Why, might you ask, should anyone want to celebrate a mathematical constant which allows you to calculate the area inside a circle?

As unlikely as it may seem, the number pi, or 3.14159… has been crucial to the development of modern life. As far back as the ancient civilizations of Babylon and Egypt, people needed approximations of pi to deal with the flooding of the Tigris, Euphrates and Nile rivers, for astronomy, and for surveying and building ziggurats and pyramids. The ancient Greeks were the first to study pi for its own mathematical sake.

Today, 4,000 years after people first discovered how useful pi could be, we are about to celebrateInternational Pi Day. The first time a day was dedicated to pi was on March 14, 1989 at the Exploratorium, a museum of science, art and human perception in San Francisco. The idea was the brainchild of Larry Shaw, a physicist at the center. 

Read more here.