part of the trailing subscript. This is a common notation for the {{w|Covariant derivative}} of a tensor field, which is commonly used in the mathematics of general relativity.
;Either High School Math Function or Incomprehensible Group Theory
:The number 2 in parentheses that follow a term would normally be the argument to a {{w|Function (mathematics)|function}}, e.g. "f(2)", which means that you should take the value (in this case 2) and find the result if manipulated by the predefined function ''f''. It is generally taught as part of algebraic mathematics already described, i.e. at {{w|Secondary school|High School}}.
:In {{w|group theory}}, however, the number 2 in parentheses could indicate a cyclic subgroup or ideal generated by two or a special case of cycle notation for elements of symmetry groups used to mean an element that keeps 2 fixed. This may be somewhat beyond high-school level.{{citation needed}}
;Oh no. Whatever this is, it's cursed.
:A symbol centered underneath another symbol is normally reserved for doing summations, where the big symbol is Σ, or some other operation applied to a sequence of numbers.
:It does not make sense to have a single number there, as indicated in the alt text. As with [[2529: Unsolved Math Problems|other things]] in Randall's comic universe, the explanation for this particular anomaly is that it is 'Cursed'. The usage mentioned in the alt text is an operation (Σ, summation) over a variable usually indicated by a letter such as i, where the operation is performed over all values of the variable, i.e. you Σ the argument over all values of i. In the "2" case, the alt text says you "you 2 the argument over all values of 2", i.e. the Σ operation has been replaced by the "2" operation and the i variable has been replaced by the "2" variable. 2 is usually not an operation, though the definition of 2 under {{w|Church_encoding#Church_numerals|church encoding}} is a function that takes in and produces functions. However, 2 is not a variable (and definitely not both at the same time).
:: Things being cursed is a common trope within recent XKCD comics which have mentioned items including [[2332:_Cursed_Chair|Cursed chairs]] and [[Category:Cursed_Connectors]]. This notation is one of the few occasions where the supernatural have demonstrable implications on science and mathematics for those foolhardy enough to use it.

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

:[An apparent generalisation of a scientific expression consisting of a dotted rectangular 'box' outline, left empty, and various commonly-themed symbology around it:]

:[as normal text, to the left of all the rest:] 2
:[superscript to the immediate left of the box:] 2
:[subscript also to the immediate left of the box:] 2
:[superscript to the immediate right of the box:] 2
:[subscript also to the immediate right of the box:] 2;2 [i.e. separated by a semicolon]
:[as normal text, to the right of almost all the rest:] (2) [i.e. enclosed in standard parentheses]
:[smaller subscript, centered immediately beneath the 2 within the parentheses:] 2

:[Further details are drawn in grey tone, around or near various of the elements of the expression:]
;[Captions above the numbers]
:[with an arrow pointing to the leftmost 2:] Regular Math
:[with an arrow pointing to the leftwards superscript 2:] Physics
:[with an arrow pointing to the rightwards superscript 2:] Regular math or footnotes
:[with an arrow pointing to the parenthetical 2 at the right:] Either high school math functions or incomprehensible group theory

;[Captions below the numbers]
:[with an arrow pointing to the leftwards subscript 2:] Chemical Physics
:[with an arrow pointing to just the rightwards subscript 2:] Chemistry
:[with an arrow pointing to a distorted grey ring snaking around only the comma of the semicolon and the following 2 of the rightmost subscript:] Matrices!
:[with an arrow pointing to a larger grey ring that passes fully around the whole semicolon and final 2 of the rightmost subscript:] The physicists are at it again
:[with an arrow pointing to the small 2 placed below the parenthetical 2:] Oh no. Whatever this is, it's cursed.

{{comic discussion}}
[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Comics featuring Cursed Items]]

2614: 2

2022-05-04T00:35:04Z

172.70.179.20:

<div style="display: none">crap</div><noinclude>:''This page refers to the comic named "2". For comic #2, see [[2: Petit Trees (sketch)]].''</noinclude>
{{notice|'''WARNING:''' The vast majority ({{#expr: {{LATESTCOMIC}} - {{PAGESINCAT:All comics|R}}}} out of {{LATESTCOMIC}}, or {{#expr: 100 - ({{PAGESINCAT:All comics|R}} / {{LATESTCOMIC}} * 100 round 0)}}%) of the pages of ExplainXKCD are currently vandalized (only {{PAGESINCAT:All comics|R}} are left). (Admins, are you there?)}}
{{comic
| number = 2614
| date = May 2, 2022
| title = 2
| image = 2.png
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.
}}

==Explanation==
{{incomplete|Created by A VERY JEALOUS NUMBER ₃½ⁿ₇₇₇ⅥⅣ₆⁸⁴⁴½⅔⅜ↆ↉↉∂, WHO DEMANDS TO HAVE THEIR OWN WEBCOMIC NEXT - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}

This demonstrates the different ways in which the number 2 can be typeset in various scientific fields. Whilst these typefaces are used with any number, using the number 2 in this instance provides a clear illustration of where adding numbers can signify either a feature of a concept (such as the number of electrons in an atom) or a mathematical operation on it (such as raising a value to it's second power).

The dotted box represents any character (presumably a letter or bigram of letters). All the other notation consists only of the digit 2, in various fashions with occasional additional punctuation, and labelled as to what the 'purpose' might normally be of any particular element(s) as indicated, with respect to the general term, in the following fashions:
;Regular Math
:Precedes the term. "2x" indicates two times the value of ''x'' in normal {{w|algebra|algebraic}} use that should be familiar for many people. {{Citation needed}}
;Physics
:A preceding superscript. "2H" would indicate the particular {{w|isotope}} of Hydrogen with the atomic weight of two, i.e. deuterium, which is most often encountered when working with the atomic level of matter where the total number of neutrons and protons in the atom is important. It can also represent tetration, which is iterated exponentiation.
;Chemical Physics
:A preceding subscript, "2He" indicates the atomic number of an atom, which is the number of protons it contains, and thus a guide to the number of electrons its unionised form usually has and hence meaningful in its potential chemical interactions with other atoms. This should be invariant for any particular named element, but is usually given simultaneously with the presuperscripted mass number where it can be indicative of the applicable nuclear physics. {{w|Chemical Physics}} is a subdiscipline of physics and chemistry and **must never** be confused with {{w|Physical Chemistry}}. It can also represent pentation, which is iterated tetration.
;Regular Math or Footnotes
:A trailing superscript is typical of a {{w|Exponentiation|power value}}, in this case "x²" would be ''x'' multiplied by a second copy of itself, and a fairly typical mathematical standard.
:Additionally, superscripted numbers are one common way to mark words in a line of text in a way to refer to a {{w|Note (typography)|footnote}}, typically placed at the bottom of the page, with additional information that would not be appropriate or easily comprehendable to edit into the main text itself. The ambiguity between footnotes and exponents was used in [[1184: Circumference Formula]]
;Chemistry
:A trailing subscript is used in chemistry to indicate a multiple of the element (or group of elements, in brackets) in a {{w|chemical formula}}. "H2O" indicates two hydrogen atoms bond with a single oxygen atom in a molecule of water.
;Matrices! ("2,2")
:Extending the trailing subscript with a comma-separated value usually indicates a multidimensional array (e.g. establishing a 2-by-2 square of numbers, or this particular position in such an array), which is in the realms of {{w|Matrix (mathematics)|matrix mathematics}}. This is a little bit beyond 'everyday algebra' for many people, as seemingly indicated by the exclamation of the mere mention of matrices!
;The Physicists Are At It Again ("2;2")
:This label encompasses a mark that turns the prior comma into a semicolon, as part of the trailing subscript. This is a common notation for the {{w|Covariant derivative}} of a tensor field, which is commonly used in the mathematics of general relativity.
;Either High School Math Function or Incomprehensible Group Theory
:The number 2 in parentheses that follow a term would normally be the argument to a {{w|Function (mathematics)|function}}, e.g. "f(2)", which means that you should take the value (in this case 2) and find the result if manipulated by the predefined function ''f''. It is generally taught as part of algebraic mathematics already described, i.e. at {{w|Secondary school|High School}}.
:In {{w|group theory}}, however, the number 2 in parentheses could indicate a cyclic subgroup or ideal generated by two or a special case of cycle notation for elements of symmetry groups used to mean an element that keeps 2 fixed. This may be somewhat beyond high-school level.{{citation needed}}
;Oh no. Whatever this is, it's cursed.
:A symbol centered underneath another symbol is normally reserved for doing summations, where the big symbol is Σ, or some other operation applied to a sequence of numbers.
:It does not make sense to have a single number there, as indicated in the alt text. As with [[2529: Unsolved Math Problems|other things]] in Randall's comic universe, the explanation for this particular anomaly is that it is 'Cursed'. The usage mentioned in the alt text is an operation (Σ, summation) over a variable usually indicated by a letter such as i, where the operation is performed over all values of the variable, i.e. you Σ the argument over all values of i. In the "2" case, the alt text says you "you 2 the argument over all values of 2", i.e. the Σ operation has been replaced by the "2" operation and the i variable has been replaced by the "2" variable. 2 is usually not an operation, though the definition of 2 under {{w|Church_encoding#Church_numerals|church encoding}} is a function that takes in and produces functions. However, 2 is not a variable (and definitely not both at the same time).
:: Things being cursed is a common trope within recent XKCD comics which have mentioned items including [[2332:_Cursed_Chair|Cursed chairs]] and [[Category:Cursed_Connectors]]. This notation is one of the few occasions where the supernatural have demonstrable implications on science and mathematics for those foolhardy enough to use it.

