explain xkcd - User contributions [en]

2343: Mathematical Symbol Fight

2020-08-08T03:27:13Z

I choose you, Blackhat!: This looks to be a continuation of the straight line explanation, not the treble clef.

{{comic
| number = 2343
| date = August 7, 2020
| title = Mathematical Symbol Fight
| image = mathematical_symbol_fight.png
| titletext = Oh no, a musician just burst in through the door confidently twirling a treble clef.
}}

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

This panel imagines which {{w|List of mathematical symbols|mathematical symbols}} would be good in a fight if they were made corporeal in two (or three) dimensions. Generally, objects with longer reach and pointier ends wind up on the "more dangerous" side of the scale, and symbols with less reach and more curves tend towards the left side.

The comic invokes [[wikipedia:surreal humour|surreal humour]] by suggesting that mathematical symbols could be handled as physical objects in the real world. Another component of the humor is the implication that it is useful to prepare to use mathematical symbols in a fight, even though mathematicians, who use mathematical symbols, usually do not conduct their debates violently (though some stories suggest that {{w|Hippasus}} was killed by his fellow Pythagoreans for his proof that irrational numbers exist), and even if they did, they wouldn't use large reproductions of their symbols as weapons.{{Citation needed}}

A straight line is farthest to the "more dangerous" side, which could possibly be a reference to the dangers posed by lines in "Flatland", because their infinitely-sharp endpoints could be difficult to see (particularly their rear end, which does not contain a gleaming eye as their front end does) and would fatally pierce whoever they chose to stab. However, taking a more literal view of the drawings, the straight line does not appear to be any thicker or thinner, or pointer, than any of the other lines.

The title text refers to a {{w|clef}}, which is not a mathematical symbol but rather a {{w|List of musical symbols|musical symbol}}. The note of concern in the text suggests musical symbols may be viewed in such fights as exotic or especially dangerous.

{| class="wikitable"
! Symbol
! Meaning
! Notes on using in a fight
|-
|ℝ
|The set of [[wikipedia:real number|real number]]s
|Megan seems to be struggling with a giant version of this symbol.
|-
|∅
|[[wikipedia:Empty set|Empty set]]
|This symbol is not very sharp, and [[White Hat]] is unable to use it in combat. It would not work as a good shield due to the hole in the symbol, but it possibly could be thrown.
|-
|>
|Greater than
|-
|α
|[[wikipedia:Alpha_(disambiguation)#Mathematics_and_statistics|Alpha]]
|-
|π
|[[wikipedia:Pi_(disambiguation)#Mathematics|pi]]
|-
| +
|[[wikipedia:Plus_and_minus_signs#Plus_sign|Plus]]
|Maybe thrown like a shuriken?
|-
|Ψ
|[[wikipedia:Psi#Mathematics|Psi]]
|It could be used as a slightly-less-functional trident or pitchfork, with a shorter handle. More particularly, it resembles a sai (which, funnily enough, is how "Psi" is pronounced).
|-
|~
|[[wikipedia:Tilde#Mathematics|tilde]], meaning "approximately", equivalent, or several transforms of a function
|A potentially dangerous throwing weapon.
|-
|⇒
|[[wikipedia:Material_conditional|Material consequence]] or [[wikipedia:Logical_consequence|Logical consequence]], meaning "implies"
|-
|⋅
|multiplication sign
|-
|Γ
|uppercase Greek letter gamma
|-
|√
|{{w|square root}} sign
|Black Hat has chosen this symbol and is using it like a polearm, something like a {{w|shepherd's crook}}.
|-
|∮
|contour integral
|-
|∫
|integral
|-
|⇀
|vector denotation
|A single-barbed spear.
|-
|θ
|[[wikipedia:Theta_function_(disambiguation)|Theta]]
|-
|∞
|infinity
|-
|∪
|union (set theory)
|-
|∈
|member of (set theory)
|Cueball is holding this. It could be used as a significantly-less-functional trident or pitchfork, if only it wasn't missing a handle like Psi. Maybe better for throwing.
|-
|∀
|"for all"
|-
|∂
|[[wikipedia:Partial derivative|partial derivative]] or [[wikipedia:Boundary_(topology)|boundary operator]]
|-
|≠
|not equal sign
|-
|#
|[[wikipedia:Cardinality|Cardinality]], [[wikipedia:Connected_sum|connected sum]] (knot theory), or [[wikipedia:Primorial|primorial]].
|Blondie uses this symbol.
|-
|-
|Δ
|[[wikipedia:Delta_(letter)|Delta]]
|-
|ζ
|Zeta
|-
|ℵ
|[[wikipedia:Aleph_number|Aleph number]]
|-
|𝜌
|italic rho
|Perhaps could be wielded as a club
|-
|→
|Implies; X→Y means that if X is true, then Y is also true
|Looks like a spear
|-
|⊥
|up tack or falsum, indicating a false proposition in logic or the bottom element in a partial order
|Held like an axe, the top of the T could be arced towards an opponent.
Held like a wishbone, two hands could be used to try to drive the point into an opponent.
|-
|⎯⎯
|Fraction bar (division) or overline (complex conjugate or mean).
|Held on one end, this could be used to stab the point, or hit with the edge
Could potentially be 'twirled' like a {{w|quarterstaff}}, {{w|bō}}, or other {{w|stick-fighting}} weapon
|-
|-
|𝄞
|Treble clef
|
|}

