10: Pi Equals

Explain xkcd: It's 'cause you're dumb.
Revision as of 05:00, 8 January 2013 by Lcarsos (talk | contribs) (Moving third "possible" to talk page. This is a common enough gag that we could keep going forever)
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Pi Equals
My most famous drawing, and one of the first I did for the site
Title text: My most famous drawing, and one of the first I did for the site


Probability of Finding Strings In Pi

There are two possible references here. One is from the book Contact by Carl Sagan, where the existence of God was shown in the last chapter to be encoded in the digits of pi. The other is an old joke of a fortune cookie with a fortune that reads "Help! I'm trapped in a fortune cookie factory!".


  • The book version of this comic (in xkcd: volume 0) has different title text from the online original: "I've put rescue instructions in e. You'll need the cheat codes for your universe, which I hid in the square root of two."
  • This is the eleventh comic originally posted to livejournal. The previous was 9: Serenity is coming out tomorrow. The next was 14: Copyright.


Pi = 3.141592653589793helpimtrappedinauniversefactory7108914...

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Interestingly, 7108914 does not occur in the first 100,000 digits of pi. However, 71089 does occur at roughly around the 2,500 digit mark. --DanB (talk) 18:17, 6 August 2012‎ (UTC)

7108914 position 13,709,690 counting from the first digit after the decimal point. The 3. is not included. --whitecat (talk) 10:43, 7 August 2012‎ (UTC)

There is a children's book called "Help, I'm a prisoner in a toothpaste factory". (talk) 17:13, 7 January 2013‎ (UTC) (please sign your comments with ~~~~)

or it's reference of the Mac OS 6 and 7 "BlueMeanies" easter egg "Help! Help! We're being held prisoner in a system software factory!". (talk) 08:59, 7 January 2013‎ (UTC) (please sign your comments with ~~~~)

In my profession - simplifications of π is equal perfection, I can throw a recurring function at it, but it will just give me more pages of numbers. Remember that pi will ultimately equal 22/7, and you'll be alright. - E-inspired (talk) 09:17, 3 March 2013 (UTC)

We still have to find "helpimtrappedinauniversefactory" @pi, even when Randall also does not know.--Dgbrt (talk) 20:48, 23 June 2013 (UTC)

You know, we could convert "helpimtrappedinauniversefactory" to the ASCII numbers and then use one of those algorithms that searches pi for a particular string of numbers... 22:40, 13 November 2013 (UTC)

While the string 72697680 (HELP) appears multiple times throughout the first 200,000,000 digits of pi (not counting the 3.), none of the resulting ASCII strings makes sense. The closest (7269768022774869990317421141) is at position 31,961,494 with the resulting string as "HELP�M0E". Note that it is the number "0" and not the letter "O". The string "104101108112" ("help") does not occur in the first 200,000,000 digits. - 08:15, 30 December 2013 (UTC)

Umm... "Of course, because pi never ends and never repeats, if you assign each number pair a letter from the alphabet and look through the digits of pi, somewhere within it is the entire work of Shakespeare, or any other piece of information that could be expressed with human language. So, ironically, somewhere in pi, there actually is the phrase stated in the comic, in a sense." This isn't guaranteed. Just because it's infinite and non-repeating doesn't mean that every possible pattern exists within it. 0.1010010001000010000010000001... is infinite and non-repeating, but it most certainly doesn't contain Shakespeare. It would only be guaranteed if the series was perfectly random over an infinite amount of time. 23:47, 14 March 2014 (UTC)

Ah, but in 0.1010010001... there is a pattern, isn't there? 1, then n number of zeroes, where n is incremented by 1 each time it is used. I don't see such patterns in 3.14159... myself. :PNSDCars5 (talk) 12:56, 23 May 2014 (UTC)
That you don't see a pattern doesn't mean there is one. That there is no pattern doesn't mean it contains every possible sequence. -- 12:14, 6 August 2014 (UTC)
Have edited it to add that this requires a proof that pi is normal. For readers, to see the flaw in NSDCars5's reasoning, consider how he might have seen the entire infinite sequence of pi's digits, then realize it's impossible without a formal proof. Which is what the proof of pi being normal would solve. As it is, we don't have that proof yet, and so we cannot say for sure that pi has every possible finite sequence. 16:31, 12 August 2014 (UTC)
I vote we modify that. It's almost certainly true that pi does include the entire works of Shakespeare, but good luck proving that. 07:29, 30 November 2014 (UTC)
If you would argue that, statistically, even one line of Hamlet or Romeo and Juliet could be found within Pi, then statistically, it would be found thousands of time with typos or mistakes first. By the time someone found ALL of Shakespeare's works lined up, first we would have found the individual works separated, millions of times, with all manner of mutations that would result from random chance. Something to consider. 16:30, 28 June 2015 (UTC)

I feel like there should be a mention that, since pi is a mathematical constant rather than a physical constant, even if you did create the universe you'd have no control over it. You might be able to influence the directions math takes and exert some control over what constants seem important, but that will only give you a few bits of control, meaning that you can only encode a message a few bits long. You could easily encode messages into the fine structure constant, but if you stick it too close to the beginning it might inhibit life, and if you stick it too far nobody will be able to measure it accurately enough to find it. 07:29, 30 November 2014 (UTC)

Whereas the fictional prisoner in a Fortune Cookies Factory may harbor hopes that once his message gets out and the finder of the message take it to the authorities who will trace it's origins and affect a rescue; no such hopes are available to the Universe Factory prisoner. Not unless the residents of the created universe have a manner of interfacing with the creators civilization. Which brings up an interesting question: Once an intelligence has deciphered a message from a higher being, do they just move on as if nothing happened, or do they now focus their resources toward ascending into the higher realm just revealed. If the latter, than our Universe Factory prisoner may have some hope after all... Mountain Hikes (talk) 08:52, 31 August 2015 (UTC)

The link to TV tropes yields "403 Forbidden", please find a different link. 18:15, 8 September 2016 (UTC)