explain xkcd - User contributions [en]

Talk:418: Stove Ownership

2015-10-04T15:20:58Z

Willy on Wheels: Willy on Wheels moved page Talk:418: Stove Ownership to Talk:418: Stove Ownership on wheels

The title text doesn't "imply" that Randall went through a frosting phase in college similar to his present-day bacon obsession; it flat-out states it. The reader need not infer anything. Also, the usage of parens to define both a "phase" and "frosting" struck me as a little bit pedantic. I suspect most, if not all, readers of both xkcd and this explainer site are well enough versed with these nuances. [[Special:Contributions/108.162.219.21|108.162.219.21]] 08:29, 21 May 2014 (UTC)

On 5/30/14, I rewrote the description. It's still marked as inaccurate or incomplete, but the revision hasn't been reviewed yet ~J. {{unsigned ip|173.245.54.44}}

Is it really necessary to describe why eating copious amounts of bacon will have adverse affects on ones health? Should we also describe the metabolic effects of eating fat on the digestive and circulatory system? I don't mean to sound so smug and cynical, but some of Randall's comics are rather self-explanatory. I believe we've satisfactorily cleaned up this explanation. {{unsigned ip|173.245.54.44}}

Okay, I explained, hopefully to the satisfaction of the editors, why eating a ton of bacon would make somebody unhealthy. Can we close this one out? Thanks[[Special:Contributions/173.245.54.44|173.245.54.44]] 01:53, 7 June 2014 (UTC)

418: Stove Ownership

2015-10-04T15:20:57Z

Willy on Wheels: Willy on Wheels moved page 418: Stove Ownership to 418: Stove Ownership on wheels

{{comic
| number =418
| date =May 2, 2008
| title =Stove Ownership
| image =stove_ownership.png
| titletext =Although maybe it's just a phase, like freshman year of college when I realized I could just buy frosting in a can.
}}

==Explanation==

This comic is a subtle statement on the epiphany many have when they reach adulthood and are on their own for the first time: No one will tell you what to do! Nobody will, however, stop you from making those poor decisions you were refrained from prior to that independence. Eating bacon whenever one wants is among them.

This line graph depicts [[Randall|Randall's]] health as a function of time after he gets to own a {{w|Kitchen stove|stove}} (or oven). The joke is that his health goes into an immediate deterioration the moment he realized that he could just cook bacon on his stove whenever he wants. When he says "he could have bacon", he means he has both the will AND means, since the stove is now his own. Before the bacon revelation his health was actually improving - this may be explained because he was now cooking his own, healthy, food rather than getting pizza delivered or having other pre-made foods/junk food.

{{w|Icing_(food)|Frosting}} (or icing) is something you use to decorate cakes. Many children enjoy frosting so much that they eat it off the cake and leave the rest behind. Frosting in a can, as mentioned in a title text is convenient because it is instant and not necessary to make from scratch. When Randall came to college he still had a very sweet tooth, so when he discovered frosting in a can, his health curve at the time also went into decline. However, that turned out to be a phase - he got over it - and he hopes it will be the same with cooking bacon.

There is now also similarly instant, pre-made bacon that can be eaten right out of the box, eliminating the need to put in any effort to prepare it. The sudden drop in health, obviously, is due to the fact that most bacon is pork belly fat and, while high in protein, its irresistible flavor cannot compare to its high fat and cholesterol content. It is one of the unhealthiest things a person can binge on.{{Citation needed}} However, this is somewhat controversial. (Google "Paleo Diet") In addition, porkless bacon made from turkey meat is also available in some places.

==Transcript==
:[A hand-drawn graph is shown.]
:[On the y-axis:]
:My overall health
:[On the x-axis:]
:Time
:[The graph is generally steady rising through 3/4 of the x-axis, where it begins a steady decline. A stapled line marks the start of this decline. Below where the line crosses the x axis this decline is labeled:]
:The day I realized I could cook bacon ''whenever I wanted''.

