• Communication Article

    By Michelle Lis
    Assistant Chair, Math Department

    Each year on March 14, the world celebrates Pi Day. It officially begins at 1:59 pm so you have 3.14159. There are parties serving pie and contests involving it. There are Pi Day t-shirts and posters. There are papers written about it and movies made about it.  Even the greeting card industry has jumped on board as you can send cards for Pi Day. Princeton, New Jersey, has a weekend long celebration for Pi Day since it coincides with Albert Einstein's birthday and he lived there from 1936 until his death in 1955.

    Pi has been manually calculated to 527 digits by William Shanks. He spent over 20 years calculating pi to 707 decimal places in 1873 but only the first 527 places were correct. It has been approximated using a computer to 13.3 trillion digits in October of 2014 (www.numberworld.org).

    Pi is one of the most recognized mathematical constants in the world (Brown, 2008).  How could a number that is so well known possibly be "old school"? A physicist Michael Harti believes we should not really care about pi but rather 2 multiplied by pi or about 6.28 which he calls "tau." Since most people reference a circle by its radius rather then its diameter, Harti believes we should be looking at the ratio of the circumference to the radius of the circle. If that were the case we would then have 2πr/r = 2π.

    If we were to celebrate Tau Day instead of Pi Day we should be gearing up for June 28. You just never know, it might catch on.




    Brown, James Robert. 2008. Philosophy of Mathematics: A Contemporary Introduction to the World of Proofs and Pictures. 2nd ed. New York, NY: Routledge.

    Harti, Michael. "Tau Manifesto." tauday.com. N.p., n.d. Web. 4 Jan. 2016

    Landau, Elizabeth. "On Pi Day, Is 'pi' under Attack?" CNN. Cable News Network, 14 Mar. 2011. Web. 04 Jan. 2016.

    Yee, Alexander J. "The First Scalable Multi-threaded Pi-benchmark for Multi-core Systems." Numberworld.org. N.p., 28 Dec. 2015. Web. 28 Dec. 2015.

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