this post was submitted on 26 Dec 2024
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How about ANY FINITE SEQUENCE AT ALL?

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[–] [email protected] 9 points 3 months ago (1 children)

https://github.com/philipl/pifs

Ο€fs is a revolutionary new file system that, instead of wasting space storing your data on your hard drive, stores your data in Ο€! You'll never run out of space again - Ο€ holds every file that could possibly exist! They said 100% compression was impossible? You're looking at it!

[–] [email protected] 7 points 3 months ago

https://github.com/philipl/pifs

I enjoyed this linked text:

If you compute it, you will be guilty of:

  • Copyright infringement (of all books, all short stories, all newspapers, all magazines, all web sites, all music, all movies, and all software, including the complete Windows source code)
  • Trademark infringement
  • Possession of child pornography
  • Espionage (unauthorized possession of top secret information)
  • Possession of DVD-cracking software
  • Possession of threats to the President
  • Possession of everyone's SSN, everyone's credit card numbers, everyone's PIN numbers, everyone's unlisted phone numbers, and everyone's passwords
  • Defaming Islam. Not technically illegal, but you'll have to go into hiding along with Salman Rushdie.
  • Defaming Scientology. Which IS illegal--just ask Keith Henson.
[–] [email protected] 76 points 3 months ago* (last edited 3 months ago) (11 children)

No, the fact that a number is infinite and non-repeating doesn't mean that and since in order to disprove something you need only one example here it is: 0.1101001000100001000001... this is a number that goes 1 and then x times 0 with x incrementing. It is infinite and non-repeating, yet doesn't contain a single 2.

[–] [email protected] 36 points 3 months ago (1 children)

This proves that an infinite, non-repeating number needn't contain any given finite numeric sequence, but it doesn't prove that an infinite, non-repeating number can't. This is not to say that Pi does contain all finite numeric sequences, just that this statement isn't sufficient to prove it can't.

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[–] [email protected] 3 points 3 months ago (2 children)

Doesn't the sequence "01" repeat? Or am I misunderstanding the term.

[–] [email protected] 2 points 3 months ago

yeah, but non-repeating in terms of decimal numbers usually mean: you cannot write it as 0.(abc), which would mean 0.abcabcabcabc...

[–] [email protected] 7 points 3 months ago

A nonrepeating number does not mean that a sequence within that number never happens again, it means that the there is no point in the number where you can predict the numbers to follow by playing back a subset of the numbers before that point on repeat. So for 01 to be the "repeating pattern", the rest of the number at some point would have to be 010101010101010101... You can find the sequence "14" at digits 2 and 3, 104 and 105, 251 and 252, and 296 and 297 (I'm sure more places as well).

[–] [email protected] 12 points 3 months ago

That was quite an elegant proof

[–] [email protected] 1 points 3 months ago (2 children)

But didn't you just give a counterexample with an infinite number? OP only said something about finite numbers.

[–] [email protected] 9 points 3 months ago

"2" is a finite sequence that doesn't exist in the example number

[–] [email protected] 19 points 3 months ago* (last edited 3 months ago) (1 children)

They were showing that another Infinite repeating sequence 0.1010010001... is infinite and non-repeating (like pi) but doesn't contain all finite numbers

[–] [email protected] 7 points 3 months ago (1 children)

You mean infinite and non- repeating?

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[–] [email protected] 6 points 3 months ago

What about in the context of Pi?

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[–] [email protected] 10 points 3 months ago (1 children)

Not just any all finite number sequence appear in pi

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[–] [email protected] 5 points 3 months ago (1 children)
[–] [email protected] 3 points 3 months ago* (last edited 3 months ago) (8 children)

Can you prove this? Or link a proof?

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[–] [email protected] 21 points 3 months ago (4 children)

0.101001000100001000001 . . .

speech-r I'm infinite and non-repeating. Can you find a 2 in me?

[–] [email protected] 1 points 3 months ago (1 children)
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[–] [email protected] 2 points 3 months ago (1 children)

Are you trying to say the answer to their question is no? Because if so, you're wrong, and if not I'm not sure what you're trying to say.

[–] [email protected] 8 points 3 months ago (1 children)

The conclusion does not follow from the premises, as evidenced by my counterexample. It could be the case that every finite string of digits appears in the decimal expansion of pi, but if that's the case, a proof would have to involve more properties than an infinite non-repeating decimal expansion. I would like to see your proof that every finite string of digits appears in the decimal expansion of pi.

[–] [email protected] -3 points 3 months ago (4 children)

Well that's just being pointlessly pedantic, obviously they fucking know that a repeating number of all zeros and ones doesn't have a two in it. This is pure reddit pedantry you're doing

[–] [email protected] 5 points 3 months ago (1 children)
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[–] [email protected] 6 points 3 months ago (2 children)

You can't prove that there isn't one somewhere

[–] [email protected] 11 points 3 months ago (1 children)

You can, it's literally the way the number is defined.

[–] [email protected] 3 points 3 months ago (1 children)
[–] [email protected] 7 points 3 months ago* (last edited 3 months ago) (9 children)

It's implicitly defined here by its decimal form:

0.101001000100001000001 . . .

The definition of this number is that the number of 0s after each 1 is given by the total previous number of 1s in the sequence. That's why it can't contain 2 despite being infinite and non-repeating.

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[–] [email protected] 4 points 3 months ago (1 children)
[–] [email protected] 2 points 3 months ago

Because you'd need to search through an infinite number of digits (unless you have access to the original formula)

[–] [email protected] -1 points 3 months ago (2 children)

Yes, this is implied. It's also why many people use digits of pi as passwords and make the password hint "easy as pi".

[–] [email protected] 11 points 3 months ago

I have a slightly unique version of this.

When I was in high school, one of the maths teachers had printed out pi to 100+ digits on tractor feed paper (FYI I am old) and run it around the top of the classroom as a nerdy bit of cornice or whatever.

Because I was so insanely clever(...), I decided to memorise pi to 20 digits to use as my school login password, being about the maximum length password you could have.

Unbeknownst to me, whoever printed it had left one of the pieces of the tractor feed folded over on itself when they hung it up, leaving out a section of the first 20 digits.

I used that password all through school, thinking i was so clever. Until i tried to unrelatedly show off my knowledge of pi and found I'd learned the wrong digits.

I still remember that password / pi to 20 wrong digits. On the one hand, what a waste of brain space. On the other hand, pretty secure password I guess?

[–] [email protected] 7 points 3 months ago (2 children)

Not sure if this is sarcasm, but I sure hope so...

[–] [email protected] 1 points 3 months ago (1 children)

It's a Criminal Minds reference, though people do use this method, including me.

[–] [email protected] 2 points 3 months ago

I use encryption and... modern... 2024 standards.

Pi, tho. I mean, you do you.

[–] [email protected] 27 points 3 months ago (1 children)

I just use the last 10 digits of pi for all my passwords.

[–] [email protected] 4 points 3 months ago (1 children)
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[–] [email protected] 9 points 3 months ago

Yes.

And if you're thinking of a compression algorithm, nope, pigeonhole principle.

[–] [email protected] 76 points 3 months ago* (last edited 3 months ago) (2 children)

A number for which that is true is called a normal number. It’s proven that almost all real numbers are normal, but it’s very difficult to prove that any particular number is normal. It hasn’t yet been proved that Ο€ is normal, though it’s generally assumed to be.

[–] [email protected] 12 points 3 months ago

I love the idea (and it's definitely true) that there are irrational numbers which, when written in a suitable base, contain the sequence of characters, "This number is provably normal" and are simultaneously not normal.

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