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[-] Moobythegoldensock@lemm.ee 22 points 1 year ago

That’s not how that works.

[-] Crul@lemm.ee 4 points 1 year ago* (last edited 1 year ago)

Doesn't it depends on whether we are talking about real or integer numbers?

EDIT: I think it also works with p-adic numbers.

[-] Moobythegoldensock@lemm.ee 2 points 1 year ago

No. In the set of real numbers it is still very possible to randomly select a number that can be written with finite digits.

[-] lntl@lemmy.ml 0 points 1 year ago

op is right, infinity is larger than you're imagining

[-] Moobythegoldensock@lemm.ee 2 points 1 year ago

OP is wrong. A truly random real number does have a much higher probability of being an irrational number or repeating rational number, but it is certainly not the case that a truly random number “will be” one of these two as terminating rational numbers are still possible to select.

[-] lntl@lemmy.ml 0 points 1 year ago* (last edited 1 year ago)

There an infinite number of numbers that have infinite length and are not irrational or repeating. Infinity is larger than youre imagining.

[-] Moobythegoldensock@lemm.ee 2 points 1 year ago

Are you referring to arbitrarily large numbers? Still essentially the same as decimals in the other direction.

Do you have a mathematical proof for the OP’s claim that a truly random number must have infinite digits?

[-] lntl@lemmy.ml 0 points 1 year ago

you're claiming OP is wrong, you need the proof homie

[-] Moobythegoldensock@lemm.ee 2 points 1 year ago* (last edited 1 year ago)

OP actually has the burden to prove their own claim, but here you go:

Suppose we create an algorithm to generate a random number, such that:

  • The first digit is the ones
  • The second digit is the tenths
  • The third digit is the tens

And so on. For example, if we generated the sequence 1, 2, 3, 4, 5, 6 it would represent the number 531.246.

For a number to be non-infinite, there must be at some point be a digit where all digits after it generate a 0.

For all numbers in our sequence, the probability of generating a 0 is 1/10: there is no point at which we cannot generate a 0. Furthermore, after the first 0 is generated at a, the odds of a+1 being 0 are also 1/10, as are the odds of a+2, a+3, and a+n. So we cannot identify a b, such that entry a+b must be >0, since the odds of any given a+b generating 0 are also 1/10.

Based on this, we can use induction to show that it is possible to generate a truly random number that is a terminating rational number, and indeed it is possible to show this for any specific number as well. For example, the number 2 can be generated by simply rolling “2, 0, 0, 0, 0, …” and there is no nth digit in the sequence that cannot be generated at 0, since the odds of any given n being 0 are still 1/10.

[-] lntl@lemmy.ml 0 points 1 year ago* (last edited 1 year ago)

For a number to be non-infinite, there must be at some point be a digit where all digits after it generate a 0.

For all numbers in our sequence, the probability of generating a 0 is 1/10: there is no point at which we cannot generate a 0. Furthermore, after the first 0 is generated at a, the odds of a+1 being 0 are also 1/10, as are the odds of a+2, a+3, and a+n. So we cannot identify a b, such that entry a+b must be >0, since the odds of any given a+b generating 0 are also 1/10.

the odds of randomly selecting 0 exactly an infinite number of times is exactly zero which is why OP is right

Probability of a=0 is (1/10)

  • Pa = (1/10)
  • Pb = (1/10)

Probability of both being 0:

  • Pa AND Pb =(1/10)*(1/10)

then for n 0s

Pn = (1/10)^n

as n -> inf, Pn -> 0

put another way, (1/10)^inf = 0

[-] ShunkW@lemmy.world 11 points 1 year ago

No it wouldn't. You don't understand how random works

[-] funkajunk@lemm.ee 10 points 1 year ago

No, if truly random it could be any number from 0 to infinity. The randomization doesn't impart any qualities to the selected number.

If you randomly selected numbers from the infinite range of numbers for an infinite number of time, you would get a result of "7" just as often as getting "3.456e11".

[-] al4s@feddit.de 3 points 1 year ago

The probability of getting a finite number is pretty much zero.

For any range [0; n], where n is finite, there are always infinitely many numbers larger than n, so the probability of getting a number in said range is n/(n+infinity). I feel very confident in saying that something with that probability will never happen.

[-] Moobythegoldensock@lemm.ee 1 points 1 year ago

The probability of getting any number with a given set of characteristics is pretty much 0, but that doesn’t mean the number doesn’t exist once generated.

[-] funkajunk@lemm.ee 0 points 1 year ago

If there's any probability of an event, on an infinite timeline, it occurs infinite times.

[-] pruwybn@discuss.tchncs.de 7 points 1 year ago

I see what you're saying (assuming you mean a random integer from 0 to infinity), but it couldn't really, since there's no such thing as an integer with infinite digits - any random integer will have finite number of digits.

The real problem is there's no way to choose a random number from 0 to infinity. Every finite number has a probability of 0, and in fact, for any number you choose, there is 0 probability that it will be less than that number. Note that 0 probability is different from "impossible" - see https://en.wikipedia.org/wiki/Almost_surely

[-] panbroggi@feddit.it 6 points 1 year ago* (last edited 1 year ago)

I think it's right

Edit:

TIL: when saying random numbers, some people think to integers, others to real numbers.

[-] Crul@lemm.ee 7 points 1 year ago* (last edited 1 year ago)

I also think that's correct... if we are talking about real numbers.

People are probably thinking about integers. I'm not sure about OP.

EDIT: I think it also works with p-adic numbers.

[-] HonoraryMancunian@lemmy.world 3 points 1 year ago

Yes real numbers, but as far as I'm aware it'll happen for integers too almost surely

[-] Crul@lemm.ee 4 points 1 year ago

I think you're confusing "arbitrarily large" with "infinitely large". See Wikipedia Arbitrarily large vs. (...) infinitely large

Furthermore, "arbitrarily large" also does not mean "infinitely large". For example, although prime numbers can be arbitrarily large, an infinitely large prime number does not exist—since all prime numbers (as well as all other integers) are finite.

[-] Crul@lemm.ee 2 points 1 year ago

For integers I disagree (but I'm not a mathematician). The set of integers with infinite digits is the empty set, so AFAIK, it has probability 0.

[-] Rhynoplaz@lemmy.world 5 points 1 year ago

Wait, are you high in the shower? Because that's a little different.

[-] spez@sh.itjust.works 3 points 1 year ago
[-] NAXLAB@lemmy.world 9 points 1 year ago
[-] johsny@lemmy.world 4 points 1 year ago

Is he here to fuck lemmy up too?

[-] spez@sh.itjust.works 1 points 1 year ago
[-] lntl@lemmy.ml 1 points 1 year ago
[-] Narrrz@kbin.social 2 points 1 year ago

are we counting an infinite number of zeroes after the decimal point, as having infinite digits? because if you specifically exclude while numbers, your output would not be truly random, though it would be essentially impossible to distinguish it from true randomness.

[-] FelipeFelop@discuss.online 1 points 1 year ago

Why would it have infinite digits? It is just as like to be 0.

[-] lntl@lemmy.ml 0 points 1 year ago

yes, don't listen to the biologists who tell you otherwise.

this post was submitted on 12 Nov 2023
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