The Exploratorium, San Francisco's hands-on science museum, is where the idea of Pi Day was born 25 years ago.
Pi is what you get when divide the circumference of a circle by the diameter. No matter the size of the circle, the answer is always pi, starting with 3.14 and going on forever.
Pi has been around since ancient times, but now it's the poster child for a mathematical movement. Pi Day also happens to be Albert Einstein's birthday. It's observed in classrooms around the country. Congress even voted to make it official.
The Internet is packed with pi propaganda and products. A Nobel Prize winning UC Berkeley professor helped create the website pizone.org.
"Pi is a number that appears all over the place in mathematics, the natural world, physics, science and exploring its properties is a great way to get kids and adults interested in science and math," Alex Filippenko said.
Physicist Larry Shaw is known as the prince of pi. He leads a pi procession including the first 125 digits of pi. Marchers circle the sacred pi shrine embedded in the center of the Exploratorium.
"It's totally the place to be if you are a numbers geek," pi enthusiast Lindsay Yazzolino said of the Exploratorium's events.
But the Exploratorium is moving. So a new pi tradition is about to start. Last year at the end of Pi Day, the shrine was lifted out of the floor and carefully placed in an appropriate storage container.
The Exploratorium's new building on the San Francisco waterfront doesn't open until next month. But on Pi Day, the hallowed shrine will be placed in its new home a few feet from the Embarcadero.
One critical part of the Pi Day celebration has always been eating pie. Thursday will be no exception. The Exploratorium will have a free celebration at 1 p.m. outside the new building. Everyone is invited to come out and join the fun as pi marches on.
ABC7 is the official television partner of the Exploratorium, which opens at its new location April 17. Over the next few weeks you'll get exclusive access and the first look at the new Exploratorium on ABC7 News.
Written and produced by Jennifer Olney