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Pi Calculated To Record 2.5 Trillion Digits

Joshua writes "Researchers from Japan have calculated Pi to over 2.5 trillion decimals using the T2K Open Supercomputer (which is currently ranked 47th in the world according to a June, 2009 report from Top500.org). This new number more than doubles the previous record of about 1.2 trillion decimals set in 2002 by another Japanese research team. Unfortunately, there still seems to be no pattern."

33 of 432 comments (clear)

  1. Congratulations! by Petersko · · Score: 4, Funny

    These researchers are now in possession of the most useless piece of information in science.

    3.14 was very useful. 3.1415? Even more so. But after that it's diminishing returns, baby. 2.5 trillion digits? Good heavens. Of course it never repeats - we kind of knew that already.

    Pointless mathematical dick-sizing. Problem is, this dick is so huge no vagina will ever make use of it.

    1. Re:Congratulations! by Anonymous Coward · · Score: 5, Funny

      The point is that someday, a computer instructed to compute pi indefinitely will simply respond, "Why don't you just go fuck yourself?" Then we'll know that the machine has achieved sentience.

    2. Re:Congratulations! by Snarfangel · · Score: 5, Funny

      The point is that someday, a computer instructed to compute pi indefinitely will simply respond, "Why don't you just go fuck yourself?" Then we'll know that the machine has achieved sentience.

      I'd be even more impressed if it said "Sure thing, I'll get right on it!" and then pretended to work while surfing the web.

      --
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    3. Re:Congratulations! by daver00 · · Score: 5, Informative

      We know without a doubt that it never repeats - if it did it would be a rational number, it has been proven to be an irrational number, moreso it is transcendental. We also know the exact pattern, take the taylor series of sin about pi/4, you get an elegant and simple series solution for pi.

      That is not the point. The point is and exercise in computing, everything we do in computing involves rational numbers only (floats) and there is substantial error involved with this. It is computationally difficult to deal with large numbers, hence any method to do this more effectively is a gain for science.

    4. Re:Congratulations! by sys.stdout.write · · Score: 5, Insightful

      Knowing (thinking) that something doesn't repeat and PROVING that it doesn't repeat are two ENTIRELY different things. I am guessing your maths/science education either stopped very early or you didn't do too well in either.

      I think it's funny that you are insulting someone's math education immediately after you imply that no proof exists showing pi not to repeat.

    5. Re:Congratulations! by east+coast · · Score: 5, Funny

      I'd be even more impressed if it said "Sure thing, I'll get right on it!" and then pretended to work while surfing the web.

      Hey! That's my job.

      They make a machine to take every job. Before I know it they'll have a machine loafing at the corner bar, smoking cigarettes and downing Jim Beam and Coke like it was water.

      --
      Dedicated Cthulhu Cultist since 4523 BC.
    6. Re:Congratulations! by commodoresloat · · Score: 5, Insightful

      They make a machine to take every job. Before I know it they'll have a machine loafing at the corner bar, smoking cigarettes and downing Jim Beam and Coke like it was water.

      I see you've met Bender.

    7. Re:Congratulations! by commodoresloat · · Score: 4, Funny

      Pointless mathematical dick-sizing. Problem is, this dick is so huge no vagina will ever make use of it.

      Huge? What are you talking about? It's barely over 3 inches!

    8. Re:Congratulations! by shiftless · · Score: 5, Funny

      I hear those black hole's are pretty loose

      Racist!

  2. Of course there's a pattern! by Anonymous Coward · · Score: 5, Insightful

    Otherwise how would you calculate it? The "pattern" is it matches the stream of digits produced by a simple algorithm!

  3. 100 years from now... by Anonymous Coward · · Score: 5, Funny

    Researchers will find that Pi begins to repeat after 2,500,000,000,001 digits.

  4. No one needs more than 50 digits by Anonymous Coward · · Score: 5, Informative

    A nice little article on why it's useless to know pi to more than 50 digits in this universe.
    http://everything2.com/title/Too%2520small%2520a%2520Universe%2520to%2520memorize%2520Pi

    1. Re:No one needs more than 50 digits by kipling · · Score: 4, Insightful

      So you are criticising my preparation for the afterlife? Other people memorise wodges of religious texts, I choose to memorise digits of pi ...

