This week’s Math Munch is brought to you by the number pi, because Wednesday (March 14th) is Pi Day!
Pi is an irrational number – meaning that it cannot be written as a ratio of integers. Consequently, it’s decimal expansion goes on and on forever without any repeats. But, that doesn’t mean people haven’t tried to list as many digits of pi as they can! This site lists the first million digits of pi. This site sings many of them – the tune is rather catchy. And here you can search for strings of numbers in the decimal expansion for pi! I searched for my birthday, 10/01/87 – it occurs 885,826 digits after the decimal point!
Remember the alphametics puzzle creator, Mike Keith? Well, he writes poems and short stories in what he calls “Pilish,” in which the lengths of successive words represent successive digits of pi. Here’s an explanation of the different forms of Pilish. Mike holds the world record for the longest and second longest texts written in Pilish – they are his book, Not A Wake, and a short story, “Cadaeic Cadenza.”
Finally, as we celebrate pi on Wednesday, we should do so with some skepticism. In the opinion of some mathematicians, pi is the wrong constant. Inspired by this article by mathematician Bob Palais, some people have been speaking up in favor of the constant tau, which is double pi. Here’s our favorite Vi Hart on the issue of pi:
You’ve heard what pi sounds like. Want to know what tau sounds like?