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

:[An apparent generalisation of a scientific expression consisting of a dotted rectangular 'box' outline, left empty, and various commonly-themed symbology around it:]

:[as normal text, to the left of all the rest:] 2
:[superscript to the immediate left of the box:] 2
:[subscript also to the immediate left of the box:] 2
:[superscript to the immediate right of the box:] 2
:[subscript also to the immediate right of the box:] 2;2 [i.e. separated by a semicolon]
:[as normal text, to the right of almost all the rest:] (2) [i.e. enclosed in standard parentheses]
:[smaller subscript, centered immediately beneath the 2 within the parentheses:] 2

:[Further details are drawn in grey tone, around or near various of the elements of the expression:]
;[Captions above the numbers]
:[with an arrow pointing to the leftmost 2:] Regular Math
:[with an arrow pointing to the leftwards superscript 2:] Physics
:[with an arrow pointing to the rightwards superscript 2:] Regular math or footnotes
:[with an arrow pointing to the parenthetical 2 at the right:] Either high school math functions or incomprehensible group theory

;[Captions below the numbers]
:[with an arrow pointing to the leftwards subscript 2:] Chemical Physics
:[with an arrow pointing to just the rightwards subscript 2:] Chemistry
:[with an arrow pointing to a distorted grey ring snaking around only the comma of the semicolon and the following 2 of the rightmost subscript:] Matrices!
:[with an arrow pointing to a larger grey ring that passes fully around the whole semicolon and final 2 of the rightmost subscript:] The physicists are at it again
:[with an arrow pointing to the small 2 placed below the parenthetical 2:] Oh no. Whatever this is, it's cursed.

{{comic discussion}}
[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Comics featuring Cursed Items]]

2614: 2

2022-05-04T00:33:54Z

172.70.179.20: Update counter

<div style="display: none">crap</div><noinclude>:''This page refers to the comic named "2". For comic #2, see [[2: Petit Trees (sketch)]].''</noinclude>
{{notice|'''WARNING:''' The vast majority ({{#expr: {{LATESTCOMIC}} - {{PAGESINCAT:All comics|R}}}} out of {{LATESTCOMIC}}, or {{#expr: 100 - ({{PAGESINCAT:All comics|R}} / {{LATESTCOMIC}} * 100 round 0)}}%) of the pages of ExplainXKCD are currently vandalized. (Admins, are you there?)}}
{{comic
| number = 2614
| date = May 2, 2022
| title = 2
| image = 2.png
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.
}}

==Explanation==
{{incomplete|Created by A VERY JEALOUS NUMBER ₃½ⁿ₇₇₇ⅥⅣ₆⁸⁴⁴½⅔⅜ↆ↉↉∂, WHO DEMANDS TO HAVE THEIR OWN WEBCOMIC NEXT - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}

This demonstrates the different ways in which the number 2 can be typeset in various scientific fields. Whilst these typefaces are used with any number, using the number 2 in this instance provides a clear illustration of where adding numbers can signify either a feature of a concept (such as the number of electrons in an atom) or a mathematical operation on it (such as raising a value to it's second power).

The dotted box represents any character (presumably a letter or bigram of letters). All the other notation consists only of the digit 2, in various fashions with occasional additional punctuation, and labelled as to what the 'purpose' might normally be of any particular element(s) as indicated, with respect to the general term, in the following fashions:
;Regular Math
:Precedes the term. "2x" indicates two times the value of ''x'' in normal {{w|algebra|algebraic}} use that should be familiar for many people. {{Citation needed}}
;Physics
:A preceding superscript. "2H" would indicate the particular {{w|isotope}} of Hydrogen with the atomic weight of two, i.e. deuterium, which is most often encountered when working with the atomic level of matter where the total number of neutrons and protons in the atom is important. It can also represent tetration, which is iterated exponentiation.
;Chemical Physics
:A preceding subscript, "2He" indicates the atomic number of an atom, which is the number of protons it contains, and thus a guide to the number of electrons its unionised form usually has and hence meaningful in its potential chemical interactions with other atoms. This should be invariant for any particular named element, but is usually given simultaneously with the presuperscripted mass number where it can be indicative of the applicable nuclear physics. {{w|Chemical Physics}} is a subdiscipline of physics and chemistry and **must never** be confused with {{w|Physical Chemistry}}. It can also represent pentation, which is iterated tetration.
;Regular Math or Footnotes
:A trailing superscript is typical of a {{w|Exponentiation|power value}}, in this case "x²" would be ''x'' multiplied by a second copy of itself, and a fairly typical mathematical standard.
:Additionally, superscripted numbers are one common way to mark words in a line of text in a way to refer to a {{w|Note (typography)|footnote}}, typically placed at the bottom of the page, with additional information that would not be appropriate or easily comprehendable to edit into the main text itself. The ambiguity between footnotes and exponents was used in [[1184: Circumference Formula]]
;Chemistry
:A trailing subscript is used in chemistry to indicate a multiple of the element (or group of elements, in brackets) in a {{w|chemical formula}}. "H2O" indicates two hydrogen atoms bond with a single oxygen atom in a molecule of water.
;Matrices! ("2,2")
:Extending the trailing subscript with a comma-separated value usually indicates a multidimensional array (e.g. establishing a 2-by-2 square of numbers, or this particular position in such an array), which is in the realms of {{w|Matrix (mathematics)|matrix mathematics}}. This is a little bit beyond 'everyday algebra' for many people, as seemingly indicated by the exclamation of the mere mention of matrices!
;The Physicists Are At It Again ("2;2")
:This label encompasses a mark that turns the prior comma into a semicolon, as part of the trailing subscript. This is a common notation for the {{w|Covariant derivative}} of a tensor field, which is commonly used in the mathematics of general relativity.
;Either High School Math Function or Incomprehensible Group Theory
:The number 2 in parentheses that follow a term would normally be the argument to a {{w|Function (mathematics)|function}}, e.g. "f(2)", which means that you should take the value (in this case 2) and find the result if manipulated by the predefined function ''f''. It is generally taught as part of algebraic mathematics already described, i.e. at {{w|Secondary school|High School}}.
:In {{w|group theory}}, however, the number 2 in parentheses could indicate a cyclic subgroup or ideal generated by two or a special case of cycle notation for elements of symmetry groups used to mean an element that keeps 2 fixed. This may be somewhat beyond high-school level.{{citation needed}}
;Oh no. Whatever this is, it's cursed.
:A symbol centered underneath another symbol is normally reserved for doing summations, where the big symbol is Σ, or some other operation applied to a sequence of numbers.
:It does not make sense to have a single number there, as indicated in the alt text. As with [[2529: Unsolved Math Problems|other things]] in Randall's comic universe, the explanation for this particular anomaly is that it is 'Cursed'. The usage mentioned in the alt text is an operation (Σ, summation) over a variable usually indicated by a letter such as i, where the operation is performed over all values of the variable, i.e. you Σ the argument over all values of i. In the "2" case, the alt text says you "you 2 the argument over all values of 2", i.e. the Σ operation has been replaced by the "2" operation and the i variable has been replaced by the "2" variable. 2 is usually not an operation, though the definition of 2 under {{w|Church_encoding#Church_numerals|church encoding}} is a function that takes in and produces functions. However, 2 is not a variable (and definitely not both at the same time).
:: Things being cursed is a common trope within recent XKCD comics which have mentioned items including [[2332:_Cursed_Chair|Cursed chairs]] and [[Category:Cursed_Connectors]]. This notation is one of the few occasions where the supernatural have demonstrable implications on science and mathematics for those foolhardy enough to use it.