      --
      -- open source? sounds like the real book --
    2. Re:No one needs more than 50 digits by commodoresloat · · Score: 4, Funny

      No one needs more than 640 digits

      Fixed that for you.

    3. Re:No one needs more than 50 digits by LS · · Score: 5, Insightful

      The article isn't really that informative. It takes things too literally, using the known size of the universe to determine the largest possible physical circle and the smallest possible length (planck length) to determine the maximum precision and he comes up with 50 digits. But it wouldn't be too hard to come up with an application that uses more than 50 digits of pi. A new encryption algorithm could use sequences in pi, but this has nothing to do with physical circles. Math is abstraction, and there are fields in math that are so abstract that you can't even correlate them with a physical measure. It's very silly to say that knowing pi to more that 50 digits is useless.

      LS

      --
      There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
  5. The pattern. by Anonymous Coward · · Score: 5, Funny

    Of course there's a pattern. I mean, otherwise, I wouldn't be able to match it with 3.[0-9]{1,}

  6. Re:Well... by Anonymous Coward · · Score: 5, Insightful

    I fail to see how not understanding the word "seems" is insightful.

  7. Re:Question about Pi and circles. . . by e9th · · Score: 5, Funny

    I've constructed a perfect circle, with a circumference of 1 meter. It's the diameter I'm having trouble with.

  8. Re:Well... by Antique+Geekmeister · · Score: 5, Interesting

    Of course there's a pattern, even a simple and elegant one. It's equal to:

    4 * (1 -1/3 + 1/5 -1/7 +1/9 -1/11 +1/13 -1/15 etc., etc., etc.)

    Just because the pattern doesn't come out pretty in a decimal representation doesn't mean it's not elegant or not a pattern.

  9. Re:Question about Pi and circles. . . by biryokumaru · · Score: 5, Insightful

    To travel from one point to another, an object must pass through all the points in between. There are an infinite number of points "in between," thus to move at all, an object must travel through an infinite number of points in a finite time. Clearly this definition of reality is flawed: stop using it.

    --
    When you're afraid to download music illegally in your own home, then the terrorists have won!
  10. I've got an even more simple pattern by sayfawa · · Score: 5, Funny

    I heard somewhere it's equal to the circumference of a circle divided by it's diameter...

    --
    Free the Quark 3 from asymptotic confinement! Bring your charm! Don't get down! All colours and flavours welcome!
    1. Re:I've got an even more simple pattern by LUH+3418 · · Score: 5, Interesting

      Well, I'm not a mathematician, but it seems to me that's precisely why there isn't a repetitive pattern in the numerical representation. If there was, that would mean the ratio can be exactly defined by a finite amount of information. It seems to me that asking for a finite decimal represensation of pi is similar to asking someone to exactly represent a circle out of line segments (or to exactly define a circle using a finite set of points). The circumference of the circle is the sum of the length of line segments delineating the circle. The problem is that you need infinitely many of them to exactly define the circle.

  11. Re:Well... by telso · · Score: 5, Interesting

    I always found the Basel problem to be the most elegant converging series involving pi (being the square root of six times the sum of the reciprocals of the squares), probably because there are so many (elegant) proofs of this (pdf), because it's so simple to understand yet not so simple to prove on a cursory inspection, and because it's the specific case that generalized to one of the most important unsolved problems in mathematics.

  12. Re:Question about Pi and circles. . . by Anonymous Coward · · Score: 5, Insightful

    Not necessarily. We can't really know about anything smaller than the Planck length, so in practical terms your paradox probably fails. The universe may be discrete on those scales.

  13. Re:Question about Pi and circles. . . by russotto · · Score: 5, Informative

    Pi was shown to be irrational in 1768 and transcendental in 1882, finally putting to rest the ancient problem of "squaring the circle".

