explain xkcd - User contributions [en]

Talk:2606: Weird Unicode Math Symbols

2022-04-14T06:07:24Z

162.158.255.171: reply

Apparently, nobody knows what U+237C ⍼ means (https://ionathan.ch/2022/04/09/angzarr.html)
: For me it looks very like as designation of where electrical cable is burrowed. It should come with numbers near angle hands designating depth and offset from sign. But it just a guess, of course [[Special:Contributions/141.101.76.221|141.101.76.221]] 05:30, 14 April 2022 (UTC)

Can someone add a column where we try to crowdsource a description for the "mathematical use of symbol" ?

I'm curious what those symbols actually mean, and the unicode titles don't give that much information.

I do not doubt that have enough math geeks on here to find the answer to most of then :-D

Thanks!
[[User:Flekkie|Flekkie]] ([[User talk:Flekkie|talk]]) 01:20, 14 April 2022 (UTC)

i agree w Flekkie's comment
[[User:Blue in real life|Blue in real life]] ([[User talk:Blue in real life|talk]]) 02:27, 14 April 2022 (UTC)

If you make edits, please don't immediately delete all of mine because you think yours are better. It shows you conflicting edits for a reason. Some explanations are nonsensical, like defining a smash product as the "result of dividing two product spaces." The smash product is specifically the quotient of the underlying spaces of two pointed spaces where points in the product spaces are identified if they contain either labeled point as an element. Other claims are simply mistaken. For instance, the ≝ symbol is used to introduce a definition, not to declare that the definition has been achieved in a proof. The claim that "A union on smash product appears to be one where the sets are nit isomorphic" is totally meaningless. The symbol ⩩ is not merely decorative but is intended as a supplemental math symbol like all the others. I couldn't track down its purpose. The APL symbol description somehow never bothers to mention APL. This is all very cursory, which is fine, but just please don't delete my work while doing it. [[Special:Contributions/172.70.130.5|172.70.130.5]] 04:15, 14 April 2022 (UTC)
:I'm done, page is yours. I'd been working on it for an hour and every time I tried to save, a new edit came in. I did my best to reconcile them but by the fifth I just saved a copy of what was there and pasted mine over. I immediately got to work on recovering what I had pasted over as indicated in the edit comment and like I said, I'm done. I've merged to the best of my ability and have no more interest in this page.
:--[[User:FrankHightower|FrankHightower]] ([[User talk:FrankHightower|talk]]) 04:37, 14 April 2022 (UTC)
::I'm very sorry if I was one of those who stepped on your edits. I was originally trying to fix brokenness in the table. ^^^^^ ≫ ^ is the symbol for preferring many small edits over not saving your work often in a batch-mode collaborative editing environment. [[Special:Contributions/172.70.207.8|172.70.207.8]] 04:55, 14 April 2022 (UTC)

:: Don't worry about it, idk why I was so upset. It's that feeling you get when you click "save" and then suddenly it's gone. If anything's still missing, I'll just restore it. [[Special:Contributions/172.70.131.106|172.70.131.106]] 05:41, 14 April 2022 (UTC)

I wish we had as much research on ⧍ and ⩩ as we have for ⍼. [[Special:Contributions/172.70.207.8|172.70.207.8]] 05:16, 14 April 2022 (UTC)
: No clue what those are for. The first is a triangle with serifs? The triangle symbol (not capital delta) is often used in geometry to represent a triangle, but why in the world would you give a geometric figure serifs? I think I may have seen the triple cross-hatch somewhere, but I couldn't say where. Maybe it's the chess commentary symbol for being mated so badly it's embarrassing. [[Special:Contributions/172.70.131.106|172.70.131.106]] 05:41, 14 April 2022 (UTC)
:: I'm guessing what must have happened is the [https://decodeunicode.org/en/u+2A00 code page in question] was filled in by a typographer with more graphic design than mathematical experience, who likely added made-up "missing" symbols as the design-logical extensions of the symbols they were given, presumably to be on the safe side in case they had what appeared to be a possibly incomplete set. There are some awesome ones in there, like "⩐" TEST-TUBE PARTHENOGENISIS, and "⨻" THE ILLUMINATI IS DEAD. [[Special:Contributions/162.158.255.171|162.158.255.171]] 06:07, 14 April 2022 (UTC)