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

Talk:156: Commented

2015-10-04T15:20:40Z

Willy on Wheels: Willy on Wheels moved page Talk:156: Commented to Talk:156: Commented on wheels

The issue date on this comic isn't filled. Can someone fix that by adding the correct issue date? [[User:Rikthoff|Rikthoff]] ([[User talk:Rikthoff|talk]]) 17:17, 3 August 2012 (EDT)

In the first two panels, it looks like he's flicking the guy off. It's not until the third panel that we actually see the subversion. I'm reasonably certain that this is intentional. [[Special:Contributions/108.162.238.117|108.162.238.117]] 02:34, 31 October 2013 (UTC)

In QtCreator, comments are dark blue. [[User:Kaa-ching|Kaa-ching]] ([[User talk:Kaa-ching|talk]]) 08:32, 31 October 2013 (UTC)

I'm surprised that no-one has picked up on the fact that the text that is being commented out is multiple lines, but there is only one double slash, therefore only one of the lines can be commented out. For both to be commented, you'd need /* ... */ --[[Special:Contributions/141.101.99.218|141.101.99.218]] 09:03, 6 November 2013 (UTC)

The title text may also be a reference to the "Your milage may vary." commonly found in the fine print in car commercials. [[Special:Contributions/108.162.216.19|108.162.216.19]] 22:28, 6 November 2013 (UTC)

I believe he's commenting out Cueball entirely, thus ignoring him and therefore any and all statements he may make. Notice in the last panel that it's not Cueball's question alone that is color-coded, but Cueball as well. {{unsigned ip|108.162.238.8}}

156: Commented

2015-10-04T15:20:38Z

Willy on Wheels: Willy on Wheels moved page 156: Commented to 156: Commented on wheels

{{comic
| number = 156
| date = September 13, 2006
| title = Commented
| image = commented.png
| titletext = Your IDE's color may vary.
}}

==Explanation==
In certain {{w|Programming language|programming languages}} (including but not limited to C (since C99), C++, C#, Java, Javascript, PHP, and Scala), inserting a double slash (//) in a line marks everything after the double slash in the line as a "comment"; i.e. something for humans to read that generally helps them understand the code better, rather than something for the computer to execute. Since all comment lines are ignored when a program is run or compiled, it is possible to simply put a double slash in front of any line of code to skip that line. This is known as "commenting out" the line.

[[Black Hat]] lifts two fingers toward [[Cueball]], forming a double slash and thereby ignoring both him and his question.

An {{w|Integrated development environment|Integrated Development Environment}} (IDE for short) is an application that programmers use to write, compile, execute, and debug code. Many IDEs color-code text to make reading the code easier. In IDEs like Eclipse and Microsoft Visual Studio, a line that is commented out will be colored green, however the color may vary depending on which IDE you use, and can usually also be customized. The title text refers to this variation among IDEs' color schemes.

==Transcript==
:[Cueball and Black Hat are talking to each other, and Black Hat is making a gesture towards Cueball.]
:Cueball: Hey, can you do me a favor?
:Black Hat: Commented!

:[The same frame from a different angle.]
:Cueball: Huh?

:[Black Hat is holding his first and second fingers parallel and at an angle, and they are green. Cueball and his next line are also green.]
:Cueball: Wait, what does that gesture even mean?

{{Comic discussion}}
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Comics with color]]
[[Category:Programming]]

Talk:870: Advertising

2015-10-04T15:20:25Z

Willy on Wheels: Willy on Wheels moved page Talk:870: Advertising to Talk:870: Advertising on wheels

But the Geico commercial doesn't say up to, it says 15% or more... ~Jfreund
:That may depend on your region. [[Special:Contributions/108.162.216.30|108.162.216.30]] 03:24, 30 November 2013 (UTC)
:Saying that something "could save you 15% or more" and saying it "could save you ''up to'' 15% or more" are the same thing. Both statements take into account the very real possibility that some percentage less than 15 could be saved.[[User:Orazor|Orazor]] ([[User talk:Orazor|talk]]) 13:37, 21 July 2014 (UTC)

Not to mention that Geico says "'''Could''' save you..." (In combination with "up to", the "could" should be "will".) [[User:Z|Z]] ([[User talk:Z|talk]]) 03:09, 18 June 2014 (UTC)

A justification for "The more you buy, the more you save" is that the more discounted products you buy, the more money you save as opposed to buying them at list price. For things we will buy anyway (e.g. food), it may be true. --[[User:Troy0|Troy0]] ([[User talk:Troy0|talk]]) 20:01, 6 July 2014 (UTC)
:Added to the article. --[[User:Troy0|Troy0]] ([[User talk:Troy0|talk]]) 04:10, 25 July 2014 (UTC)
::It doesn't work when the items can expire. [[User:Cflare|Cflare]] ([[User talk:Cflare|talk]]) 14:38, 14 August 2014 (UTC)
:::it does to a certain point- my family can eat a lot of food before it expires, especially if it's something we like. {{unsigned ip|108.162.237.163}}

Brilliant comic Randall. I wonder what your next one is about.

