Main Page

Explain xkcd: It's 'cause you're dumb.
Jump to: navigation, search

Welcome to the explain xkcd wiki!
We have an explanation for all 2217 xkcd comics, and only 22 (1%) are incomplete. Help us finish them!

Latest comic

Go to this comic explanation

53 Cards
Well, there's one right here at the bottom, where it says "53."
Title text: Well, there's one right here at the bottom, where it says "53."


Ambox notice.png This explanation may be incomplete or incorrect: Created by a 53-CARD DECK. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.

In this comic Cueball claims that he has found a way to manipulate a 52-card deck into a 53-card deck with only shuffling and rearranging. This is absurd, since there is no way for new cards to be incorporated, thus violating the laws of conservation, as well as fundamental rules of logic that would be in place even in a universe that had different conservation rules. He backs up this claim with a diagram containing random mathematical jargon and challenges Ponytail to find an error. However, the given math is sufficiently esoteric that an error cannot easily be found. It's possible that the process involves the Banach-Tarski paradox at some step.

The caption below the comic states that this is how Randall feels when talking to someone who likes the theory of perpetual motion, motion of macroscopic bodies that, barring mechanical damage, continues indefinitely. This is impossible according to currently known laws of physics, since such motion would entail producing energy out of nothing in order to overcome friction, but adherents still believe it is possible. The comic draws comparison between conservation of energy and conservation of cards in a deck.

In the title text, Ponytail responds to Cueball's challenge with snark, claiming that the most obvious error is the fact that the formula's result is "53". This doesn't actually prove that there is an error in Cueball's math, but Ponytail refuses to entertain the possibility that 52 items can become 53 items without having any items added to the system in the process – similar to how energy can be transferred but never produced.


Ambox notice.png This transcript is incomplete. Please help editing it! Thanks.
Cueball: I've found a way to turn a 52-card deck into 53 cards by shuffling and rearranging them.
Ponytail: No, you haven't.
Cueball: How do you know?! I challenge you to find an error in my math!
Caption: Every conversation between a physicist and a perpetual motion enthusiast.

Is this out of date? Clicking here will fix that.

New here?

Last 7 days (Top 10)

Lots of people contribute to make this wiki a success. Many of the recent contributors, listed above, have just joined. You can do it too! Create your account here.

You can read a brief introduction about this wiki at explain xkcd. Feel free to sign up for an account and contribute to the wiki! We need explanations for comics, characters, themes and everything in between. If it is referenced in an xkcd web comic, it should be here.

  • There are incomplete explanations listed here. Feel free to help out by expanding them!
  • We sell advertising space to pay for our server costs. To learn more, go here.


Don't be a jerk.

There are a lot of comics that don't have set-in-stone explanations; feel free to put multiple interpretations in the wiki page for each comic.

If you want to talk about a specific comic, use its discussion page.

Please only submit material directly related to (and helping everyone better understand) xkcd... and of course only submit material that can legally be posted (and freely edited). Off-topic or other inappropriate content is subject to removal or modification at admin discretion, and users who repeatedly post such content will be blocked.

If you need assistance from an admin, post a message to the Admin requests board.