explain xkcd - User contributions [en]

1516: Win by Induction

2015-04-24T09:30:10Z

Stephan Schulz: /* Transcript */ Fix Wikilink

{{comic
| number = 1516
| date = April 24, 2015
| title = Win by Induction
| image = win by induction.png
| titletext = This would be bad enough, but every 30th or 40th pokéball has TWO of them inside.
}}

==Explanation==
{{incomplete|This explanation is quite short, and the title text is not explained}}
{{w|Pikachu}} is a type of {{w|Pokémon}} from the cartoon series Pokémon. In the show, characters frequently 'fight' each other. This involves both characters choosing a Pokémon, who will then attack each other. Choosing a Pokémon is done by saying "I choose you, - name of the Pokémon -", and throwing a Pokéball to the ground. A Pokémon then appears from the Pokéball.
This comic suggests that a Pokémon chosen at some point was a Pikachu, but that this Pikachu does not intend to fight himself: carrying a Pokéball instead, Pikachu chooses another Pikachu to fight for him. This process then repeats itself. Behind the Pikachu with the Pokéball is a long line of other Pikachu's, suggesting that this process has been going on for a while.
The joke in this comic comes from analogy with the mathematical proof by induction, which is a proof with a base case, followed by a never ending sequence of steps, in which each step leads to the next, thus proving something for all cases. This title seems to suggest that the process of Pikachu's choosing Pikachu's will not end, effectively postponing the battle until the other Pokémon (not depicted) gives up.

If there was single Pikachu in each ball, this would spawn infinite, but countable, number of Pikachu (as many as integer numbers, N), forming a single line. If, as title text suggests, there's occasionally two of them in a Pokéball, this would lead to an exponential growth, forming a huge mob.

==Transcript==
[There's a long queue of {{w|Pikachu}}s just out from their ball, standing in front of Megan and Cueball on the right, Cueball holding an opened pokeball while Megan checks the time on her watch. The front most Pikachu speaks.]

Front most Pikachu: Pikachu, I choose ''you''!

{{comic discussion}}


[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Time]]
[[Category:Time management]]

Talk:1516: Win by Induction

2015-04-24T09:28:28Z

Stephan Schulz: Agree

Is the alt text a reference to double-yolkers (eggs with two yolks)? [http://www.bbc.co.uk/news/magazine-16118149 They're only about 1 in every 1000] but it seems like an obvious reference. --[[User:Fenn|Fenn]] ([[User talk:Fenn|talk]]) 08:32, 24 April 2015 (UTC)
:Makes sense to me. I didn't even think of double yolks until you mentioned it here. [[Special:Contributions/173.245.50.89|173.245.50.89]] 09:04, 24 April 2015 (UTC)BK201

The explanation currently says that doubling makes it uncountably infinite. I'm pretty sure that doubling at each step (or every few steps) is still a countable infinite set. Proof here: http://practicaltypography.com/the-infinite-pixel-screen.html (see section "The internet demands a recount", because the first attempt is wrong). We can also prove it using the same argument as when proving that N x N is countable infinite (making zig-zag), but in this case making a breadth-first search of the tree of Pikachus: map 1 to the first Pikachu, map 2 and 3 to the two Pikachus at the second level, map 4, 5, 6, 7 to the four Pikachus at the third level, map (2^(n-1))…((2^n) - 1) to the 2^(n-1) Pikachus at level n.
:Saw this too late. Yes, I agree, and I have fixed it accordingly. --[[User:Stephan Schulz|Stephan Schulz]] ([[User talk:Stephan Schulz|talk]]) 09:28, 24 April 2015 (UTC)

1516: Win by Induction

2015-04-24T09:27:25Z

Stephan Schulz: I can count exponential growth (count the first generation (finite), then count the second (still finite), then count the third (still finite), and so on.

{{comic
| number = 1516
| date = April 24, 2015
| title = Win by Induction
| image = win by induction.png
| titletext = This would be bad enough, but every 30th or 40th pokéball has TWO of them inside.
}}

==Explanation==
{{incomplete|This explanation is quite short, and the title text is not explained}}
{{w|Pikachu}} is a type of {{w|Pokémon}} from the cartoon series Pokémon. In the show, characters frequently 'fight' each other. This involves both characters choosing a Pokémon, who will then attack each other. Choosing a Pokémon is done by saying "I choose you, - name of the Pokémon -", and throwing a Pokéball to the ground. A Pokémon then appears from the Pokéball.
This comic suggests that a Pokémon chosen at some point was a Pikachu, but that this Pikachu does not intend to fight himself: carrying a Pokéball instead, Pikachu chooses another Pikachu to fight for him. This process then repeats itself. Behind the Pikachu with the Pokéball is a long line of other Pikachu's, suggesting that this process has been going on for a while.
The joke in this comic comes from analogy with the mathematical proof by induction, which is a proof with a base case, followed by a never ending sequence of steps, in which each step leads to the next, thus proving something for all cases. This title seems to suggest that the process of Pikachu's choosing Pikachu's will not end, effectively postponing the battle until the other Pokémon (not depicted) gives up.

If there was single Pikachu in each ball, this would spawn infinite, but countable, number of Pikachu (as many as integer numbers, N), forming a single line. If, as title text suggests, there's occasionally two of them in a Pokéball, this would lead to an exponential growth, forming a huge mob.