[[User:Weatherlawyer| I used Google News BEFORE it was clickbait]] ([[User talk:Weatherlawyer|talk]]) 00:20, 24 January 2015 (UTC)

Doesn't the title text imply that Randall realised nothing is truly free and concluded that Santa wanted something from him, prompting his parents to reveal the big secret? (I conclude this based on Randall claiming that these two events are related) [[Special:Contributions/141.101.104.49|141.101.104.49]] 21:16, 25 April 2015 (UTC)

Given that "up to x or more" must necessarily be true, how can it be "construed as false advertising?" Meaningless advertising, yes; false, no.[[Special:Contributions/173.245.50.174|173.245.50.174]] 04:22, 4 September 2015 (UTC)

I just spent 2% of my life looking for the fine print to that FREE* drink
(* given during time of kidney-harvesting scam test. Limit one per customer. No purchase necessary to win. Please see rules to apply.)[[User:Beastachu|Beastachu]] ([[User talk:Beastachu|talk]]) 10:33, 13 September 2015 (UTC)

870: Advertising

2015-10-04T15:20:23Z

Willy on Wheels: Willy on Wheels moved page 870: Advertising to 870: Advertising on wheels

{{comic
| number = 870
| date = March 9, 2011
| title = Advertising
| image = mathematically annoying.png
| titletext = I remember the exact moment in my childhood when I realized, while reading a flyer, that nobody would ever spend money solely to tell me they wanted to give me something for nothing. It's a much more vivid memory than the (related) parental Santa talk.
}}

==Explanation==
This comic pokes fun at some advertising tricks, analyzing them mathematically.

*"Up to 15% or more" is a reference to the {{w|Geico}} car insurance commercial catchphrase: "15 minutes could save you up to 15% or more on car insurance." "Up to" means "less than or equal to," so the phrase means "less than, equal to, or more than 15%," which is a {{w|tautology}}, and could be construed as false advertising.

:The first line uses notation from {{w|set theory}} and reads out as: The {{w|Union (set theory)|union}} of {{w|Set (mathematics)|sets}} A and B equals the set of all x, such that x is {{w|Inequality (mathematics)|less than or equal to}} 15, or greater than 15, which equals the set of all {{w|real numbers}}.

:Below is a {{w|number line}} (with the numbers being interpreted as {{w|percentages}}) the black dot indicates that the number 15 is included, and the white dot indicates that 15 is not included, but only strictly bigger numbers.

:Geico's ad is also referenced and discredited in [[42: Geico]].

*Some things in life are free. However, typically not those aggressively advertised, with a capital "free!" splashed right over the ads, followed by a small asterisk, indicating the presence of a {{w|fine print}}, ensuring that they are only technically not guilty of {{w|false advertising}}. (Get a '''FREE'''* drink!)

:The little formula [[Randall]] gives, is to calculate the least amount of money that they expect to make from you. The suggestion is that they expect their income from the ad to be at least equal to what they paid for it. (*with the purchase of a $6 meal)

*Some sales are based on a scaling percentage rate - for example, all items are 20% off, but if you spend more than $200, you get 30% off instead, and so on. These are almost universally proclaimed with a phrase like "The more you spend, the more you save!" This is of course nonsense, as "spending" is the opposite of "saving", and the deal is there to make you spend more.

:Note that an alternative phrasing "The more you buy, the more you save" is not strictly a contradiction. In some situations, the total number of items you intend to buy may place you just below the spending threshold that would qualify you for an additional discount; you can strategically buy additional items to place you just past the threshold. Despite buying a greater quantity of items, after the discount is applied, you will have spent less money, and thus saved more. (Though savvy retailers will attempt to avert this by placing this exploitable range higher than the cost of what any consumer reasonably needs, forcing them to spend more to qualify for the discount.)

:Or, "The more you buy, the more you save" just means that that the more discounted products you buy, the more money you save as opposed to buying them at list price. For things we will buy anyway (e.g. food), it may be true.