  14. Re:Question about Pi and circles. . . by godrik · · Score: 5, Informative

    I believe you are confusing rational numbers and real numbers. rational numbers are those that can be expressed as p/q where p and q are prime integers. The existence of real numbers that are not rational follows from cantor's diagonal argument : http://en.wikipedia.org/wiki/Cantor's_diagonal_argument

    Proofs of the irrationality of pi can be found on wikipedia : proof

    The sqr root of a negative is not defined in the real set but only in the complex set. http://en.wikipedia.org/wiki/Complex_numbers

  15. Re:Well... by Kagura · · Score: 4, Funny

    00000001 110000000
    00001110 001110000
    00110000 000001100
    01000000 000000010
    01000000 000000010
    01000000 000000010
    00110000 000001100
    00001110 001110000
    00000001 110000000

    About two trillin digits down the line, in base 2, scientists discovered a curious pattern... is it purely random, or perhaps a message from the Creators?

  16. Pi should be 2 pi by The_Duck271 · · Score: 4, Interesting

    There's a good argument that the choice of pi = (circumference / diameter) was unfortunate; it should have been (circumference / radius). In the light of modern mathematics it seems clear that the radius is more "fundamental" than the diameter; choosing pi = (circumference / radius) = 6.28... gives a number of nice things like:
    A = (1/2)pi r^2, just as E = (1/2)m v^2 or d = (1/2)a t^2, and for the same reason.
    In general, in the current convention, 2pi seems to show up a lot more than pi, e.g. there are 2pi radians in a circle, sin(x) has period 2pi, etc. All these would become simply pi with the (circumference / radius) convention

  17. Compression by The_mad_linguist · · Score: 4, Funny

    Wait, we can record a ridiculous amount of data (2.5 trillion digits!) just by calculating pi?

    Best.

    Compression Algorithm.

    Evar!

  18. Re:Question about Pi and circles. . . by YttriumOxide · · Score: 4, Informative

    Not necessarily. We can't really know about anything smaller than the Planck length, so in practical terms your paradox probably fails. The universe may be discrete on those scales.

    Mod parent up - AC or not... I had to scroll a LONG way before seeing this argument and was going to post it myself if no-one else had. There's a lot of "weird" points about the universe that just don't seem to make sense. Posts such as the GP saying, "Clearly this definition of reality is flawed: stop using it." (with regard to travelling through an infinite number of points in a finite time) are all well and good, but don't go anywhere towards explaining WHY this definition is flawed. By defining the universe as discrete rather than continuous, it is no longer flawed, as with many other oddities and apparent paradoxes.

    This would also potentially have an interesting effect on Pi in that if the number itself is truly irrational, then it's also wrong for every case we're using it - we actually should HAVE TO round it off somewhere to be correct when using it in models of the physical universe.

    --
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  19. Re:Well... by severoon · · Score: 4, Informative

    The f1r5t p0st is right. Just b/c we haven't found one yet doesn't mean there isn't one. However, the fact that Johann Lambert proved it in 1768...does.

    --
    but have you considered the following argument: shut up.
  20. why we do this sort of stuff by wickerprints · · Score: 4, Insightful

    It's a great way to test the performance of these supercomputers, to ensure that their calculations are correct. The calculation of pi to additional decimal places beyond what was previously known is never done with just a single method--otherwise, it is impossible to verify the additional digits. It is always done with two different algorithms to ensure that the result is valid. There are many rapidly converging algorithms (e.g., variations on AM-GM methods can be quadratically convergent or better; BBP-type digit extraction methods; and of course, classic Ramanujan series-type methods). However, computing pi to so many decimal places has much less to do with the chosen algorithm than it has to do with the memory- and computing time-efficient implementations of such algorithms in massively parallel architectures. Thus these calculations serve as very good tests for the robustness of supercomputers. The result is also verifiable to previously known digits, and even beyond the previous record, it is possible to perform statistical analyses to determine whether there are any significant deviations in the distribution of digit frequencies.

    So, in summary, it is hardly a useless computation. Not that you're going to get an explanation like this from your usual news sources, which generally do not write for technical audiences.

    Also note that distributed computing resources such as Folding@home, or even the Great Internet Mersenne Prime Search don't bother with calculating pi, as the purpose of these projects is to make new discovers in their respective fields of interest.

  21. Re:Well... by arotenbe · · Score: 4, Informative

    There are, however, irrational--indeed, transcendental--numbers that follow a discernible decimal pattern, like the Liouville constant.

    --
    Tomato wedge sperm darts that are Republican.