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Google Smashes the World Record For Calculating Digits of Pi (wired.co.uk)

Pi just got bigger. Google's Compute Engine has calculated the most digits of pi ever, setting a new world record. From a report: Emma Haruka Iwao, who works in high performance computing and programming language communities at Google, used infrastructure powered by Google Cloud to calculate 31.4 trillion digits of pi. The previous world record was set by Peter Trueb in 2016, who calculated the digits of pi to 22.4 trillion digits. This is the first time that a publicly available cloud software has been used for a pi calculation of this magnitude.

Iwao became fascinated by pi when she learned about it in math class at school. At university, one of her professors, Daisuke Takahashi, was the record holder for the most-calculated digits of pi using a supercomputer. Now, y-cruncher is the software of choice for pi enthusiasts. Created in 2009, y-cruncher is designed to compute mathematical constants like pi to trillions of digits. "You need a pretty big computer to break the world record," says Iwao. "But you can't just do this with a computer from a hardware store, so people have previously built custom machines." In September of 2018, Iwao started to consider how the process of calculating even more digits of pi would work technically. Something which came up quickly was the amount of data that would be necessary to carry out the calculations, and store them -- 170 terabytes of data, which wouldn't be easily hosted by a piece of hardware. Rather than building a whole new machine Iwao used Google Cloud.

Iwao used 25 virtual machines to carry out those calculations. "But instead of clicking that virtual machine button 25 times, I automated it," she explains. "You can do it in a couple of minutes, but if you needed that many computers, it could take days just to get the next ones set up." Iwao ran y-cruncher on those 25 virtual machines, continuously, for 121 days.

22 of 132 comments (clear)

  1. Re:Where... by hcs_$reboot · · Score: 4, Funny

    You can get even more precision: 10 (in pi base)

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  2. Re:Where... by Jason+Levine · · Score: 5, Funny

    Back in college, I jokingly sent my friend 1 million digits of PI. This was on a VAX terminal college e-mail system and he didn't know how to delete the message without scrolling through the entire thing. So he sat there hitting page down over and over until he reached the bottom. For some reason, he didn't seem to appreciate the practical joke.

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  3. Tolerance for error by Black+Parrot · · Score: 2

    So if her last digit was wrong, how far off would she be on a calculation of the diameter of the observable universe?

    Does pi have any meaning when you get details beyond the Planck length?

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    1. Re:Tolerance for error by kalpol · · Score: 3, Informative

      I've read somewhere you only need 40 digits to calculate the diameter of a circle the size of the observable universe to a precision within the diameter of a hydrogen atom.

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    2. Re:Tolerance for error by ImprovOmega · · Score: 4, Informative

      Regarding your edit, you do mean precision. And the measure I prefer is computing the volume in cubes with Planck-length edges of a sphere with the diameter of the observable universe. But even that only takes you out to 200 or so digits.

      Here's some data on the size of the observable universe in Planck-lengths. 200 digits of pi should be sufficient to precisely compute the number of Planck-length cubed units in our observable universe. From a strictly physical perspective, more than this level of precision in meaningless.

  4. Hardware Store by sycodon · · Score: 4, Funny

    "But you can't just do this with a computer from a hardware store...

    I always get my computers from Home Depot.

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    1. Re:Hardware Store by pslytely+psycho · · Score: 2

      Home Depot?
      Don't you know "Ace is the Place?"

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  5. Re:Where... by xonen · · Score: 2

    It's waiting for the copyright lawyers from Hollywood to make a claim.

    After all, the binary data from every move that was ever made and ever will be made is already in the number pi.

    Actually, if you would describe the whole universe in binary format -or decimal if you wish-, it's already in the number pi. Somewhere.

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  6. Why does the headline say Google? by Anonymous Coward · · Score: 2, Insightful

    Google did nothing other than sell the environment. Maybe the headline should say Intel because it may have built the actual hardware, or Cisco because its switches were used somewhere?

  7. Re:Where... by badboy_tw2002 · · Score: 2

    Remind me of the time I drop rock on friend Grog. He not like rock smash him. He beat me with club. Then saber tooth tiger eat whole family. Me laugh last!

  8. Re:Where... by MrLogic17 · · Score: 2

    You mean 1.0 (in base pi), right?

  9. Re:How to prove it? by DickBreath · · Score: 2, Interesting

    If it is an algorithm calculating PI, it would be mathematically provably correct. This formula (there are more than one) calculate PI to arbitrary precision. All that is left to question is the correctness of the implementation.

    Since PI has been independently calculated by so many different implementations over time, the initial digits of them can be cross checked for correctness. One early effort, was it in the 1950s maybe(?) calculated PI to 2000 places, and that was called a 'stunt' to show off a computer. If other implementations get the same first 2000 places, can we assume their implementation of whatever formula they use is correct?

    Maybe you're saying something different: that someone could commit fraud by stopping generating PI and then substituting a random number generator. In that case, their results will disagree with the next person who tries to beat their record and it will be obvious.

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  10. OK, that's just sad. Really. by grep+-v+'.*'+* · · Score: 4, Funny

    "But instead of clicking that virtual machine button 25 times, I automated it,"

    She needs 170 terabytes of space across 25 computers for 121 days to produce 31.4 (Ha!) trillion digits. And she's worried about clicking a button a few times?? Hell, even I'm not that anal unless it was a trivial solution. (for a in `seq 1 25` ; do ./push ; done)

    First world problems, I guess.

    So in all seriousness, how do you check that? Run it again and see if it produces the same number? If there's a timing bug, it'll differ. If there's (say) a BAD timing bug, it won't; but might differ on a different machine. Or numeric coprocessor problems: One Two Three. Or cosmic rays actually flipping a bit somewhere. (ECC CPUs?) I realize this is all fun and games, but how do you know that it's actually correct? See if you can use it to successfully square the circle, in which case it's not?

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  11. Re:Where... by chaotixx · · Score: 2

    Whats the file size in terms of Firefox Send?

    It it's too big, just compress it.

  12. I wonder how much it cost by turp182 · · Score: 4, Interesting

    In terms of electricity.

    Or how much would it have cost someone who doesn't work at Google.

    25 servers, 121 days, 170 terabytes of data.

    And then the real question, was it really WORTH it?

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  13. Re:Where... by AmiMoJo · · Score: 3, Interesting

    Actually, if you would describe the whole universe in binary format -or decimal if you wish-, it's already in the number pi. Somewhere.

    Can't be, because some universal constants are irrational, and therefore cannot be in another number.

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  14. Re:Where... by squiggleslash · · Score: 2

    Probably not, 1 in any base is 1. A number in its own base is 10. (Hence ten, in decimal, is written 10, and two, in binary, is written 10.)

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  15. Why would you calculate Pi to so many digits? by DrSpock11 · · Score: 2, Funny

    Seems irrational to me.

  16. Re:Where... by MrLogic17 · · Score: 2

    *sigh* I knew that.

    [slowly turns in nerd-card]

  17. Re:Where... by Trailer+Trash · · Score: 3, Funny

    Whats the file size in terms of Firefox Send?

    It it's too big, just compress it.

    And if that doesn't work, compress it again!

  18. Re:Today is PI day by Killall+-9+Bash · · Score: 2

    Observing a holiday changes it.

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  19. Re: Where... by Bengie · · Score: 3, Funny

    Would you say that it's irrational to do so?