For those who don't celebrate Christmas, {{w|Santa Claus}} is a mythical person responsible for delivering presents to good children on Christmas Eve. Randall explains in the title text that his realization of the middle panel is more vivid than when his parents first told him Santa Claus was not real. Although most small children are traumatized after learning Santa Claus is not real, it is a testament to Randall's level of geekiness that he is more concerned with the first revelation.

==Transcript==
:Mathematically Annoying Advertising:

:A ∪ B = {x:x ≤ 15 or x > 15} = ℝ
:[line graph representing the above equation.]
:When discussing real numbers, it is impossible to get more vague than "up to 15% or more".

:["FREE!*" in large text, with substantial illegible fine print.]
:If someone has paid $x to have the word "free" typeset for you and N other people to read, their expected value for the money that will move from you to them is at least $(x / (N+1))

:[Graph representing inverse relationship between "amount you spend" on the y axis and "amount you save" on the x axis.]
:It would be difficult for the phrase "the more you spend the more you save" to be more wrong.

==Trivia==
Randall changed the image name from advertising.png to mathematically_annoying.png, since adblocking extensions interpreted it as an ad and made the comic blank. He had the same problem again just three months later with [[906: Advertising Discovery]].

{{comic discussion}}
[[Category:Math]]
[[Category:Charts]]

Talk:508: Drapes

2015-10-04T15:19:53Z

Willy on Wheels: Willy on Wheels moved page Talk:508: Drapes to Talk:508: Drapes on wheels

Or it turns out she is Beret Guys sister and thought Cueball meant the interior design of her apartment.[[Special:Contributions/99.102.154.28|99.102.154.28]] 21:08, 13 August 2013 (UTC)

----

From my own image development work, the 3D effect of the hair in the comic can be achieved one of two ways. A layer consisting of the hair must exist on its own and then be duplicated on a new layer. The coloured layer must be in front of the noncoloured (original) layer:

:Simple method: desaturate (and darken as necessary) the original layer (its Z order causes it to be behind the coloured layer), offsetting it as desired. Then merge.

:Emboss method: desaturate and emboss the old layer (it should be behind the coloured layer as in the Simple method), and set the opacity of the new layer to 50%. Merge both layers together - as the desaturation and 50% opacity results in a 50% desaturation of the merged layer, adjust the saturation to restore the colour. [[User:Thokling|Thokling]] ([[User talk:Thokling|talk]]) 08:56, 25 September 2013 (UTC)

"[T]he woman's hair [...] is orange[.]" Seems blonde to me. --[[User:Troy0|Troy0]] ([[User talk:Troy0|talk]]) 04:47, 25 July 2014 (UTC)

'''/!\WARNING/!\
The fourth wall may have been broken!!!
''' {{unsigned ip|173.245.56.180}}

And then, it turns out that the woman in the comic is a werewolf and was talking about her fur during the full moon (no I don't think it is, I'm just being silly). -Pennpenn [[Special:Contributions/108.162.250.162|108.162.250.162]] 01:59, 30 June 2015 (UTC)

508: Drapes

2015-10-04T15:19:51Z

Willy on Wheels: Willy on Wheels moved page 508: Drapes to 508: Drapes on wheels

{{comic
| number = 508
| date = November 24, 2008
| title = Drapes
| image = drapes.png
| titletext = Wait, what?
}}

==Explanation==
For those not familiar, this comic is a play on the classic question guys ask women, where drapes=head hair and carpet=pubic hair. The assumption is that some people artificially dye their head hair, but typically would not dye other body hair. The question is essentially asking "Are you a 'natural' red-head/blonde/etc.?". The classic question doesn't mention upholstery, hence [[Cueball]]'s confusion. There is some speculation about other body/arm/leg/arm-pit hair interpretations for [http://www.urbandictionary.com/define.php?term=upholstery upholstery].

This comic could also be a [[917|self-referential joke]] where the furniture is a double entendre to the art of the comic itself. The "carpet" is the white background of the comic, which matches the black "drapes" of Cueball, the woman, and the words. The "upholstery", in this case, is the woman's hair, which is colored and heavily bordered to create a 3D effect, which does not at all match the rest of this comic. The fact that Cueball seems confused (as per the last panel and title text) suggests the {{w|fourth wall}} may have been broken.