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

Mathematical Symbols

[Subheading]

by how useful they would be in a fight

more useful

⟶

ℝ ∅ > α π + Ψ ~ ⇒ ⋅ Γ √ ∮ ∫ ⇀
θ ∞ ∪ ∈ ∀ ∂ ≠ # Δ ζ ℵ 𝜌 → ⊥ ⎯

[Below the (number?) line, eight characters fight each other, using some of the symbols mentioned above as weapons.]

[The characters hold more "useful" weapons from left to right, correlating with the chart.]

[Megan is awkwardly handling a giant "ℝ".]

[White Hat is holding an "∅" with both hands, as a shield.]

[Cueball is holding an "∈" in both hands, with its "tines" pointed towards Blondie, who is swatting at him with a "#".]

[Ponytail is leaping at Danish, swinging a "ρ" like an axe, while Danish is leaning back and thrusting a "→" back at her.]

[Black Hat is swinging a long "√" like a polearm at Hairy, who is holding a long "⎯" defensively.]

-
List of symbols from left to right (by rightmost edge):

ℝ θ ∅ ∞ > ∪ α ∈ ∀ π ∂ + ≠ Ψ # ~ △ ζ ⇒ ⋅ ℵ Γ 𝜌 √ → ∮ ∫ ⊥ ⇀ ⎯

Note: Where two symbols had similar right-most edges, the overlay grid on an ASUS pro-art display was used to decide which one went further right.

{{comic discussion}}
[[Category:Math]]
[[Category:Music]]
[[Category:Charts]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Danish]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Blondie]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Hairy]]

2225: Voting Referendum

2019-11-06T20:30:25Z

I choose you, Blackhat!:

{{comic
| number = 2225
| date = November 6, 2019
| title = Voting Referendum
| image = voting_referendum.png
| titletext = The weirdest quirk of the Borda count is that Jean-Charles de Borda automatically gets one point; luckily this has no consequences except in cases of extremely low turnout.
}}

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

The day before this comic's publication was an election day throughout the USA, primarily for local and state issues (normal elections for federal offices of the President, Senate, and House of Representatives are always in even years), so the topic of today's comic highlights many different methods for conducting elections and counting votes. The comic depicts an election ballot referendum for voters to select the method to be used in future elections.

The aim of political elections is to determine which of the candidates standing for election is favoured by the majority of voters. In a simple two person contest, this process is trivial, since whichever candidate receives the most votes will be the one that the majority of voters prefer. This {{w|First-past-the-post_voting}} system works well for simple cases, but for elections with more than two candidates this system may result in a candidate being elected who less than 50% of the voters would prefer.

For example, in a contest with three candidates; A, B and C, where candidate A received 41% of the vote, candidate B 40% and candidate C 19%, then candidate A will be elected, even though some of the voters who chose candidate C might have preferred candidate B as their second choice instead of candidate A, leading to a result which pleases fewer than half of the population.

* '''First past the post'''

* '''Top-two primary'''

* '''Louisiana primary'''

* '''Cumulative voting'''

* '''Approval voting'''
In this system, each candidate is listed as a yes/no choice, where the voters can choose which candidate they approve of winning the election, and which ones they do not approve of. The winner of the election is the candidate with the highest approval rate.

In the XKCD ballot, the approval option is presented as a checkbox, where a check in the box is "approve" or an empty box is "disapprove".