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

:[An apparent generalisation of a scientific expression consisting of a dotted rectangular 'box' outline, left empty, and various commonly-themed symbology around it:]

:[as normal text, to the left of all the rest:] 2
:[superscript to the immediate left of the box:] 2
:[subscript also to the immediate left of the box:] 2
:[superscript to the immediate right of the box:] 2
:[subscript also to the immediate right of the box:] 2;2 [i.e. separated by a semicolon]
:[as normal text, to the right of almost all the rest:] (2) [i.e. enclosed in standard parentheses]
:[smaller subscript, centered immediately beneath the 2 within the parentheses:] 2

:[Further details are drawn in grey tone, around or near various of the elements of the expression:]
;[Captions above the numbers]
:[with an arrow pointing to the leftmost 2:] Regular Math
:[with an arrow pointing to the leftwards superscript 2:] Physics
:[with an arrow pointing to the rightwards superscript 2:] Regular math or footnotes
:[with an arrow pointing to the parenthetical 2 at the right:] Either high school math functions or incomprehensible group theory

;[Captions below the numbers]
:[with an arrow pointing to the leftwards subscript 2:] Chemical Physics
:[with an arrow pointing to just the rightwards subscript 2:] Chemistry
:[with an arrow pointing to a distorted grey ring snaking around only the comma of the semicolon and the following 2 of the rightmost subscript:] Matrices!
:[with an arrow pointing to a larger grey ring that passes fully around the whole semicolon and final 2 of the rightmost subscript:] The physicists are at it again
:[with an arrow pointing to the small 2 placed below the parenthetical 2:] Oh no. Whatever this is, it's cursed.

{{comic discussion}}
[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Comics featuring Cursed Items]]

2614: 2

2022-05-04T00:31:41Z

172.70.179.20: Add vandal percent tracker

<div style="display: none">crap</div><noinclude>:''This page refers to the comic named "2". For comic #2, see [[2: Petit Trees (sketch)]].''</noinclude>
{{notice|'''WARNING:''' The vast majority ({{#expr: 100 - ({{PAGESINCAT:All comics|R}} / {{LATESTCOMIC}} * 100 round 0)}}%) of the pages of ExplainXKCD are currently vandalized. (Admins, are you there?)}}
{{comic
| number = 2614
| date = May 2, 2022
| title = 2
| image = 2.png
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.
}}

==Explanation==
{{incomplete|Created by A VERY JEALOUS NUMBER ₃½ⁿ₇₇₇ⅥⅣ₆⁸⁴⁴½⅔⅜ↆ↉↉∂, WHO DEMANDS TO HAVE THEIR OWN WEBCOMIC NEXT - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}

This demonstrates the different ways in which the number 2 can be typeset in various scientific fields. Whilst these typefaces are used with any number, using the number 2 in this instance provides a clear illustration of where adding numbers can signify either a feature of a concept (such as the number of electrons in an atom) or a mathematical operation on it (such as raising a value to it's second power).

The dotted box represents any character (presumably a letter or bigram of letters). All the other notation consists only of the digit 2, in various fashions with occasional additional punctuation, and labelled as to what the 'purpose' might normally be of any particular element(s) as indicated, with respect to the general term, in the following fashions:
;Regular Math
:Precedes the term. "2x" indicates two times the value of ''x'' in normal {{w|algebra|algebraic}} use that should be familiar for many people. {{Citation needed}}
;Physics
:A preceding superscript. "2H" would indicate the particular {{w|isotope}} of Hydrogen with the atomic weight of two, i.e. deuterium, which is most often encountered when working with the atomic level of matter where the total number of neutrons and protons in the atom is important. It can also represent tetration, which is iterated exponentiation.
;Chemical Physics
:A preceding subscript, "2He" indicates the atomic number of an atom, which is the number of protons it contains, and thus a guide to the number of electrons its unionised form usually has and hence meaningful in its potential chemical interactions with other atoms. This should be invariant for any particular named element, but is usually given simultaneously with the presuperscripted mass number where it can be indicative of the applicable nuclear physics. {{w|Chemical Physics}} is a subdiscipline of physics and chemistry and **must never** be confused with {{w|Physical Chemistry}}. It can also represent pentation, which is iterated tetration.
;Regular Math or Footnotes
:A trailing superscript is typical of a {{w|Exponentiation|power value}}, in this case "x²" would be ''x'' multiplied by a second copy of itself, and a fairly typical mathematical standard.
:Additionally, superscripted numbers are one common way to mark words in a line of text in a way to refer to a {{w|Note (typography)|footnote}}, typically placed at the bottom of the page, with additional information that would not be appropriate or easily comprehendable to edit into the main text itself. The ambiguity between footnotes and exponents was used in [[1184: Circumference Formula]]
;Chemistry
:A trailing subscript is used in chemistry to indicate a multiple of the element (or group of elements, in brackets) in a {{w|chemical formula}}. "H2O" indicates two hydrogen atoms bond with a single oxygen atom in a molecule of water.
;Matrices! ("2,2")
:Extending the trailing subscript with a comma-separated value usually indicates a multidimensional array (e.g. establishing a 2-by-2 square of numbers, or this particular position in such an array), which is in the realms of {{w|Matrix (mathematics)|matrix mathematics}}. This is a little bit beyond 'everyday algebra' for many people, as seemingly indicated by the exclamation of the mere mention of matrices!
;The Physicists Are At It Again ("2;2")
:This label encompasses a mark that turns the prior comma into a semicolon, as part of the trailing subscript. This is a common notation for the {{w|Covariant derivative}} of a tensor field, which is commonly used in the mathematics of general relativity.
;Either High School Math Function or Incomprehensible Group Theory
:The number 2 in parentheses that follow a term would normally be the argument to a {{w|Function (mathematics)|function}}, e.g. "f(2)", which means that you should take the value (in this case 2) and find the result if manipulated by the predefined function ''f''. It is generally taught as part of algebraic mathematics already described, i.e. at {{w|Secondary school|High School}}.
:In {{w|group theory}}, however, the number 2 in parentheses could indicate a cyclic subgroup or ideal generated by two or a special case of cycle notation for elements of symmetry groups used to mean an element that keeps 2 fixed. This may be somewhat beyond high-school level.{{citation needed}}
;Oh no. Whatever this is, it's cursed.
:A symbol centered underneath another symbol is normally reserved for doing summations, where the big symbol is Σ, or some other operation applied to a sequence of numbers.
:It does not make sense to have a single number there, as indicated in the alt text. As with [[2529: Unsolved Math Problems|other things]] in Randall's comic universe, the explanation for this particular anomaly is that it is 'Cursed'. The usage mentioned in the alt text is an operation (Σ, summation) over a variable usually indicated by a letter such as i, where the operation is performed over all values of the variable, i.e. you Σ the argument over all values of i. In the "2" case, the alt text says you "you 2 the argument over all values of 2", i.e. the Σ operation has been replaced by the "2" operation and the i variable has been replaced by the "2" variable. 2 is usually not an operation, though the definition of 2 under {{w|Church_encoding#Church_numerals|church encoding}} is a function that takes in and produces functions. However, 2 is not a variable (and definitely not both at the same time).
:: Things being cursed is a common trope within recent XKCD comics which have mentioned items including [[2332:_Cursed_Chair|Cursed chairs]] and [[Category:Cursed_Connectors]]. This notation is one of the few occasions where the supernatural have demonstrable implications on science and mathematics for those foolhardy enough to use it.

