Pi Day--not
Pi Approximation Day, i.e. 22/7--is today, and I'm glad. While I didn't take the sciences route after high school, I did heartily enjoy my mathematics and geometry classes, and there's something wonderful about
π, the irrational number (3.14159...) that manages the ratio of any Euclidean plane circle's circumference to its diameter, is a number of note. It's certainly the irrational number that I, and other non-mathematicians, have the greatest acquaintance with--
e isn't obviously relevant, but the size of a circle certainly is! Why is π that irrational number? What is its history? What is its meaning?
David Blatner's 1999
The Joy of Pi (official site
here) explains all this. Very readable, in the almost jocular tone of the 1990s popular science subgenre that I'd not realized I'd missed until I read Blatner's clear prose,
The Joy of Pi does a very nice job of this, explaining how the need of architects in the ancient Middle East and China to build durable buildings and of land surveyors or allocate land led first to approximations of the value of π, then to the first calculations of the number, then to the ever-continuing, never-ending, refinements of the value of this number. π, it seems, has become iconic, the numbers of digits of π calculated--in the billions at Blatner's writing--being irrelevant for any real-world application. π is an irrational number of transcendant importance, worthy of effort by mathematicians as famously competent as the Chudnovsky brothers or as wacked-out as any number of cranks who believe that their value of π reveals the true nature of the universe. Indeed,
The Joy of Pi ends with Carl Sagan's
Contact and the meaning--it turns out--our universe's creators embedded in that number. All of this, mind, with text quite literally wrapped by the first million digits of pi wrapping from front to back cover.
A slim read,
The Joy of Pi is a great read. Do read it; even non-math fans will get caught up by the human side. Who doesn't want to find out why the universe works the mysterious ways it does?