Divide any circle’s circumference by its diameter and you get pi. But what, exactly, are its digits? Measuring physical ...

Celebrate Pi Day and read all about how this number pops up across math and science on our special Pi Day page. Grab something circular, like a cup, measure the distance around the circle, and divide ...

Uncover the surprising connection between Ramanujan's pi formulas and the universe. Learn how his century-old math helps explain turbulence, black holes, and more.

The holiday was created in 1988 by Larry Shaw, a physicist at the Exploratorium science museum in San Francisco.