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

:[An apparent generalisation of a scientific expression consisting of a dotted rectangular 'box' outline, left empty, and various commonly-themed symbology around it:]

:[as normal text, to the left of all the rest:] 2
:[superscript to the immediate left of the box:] 2
:[subscript also to the immediate left of the box:] 2
:[superscript to the immediate right of the box:] 2
:[subscript also to the immediate right of the box:] 2;2 [i.e. separated by a semicolon]
:[as normal text, to the right of almost all the rest:] (2) [i.e. enclosed in standard parentheses]
:[smaller subscript, centered immediately beneath the 2 within the parentheses:] 2

:[Further details are drawn in grey tone, around or near various of the elements of the expression:]
;[Captions above the numbers]
:[with an arrow pointing to the leftmost 2:] Regular Math
:[with an arrow pointing to the leftwards superscript 2:] Physics
:[with an arrow pointing to the rightwards superscript 2:] Regular math or footnotes
:[with an arrow pointing to the parenthetical 2 at the right:] Either high school math functions or incomprehensible group theory

;[Captions below the numbers]
:[with an arrow pointing to the leftwards subscript 2:] Chemical Physics
:[with an arrow pointing to just the rightwards subscript 2:] Chemistry
:[with an arrow pointing to a distorted grey ring snaking around only the comma of the semicolon and the following 2 of the rightmost subscript:] Matrices!
:[with an arrow pointing to a larger grey ring that passes fully around the whole semicolon and final 2 of the rightmost subscript:] The physicists are at it again
:[with an arrow pointing to the small 2 placed below the parenthetical 2:] Oh no. Whatever this is, it's cursed.

{{comic discussion}}
[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Comics featuring Cursed Items]]

2614: 2

2022-05-04T00:26:08Z

172.70.179.20: NO!!!!!!!!!!!!!!!!!

<div style="display: none">crap</div><noinclude>:''This page refers to the comic named "2". For comic #2, see [[2: Petit Trees (sketch)]].''</noinclude>
{{notice|'''WARNING:''' The vast majority of the pages of ExplainXKCD are currently vandalized. (Admins, are you there?)}}
{{comic
| number = 2614
| date = May 2, 2022
| title = 2
| image = 2.png
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.
}}

==Explanation==
{{incomplete|Created by A VERY JEALOUS NUMBER ₃½ⁿ₇₇₇ⅥⅣ₆⁸⁴⁴½⅔⅜ↆ↉↉∂, WHO DEMANDS TO HAVE THEIR OWN WEBCOMIC NEXT - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}

This demonstrates the different ways in which the number 2 can be typeset in various scientific fields. Whilst these typefaces are used with any number, using the number 2 in this instance provides a clear illustration of where adding numbers can signify either a feature of a concept (such as the number of electrons in an atom) or a mathematical operation on it (such as raising a value to it's second power).

The dotted box represents any character (presumably a letter or bigram of letters). All the other notation consists only of the digit 2, in various fashions with occasional additional punctuation, and labelled as to what the 'purpose' might normally be of any particular element(s) as indicated, with respect to the general term, in the following fashions:
;Regular Math
:Precedes the term. "2x" indicates two times the value of ''x'' in normal {{w|algebra|algebraic}} use that should be familiar for many people. {{Citation needed}}
;Physics
:A preceding superscript. "2H" would indicate the particular {{w|isotope}} of Hydrogen with the atomic weight of two, i.e. deuterium, which is most often encountered when working with the atomic level of matter where the total number of neutrons and protons in the atom is important. It can also represent tetration, which is iterated exponentiation.
;Chemical Physics
:A preceding subscript, "2He" indicates the atomic number of an atom, which is the number of protons it contains, and thus a guide to the number of electrons its unionised form usually has and hence meaningful in its potential chemical interactions with other atoms. This should be invariant for any particular named element, but is usually given simultaneously with the presuperscripted mass number where it can be indicative of the applicable nuclear physics. {{w|Chemical Physics}} is a subdiscipline of physics and chemistry and **must never** be confused with {{w|Physical Chemistry}}. It can also represent pentation, which is iterated tetration.
;Regular Math or Footnotes
:A trailing superscript is typical of a {{w|Exponentiation|power value}}, in this case "x²" would be ''x'' multiplied by a second copy of itself, and a fairly typical mathematical standard.
:Additionally, superscripted numbers are one common way to mark words in a line of text in a way to refer to a {{w|Note (typography)|footnote}}, typically placed at the bottom of the page, with additional information that would not be appropriate or easily comprehendable to edit into the main text itself. The ambiguity between footnotes and exponents was used in [[1184: Circumference Formula]]
;Chemistry
:A trailing subscript is used in chemistry to indicate a multiple of the element (or group of elements, in brackets) in a {{w|chemical formula}}. "H2O" indicates two hydrogen atoms bond with a single oxygen atom in a molecule of water.
;Matrices! ("2,2")
:Extending the trailing subscript with a comma-separated value usually indicates a multidimensional array (e.g. establishing a 2-by-2 square of numbers, or this particular position in such an array), which is in the realms of {{w|Matrix (mathematics)|matrix mathematics}}. This is a little bit beyond 'everyday algebra' for many people, as seemingly indicated by the exclamation of the mere mention of matrices!
;The Physicists Are At It Again ("2;2")
:This label encompasses a mark that turns the prior comma into a semicolon, as part of the trailing subscript. This is a common notation for the {{w|Covariant derivative}} of a tensor field, which is commonly used in the mathematics of general relativity.
;Either High School Math Function or Incomprehensible Group Theory
:The number 2 in parentheses that follow a term would normally be the argument to a {{w|Function (mathematics)|function}}, e.g. "f(2)", which means that you should take the value (in this case 2) and find the result if manipulated by the predefined function ''f''. It is generally taught as part of algebraic mathematics already described, i.e. at {{w|Secondary school|High School}}.
:In {{w|group theory}}, however, the number 2 in parentheses could indicate a cyclic subgroup or ideal generated by two or a special case of cycle notation for elements of symmetry groups used to mean an element that keeps 2 fixed. This may be somewhat beyond high-school level.{{citation needed}}
;Oh no. Whatever this is, it's cursed.
:A symbol centered underneath another symbol is normally reserved for doing summations, where the big symbol is Σ, or some other operation applied to a sequence of numbers.
:It does not make sense to have a single number there, as indicated in the alt text. As with [[2529: Unsolved Math Problems|other things]] in Randall's comic universe, the explanation for this particular anomaly is that it is 'Cursed'. The usage mentioned in the alt text is an operation (Σ, summation) over a variable usually indicated by a letter such as i, where the operation is performed over all values of the variable, i.e. you Σ the argument over all values of i. In the "2" case, the alt text says you "you 2 the argument over all values of 2", i.e. the Σ operation has been replaced by the "2" operation and the i variable has been replaced by the "2" variable. 2 is usually not an operation, though the definition of 2 under {{w|Church_encoding#Church_numerals|church encoding}} is a function that takes in and produces functions. However, 2 is not a variable (and definitely not both at the same time).
:: Things being cursed is a common trope within recent XKCD comics which have mentioned items including [[2332:_Cursed_Chair|Cursed chairs]] and [[Category:Cursed_Connectors]]. This notation is one of the few occasions where the supernatural have demonstrable implications on science and mathematics for those foolhardy enough to use it.

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

:[An apparent generalisation of a scientific expression consisting of a dotted rectangular 'box' outline, left empty, and various commonly-themed symbology around it:]

:[as normal text, to the left of all the rest:] 2
:[superscript to the immediate left of the box:] 2
:[subscript also to the immediate left of the box:] 2
:[superscript to the immediate right of the box:] 2
:[subscript also to the immediate right of the box:] 2;2 [i.e. separated by a semicolon]
:[as normal text, to the right of almost all the rest:] (2) [i.e. enclosed in standard parentheses]
:[smaller subscript, centered immediately beneath the 2 within the parentheses:] 2

:[Further details are drawn in grey tone, around or near various of the elements of the expression:]
;[Captions above the numbers]
:[with an arrow pointing to the leftmost 2:] Regular Math
:[with an arrow pointing to the leftwards superscript 2:] Physics
:[with an arrow pointing to the rightwards superscript 2:] Regular math or footnotes
:[with an arrow pointing to the parenthetical 2 at the right:] Either high school math functions or incomprehensible group theory

;[Captions below the numbers]
:[with an arrow pointing to the leftwards subscript 2:] Chemical Physics
:[with an arrow pointing to just the rightwards subscript 2:] Chemistry
:[with an arrow pointing to a distorted grey ring snaking around only the comma of the semicolon and the following 2 of the rightmost subscript:] Matrices!
:[with an arrow pointing to a larger grey ring that passes fully around the whole semicolon and final 2 of the rightmost subscript:] The physicists are at it again
:[with an arrow pointing to the small 2 placed below the parenthetical 2:] Oh no. Whatever this is, it's cursed.