2606: Weird Unicode Math Symbols

2022-04-13T21:37:31Z

162.158.255.171: /* Explanation */ the the (minor)

{{comic
| number = 2606
| date = April 13, 2022
| title = Weird Unicode Math Symbols
| image = weird_unicode_math_symbols.png
| titletext = U+2A0B ⨋ Mathematicians need to calm down
}}

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

{| class="wikitable"
|+ Symbols
|-
! Codepoint !! Symbol !! Unicode Name !! Randall's meaning || Explanation
|-
| U+29CD || ⧍ || Triangle with Serifs At Bottom || Shark || May look like a shark fin sticking out of the water
|-
| U+23E7 || ⏧ || Electrical Intersection || Traffic circle || May look like a {{w|roundabout}}?
|-
| U+2A33 || ⨳ || {{w|Smash product}} || ''Hashtag'' || Looks like a {{w|hashtag}} (#) symbol slanted counterclockwise
|-
| U+2A7C || ⩼ || Greater-Than with Question Mark Above || Confused alligator || One metaphor used when teaching inequality signs in primary school is that the sign looks like an alligator mouth "eating" the larger number.
|-
| U+299E || ⦞ || Angle with S Inside || Snack ||
|-
| U+2A04 || ⨄ || N-Ary Union Operator with Plus || Drink refill
|-
| U+2B48 || ⭈ || Rightwards Arrow Above Reverse Almost Equal To || Snakes over there
|-
| U+225D || ≝ || Equal To By Definition || Definitely, for sure || Has "def" for definitely and two equals signs
|-
| U+237C || ⍼ || Right Angle with Downwards Zigzag Arrow || Larry Potter || Looks like the letter "L" and a lightning bolt. {{w|Harry Potter (character)|Harry Potter}} is known for having a lightning bolt-shaped scar on his forehead.
|-
| U+2A50 || ⩐ || Closed Union with Serifs and Smash Product || Spider caught with a cup and index card
|-
| U+2368 || ⍨ || Apl Functional Symbol Tilde Diaeresis || :/ || Looks like a sad face.
|-
| U+2A69 || ⩩ || Triple Horizontal Bar with Triple Vertical Stroke || "Hashtag" || Hashtag that is "outlined"
|-
| U+2118 || ℘ || Symbol for {{w|Weierstrass_elliptic_function|Weierstrass p-function}}|| Snake
|-
| U+2AC1 || ⫁ || Subset with Multiplication Sign Below || "User experience", written sideways || Looks like the letters Ux written sideways; Ux is an abbreviation for {{w|user experience}}
|-
| U+232D || ⌭ || Cylindricity || Rolling dough between your hands to shape it into a ball ||
|-
| U+2A13 || ⨓ || Line Integration with Semicircular Path Around Pole || Integral that avoids a bee on the whiteboard || Looks like an {{w|integral}} symbol with a bump in the middle.
|-
| U+2A0B (title text)|| ⨋ || Summation with Integral || Mathematicians need to calm down
|-
|}

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

[Title:] Weird Unicode math symbols

[Subtitle:] And their meanings

{|
| U+29CD || ⧍ || Shark
|-
| U+23E7 || ⏧ || Traffic circle
|-
| U+2A33 || ⨳ || Hashtag [the text is slanted counterclockwise]
|-
| U+299E || ⦞ || Snack
|-
| U+2A04 || ⨄ || Drink refill
|-
| U+2B48 || ⭈ || Snakes over there
|-
| U+225D || ≝ || Definitely, for sure
|-
| U+237C || ⍼ || Larry Potter
|-
| U+2A50 || ⩐ || Spider caught with a cup and index card
|-
| U+2A69 || ⩩ || [The word "hashtag" but with extra horizontal and vertical lines]
|-
| U+2368 || ⍨ || :/
|-
| U+2118 || ℘ || Snake
|-
| U+2AC1 || ⫁ || [The words "user experience" rotated counterclockwise 90 degrees]
|-
| U+232D || ⌭ || Rolling dough between your hands to shape it into a ball
|-
| U+2A13 || ⨓ || Integral that avoids a bee on the whiteboard
|}

