Pi Day is Born
March 14th, 1988
(Note: While the image is AI generated, the research and writing was carried out by a human, me).
Today 36 years ago, Larry Shaw, an employee of San Francisco’s exploratorium, organized the first celebration of the mathematical constant pi, 3.14…, which has since become an international annual event for students of the mathematical sciences and others passionate about mathematics. Celebrations typically involve eating pie or holding contests on the recitation of its digits. In 2019, UNESCO designated pi day as the “international day of mathematics”.
Pi is by far the most famous irrational number in all of math and science, and it has been so for a long time. Babylonian clay tablets from about 4000 years ago have been found which imply that they approximated it as 25/8=3.125, and there is evidence that the Egyptians around the same time approximated it as 256/81. The first recorded method of calculating pi was found almost 2300 years ago by Archimedes, using what he called his “method of exhaustion” a precursor of modern calculus. There have also been regressive attempts at defining pi. For instance, in 1897 the Indiana legislature considered a bill that implied that, by fiat, pi=3.2, which evidently failed to pass because a mathematics professor happened to be present at the session.
Elementary school kids learn about pi first in the context of the ratio of the circumference of a circle to its diameter, but the constant has an eerie tendency to crop up in the most unexpected of places, such as in probability. The Indian mathematical prodigy Ramanujan found several infinite series converging to pi in the early 20th century, but as he only wrote the formulas in his notebooks, it is unknown how he arrived at this findings. Pi appears often in the context of oscillations, which is ultimately why it appears in what has been called “the most remarkable equation of mathematics” , Euler’s identity. The mathematics Youtube channel 3blue1brown popularized a highly surprising appearance of pi in the context of two blocks colliding with each other and a wall elastically on a frictionless plane.