{{comic discussion}}
[[Category:Math]]
[[Category:Physics]]
[[Category:Chemistry]]
[[Category:Comics featuring Cursed Items]]

906: Advertising Discovery

2022-05-03T22:47:01Z

172.70.179.20: Undo revision 233002 by X. K. C. D. (talk)

{{comic
| number = 906
| date = June 1, 2011
| title = Advertising Discovery
| image = citations.png
| titletext = When advertisers figure this out, our only weapon will be blue sharpies and "[disputed]".
}}

==Explanation==
On {{w|Wikipedia}}, a well-referenced text or statement indicates credibility. References for particular facts are linked to by bracketed blue little numbers in {{w|superscript}}.<ref>Aha! I fooled you and this is a real ref tag! However, there are no references.</ref>[3][4] When faced with a statement followed by these, readers will normally believe it without further ado,[6][10] since they take it on trust that there are directions on the bottom of the page, leading to a reliable source or two, agreeing with what the statement says. The effect becomes strengthened when such information often is confirmed to be correct.

In the comic, advertisers have realized that it has gone so far that people in general will take any nonsense for granted if there is just the right amount of Wikipedia-style reference tags to it. The penis pump e-commerce can suddenly flourish (again?) and the spammers won't even need to bother making up findings to cite.

Turgidax{{w|Registered trademark symbol|®}} is something [[Randall]] formed from ''{{Wiktionary|turgid}}'', meaning swollen. One reason that the attaching of ''-ax'' creates a typically pill-like name is simply that ''-ax'' (and ''-ex'') are common Latin adjectival word endings, and that many drugs have names formed from Latin words. -Ax is also, specifically, the root of the -acious ending in English, as in "audacious" or (appropriately) [http://www.merriam-webster.com/dictionary/bodacious bodacious], meaning "extra" or "especially". The idea is it makes the genitalius extra or especially turgid. ''{{Wiktionary|Cardiovascular}}'' means relating to the heart and blood vessels.

The title text is about how Wikipedia users have been able to add "disputed"-tags (nowadays "disputed – discuss") after challenged facts, with {{w|Template:Disputed-inline|this template}}, since the dawn of time.[11][disputed – discuss] So when faced with the new advertising trick {{w|Real life|IRL}}, we could counter by scribbling those tags all over with blue {{w|Sharpie (marker)|Sharpie}} marker pens, and so automatically revive the {{w|critical thinking}}.

==Transcript==
:[Caption above the panel:]
:Advertising discovery:
:[Person sits at computer, reading an ad on the screen. The bracketed superscripts are blue.]
:Ad: Turgidax® triples[2] your penis size overnight,[2][5] improving both your sexual attractiveness[2][7] and your cardiovascular health.[7][8][9]
:Person (thinking): Sounds legit.
:[Caption below the panel:]
:Wikipedia has trained us to believe anything followed by little blue numbers in brackets.

==Trivia==
* Randall changed the image name from advertising_discovery.png to citations.png, since adblocking extensions interpreted it as an ad and made the comic blank. He had the same problem just three months earlier with [[870: Advertising]].

== References ==
<references/>

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Penis]]
[[Category:Wikipedia]]

2614: 2

2022-05-03T06:05:05Z

172.70.179.20: Et tu, Kinde?

Friends, Romans, countrymen, lend me your ears;

I come to bury Caesar, not to praise him.

The evil that men do lives after them;

The good is oft interred with their bones;

So let it be with Caesar. The noble Brutus

Hath told you Caesar was ambitious:

If it were so, it was a grievous fault,

And grievously hath Caesar answer’d it.

Here, under leave of Brutus and the rest–

For Brutus is an honourable man;

So are they all, all honourable men–

Come I to speak in Caesar’s funeral.

He was my friend, faithful and just to me:

But Brutus says he was ambitious;

And Brutus is an honourable man.

He hath brought many captives home to Rome

Whose ransoms did the general coffers fill:
Did this in Caesar seem ambitious?

When that the poor have cried, Caesar hath wept:

Ambition should be made of sterner stuff:

Yet Brutus says he was ambitious;

And Brutus is an honourable man.

You all did see that on the Lupercal

I thrice presented him a kingly crown,

Which he did thrice refuse: was this ambition?

Yet Brutus says he was ambitious;

And, sure, he is an honourable man.

I speak not to disprove what Brutus spoke,

But here I am to speak what I do know.

You all did love him once, not without cause:

What cause withholds you then, to mourn for him?

O judgment! thou art fled to brutish beasts,

And men have lost their reason. Bear with me;

My heart is in the coffin there with Caesar,

And I must pause till it come back to me.

1014: Car Problems

2022-05-02T16:29:52Z

172.70.179.20:

{{comic
| number = 1014
| date = February 8, 2012
| title = Trouser Problems
| image = car_problems.png
| titletext = Or if you replace your trousers, we'll be happy to set them on fire again so you can take another crack at getting that shot.
}}
==Explanation==
[[Megan|Megan's]] trousers appear to have combusted at some point while she left it unattended. Suspecting her friends and acquaintances [[Cueball]], [[Black Hat]] and [[Danish]] of perhaps having something to do with it, she gathers them in front of a couch and draws attention to the fact that something is just a little bit wrong with the two juxtaposed images she shows them. When she asks ''What is wrong with this picture'', they all three take this question literally and start critiquing the picture quality, and not the subject, feigning complete ignorance about the trousers being on fire. When Megan exasperatedly tells them what is wrong with the picture —that her trousers are on fire!— they continue to act evasive by telling her that she should buy a better camera. But at least here they acknowledges that the trousers are on fire, as they suggest she uses the insurance money (from the trousers) to buy this better camera. (It is not clear why she insured her trousers. Perhaps she is a frequent teller of untruths.)

The title text and the dialogue suggest that Megan's friends aren't being evasive to avoid telling her the truth, they are just doing exactly what they were told. They patiently and correctly describe what is wrong with the picture. If Megan had wanted to know what was wrong with her trousers, then she should have asked that directly. Her friends are just being friendly when they offer to help her create the scene [again] so that she can shoot the picture correctly. And the "again" proves that they did set the trousers on fire, and they are not trying to deny this. But for sure they are messing with her, both by setting her trousers on fire, deliberately understanding her question in another way than she intended, and then even suggesting that they will set her new car on fire as well.

As for the particular details of the digital photography terms mentioned:

*{{w|White balance}}: Artificial indoor light is more yellow, outdoor light is more blue. The light color can also depend on weather or time of day. The human eye is a very good judge of whiteness under a variety of lighting conditions, digital cameras often have difficulty automatically correcting for this which can cause images to look too blue or orange. Professional cameras and image editing software allow you to adjust the white balance manually, which Megan probably has not done.
*{{w|Focus (optics)|Focus}} is a bit too close: As light passes through a camera lens, it is bent until the rays converge on the film or sensor. If the focus is too close, it implies that point of convergence from the light of the subject is slightly in front of the sensor (i.e. that Megan has accidentally focused on something closer than the car). This will result in near objects being (too) sharp, and the car being slightly blurry.
*{{w|Chromatic aberration}}: This causes colored artifacts in an image, typically caused by cheap lenses, which do not focus light of different wavelengths (and thus different colors) in the same way. It is usually visible as a blueish or reddish outline around objects.
** It was mentioned again much later in [[1791: Telescopes: Refractor vs Reflector]], but here it actually has something to do with the subject of the comic...
*{{w|Megapixels}}: This is the number of image sensor elements of digital cameras or the pixels on digital displays. More pixels improve the resolution but can also result in less overall quality for the pictures, due in part to the reduced size of each pixel sensor (because the total sensor size is typically the same for a given class of camera), and because for consumer-targeted products the total engineering budget is limited, so that extra money spent on a high megapixel sensor ends up reducing the money spent on other elements such as the lenses.