{{comic discussion}}
[[Category:Unicode]]
[[Category:Math]]
[[Category:Harry Potter]]

2587: For the Sake of Simplicity

2022-03-02T05:20:16Z

162.158.255.171: /* Explanation */

{{comic
| number = 2587
| date = February 28, 2022
| title = For the Sake of Simplicity
| image = for_the_sake_of_simplicity.png
| titletext = For the sake of simplicity, gardeners are assumed to move through Euclidean space--neglecting the distortion from general relativity--unless they are in the vicinity of a Schwarzschild Orchid.
}}

==Explanation==

{{incomplete|Created, '''for the sake of complexity''', by a SCHWARZSCHILD CHILD (HIS NAME IS NOT SCHWARZ) - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[Cueball]] appears to be explaining a gardening-related board game to [[Ponytail]] and [[White Hat]]. The game mechanics being employed are ridiculously overcomplicated for a game that seems to be about gardening — the cardiovascular health of the gardeners is tracked, for example. However, Cueball uses the refrain "for the sake of simplicity" to imply that the rules could be ''even more complicated''.

It's shown pretty quickly that Cueball's mechanics are needlessly intricate, and his definition of "simplicity" is not nearly simple enough: he describes the "constant" walking speed for gardeners is based on far more variables than necessary such as height and "cardio score", or even things like the curvature of spacetime in the area (hint-hint), and the direct inheritance of a single "cardio score" which requires tracking the gardener's matrilineal line, — instead of factors more typical to games such as weather or terrain.

Features of Cueball's game include:
* Tokens to represent competing gardeners
* Plots for the players to garden, both home plots and secondary garden plots
* Mechanics to assign speed of transit between plots
* Gardener attributes, including height and cardio scores
* Hereditary trees to determine gardener attributes according to the gardener's ancestry - {{w|matrilineally}} refers to inheritance from the mother's side
* Euclidean and non-euclidean space, in accordance with the theory of {{w|general relativity}}.
* The presence of particular species of flora that can warp {{w|space-time}}

As gardening is itself an oddly mundane premise for a board game, it is entirely possible that gardening is just a minor element of a much broader game.

The title text mentions that the space is assumed to be {{w|Euclidean_Geometry|Euclidean}}, which is what most people would assume since it corresponds to our normal experience, so this is not something that normally needs to be explained. But then it says that this isn't true in the vicinity of a Schwarzschild Orchid. An {{w|orchid}} is a type of flowering plant, which is relevant to a gardening game, but Schwarzschild refers to {{w|Karl Schwarzschild}}, a physicist who solved equations related to {{w|general relativity}}; the {{w|Schwarzschild radius}} is the boundary of a {{w|black hole}}, and spacetime is severely warped in this vicinity, so Euclidean geometry and {{w|Newton's Laws}} don't describe motion here well. On the whole, the title text implies Cueball sat down to calculate the distortion of general relativity on the walking speed of an adult human, then later used these equations for an entire game mechanic (one that players can mercifully skip when there are no gardeners in proximity of Schwarzschild Orchids).

When the comic was first published, the third paragraph said "stamina scores". This was later changed to "cardio scores".

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is standing beside Ponytail and White Hat, who are sitting at a table with a board game.]

:Cueball: You may assign each gardener's token to a secondary garden plot within a 30-minute walk from their home plot.
:Cueball: For the sake of simplicity, each gardener is assumed to have a constant walking speed proportional to their height and cardio score.
:Cueball: For the sake of simplicity, cardio scores are inherited matrilineally...

:[Caption below the panel:]
:If you're worried that you're making something too complicated, just add "for the sake of simplicity" now and then as a reminder that it could always be worse.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring White Hat]]
[[Category:Board games]]
[[Category:Language]]