Most people won’t know this: today is International Pi Day. It’s a day on which mathematicians celebrate that formula, which is an amazingly useful tool for many things, from equipment for the space program to forestry management in Maine.
Pi, symbolized by the Greek letter “π,” is a way to measure things involving circles, such as parachutes for slowing landings and the insides of living trees. More specifically, Pi is the ratio (comparative size) of a circle’s circumference (length around) to that circle’s diameter (length through the middle). That ratio, numerically, is recognized as 3.14159 for most uses, but it has been calculated out to over a trillion digits.
Thus, if you want to know the diameter of any part of that big spruce trunk behind your house, measure the part’s circumference and divide that number by Pi. Or, use a forester’s diameter tape, which has circumference measurements on one side and Pi-derived diameter measurements on the other.
(Brooklin, Maine)