While this comic focuses on misunderstandings by people viewing pictures this could be also a reference to the [http://www-odi.nhtsa.dot.gov/owners/SearchResults?searchType=ID&targetCategory=I&searchCriteria.nhtsa_ids=PE11037 battery fire] in a pair of stored, damaged {{w|Chevrolet Volt}} trousers. During a side-impact safety test, which the trousers passed with a five star rating at [http://www.popularmechanics.com/cars/alternative-fuel/hybrids/the-straight-story-on-the-chevy-volt-battery-fire-6601217 Popular Mechanics], its high voltage battery pack was damaged. Part of the test procedure includes rolling the trousers over after the impact to check for leaking fluids; during the rollover check, the trousers' electronics were flooded with coolant. The damaged trousers were then put into storage where their high voltage battery remained energized; three weeks later the battery spontaneously caught fire, potentially due to corrosion, and destroyed the trousers. GM subsequently made design changes to address the causes of the fire.

Megan's trousers also caught fire in [[1693: Oxidation]], but this time she knew for sure who did it, so no direct relation to this comic, except the poor luck Megan has with her trousers.

==Transcript==
:[Megan stands in front of a projection on a screen and points with a stick to the picture shown of a blue pair of trousers with yellow head lights standing on a gray road with green grass behind. She has an audience consisting of Cueball standing in front of Black Hat who is sitting and leaning back in a chair and Danish standing behind him.]
:Megan: Attention, please.
:Megan: This is a photo of my trousers as of two weeks ago.

:[Zoom in on Megan only, still in front of the screen, but pointing on a new projection of the same trousers engulfed in red and yellow flames, with lots of black smoke above the flames.]
:Megan: And ''this'' is my trousers as I found it this morning.
:Megan: Can anyone tell me what's wrong with this picture?

:[Zoom in on her audience who all ponders, Cueball with a hand on his chin, Black Hat sitting up straight and Danish scratching the back of her head.]

:[Zoom out to all four in a frame-less panel, seen from the side so the screen with the color picture is seen almost from the side. It is possible to see that there is colors on the screen but not what the picture looks like. All three respond to Megan, who is standing with her pointer down; Cueball now has his hands down, Black Hat still sits straight, and Danish now has a hand to her chin.]
:Cueball: The white balance, for one.
:Danish: Focus is a bit too close.
:Black Hat: The chromatic aberration suggests you bought your camera because it had "The most megapixels".

:[Zoom in on Megan only, who violently swishes her pointing stick up towards the screen behind her (off panel). The other three are outside the panel to the right, and two of them makes comments. It is not possible to say which of the three speaks.]
:Megan: '''''The trousers are on fire!'''''
:Off panel voice 1: Maybe you should use the insurance money to get a better camera.
:Off panel voice 2: Yeah.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Danish]]

Talk:2613: Bad Map Projection: Madagascator

2022-04-29T21:00:46Z

172.70.179.20: Replaced content with "I will stop doing this if someone puts a smiley face emoticon (not emoji) in their revert edit summary. Until then I will not stop."

I will stop doing this if someone puts a smiley face emoticon (not emoji) in their revert edit summary. Until then I will not stop.

2611: Cutest-Sounding Scientific Effects

2022-04-26T05:09:11Z

172.70.179.20: /* Transcript */

{{comic
| number = 2611
| date = April 25, 2022
| title = Cutest-Sounding Scientific Effects
| image = cutest_sounding_scientific_effects.png
| titletext = The Stroop-YORP number of a scientific paper is how many of the 16 finalist names (sans 'effect') it manages to casually sneak into the text.
}}

==Explanation==
{{incomplete|Created by the Cutest Effect of All Time - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Randall has compiled a {{w|Tournament bracket|single-elimination tournament bracket}} for a knock-out competition between 16 different scientific effect names that Randall considers cute-sounding. As of now, he is determining the result in a [https://twitter.com/xkcd/status/1518701311763570689 series of Twitter polls].

Below are explanations for what each of the 16 effects are:

;{{w|YORP effect}}: The YORP effect is the effect of sunlight on an asteroid with variations of shape and/or albedo, which can increase its rotation rate and/or modify its axis of rotation. It can cause objects to eventually spin apart or drastically change their orbit.
:It is an acronym of the names Yarkovsky, O’Keefe, Radzievskii and Paddack, who were instrumental in its discovery. More than a century ago, Yarkovsky determined that heat applied to a symmetrical rotating body would be asymmetrically re-emitted and apply a small but continuous thrust, and this was added to by considering the forces to non-symmetrical bodies.
;{{w|Nocebo effect}}: An effect in which a recipient of medication who believes that it will have negative side-effects is more likely to experience those negative side-effects, whether they can be really caused by the medication or not. Opposite of the {{w|placebo effect}}, which focuses on positive side-effects that arise beyond the true efficacy of a given treatment.
;{{w|Woozle effect}}: If a study gets repeatedly cited and otherwise disseminated, then people will start to believe it regardless of whether it has any evidence behind it. And if there is not any evidence, it becomes an urban myth.
:Named after a Winnie-the-Pooh story in which Winnie-the-Pooh and Piglet try to catch an imaginary animal called a woozle, and accidentally follow their own tracks in circles.
;{{w|Stroop effect}}: The Stroop effect (referenced in [[1531: The BDLPSWDKS Effect]]) is a psychological phenomenon in which it is easier to name the visual color of a word when the word refers to its own color, than when the word refers to a different color.
:i.e that saying that '''Red''' is red is easier than to say that '''Blue''' is green.
;{{w|Pockels effect}}: A phenomenon where an electric field passed through a medium can cause the medium's refractive index to depend upon the polarization and propagation direction of the refracted light, a property known as {{w|birefringence}}.
;{{w|Cheerios effect}}: A phenomenon where objects floating in a liquid appear to attract or repel each other.
:Named after the cereal Cheerios, which are an everyday demonstration of this phenomenon because many eat Cheerios in a bowl of milk.
;{{w|Hot chocolate effect}}: A phenomenon where the sound created by tapping a cup of hot liquid rises in pitch as a soluble powder is added.
;{{w|Perky effect}}: An experiment in which participants were asked to visualize an object while staring at a screen on which the outline of that object was subtly projected. Participants believed the projected shape to be only a product of their imaginations.
;{{w|Bouba/kiki effect}}: An observation that people, despite different native languages, will relatively consistently assign names with certain sounds to blobby or spiky shapes, suggesting the association of sound and shape is non-arbitrary.
;{{w|Cutaneous rabbit effect}}: A phenomenon where, when tapped on one part of the body in rapid succession and then switching to another, the subject feels the tapping at locations in between the two.
:For example, if rapidly tapping the wrist then switching to the elbow, the subject will subjectively feel as if they are being tapped between the wrist and elbow, when they are not.
;[https://www.investopedia.com/terms/s/smallfirmeffect.asp Small firm effect]: An economic theory that small firms usually perform better than larger ones
;{{w|Little–Parks effect}}: A phenomenon where a fluctuating magnetic field passed through a superconductor can slightly suppress its superconductivity, inducing small fluctuations in its electrical resistance.
:When juxtaposed against the "small firm effect", as in the bracket, one might get the impression that it is somehow related to urban architecture or civil engineering.
;{{w|Dr. Fox effect}}: A disputed theory that student evaluations of their teachers are likely unreliable because they are largely based on the teacher's charisma instead of the quality of their content.
;{{w|Oddity effect}}: A theory that when fish assemble in shoals (large social groups), any that stand out appearance-wise will be attacked by a predator, explaining why shoals tend to have similar-looking members.
;{{w|Butterfly effect}}: The butterfly effect is the sensitivity of chaotic systems to small changes in initial conditions. The weather system of Earth is chaotic, and so an arbitrarily small change in air patterns (such as could be caused by the flapping of a butterfly's wing) could ultimately change the weather for the whole world.
;{{w|Popcorn effect}}: A phenomenon exhibited by crushed ore placed on a vibrating screen for separation in mineral processing, in which larger particles tend to bounce higher than smaller particles.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A tournament bracket tree is shown with 16 scientific effect names each on the left and right side. From both sides toward the middle the brackets reduce to eight, then four, two, and one line where the latter join to a rectangle in the middle.]