==Transcript==
[There's a long queue of {{w|Pikachus}} just out from their ball, standing in front of Megan and Cueball on the right, Cueball holding an opened pokeball while Megan checks the time on her watch. The front most Pikachu speaks.]

Front most Pikachu: Pikachu, I choose ''you''!

{{comic discussion}}


[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Time]]
[[Category:Time management]]

1464: Santa

2014-12-24T08:49:45Z

Stephan Schulz: /* Explanation */ Add source of philosophy

{{comic
| number = 1464
| date = December 24, 2014
| title = Santa
| image = santa.png
| titletext = He probably just poops over the side of the sleigh.
}}

==Explanation==
This comic refers to the common tradition of leaving milk and cookies out on Christmas Eve for Santa Claus. If one assumes that Santa eats even a small percentage of the sweets left out for him, the question comes up where all the cookies ''go''. Megan concludes that, since Santa isn't ''that'' large, he must poop them out somewhere, and where else is a better and more convenient spot than our houses?

Cueball disagrees, saying it cannot be so. Megan replies that mass cannot disappear completely; it has to go somewhere, to which Cueball comments that Santa has a magic bag in which be could poop. The magic bag referenced is the bag in which he carries all the Christmas presents he delivers on Christmas Eve. It is called 'magic' because a bag large enough to carry millions of presents would be much too heavy and unbalanced to carry on a sleigh pulled by only eight (or nine) reigndeer. Thus, there must be a larger space inside the bag. Megan is disgusted at the thought of Santa pooping on peoples' presents. Cueball proposes a third theory: that only a few houses are pooped in, but those that are are pooped in in large quantities. Megan says that there may not be anyone that naughty in the world (referencing the myth that Santa will leave coal (or in this case, feces), instead of presents, for those who misbehave.) Cueball replies that it is randomly determined whose house is pooped in. He starts saying [https://en.wikipedia.org/wiki/Spock Spock's] aphorism: 'the needs of the many outweigh the needs of the few', meaning that it is better that a small number of people suffer miserably than many suffer a bit.

The title text puts forth yet another theory: that Santa doesn't poop in houses at all, but off the side of his sleigh.

According to [[1070: Words for Small Sets]], a few is referring to "anywhere from 2 to 5". Currently, there are 1.9 billion children in the world, assuming Santa eats one in every 5 cookies, he consumes 380 million cookies in a 48 hour period, due to the convenience of time zones. According to Google, a chocolate-chip cookie contains approximately 140 calories, therefore Santa consumes 53.2 billion in the period of 2 days, 26.6 billion per day. As a man should have a daily intake of 2500 calories per day, Santa has 10640000 times the amount of daily calories required over the period of two days, sufficient to last for over 59111 years, or over 59 millenniums.

In reality, since Santa is <strike>only a myth</strike> [http://knowyourmeme.com/memes/its-still-real-to-me-damn-it still real to me dammit]!<strike>, we're all safe from the risk of him depositing in our toilets.</strike>

==Transcript==
:Megan: Say Santa eats a cookie at every few houses. That's hundreds of tons. By the end of the night, he should be a hulking seven-story behemoth.
:But he's not.

:Cueball: What are you...
:Megan: Does Santa poop in our houses?

:Cueball: No way.
:Megan: That mass must be going somewhere.
:Cueball: He has that magic bag...
:Megan: You think he poops in the bag of ''presents''?

:Cueball: Maybe instead of pooping in every few houses, he waits, and then in a few houses, he poops a ''lot''.
:Megan: What if no one's been ''that'' naughty?
:Cueball: He picks at random. The needs of the many...
{{comic discussion}}

1353: Heartbleed

2014-04-09T06:28:30Z

Stephan Schulz: /* Explanation */ Add reference

{{comic
| number = 1353
| date = April 9, 2014
| title = Heartbleed
| image = heartbleed.png
| titletext = I looked at some of the data dumps from vulnerable sites, and it was ... bad. I saw emails, passwords, password hints. SSL keys and session cookies. Important servers brimming with visitor IPs. Attack ships on fire off the shoulder of Orion, c-beams glittering in the dark near the Tannhäuser Gate. I should probably patch OpenSSL.
}}

==Explanation==

The mouseover text cites the [http://en.wikipedia.org/wiki/Tears_in_rain_soliloquy Tears in rain soliloquy], the dying words of the replicant and main antagonist Roy Batty (played by Rutger Hauer) in [http://en.wikipedia.org/wiki/Blade_Runner Blade Runner].

{{incomplete|Created by a BOT - Please change this comment when editing this page.}}

==Transcript==
:Megan: Heartbleed must be the worst web security lapse ever.
:Cueball: Worst so far. Give us time.
:Megan: I mean, this bug isn't just broken encryption.
:Megan: It lets website visitors make a server dispense random memory contents.
:Megan: It's not just keys. It's traffic data. Emails. Passwords. Erotic faniction.
:Cueball: Is '''everything''' compromised?
:Megan: Well, the attack is limited to data stored in computer memory.
:Cueball: So paper is safe. And clay tablets.
:Megan: Our imaginations too.
:Cueball: See, we'll be fine.

{{comic discussion}}