* '''Multiple non-transferable vote'''

* '''Instant runoff voting'''
In this system, people vote for all the candidates, or perhaps their favorite three, but assign different preferences to each candidate they vote for, as in 1 for their first choice, 2 for the second, 3 for their third, etc. If enough people vote for a candidate as their first choice to clear 50%, that person wins. If not, the person with the least votes gets eliminated, and anyone who voted for that person has their next (slightly less favorable) choice automatically move up a rung. The 50% mark is again checked, and if no winner another lowest-voted candidate is eliminated. Eventually one candidate will emerge victorious, and overall that person will have been liked by the voters more than anyone else. The advantages of this system are there is rarely a need to have another election if things are close (the information is already there to "instantly" recalculate the vote based on additional voter preferences), and there is no concept of a "spoiler" candidate taking votes away from your favorite. If people are truly voting their favorite, second favorite, etc., no vote need be seen as being thrown away. For example, a voter really likes the Hippo candidate even though few others do. They can still vote that candidate #1 and the apparently-popular Giraffe candidate 2nd, knowing that if Hippo is eliminated, they have still voted for Giraffe and that vote counts. If it turns out people secretly really like Hippo, however, that candidate actually has a real chance because people are not trying to guess what candidate everyone else will vote for in order to ensure Vulture doesn't get in.

On this weird XKCD ballot, we see this type of ranking between this type of voting (''Instant runoff voting'') and the two that follow (''Single transferable vote'' and ''Borda count'').

* '''Single transferable vote'''

* '''Borda count'''

==Transcript==
Voting Referendum

Which voting system should we use?

* (empty radio button) First past the post
* (empty radio button) Top-two primary
* (filled radio button) Louisiana primary
* (two filled, one empty radio button) Cumulative voting
* (checked box) Approval voting
* (checked box) Multiple non-transferrable vote
* (box marked "3") Instant runoff voting
* (box marked "1") Single transferrable vote
* (box marked "2") Borda count
* (slider with value slightly below half) Range voting

The referendum went well, but we can't figure out how to count the ballots.

{{comic discussion}}

2155: Swimming

2019-05-28T01:06:17Z

I choose you, Blackhat!:

{{comic
| number = 2155
| date = May 27, 2019
| title = Swimming
| before = [[#Explanation|↓ Skip to explanation ↓]]
| image = swimming.png
| titletext = "You don't know how high above you the sky goes, but you're not freaking out about that." "Well, NOW I am!"
}}

==Explanation==
{{incomplete|Created by a CONTINENTAL SHELF. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
This comic is about an irrational fear about the depth of water beneath oneself. Whenever you don't explicitly know how deep the water is, and cannot see the bottom, there is nothing preventing the sea/lake/riverbed from being exceptionally far away. This phenomenon is actually quite common with many bodies of water having a relatively shallow shelf extending a short ways out from land. These typically end with little to no warning, giving rise to the fear that is depicted here.

It is an '''irrational''' fear because if one is swimming, the depth of the water underneath is not important to safety. If one is wading, presumably one would feel the bottom drop away.

===Related comics===
*In [[731: Desert Island]] a similar vision of not knowing what is beneath the surface is depicted.
*Randall provided the depths of various bodies of water without mentioning any specific fears in [[1040: Lakes and Oceans]].
*The title text may be a reference to [[1115: Sky]], where [[Megan]] similarly starts freaking out about the depth of the sky.
*[[what if%3F]] #103 covers what would happen if all the bodies of water vanished. It refers to the sharp drop-off of the continental shelf, and divides boats into two categories: those over the shelf that crash within a few seconds, and those past the shelf that take up to a minute to reach bottom.

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

Comic is a single panel - 6-7 times higher than it is wide.

Megan - neck deep in water - standing near an extreme drop off. (Continental shelf?) This part of the comic is the very top, and the characters are drawn much smaller than usual.

"It's OK, I can still touch bottom here."

As you scroll down the tall image there are some deep water fish, a jellyfish, and an octopus, a bottom ledge with a beach umbrella on it, and another drop off.

Caption:
I love swimming, but occasionally I realize I don't know how deep the water under me is and it freaks me out.

{{comic discussion}}

[[Category:Large drawings‏‎]]

2090: Feathered Dinosaur Venn Diagram

2018-12-27T00:34:55Z

I choose you, Blackhat!: Adding Title Text description. Also removing the incomplete tag, this appears to complete the entry.

{{comic
| number = 2090
| date = December 26, 2018
| title = Feathered Dinosaur Venn Diagram
| image = feathered_dinosaur_venn_diagram.png
| titletext = My pet theory is that in real life, the kid at the beginning of Jurassic Park who made fun of the 'six-foot turkey' never got a talking-to from Dr. Grant, and grew up to produce several of the movie's sequels.
}}

==Explanation==
Translated plainly, this comic reads "People who don't think feathered dinosaurs sound scary, have never tried to fight an ostrich."

This comic is a jab at people who dismiss the idea of dinosaurs having feathers just because they don't sound deadly. Adding feathers to a reptile can trigger a cognitive dissonance; people today see feathers and think of harmless birds.

