By Willy Stewart, PE

Pi Day is this Wednesday, March 14 (3.14 of course!).

Why are we so interested in Pi Day at Stewart? Because we are Pi!

If you took any math class in high school or college, you realize that the world around us “revolves” around Pi. If it is not straight, and hardly anything in this universe is, then Pi is part of the equation.

The ancient Babylonians calculated the area of a circle by taking 3 times the square of its radius, which gave a value of Pi = 3. One Babylonian tablet (ca. 1900-1680 BC) indicates a value of 3.125 for Pi, which is a closer approximation.

Pi has been known for almost 4,000 years but even if we took the number of seconds in those 4,000 years and calculated Pi to that number of places, we would still only be approximating its actual value. The record of manual approximation of Pi is held by William Shanks, who calculated 527 digits correctly in the years preceding 1873. Pretty impressive! Since the middle of the 20^{th} century, the approximation of Pi has been the task of computers, and in November 2016, one team took 105 days to verify 22.4 TRILLION digits of Pi.

*“Record approximations of pi” graph*

If you want to find your birthday within the Pi digits, __this website__ will allow you to do that. My birthday starts at the 7,277^{th} digit of Pi. Some of us are just nerdy enough that we need to know that!

Pi rules the universe and it is used all the time by NASA scientists and engineers to explore other planets. __This website__ has fun opportunities to solve stellar math problems faced by NASA scientists and engineers every day. __This site__ has dozens of interesting facts and fun information about Pi, including the one Pi Day Rap to end all Pi Day Raps (thank goodness!)

Pi shows up everywhere that circles do, and it appears in equations used by engineers of all disciplines, from the volume of a sphere:

To the buckling formula:

We need Pi in our world. It rounds us out nicely. Although the same could be said for pie, at Stewart, it’s Pi we love, so we celebrate it with our friends on March 14. Happy Pi Day, everyone!