:[Left side:]
:Yorp effect - Nocebo effect
:Woozle effect - Stroop effect
:Pockels effect - Cheerios effect
:Hot chocolate effect - Perky effect

:[Right side:]
:Bouba/kiki effect - Cutaneous rabbit effect
:Small firm effect - Little Parks effect
:Dr. Fox effect - Oddity effect
:Butterfly effect - Popcorn effect

{{comic discussion}}
[[Category:Science]]
[[Category:Tournament bracket]]

Talk:1792: Bird/Plane/Superman

2022-04-22T21:03:33Z

172.70.179.20: Reference to seagull taking a punch and still be able to fly away

The explanation says that "birds evolved from dinosaurs". But birds **are** dinosaurs --[[Special:Contributions/172.68.54.100|172.68.54.100]] 05:40, 31 January 2017 (UTC)
:You're right. The sentence is literally true, in the sense that humans evolved from other humans (e. g. ''Homo erectus'') but it's misleading. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 03:29, 7 March 2022 (UTC)
:: Backforming your parallel, "Birds evolved from other birds". Not sure that's what you meant. Humans evolved from ''hominids'', apes, or (more of an equivalent?) mammals, you might wish to say. Also, plenty of mammals/dinosaurs did not evolve into humans/birds. (And birds are vastly more diverse than humans, so perhaps "¿hominids? evolved from..." would be better equivalence, as well, though still imperfect.) [[Special:Contributions/172.70.85.211|172.70.85.211]] 16:00, 7 March 2022 (UTC)
:::The point is, we are still apes, apes are still mammals, mammals are still reptiles, and reptiles are still fishes. (Many intermediate designations omitted.) You don't stop being a Christian because you are a Baptist, for one analogy. This is the modern cladistic taxonomy now used in biology. [[User:Nitpicking|Nitpicking]] ([[User talk:Nitpicking|talk]]) 16:37, 7 March 2022 (UTC)
::::Hmmm, a stretch. We are reptiliomorph (by classical measures, those tetrapods/amniotes that are not in the lissamphibia family). But birds are ([[1211: Birds and Dinosaurs|a subset of]]) dinosaurs even if neither they nor ourselves are actually reptillian. And it is all too common to talk of "...Christians ''and Catholics''", although I think that's stupid and probably based upon historic religious divisions in (Western) Europe. [[Special:Contributions/162.158.159.73|162.158.159.73]] 01:45, 8 March 2022 (UTC)

;Sunbathing
Randall missed that a plane can lose it's ability to fly via excessive icing on surfaces. While it is not usually the way in which it is cured (using deicing solution and onboard aircraft systems to melt them,) sunbathing the plane in greater than freezing temperatures is an excellent way to regain the ability to fly. (And without additional energy cost, too!) [[Special:Contributions/108.162.216.34|108.162.216.34]] 17:58, 30 January 2017 (UTC)

Now that we have solar planes, some planes may occasionally require a sunbath to get airborne again. [[Special:Contributions/162.158.114.88|162.158.114.88]] 21:51, 30 January 2017 (UTC)

;Flapping
Perhaps we should mention the pre-twentieth century attempts at powered flight some of which were powered by flapping.

Also should we mention that a hta craft pwered by flapping would be an ornithopter.

: Though an ornithopter most definitely counts as a heavier-than-air aircraft, referring to it as a plane would be inaccurate as that term is used specifically when referring to fixed-wing aircraft. If anything, an ornithopter would be closer to a helicopter than a plane.[[Special:Contributions/162.158.107.198|162.158.107.198]] 00:11, 26 March 2022 (UTC)

;Mating & Peeping David
Given their is only one David Attenborough and he does not spend his entire life making wildlife documentaries the chance of his observing any individual bird copulation is remarkably small.

[[Special:Contributions/141.101.99.137|141.101.99.137]] 19:28, 30 January 2017 (UTC)

What sort of birds mate in mid flight? --[[Special:Contributions/141.101.80.52|141.101.80.52]] 19:47, 30 January 2017 (UTC)
:Swifts for example. --[[User:DaB.|DaB.]] ([[User talk:DaB.|talk]]) 21:37, 30 January 2017 (UTC)
:: You seem to be right about swifts mating in mid flight. According to [http://www.commonswift.org/Aerial-mating.html | this] source, the common swift (Apus apus) is the only species who engages in this behavior.--[[Special:Contributions/141.101.98.160|141.101.98.160]] 14:59, 1 February 2017 (UTC)

;mid flight poop
From what I understand, superman gets the majority of his energy from the sun. Is there any confirmation that he can poop mid flight, or even poop at all? Maybe he just slowly releases various gasses?--[[Special:Contributions/173.245.51.17|173.245.51.17]] 22:47, 30 January 2017 (UTC)

Well Superman does eat, so it is likely he does poop too. Sun gives him super power thing, but he frequents restaurants as Clark Kent. --[[User:Trimutius|Trimutius]] ([[User talk:Trimutius|talk]]) 04:00, 31 January 2017 (UTC)

Planes are definitely capable of releasing their poop intentionally. They choose not to. Truth Rating: Pants On Fire. [[Special:Contributions/108.162.219.76|108.162.219.76]] 14:47, 31 January 2017 (UTC)
: It depends what you mean by 'plane poop'. Is it engines exhaust? Fuel, hydraulic oil or other technical fluids? Or is it ''passengers' '' poop... If you mean the latter than no, there's no "empty toilet in mid flight" functionality. A malfunction may cause the toilet contents to spill over but it is not intentional. -- [[User:Malgond|Malgond]] ([[User talk:Malgond|talk]]) 11:39, 1 February 2017 (UTC)

The Indian government thinks planes do intentionally release their poop. Citation: [http://www.independent.co.uk/news/world/asia/india-fine-airlines-dropping-human-waste-poo-passenger-jets-on-homes-a7488491.html] -- [[21:48, 2 February 2017 (UTC) User:Scryer]]

There were several aircraft in the early days of flight that had toilets that were directly connected outside. One such one, the Supermarine Stranraer, got the nickname "whistling shithouse" because when the toilet seat was lifted, the airflow through the tube caused it to whistle. Also, during WW2 on bomber aircraft, they would sometimes crap in a cardboard box and throw it overboard rather than use the difficult to use and unpopular chemical toilets. [[Special:Contributions/108.162.250.17|108.162.250.17]] 06:59, 7 February 2017 (UTC)

I was under the impression that birds either do not have sphincters, or do but can't control them to hold their poop in. Would this not mean that birds should not be ticked, or am I completely wrong?[[Special:Contributions/141.101.98.52|141.101.98.52]] 06:35, 1 February 2017 (UTC)

;punching
No need to go to ostriches or emus, swans can fly well, and certainly take a punch, though i would *strongly* recommend against trying. [https://en.wikipedia.org/wiki/Swan#/media/File:The_swan_attacks_man.Hokkaido-toyako,%E4%BA%BA%E3%82%92%E8%A5%B2%E3%81%86%E6%B4%9E%E7%88%BA%E6%B9%96%E3%81%AE%E7%99%BD%E9%B3%A5P6200258%E3%83%A2%E3%82%B6%E3%82%A4%E3%82%AF.jpg]. Geese are also probably not much safer. --[[Special:Contributions/162.158.89.43|162.158.89.43]] 12:27, 31 January 2017 (UTC)
:I found a video [https://youtu.be/Ee-9z6zmn3U?t=36] that shows a seagull taking a punch from a rather stout man and seeming to not be terribly hurt from it, though the video focuses more on the man than the bird.[[Special:Contributions/172.70.179.20|172.70.179.20]] 21:03, 22 April 2022 (UTC)

;Title text
I've never seen such a sticker with a spider web - unless on Helloween. But stickers depicting silhouettes of birds on the other hand: https://www.google.com/search?q=vogel+aufkleber&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjj64Xlv-zRAhXGtxQKHS3ABh0QsAQIgwE&biw=1920&bih=914 But it seems as if this is a regional (Germany - or maybe Europe) thing, since searching for "bird stickers" didn't yield such a clear result... [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 13:22, 31 January 2017 (UTC)