==Transcript==
:Cueball: So, does the carpet match the drapes?

:Woman: Yeah. But not the upholstery.

:[Woman walks away.]

:[Cueball scratches his head, confused.]

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

Talk:1184: Circumference Formula

2015-10-04T15:19:39Z

Willy on Wheels: Willy on Wheels moved page Talk:1184: Circumference Formula to Talk:1184: Circumference Formula on wheels

:Tau x Radius, superscript 2
::Since tau is more commonly used for the Golden Ratio, that's a silly idea. [[Special:Contributions/121.74.169.237|121.74.169.237]] 11:13, 23 September 2013 (UTC)
:::You may be confusing tau with phi. I've never seen the golden ratio represented by anything other than phi. I've also never seen tau representing anything other than 2pi. [[Special:Contributions/108.162.219.7|108.162.219.7]] 19:25, 10 May 2014 (UTC)

:Leaves one wondering what the superscript 1 refers. {{unsigned|‎74.215.40.250}}
::It's 2''πr''2, '''not''' ''τr''2. —[[Special:Contributions/173.199.215.5|173.199.215.5]] 05:37, 11 March 2013 (UTC)
:::You're missing the point. ''τ'' == 2''π'' and is considered better than using ''π'' by some people {{unsigned|138.195.69.136}}
::::Only for very loose definitions of "better." [[Special:Contributions/71.201.53.130|71.201.53.130]] 14:59, 11 March 2013 (UTC)
::::Whoa! Never heard about that before, but after 2 hrs or so, I think I'm getting convinced! Check this site out: http://tauday.com/ What do you think? –[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 18:06, 11 March 2013 (UTC)
:::::Ok so τ might make more sense than π but as comic [[1179]] pointed out, both pi-day and tau-day are wrong. [[User:Tharkon|Tharkon]] ([[User talk:Tharkon|talk]]) 13:23, 3 August 2014 (UTC)

::I think tau is pointless. Using tau what then happens to Euler's famous formula, the most beautiful equation of them all? Pi shows up in so many different ways and places in mathematics. Tau appears pretty much only in the formula for a circle's circumference. Why bother needlessly proliferating symbols? [[User:J Milstein|J Milstein]] ([[User talk:J Milstein|talk]]) 18:17, 11 March 2013 (UTC)
::: Surface area of a sphere is 2τr^2, or if you want to get pi in there ''π''d^2 {{unsigned ip|108.162.218.101}}

:::RE: Euler's Identity: e^(tau*i) - 1 = 0 --[[User:Max Nanasy|Max Nanasy]] ([[User talk:Max Nanasy|talk]]) 18:27, 11 March 2013 (UTC)
::::Ok, that works [[User:J Milstein|J Milstein]] ([[User talk:J Milstein|talk]]) 17:05, 13 March 2013 (UTC)
::::Why not just e^(tau*i) = 1. Do you routinely do 2 + 2 - 4 = 0?[[Special:Contributions/206.181.86.98|206.181.86.98]] 20:31, 13 March 2013 (UTC)
:::::Because:
:::::* Symmetry wrt the original Euler's Identity (e^(pi*i) + 1 = 0)
:::::* According to http://en.wikipedia.org/wiki/Euler's_identity#Mathematical_beauty, "in algebra and other areas of mathematics, equations are commonly written with zero on one side of the equals sign."
:::::--[[User:Max Nanasy|Max Nanasy]] ([[User talk:Max Nanasy|talk]]) 00:35, 14 March 2013 (UTC)
::::::I think Euler only did that because he disliked negative numbers. It really is less a deal than people make of it.[[Special:Contributions/206.181.86.98|206.181.86.98]] 03:02, 15 March 2013 (UTC)
:::::::Also, it uses the five most important constants in mathematics: ''e'', ''π'' (or ''τ''), ''i'', 1, and 0. [[User:Curtmack|Curtmack]] ([[User talk:Curtmack|talk]]) 20:33, 30 April 2013 (UTC)
::::The tau variant of Euler's identity above, ''e^(tau*i)=1'', appears to miss the point. Normally, a positivt number to the power of any real number is positive. Thus ''i'' could be any normal number. Well, not any number. ''i'' could be 0 and the equation will hold. With pi however, ''e^(pi*i)=-1'', ''i'' must be magical. /David A [[Special:Contributions/141.101.80.111|141.101.80.111]] 23:53, 9 November 2013 (UTC)
:::[http://tauday.com/tau-manifesto The tau manifesto] fairly well convinced me that all occurances of π in mathematics utimately trace back from the formula C = 2''πr''. If so, π naturally ''enter'' calculations as 2π. Can anyone find a counterexample to this thesis? –[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 00:29, 14 March 2013 (UTC)
::::How could there be a counter-example? I think it is true. In complex analysis, it really should be 2π, and thus Gaussian integrals. And then number theory applications. Even [http://www.jstor.org/discover/10.2307/2589152?uid=3739704&uid=2&uid=4&uid=3739256&sid=21101976916347 this] neat result really stems from trig identities, so it really is a result for 2π. [[Special:Contributions/206.181.86.98|206.181.86.98]] 02:59, 15 March 2013 (UTC)
:From what I understand, the thesis from the tau-proponents is that 2*pi is the fundamental natural constant, and that virtually ''every time'' that pi shows up without the factor 2, there originally was a factor two that was cancelled out. –[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 01:53, 12 March 2013 (UTC)
:For everyone who suddenly started a debate about 2pi and tau: http://xkcd.com/1292/ [[Special:Contributions/108.162.222.61|108.162.222.61]] 06:58, 4 May 2014 (UTC)