The title text refers to "[http://jurassicpark.wikia.com/wiki/Volunteer_Boy Volunteer Boy]", a kid in the beginning of Jurassic Park who dismisses a raptor fossil as a "six-foot turkey". Dr. Grant uses a fossil of a raptor talon to imply that a raptor would slice open his belly and eat him while he's still alive. This scares the kid into respecting the raptor. The title text theorizes that if he didn't get that pep talk, and continued to think of dinosaurs as "six-foot turkeys", then he would grow up to make some of the contested sequels in the franchise.

The diagram is in actuality a {{w|Euler diagram}}, rather than a Venn diagram. A Venn diagram shows all possible combinations of two sets, including those with no elements, and as such all of the circles must intersect. A Euler diagram only depicts the non-empty combinations, and therefore does not have this constraint. However, this is a technicality, and many people use the words interchangeably.

The Euler diagram is explaining that the ostrich (and a few other avian species) are in fact deadly. The point is that anyone who has tried to fight an ostrich would be scared of a dinosaur with feathers.

==Transcript==
{{incomplete transcript}}
:[The comic shows a rectangular panel containing two circles, side by side. A caption is underneath each circle.]

:Left circle caption: People Who Don't Think Feathered Dinosaurs Sound Scary

:Right circle caption: People Who Have Tried To Fight An Ostrich

{{comic discussion}}

[[Category:Dinosaurs]]
[[Category:Jurassic Park]]

1271: Highlighting

2018-06-15T01:07:28Z

I choose you, Blackhat!: After all these years, I only just noticed the square in the second example.

{{comic
| number = 1271
| date = September 30, 2013
| title = Highlighting
| image = highlighting.png
| titletext = And if clicking on any word pops up a site-search for articles about that word, I will close all windows in a panic and never come back.
}}

==Explanation==
A number of people find it easier to read long texts by marking their place as they move through the reading. When done on paper, this may be done with a ruler or pencil. On-screen, however, one of the most effective methods is by highlighting the text being read. People accustomed to this form of reading often do it absentmindedly. Some people simply highlight parts of an article they're consulting without regards to which line they're currently reading, just to occupy their hands.

Highlighting, however, has the potential to create shapes on screen. Randall is referring to the fact that the shapes created may occasionally be symmetrical, which creates satisfaction. Different highlighting patterns may be caused by the user's browser, the site provided, or by simply dragging one's cursor across the screen with the mouse button held down, and releasing at different patterns..

The top example shows tight-fitting highlight syntax, which only covers the text of the paragraph. This is the most common result of highlighting an entire paragraph, but as paragraphs are rarely symmetrical, this example is marked by an X.

The second example starts the highlighting a few words in an continues to the end of the paragraph, while the third example begins another half-word in and continues down a line and a word before ending. Both of these patterns would be caused by manually highlighting the text with the mouse button, rather than rapidly-clicking until a segment is highlighted. The second example forms a square where the three lines of highlighted text overlap, while the third has rotational symmetry of the selected region; both are marked with checks.

The fourth example highlights the entire paragraph, as well as the whitespace caused by the indentation of the paragraph and at the end of the paragraph when the last line does not continue to the opposite margin. This example has both rotational and divisible symmetry, and is marked with a check.

The fifth example highlights the whitespace after the end of the paragraph, but not the whitespace of the indentation, leaving an odd block at the start of it. This ruins the paragraph's symmetry, and so this example is marked with an X.

The bottom example refers to the practice of websites adding a script to disable highlighting, often to discourage readers from copying their content. This creates a great dissatisfaction in readers accustomed to highlight as they read, shown by the many overlapping "X"s.

The title text refers to the practice of websites of adding a script that searches upon clicking any word in the text; most notably done by Yahoo! news in years prior. The search may be of the site, the web, or of an advertisement provider. The script sometimes creates a popup, which, Randall says, causes him to "panic", and consequently never want to return to the site again. It is in fact quite annoying to the occasional highlighter, causing him to lose his place and interrupting his train of thought.

==Transcript==
:[A paragraph of text is shown. The highlight starts away from the leftmost edge of the highlight, and is a different distance to that between the rightmost edge of the highlight and the highlight end. Red X.]
:[A paragraph is shown. The highlight's starting point, end point, and number of lines included is such that there is an internal square in the middle, illustrated in green. Green tick.]
:[A paragraph is shown. Not only does it have an internal square, but the distance between the leftmost edge and the highlight start point is the same as the distance between the rightmost edge and the highlight end point. Green tick.]
:[A paragraph is shown. The entire paragraph is highlighted, making one big rectangle. Green tick.]
:[A paragraph is shown. The whole paragraph is selected, but the highlight starts away from the leftmost margin. This is shown with a red box, an arrow, and "?!?!". Red X.]
:[A paragraph is shown. Over the top is overlaid "[Clicking to highlight text is disabled]". Many, many red Xes.]
:I absentmindedly select random blocks of text as I read, and feel subconsciously satisfied when the highlighted area makes a symmetrical shape.

