Happy Pi Day!

When I was a teacher, on March 14, I'd take packaged snack cakes to school to share with my students. We'd eat them, of course. Eventually. First, though, we'd measure circumference and diameter and figure the area. Because today isn't about snack cakes, or even pie. It's Pi Day!

Pi is one of those things that has the power to confound. It's a mathematical concept approximated as 3.14 (hence March 14) which represents the ratio of a circle to its diameter. In actuality, Pi has over 1 trillion digits past the decimal point -- and it never repeats!

OK, so middle schoolers like Pi Day because their teachers inevitably feed them. But what, really, is so important about pi?

Steven Stogartz wrote for The New Yorker, "What distinguishes pi from all other numbers is its connection to cycles. For those of us interested in the applications of mathematics to the real world, this makes pi indispensable. Whenever we think about rhythms—processes that repeat periodically, with a fixed tempo, like a pulsing heart or a planet orbiting the sun—we inevitably encounter pi." Engineers use pi to design buildings that can withstand earthquakes. Scientists who study ocean waves use pi in their calculations. Our ability to communicate wirelessly -- in other words: by cell phone -- are dependent on electromagnetic waves, which can also be measured using pi.

As you're enjoying a slice of pie, and rolling your eyes at mathematicians for getting so excited about 3.141592653..., realize that pi is necessary to our wireless world.