Not completely sure Earth Prime is from Sliders, but it's true it's the [http://en.wikipedia.org/wiki/Earth_Prime only one named exactly that] ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:54, 11 March 2013 (UTC)

There's also a [http://dc.wikia.com/wiki/Prime_Earth Prime Earth] now. Just so DC can screw with us. [[User:Hogtree Octovish|Hogtree Octovish]] ([[User talk:Hogtree Octovish|talk]]) 10:40, 11 March 2013 (UTC)

I still don't get it.[[Special:Contributions/49.176.102.213|49.176.102.213]] 12:41, 11 March 2013 (UTC)

:If you don't get it, you don't need to get it [[User:J Milstein|J Milstein]] ([[User talk:J Milstein|talk]]) 18:07, 11 March 2013 (UTC)

Well, that was lame. --[[Special:Contributions/87.122.60.227|87.122.60.227]] 17:19, 11 March 2013 (UTC)

This comic illustrates the strategy of "The Unconsummated Asterisk", from the essay "Mathmanship" by Nicholas Vanserg (available at [http://e-science.ru/forum/index.php?act=attach&type=post&id=7701]).
<blockquote>
The other side of the asterisk gambit is to use a superscript as a key to a real footnote. The knowledge‐seeker reads that S is – 36.714 calories and thinks "Gee what a whale of a lot of calories" until he reads to the bottom of the page, finds footnote 14 and says "oh."
</blockquote>
For bonus points, Randall could have used also "Pi-Throwing":
<blockquote>
For example every schoolboy knows what π stands for so you can hold him at bay by heaving some entirely different kind of π into the equation. The poor fellow will automatically multiply by 3.1416, then begin wondering how a π got into the act anyhow, and finally discover that all the while π was osmotic pressure. If you are careful not to warn him, this one is good for a delay of about an hour and a half.
</blockquote> [[User:Chymicus|Chymicus]] ([[User talk:Chymicus|talk]]) 19:01, 11 March 2013 (UTC)
:Another good one is π as a symbol for profit in financial discussions. -[[User:DrGaellon|DrGaellon]] ([[User talk:DrGaellon|talk]] | [[Special:Contributions/DrGaellon|contribs]]) 23:23, 25 March 2013 (UTC)

I believe the current description of prime as denoting derivatives is true but irrelevant. Since the area and circumference refers to geometry (not really calculus), it's more likely that the title text is referring to the common use of primes in geometry. For example, there might be two or more parallel lines that are denoted by x, x′, x′′, etc. Wikipedia also notes another geometric use of {{w|prime}}: "if a point is represented by the Cartesian coordinates (x, y), then that point rotated, translated or reflected might be represented as (x′, y′)." [[User:S|S]] ([[User talk:S|talk]]) 23:32, 11 March 2013 (UTC)

that is so wrong, i feel my mind corrupted now. -- [[User:Anarcat|Anarcat]] ([[User talk:Anarcat|talk]]) 23:57, 11 March 2013 (UTC)