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

1984: Misinterpretation

2018-06-15T00:17:57Z

I choose you, Blackhat!: This is not quite the "Perfect Solution Fallacy", the Nirvana Fallacy has an ideal, but unachievable, solution that makes real world solutions seem inadequate.

{{comic
| number = 1984
| date = April 23, 2018
| title = Misinterpretation
| image = misinterpretation.png
| titletext = "But there are seven billion people in the world! I can't possibly stop to consider how ALL of them might interpret something!" "Ah, yes, there's no middle ground between 'taking personal responsibility for the thoughts and feelings of every single person on Earth' and 'covering your eyes and ears and yelling logically correct statements into the void.' That's a very insightful point and not at all inane."
}}

==Explanation==
[[Cueball]] is complaining that people are mad at him ''again'' because of a misinterpretation of his statements. This is referenced by the comic's title. He complains that since he (believes he is) is being perfectly clear, it cannot be his fault that everyone misinterprets him. The off-screen voice sarcastically agrees that communication is an activity that only involves one person; in fact, of course, it [https://en.wikipedia.org/wiki/Communication#Models famously involves a least two].

Cueball speaks as though his communications are complete and perfect once he has finished making them. The reality is that communication can't be considered complete until the message has also been received and understood. Cueball is failing to take into account the need for partnership between sender and receiver, and doesn't realise that the problem may well be in the way he carries out his side of the transaction rather than in the way ''everybody'' else is carrying out theirs.

In the title text, Cueball then answers that he cannot possibly account for the many possible interpretations which the message, potentially reaching the whole world, could acquire. This is an example of the {{w|Nirvana fallacy}}. Cueball's idealized solution is to consider how every person on Earth would interpret the message, so Cueball rejects doing anything less as insufficient; however, actually figuring out how every person on Earth would interpret the message is unfeasible, so Cueball doesn't do that either. The reply comes once again sarcastically, deriding his point and saying that a middle ground between taking up such an effort and entirely avoiding it must be reached.

This avoidance is phrased using a [[762: Analogies|simile]] as “covering your eyes and ears and yelling logically correct statements into the void”, implying that no one would understand the logical sentences (thus the void), and would instead read them more naturally – and also that ignoring the appalled reaction of listeners to their own interpretation of the sentences is similar to covering your eyes and ears. This action makes communication more difficult through the popular{{Citation needed}} means of speech, text and sign language. If the hands are occupied with covering either part, then Braille communication is also impossible. Therefore, the action of “covering your eyes and ears” is a metaphor for deliberately making it more difficult to communicate with oneself. The simile might also mean that Cueball subconsciously rejects criticism as it would hurt his ego.

It is clear that Cueball is acting as a straw man to further Randall's point, and the off-panel character is portrayed as the (sarcastic) voice of reason.

Randall returns to a recurring theme in his comics, regarding, in contexts of communication, the responsibility of the speaker for how they are interpreted. Having gradually gotten less subtle, this theme is now laid bare, there being no joke other than the sarcasm. What follows is a chronological history of this theme.

*Much earlier than the other comics below, but related, [[169: Words that End in GRY]] is a surreal reprimand upon people who act smug when their bad communication is misunderstood.
*The title text of [[1028: Communication]] notes that “Anyone who says that they're great at communicating but 'people are bad at listening' is confused about how communication works.”
*The title text of [[1860: Communicating]] also asserts that the responsibility of a misunderstanding lies with the speaker, not the listener — a theme explored in the comic via the character Humpty Dumpty.
*The comic [[1911: Defensive Profile]] implies that a person who boasts of having “no filter” in their (social media) speech is actually merely insecure about making people mad with their statements.

This theme is part of the larger category of comics about [[:Category:Social interactions|social interactions]].

==Transcript==
:[Cueball is sitting in an office chair at a desk in front of a laptop with his hands raised above the keyboard. An off-panel person replies to his remarks.]
:Cueball: Ugh, people are mad at me again because they don't read carefully.
:Cueball: I'm being perfectly clear. It's not '''''my''''' fault if everyone misinterprets what I say.
:Off-panel person: Wow, sounds like you're great at communicating, an activity that famously involves just one person.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Social interactions]]