Yesterday was Pi Day. It was, in fact, the Pi Day of the Century and, for most people, the Pi Day of a Lifetime. It is possible that some individuals will see Pi Days like the most recent twice in their lifetimes but the chances are good that they will be either too young or too old to wield their own fork on either occasion.

Pi is the name (actually the Greek letter π) given to the ratio of a circle’s circumference to its diameter. It is an irrational number which means calculating it leads to an infinite number of decimal places. To keep discussions from being infinitely long (although they may still be irrational), the number 3.14 is often used as a reasonable approximation. Since folks in the USA usually write dates as mm/dd/yy, the fourteenth of March looks a lot like the short form pi and some clever person, taking advantage of the fact that the Greek letter and the English language name of a tasty edible are homophones, decided to call March 14 Pi Day and celebrate pie. In addition to being limited to people who speak English, the holiday is pretty much restricted to the United States of America. For most of the rest of the world, including other residents of North America, yesterday was 14/3/15 with no connection to either circles or baked goods. But, for English speakers living between Mexico and Canada, yesterday was 3/14/15. The short form pi, when extended by a couple of digits, is 3.1415 and those two digits are what make yesterday the Pi Day of the Century.

I chose to celebrate my Pi Day of a Lifetime at the Bluebird Bakery in Glendale. Glendale is known for its black squirrels and has a number of squirrel statues — almost none of which are black — displayed around town. This was my second Pi Day visit to the Bluebird and I’m sure it won’t be my last. There are some very good goodies here.

That’s a peanut butter pie at the top of this post and several other varieties were available as well. I settled on key lime since it sort of hints at warmth and sunshine and that’s something I’m definitely ready for. The approximation of pi can be extended as far as desired and it is a simple matter to get the clock involved along with the calendar. I took the picture of my slice of pie exactly twenty-six minutes after 9:00 AM then carefully timed the eating so that I chomped down on the first bite at exactly 3/14/15 9:26:53.

The basis for Pi Day may be silly but some of its effects are not. Silliness is just the thing for drawing attention and the day is being used more and more to make kids aware of the practical uses of pi and some of those other numbers, too. Some area libraries and museums offered pi/pie related activities and an evening program at the Cincinnati Observatory Center demonstrated practical applications of pi along with pieces of pie from local restaurants. Throw in a mention or two of it being Albert Einstein’s birthday and those kids may just learn a little history, math, and astronomy without it hurting a bit.