This explanation was hillarious -- where is the up-vote button ?? [[User:Spongebog|Spongebog]] ([[User talk:Spongebog|talk]])

:+1 [[User:Smperron|Smperron]] ([[User talk:Smperron|talk]]) 16:33, 13 March 2013 (UTC)

So, where's todays comic? How many times has Randal been late?[[Special:Contributions/70.199.225.225|70.199.225.225]] 16:15, 13 March 2013 (UTC)

:Today's comic was posted just a few minutes ago. I'm anxiously awaiting its explanation as it picks on a programming language I'm not familiar with (possibly SQL). [[User:Smperron|Smperron]] ([[User talk:Smperron|talk]]) 16:33, 13 March 2013 (UTC)

It uses pseudocode. The new one is about sorting algorithms in general, not any particular language. [[Special:Contributions/130.245.231.101|130.245.231.101]] 17:00, 13 March 2013 (UTC)

Perhaps it's just me, but did no one see the "square the circle" gag...? --[[Special:Contributions/128.232.142.37|128.232.142.37]] 09:24, 14 March 2013 (UTC) No one but you saw the square-the-circle gag, because it's not there. For it to be there, it would require this: (2πr)² [[User:J Milstein|J Milstein]] ([[User talk:J Milstein|talk]]) 15:31, 14 March 2013 (UTC)

This one threw me for a loop for the longest time because I learned to use πd to find circumference, not 2πr. Anyone else learn that way? (Knowing how my brain works, it is equally possible I taught myself to use πd as a shortcut, and was in fact taught 2πr by my teachers.) [[User:Boct1584|Boct1584]] ([[User talk:Boct1584|talk]]) 22:20, 31 March 2015 (UTC)

I thought the joke in the title text was that primes can refer to successive derivatives. [[Special:Contributions/108.162.221.150|108.162.221.150]] 05:05, 19 August 2015 (UTC)

1184: Circumference Formula

2015-10-04T15:19:37Z

Willy on Wheels: Willy on Wheels moved page 1184: Circumference Formula to 1184: Circumference Formula on wheels

{{comic
| number = 1184
| date = March 11, 2013
| title = Circumference Formula
| image = circumference_formula.png
| titletext = Assume r' refers to the radius of Earth Prime, and r'<nowiki/>' means radius in inches.
}}

==Explanation==
The {{w|circumference}} C of a {{w|circle}} is 2{{w|pi|π}}''r'', where ''r'' is the {{w|radius}} of the circle. [[Randall]] then makes a {{w|Note (typography)|footnote}} about ''r'', using 2. This creates a typographical ambiguity, since a superscript 2 can also be an exponent (as in ''x''2). The comical purpose of this ambiguity is that the formula initially makes an appearance of a mistake and confusion with the formula for the ''{{w|area}}'' of the circle: A = π''r'' 2. If and only if the reader realizes that the superscript text is a reference to a footnote will they understand that the author has in fact supplied the correct formula.

The title text makes a related joke. Randall has used r′ (r-{{w|Prime (symbol)|prime}}) and r″ (r-prime-prime, typically pronounced as ''r double prime''). The title text can be explained thusly:

Like many symbols, prime has widely differing meanings depending on context. In mathematics prime is often employed to distinguish corresponding components in analogous systems. For example, in a description of a basic physical system, if the velocity of an object is denoted with the variable ''v'', the velocity of that object at time=0 may be denoted with ''v′''. Playing off this use of prime, Randall has selected the radius of {{w|Earth Prime}}, a concept used in speculative fiction with parallel universes and multiple Earths. Earth Prime is our Earth (or at least the Earth from which the protagonists originate).

However, other disciplines use prime to mean other things. In timekeeping and navigations ′ denotes minutes (fractions of hours or degrees, respectively) and ″ denotes seconds (fractions of minutes). In the United States and some other places not using meters to measure distance, ′ denotes feet and ″ denotes {{w|inches}}.

The suggestion of using r′ or r″ does not cause any mathematical confusion, but using the former to denote the radius of a specific object and the latter to denote a radius using a specific unit of measurement would be highly esoteric.

2 These are not intended to indicate the presence of a footn... oh, never mind.

==Transcript==
:Circumference of a circle:
:2πr2
:2The circle's radius

{{comic discussion}}
[[Category:Math]]