On March 14, the Exploratorium is the place to celebrate pi. A procession of digits circled the Exploratorium's new golden pi shrine approximately 3.14 times while kids tossed pizza pie and ate apple" pie.
The Exploratorium's Larry Shaw leads the annual procession. Think of him as the pi piper; 25 years ago, he created Pi Day.
"I was just curious about pi, and eating pie with pi," he said.
Over the past quarter century, Pi Day has spiraled out from its birthplace to celebrations all around the world, including right up the street at some San Francisco high schools.
It turns out Pi Day falls just as Anne Lyon's geometry class begins its study of circles. After all, pi is the circumference of a circle divided by its diameter -- a number that's estimated at 3.14, but actually goes on forever. So to help them remember it forever, how about circles filled with apple and strawberry rhubarb?
"My favorite part of Pi Day is pi -- both the number and the food -- the food more so a little bit," freshman Lorenzo Barrar said.
Pairing pie with pi became so popular that Congress actually passed a bill declaring March 14 Pi Day.
It's an even more special day for the Exploratorium's senior scientist. Charles Carson and his physics teacher sweetheart were married at 3:14 p.m., standing on that pi shrine and had a bite of pie to celebrate their infinite union.