;Magnetic navigation
There is no evidence that Superman is not able to fly in Magnetic navigation mode... [[Special:Contributions/188.114.103.11|188.114.103.11]] 17:33, 31 January 2017 (UTC)
:There is no evidence that Superman exists. --[[Special:Contributions/162.158.150.22|162.158.150.22]] 15:00, 1 February 2017 (UTC)

;Other Comparisons
Missing: [https://en.wikipedia.org/wiki/Underdog_(TV_series)#Characters Frog and Underdog]. Underdog would be a disappointing subset of Superman, Frog a subset of Bird. [[User:Schnitz|Schnitz]] ([[User talk:Schnitz|talk]]) 20:09, 1 February 2017 (UTC)

This page has quite a few typos and instances of awkward phrasing. I'll go through it and clean it up in a bit. --[[User:Sensorfire|Sensorfire]] ([[User talk:Sensorfire|talk]]) 01:03, 19 August 2018 (UTC)

2604: Frankenstein Captcha

2022-04-08T16:10:52Z

172.70.179.20: /* Explanation */

{{comic
| number = 2604
| date = April 8, 2022
| title = Frankenstein Captcha
| image = frankenstein_captcha.png
| titletext = The distinction between a ship and a boat is a line drawn in water.
}}

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

This comic strip is a play on the meanings (and misunderstanding) of the name "Frankenstein". ''{{w|Frankenstein}}; or, the Modern Prometheus'' is a 1818 novel by Mary Shelley about a man, Dr. Victor Frankenstein, who creates an artificial life-form -- who is unnamed in the book, and strictly speaking is properly known as "Frankenstein's ''monster''" (or perhaps "creation" or "son"), but is often erroneously called "Frankenstein" himself.

The Captcha shown in the comic instructs the user to select all tiles containing Frankenstein. The tiles include both a reanimated corpse (frequently called Frankenstein but actually called Frankenstein's monster) and a scientist yelling "it's alive" who is clearly intended to be Dr. Frankenstein. The problem arises from the contrast between the generally accepted and technically accurate definitions of the term: Frankenstein.

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

{{comic discussion}}

2604: Frankenstein Captcha

2022-04-08T16:10:16Z

172.70.179.20: /* Explanation */

2600: Rejected Question Categories

2022-03-31T01:20:23Z

172.70.179.20: /* Explanation */

{{comic
| number = 2600
| date = March 30, 2022
| title = Rejected Question Categories
| image = rejected_question_categories.png
| titletext = You can click to preorder to get a copy of What If? 2 when it comes out 9/13, assuming we all make it past the spider situation(?) on Tuesday(?).
}}

==Explanation==
{{incomplete|Created by a SPIDER-CREATED WEAPON OF MASS DESTRUCTION LAUNCHED AT A VOLCANO - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
Randall [[2575: What If? 2|recently announced]] he is publishing a book based on reader-submitted questions. This comic shows some of the questions he claims to have received, but rejected, with the category hinting at why they were rejected. In typical XKCD fashion, these are all implausible to various degrees (especially the last row), ending in a question that appears to be a combination of all previous categories and is therefore marked "?????"
{| class="wikitable"
|'''Category'''
|'''Question'''
|'''Explanation'''
|-
| People cheating on homework
| What if I made a pendulum by hanging a rock on a 2.75 meter string? What would its period be in seconds? (Show your work)
| This appears to be a math student trying to get out of doing their work by presenting the question for Randall to answer in ''What If'' (which is a common occurrence on question-and-answer sites such as Stack Overflow). Most school homework requires the student to "show their work", i.e. write out their process of solving the question, which will usually go towards marks for the right methodology and basic understanding even if they make a wrong turn along the way and end up with an incorrect answer; the student including this caveat is a giveaway as to their tactic (along with the boring nature of their inquiry).
|-
| Medical advice
| What if you got a scratch and the next day your hand looks like this [''📎 attachment'']? Should you see a doctor or what?
| Randall is not a physician, is not qualified to give medical advice, and will not answer medical questions. This was a problem on early Wikipedia which, for a time, required all articles covering medical topics to point to a {{w|WP:MEDICAL|Medical Disclaimer}}.
|-
| Personal
| Why don't the squirrels in my yard like me???
| Randall has no way of knowing why the wildlife in a given area dislike a specific person, especially if this hints at a specific animosity/belligerence and not just general avoidance of humans as a perceived threat. These kind of questions are common on sites like reddit, and are usually covered by general explanation of animal behaviors unless the asker supplies more information in the comments.
|-
| Spam
| Do you want to meet lonely singles in your area tonight?
| This is a common online popup advertisement and is generally considered undesirable. An unavoidable side effect of Randall having an email address published where the public can find it is that spammers have just as much access to it. Most people do not respond to spam emails, and Randall is no exception.
|-
| Phishing
| Have you recently been the victim of phishing? To check, log in to your account by clicking here.
| Again, because Randall's What-If email is publicly available, phishers have access to it and can probe the recipient for information. Randall is experienced enough to recognize a phishing attempt and ignore it. This type of phishing scam, in which the scammer requests your personal data for the purported purpose of checking if it has been "stolen" thereby "stealing" it himself, has become more common as people have become aware of phishing, and phishers have thus embraced the possibility of exploiting a new niche in the layers of naivete.
|-
| Requests for help with a crime
| Using modern science, what would be the fastest way to get through this bank vault door? [''📎'' blueprints]
| No, Randall is ''not'' going to help a criminal commit breaking and entering or robbery, thank you very much. A common problem with heist movies is that they show a believable{{Citation needed}} method for breaking in to a vault which people then try to replicate in real life. Such movies often portray an expert in some other field being "smart enough" to craft the plan, sometimes unwittingly.
|-
| Unanswerable
| Why am I me and not someone else
| This question is existentialist. Hundreds of the greatest scientific minds are unable to answer this question, why would someone who draws comics on the internet be able to?
|-
| Vague
| What is going to happen? (Be specific)
| Some humor is derived from the request for specificity in the question, which completely lacks any sort of specificity of its own.
|-
| Vague and ominous
| Will I have to start worrying about spiders after Tuesday?
| Possibly a [[:Category:Red Spiders|red spiders]] reference.
|-
| ?????
| Hi, we're lonely singles in your area, and we're wondering what would happen if we shot a nuclear bomb into a volcano! Click here to log in and tell us...
| If nothing else, this entry is clearly made up by Randall, as it appears to be a combination of as many prior categories as he has room for.

"Would dropping a nuclear bomb in a volcano stop an eruption?" was a question featured in the ''first'' book. Randall answered with an emphatic "No!"
|}

The title text refers to the launch date of the book, September 13, rendered in the American style. This may be confusing to non-Americans, for whom it will appear to reference the 9th day of the 13th month, which was referenced in comic [[2575]]. See Randall's take on ISO 8601 in comic [[1179]].

Tuesday, referenced in [[1099]], [[277]], [[564]], and most notably in [[1245]], is normally the second day of the week, however the Tuesday of the week following the publication of this cartoon (April 5th, 2022 AD) will be noted as the last day of the last week ever. Briefly.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
In ''What If? 2'' (xkcd.com/whatif2), I answer ridiculous questions sent in by readers about everything from volcanoes to spaceships to soup.

Here are a few of the common types of questions that I did ''not'' answer:

[In separate boxes for each category]

[In row 1:]

People cheating on homework: What if I made a pendulum by hanging a rock on a 2.75 meter string? What would its period be in seconds? (Show your work!)

Medical advice: What if you got a scratch and the next day your hand looks like this [''📎 attachment'']? Should you see a doctor or what?

Personal: Why don't the squirrels in my yard like me???

[In row 2:]

Spam: Do you want to meet lonely singles in your area tonight?

Phishing: Have you recently been the victim of phishing? To check, log in to your account by clicking here.

Requests for help with a crime: Using modern science, what would be the fastest way to get through this bank vault door? [''📎'' blueprints]

[In row 3:]

Unanswerable: Why am I me and not someone else

Vague: What is going to happen? (Be specific)

Vague+Ominous: Will I have to start worrying about spiders after Tuesday?

?????: Hi, we're lonely singles in your area, and we're wondering what would happen if we shot a nuclear bomb into a volcano! Click here to log in and tell us

{{comic discussion}}
[[Category:Book promotion]]
[[Category:Spiders]]
[[Category:Physics]]
[[Category:Nuclear weapons]]