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Blue Gene/P Reaches Sixty-Trillionth of Pi Squared

Posted by timothy on from the just-warming-it-up dept.

Reader Dr.Who notes that an Australian research team using IBM's Blue Gene/P supercomputer has calculated the sixty-trillionth binary digit of Pi-squared, a task which took several months of processing. Snipping from the article, the Dr. writes: "'A value of Pi to 40 digits would be more than enough to compute the circumference of the Milky Way galaxy to an error less than the size of a proton.' The article goes on to cite use of computationally complex algorithms to detect errors in computer hardware. The article references a blog which has more background. Disclaimers: I attended graduate school at U.C. Berkeley. I am presently employed by a software company that sells an infrastructure product named PI."

26 of 212 comments (clear)

  1. Different outcomes by garcia · · Score: 5, Funny

    From the blurb:

    Disclaimers: I attended graduate school at U.C. Berkeley. I am presently employed by a software company that sells an infrastructure product named PI.

    Oh, I expected the sentence to end with, "...and I still don't know why the fuck anyone cares about a number this long."

    I'm going to the bar. Who's with me?

    1. Re:Different outcomes by chebucto · · Score: 2

      After waiting minutes for an answer, I decided to RTFA and, well, there is a reason (or at least a good excuse)

      one application for computing the digits of Pi is to test the integrity of computer hardware and software, which is a focus of Baileyâ(TM)s research at Berkeley Lab. âoeIf two separate computations of digits of Pi, say using different algorithms, are in agreement except perhaps for a few trailing digits at the end, then almost certainly both computers performed trillions of operations flawlessy"

      --
      The English word fart is one of the oldest words in the English vocabulary.
    2. Re:Different outcomes by maxwell+demon · · Score: 2

      Well, pi just has an infinitely long period. :-)

      --
      The Tao of math: The numbers you can count are not the real numbers.
    3. Re:Different outcomes by SuricouRaven · · Score: 2

      So compare digits sixty trillion, sixty-trillion and one, sixty-trillion and two... if they manage to match a thousand consecutive digits, the chance of doing that just by luck is 1/(2^2000). Or about 10^-602. Not a lot.

      Tiny but non-zero probabilities make mathematicians sleep restlessly. It's just untidy.

    4. Re:Different outcomes by StripedCow · · Score: 2

      why the fuck anyone cares about a number this long

      Because... if we have more binary digits of Pi, we can search for subsequences of digits representing mp3 songs. Using that, we can show that RIAA is wrong, because as a matter of fact, you can't copyright mathematics.

      --
      If Pandora's box is destined to be opened, *I* want to be the one to open it.
  2. How many digists of pi do you know? by TroyM · · Score: 3, Informative

    http://www.toothpastefordinner.com/031208/how-many-digits-of-pi-do-you-know.gif

    1. Re:How many digists of pi do you know? by MoonBuggy · · Score: 3, Interesting

      Re:How many digists of pi do you know?

      ...one?

    2. Re:How many digists of pi do you know? by jamesh · · Score: 2

      about 5 probably. My daughter can recite 50 or 100 or something like that.

    3. Re:How many digists of pi do you know? by the_humeister · · Score: 4, Informative

      I know all of them. I just don't know which order they go in.

    4. Re:How many digists of pi do you know? by Abstrackt · · Score: 4, Informative

      "How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics!" There you go, Pi to 14 digits in an easy to remember package. Count the letters in each word to get the right digits.

      --
      They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance. - Terry Pratchett
    5. Re:How many digists of pi do you know? by arth1 · · Score: 2

      "50 or 100 or something like that"?
      That's like saying you have "1 or 2 cars or something like that" -- far too imprecise to be useful. In fact, 0 would satisfy "50 or 100 or something like that".

    6. Re:How many digists of pi do you know? by arth1 · · Score: 2

      "How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics!" There you go, Pi to 14 digits in an easy to remember package. Count the letters in each word to get the right digits.

      Easily beaten by this common and far more memorable verse:

      How I wish I could enumerate Pi
      "Eureka!" cried the great inventor
      "Christmas pudding, Christmas pie
      is the problem's very center!"

      After hearing that one once, I could not help but remember pi to 20 decimals.

      If I want to be more precise, arccos(-1) will do.

    7. Re:How many digists of pi do you know? by dbc · · Score: 2

      Ha ha.... while true, I sympathize with the grandparent. My daughter is also a Pi digit memorizer. She adds a few digits every so often, I can't keep track of how many she knows. I'd guess 75 or 100 or something like that. :) I don't think she knows or cares exactly how many digits of Pi she has memorized, as long as it is more digits than anyone else she meets...

  3. Re:pi Squared? by MoonBuggy · · Score: 2

    Can't you just square Pi?

    Well, yes, but doing so to vast precision requires you to to crunch a vast number of digits of pi, so I imagine it's all largely the same in the end.

  4. Not a disclaimer ... by Anonymous Coward · · Score: 2, Informative

    "Disclaimers: I attended graduate school at U.C. Berkeley. I am presently employed by a software company that sells an infrastructure product named PI.""

    That's *not* a DISCLAIMER. That's a DISCLOSURE.

  5. Re:Only one binary digit? by stillnotelf · · Score: 4, Funny

    Well, it's a quantum supercomputer, so...yes.

  6. Numberists! by 2.7182 · · Score: 2

    Why not compute digits of e? What's all this obsession with pi? For me, this time it's personal.

    1. Re:Numberists! by biryokumaru · · Score: 2

      They should calculate pi*e. Knowing that number to such detail would be... delicious.

      --
      When you're afraid to download music illegally in your own home, then the terrorists have won!
    2. Re:Numberists! by Eudial · · Score: 5, Interesting

      Especially given that pi is a stupid constant that makes no sense.

      --
      GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
  7. Re:Only one binary digit? by Daniel+Dvorkin · · Score: 2

    1, in base pi.

    --
    The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
  8. Easy to calculate by Lulu+of+the+Lotus-Ea · · Score: 2

    It's plain easy to calculate the sixty-trillionth digit of Pi... as long as you don't care about the digits that come before it: http://www.sciencenews.org/sn_arc98/2_28_98/mathland.htm.

    --
    Buy Text Processing in Python
  9. Re:Pi not useful at galactic scale to high accurac by martin-boundary · · Score: 2

    Only kind of. Ever hear about the Gauss Bonnet theorem? In a curved space, the value of Pi still matters.

  10. Re:Error in, error out by martas · · Score: 2

    That was clearly meant for illustrative purposes; the complete statement would have been "if you knew the precise radius of a circular object approximately the size of the Milky Way galaxy, then a value of Pi to 40 digits would be more than enough to compute its circumference to an error less than the size of a proton." It was left up to the reader to infer the precise meaning of the shortened statement. Apparently you failed to do so, either due to lack of ability, or because you had adversarial intentions (e.g. wanted to demonstrate your intelligence by finding an error in the article, however inconsequential to the main issue at hand).

    --
    weinersmith
  11. A time to crack wise... by Torodung · · Score: 2

    I think it would be tremendously funny to find out, at some suitably ridiculous decimal place, that all subsequent places are zero repeating. It would utterly break some people's heads to find out that the number is only "very, very particular," rather than "irrational."

    It is the one hope that holds my interest when I read about crunching these numbers.

    1. Re:A time to crack wise... by Anonymous Coward · · Score: 3, Informative

      I'm sorry to destroy your one hope.

  12. Re:What a waste of time! by aquila.solo · · Score: 2

    Since they're calculating in binary, your taking ten attempts to guess isn't really something to brag about. ;-)