Finding book ISBN numbers in Pi

boing
21

Move over, Intelligent Design, hello Bookish Design

22

We might be onto something. Quick! To the lawyers!

23

It’s a functional output with a non-random seed, so it is definitely not random. The decision to use pi instead of tau is arbitrary, but the number itself describes a natural relationship.

I really don’t know if full texts of things can appear in pi, because there would have to be a rather frequent use of certain codes like 32 (space bar in ISO-8859-1) that probably wouldn’t occur until pi had been calculated and recorded on a medium larger than the universe itself. This is without considering the problem of how to many digits to parse at once.

26

obligatory Borges story

http://hyperdiscordia.crywalt.com/library_of_babel.html

also, https://github.com/philipl/pifs

3 Likes
27

Yes, known about The Library of Babel for ages – but I’m amazed at pifs. Apparently someone has actually implemented the idea of using PI as a data storage technique – even if it is completely impractical.

1 Like
28

You probably mean whether π is a normal number. That is suspected but not proven.

3 Likes
31

See the wonderful poem “Pi” by Wislawa Szymborska. There’s one translation here: http://katherinestange.com/mathweb/p_p2.html

32

Thank you!
Have been scrolling thru the comments wondering if anybody would challenge that assertion.

33

[quote=“L_Mariachi, post:18, topic:50117”]
Is this actually true? It feels true but I suspect there’s some weird set theory catch.[/quote]

It might be possible for it to be true of a given normal number, but there’s certainly no reason to assume it’s true in principle.

I’m not aware of any current proofs either way on this, but then I’m some years out of date on the literature.

34

thank you!!

35

  1. “ISBN number” is an abomination up with which I will not put.

  2. Let me know when “978-0156027328” is found in the decimal sequence.

3 Likes
36

Is 867-5309 in there?

Edit: yes.

2 Likes
37

I’ve got a simpler proof.

There’s an infinite number of unique numbers between 0 and 1.

None of those numbers are 2.

38

If and where “0-553-07130-0” appears in the expansion of π, it will lead to Dan Galouye’s “Infinite Man”, a Lathe-of-Heaven-themed novel in which (among other unsettling events) π is transformed into a rational number.

39

XKCD did it.

It makes me wonder what the encoding would be; how many digits per letter? And then you’d end up with multiple possible readthroughs of pi, because of multiple possible encodings.

Also, you can get every photograph ever taken at any resolution by inferring RGB values.

41

@Sidsalinger, you are in the ballpark but it seems that you are playing a different game.

Cantor Diagonailization does not refute the existence of any sequence of numbers. All it shows is that any attempt to completely enumerate a set of reals is futile as one can always find a number not in the set.

Trivial example:

For the set N = { x | 0 < x < 1 } where x is a real number, contains the numbers

0.1111…
0.2222…
0.3333…

We know that this list is not exhaustive as we can use diagonalization to arrive at 0.2345… which is in N as 0 < 0.2345 < 1, but not a part of our attempt to enumerate all the Real numbers in N.

Having found a counterexample, lets update our attempt to count the Reals. Now we have
0.1111…
0.2222…
0.3333…
0.2345…

We know this list is not exhaustive because we can use diagonalization to show our list is not exhaustive because 0.2346… is not in the list but 0 < 0.2346 < 1 and therefore in N.

Repeat this process, forever, and we will not have even begun to enumerate the Reals between 0 and 1.

So for any finite sequence of integers ,4523452352345234 for instance, exists in N if we disregard the digits before and after our random sequence.

0 < 0.xxxxxxx4523452352345234xxxxxx… < 1

@ghostly1, We are talking about sequences of digits in an infinite list, not magnitudes. The set { x | 0 < x < 1 } contains an unbounded number of digits of 2.

Thanks guys for the opportunity to put this book lernin to use again!

43

No, WE’re talking about whether something being infinite means that it contains everything. The initial topic was about sequences of digits in an infinite list, but we moved on into a subtopic about the qualities of infinity itself. And even though there are infinite individual numbers between 0 and 1, none of them is 2. Some contain the digit 2, but none IS 2.

44

Hi folks, Geoff here, the “brains” behind this silly little project. Please allow me to address a few issues:

0: Yes, whether Pi is normal is, to the best of my knowledge, still unknown, although if it’s not it may still contain every possible ISBN (it’s fairly likely in fact, even if it’s not normal)

1: Yes, “ISBN number” is an abomination for which I apologise profusely.

2: I searched for the 13 digit variant of ISBNs rather than the older 10 digit version because an ISBN10 can have a check digit of “10” which is represented as an X - Pi doesn’t contain X’s.

3: As a point of interest, I found hundreds, if not thousands of “valid” ISBNs which hadn’t been assigned, compared to the three assigned ones. This was five years ago, so there may be additional books beating my “top three” to be found now or in the future.

3 Likes
45

Uh huh… so 1 < 2, gotcha.

Thanks for the insight, Copernicus.

46

I know you’re working on some kind of branding for yourself where acting like an ass and deliberately missing the point is an integral part of that, but, you know, you CAN take a break now and then.