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It seems this Show HN proves you rather wrong. I understand the point, you use a different format for your dates than the US. But the point of this Show HN is t

It seems this Show HN proves you rather wrong. I understand the point, you use a different format for your dates than the US. But the point of this Show HN is that all number sequences can be found within the digits of pi quite easily. Very neat demonstration!

Jaruzel 10y ago
you use a different format for your dates than the US 'I' use? I think you'll find everyone uses a different format than the US. ...the point of this Show HN is that all number sequences can be found within the digits of pi... Everyone already knows this. I'm just struggling with the wall-to-wall 'Pi Day' articles all over the tech web and Facebook right now. I make no apology.
- justusthane 10y ago
  everyone uses a different format than the US. 'Everyone uses'? What about all the people in the U.S.?
- tossaway1 10y ago
  > 'I' use? I think you'll find everyone uses a different format than the US. The plural of "you" in English is"you"...
- atonse 10y ago
  It's always fashionable to make fun of the US doing things its own way, when that's just seldom true. You're mostly right that nobody else uses MMDDYYYY (although many countries use it as a secondary format). But it's not like there's a consistent format that _everyone else_ uses. There are 2-3 different formats spread around the world, with no real consistency in why some pick a particular format.
- ska 10y ago
  Everyone already knows this. That's funny, because we have not proven it to be true.
  - lutusp 10y ago
    It's also an argumentum ad populum.
oneeyedpigeon 10y ago
> all number sequences can be found within the digits of pi quite easily I dispute that, although I guess the general brute-force solution is 'easy' given infinite time.
- geofft 10y ago
  Yeah, this isn't known to be true. pi has not been proven to be a disjunctive number (a real number whose expansion contains all possible finite strings), let alone a normal number (where all finite strings occur with the probability you'd expect if the digits were random). Both of these, however, are generally conjectured to be true, but it's just a conjecture. https://oeis.org/wiki/Disjunctive_numbers#Is_pi_a_disjunctive_number.3F https://oeis.org/wiki/Disjunctive_numbers#Is_pi_a_disjunctiv... https://en.wikipedia.org/wiki/Normal_number https://en.wikipedia.org/wiki/Normal_number
- lutusp 10y ago
  >> all number sequences can be found within the digits of pi quite easily > I dispute that, although I guess the general brute-force solution is 'easy' given infinite time. Look at it this way -- if it were not true, then the digits of Pi would not be normally distributed (see https://en.wikipedia.org/wiki/Normal_number https://en.wikipedia.org/wiki/Normal_number), and that would be a rather extraordinary mathematical finding. If Pi's digits are normally distributed, then one can reliably predict the time required for finding any particular digit sequence using probability theory. And given the presumption of normalcy, that probability is the same for any digit sequence of a given length. The probability for finding a given test digit sequence in the first 100 million digits of Pi is given here: https://www.angio.net/pi/whynotpi.html https://www.angio.net/pi/whynotpi.html But it has to be emphasized that, given a finite test sequence and an infinite sequence of Pi's digits as a search space, the probability is 1.0.
  - oneeyedpigeon 10y ago
    You're both giving me too much credit. I was merely making the less sophisticated point that it's not 'easy' to find an arbitrary-length sequence in pi because that might take longer than the lifespan of the universe when the needle gets long enough. Your response was much more interesting, though, thanks :)

Jaruzel 10y ago

you use a different format for your dates than the US 'I' use? I think you'll find everyone uses a different format than the US. ...the point of this Show HN is that all number sequences can be found within the digits of pi... Everyone already knows this. I'm just struggling with the wall-to-wall 'Pi Day' articles all over the tech web and Facebook right now. I make no apology.

justusthane 10y ago
everyone uses a different format than the US. 'Everyone uses'? What about all the people in the U.S.?
tossaway1 10y ago
> 'I' use? I think you'll find everyone uses a different format than the US. The plural of "you" in English is"you"...
atonse 10y ago
It's always fashionable to make fun of the US doing things its own way, when that's just seldom true. You're mostly right that nobody else uses MMDDYYYY (although many countries use it as a secondary format). But it's not like there's a consistent format that _everyone else_ uses. There are 2-3 different formats spread around the world, with no real consistency in why some pick a particular format.
ska 10y ago
Everyone already knows this. That's funny, because we have not proven it to be true.
- lutusp 10y ago
  It's also an argumentum ad populum.

oneeyedpigeon 10y ago

> all number sequences can be found within the digits of pi quite easily I dispute that, although I guess the general brute-force solution is 'easy' given infinite time.

geofft 10y ago
Yeah, this isn't known to be true. pi has not been proven to be a disjunctive number (a real number whose expansion contains all possible finite strings), let alone a normal number (where all finite strings occur with the probability you'd expect if the digits were random). Both of these, however, are generally conjectured to be true, but it's just a conjecture. https://oeis.org/wiki/Disjunctive_numbers#Is_pi_a_disjunctive_number.3F https://oeis.org/wiki/Disjunctive_numbers#Is_pi_a_disjunctiv... https://en.wikipedia.org/wiki/Normal_number https://en.wikipedia.org/wiki/Normal_number
lutusp 10y ago
>> all number sequences can be found within the digits of pi quite easily > I dispute that, although I guess the general brute-force solution is 'easy' given infinite time. Look at it this way -- if it were not true, then the digits of Pi would not be normally distributed (see https://en.wikipedia.org/wiki/Normal_number https://en.wikipedia.org/wiki/Normal_number), and that would be a rather extraordinary mathematical finding. If Pi's digits are normally distributed, then one can reliably predict the time required for finding any particular digit sequence using probability theory. And given the presumption of normalcy, that probability is the same for any digit sequence of a given length. The probability for finding a given test digit sequence in the first 100 million digits of Pi is given here: https://www.angio.net/pi/whynotpi.html https://www.angio.net/pi/whynotpi.html But it has to be emphasized that, given a finite test sequence and an infinite sequence of Pi's digits as a search space, the probability is 1.0.
- oneeyedpigeon 10y ago
  You're both giving me too much credit. I was merely making the less sophisticated point that it's not 'easy' to find an arbitrary-length sequence in pi because that might take longer than the lifespan of the universe when the needle gets long enough. Your response was much more interesting, though, thanks :)