Amazingly, a pie is one of the best ways to illustrate pi. Take the circumference around the pie and divide it by the diameter across the pie. The resulting fraction is pi, a delicious ratio for a circle that divides into an infinity of non-repeating numbers. It starts off with 3.14159… which explains why Monday, March 14 is Pi Day at the downtown public library.
The brainchild of Tom Biesanz and Ruth Wishengrad, both freelance math educators in Santa Barbara, and with the enthusiastic support of the library’s Jody Thomas, Pi Day brings the playful approach mathematicians enjoy when they goof around with numbers.
Nothing illustrates that better than the Pi Clock developed by Skona Brittain, who has loved math since she was a little girl and took her master’s degree in the subject at Princeton. The expression at four o’clock, for instance, uses another infinite sequence — based in part on the Leibniz formula — that results in the number 4. When asked what Leibniz represents, Brittain laughed and said it means pi, too, but is a fun way to get there.
Brittain will explain more at the celebration and display some of her clocks, and Biesanz, Wishengrad, and Thomas have organized more games, Lego robotics, and art projects, all around the concept of having fun with math. There’s even an Albert Einstein dress-up contest; he would have turned 137 years old on Monday. Pi may go on forever, but the library event is limited to 4:30-7 p.m.