The 21st annual Pi Day was celebrated at the Exploratorium on March 14, also known as 3.14159 and the date of Albert Einstein's birthday to mathematicians and Pi enthusiasts.

Pi Day events included a procession of over 100 digits of Pi throughout the museum and ended with a treat of berry and apple pie for the participants.

Pi Day followed tradition this year with a live web cast from inside the Exploratorium onto the museum's Web site. Staff educator's Lori Lambertson and Ron Hipschman hosted the web cast and invited Larry Shaw, Pi Day founder, to join.

Both Lambertson and Hipschman are both alumnae from SF State. After getting his Bachelor's degree in physics, Hipschman went on to be a professor at SF State for ten years, teaching Physics 101 to students from all different majors.

"I've been with the Exploratorium for 38 years and I just love it more than anything," said Hipschman, "I'm the Senior Assistant of Administration but my official title is "loose cannon"."

The live show was broadcasting in the center of the museum, while dozens of visitors watched to learn more about the infinite and irrational number. Shaw was proud to announce that it was the first day that U.S Congress had also recognized Pi Day as a national holiday.

One activity allowed participants see how Pi was originated. Children and adults gathered in a circle to make a circumference, while Lambertson, made diameters in the circle with a length of string. After she made three diameters and was left with only a fraction of string to make one more, onlookers were fascinated of where Pi comes from.

"Many people, including adults, don't know what Pi is," said Lambertson.

"Most schools just tell you it's a number and you learn how to punch it into your calculator without ever knowing its meaning," she said.

A live broadcast from Maryland at the Howard B. Owens Science Center displayed how staff educator, Virginia Casbourne, taught a group of kindergartners about Pi by making a chain of colored paper that corresponded to the different digits.

Hipschman shared a widespread love of Pi with "Piems" or, Pi poems, including haiku's and limericks devoted to the mysterious calculation. He also used Piphilology, which is a mnemonic technique used to remember the digits using words-- "How I need a drink, alcoholic in nature, after the tough chapters involving quantum mechanics," said Hipschman.

Afterwards, Shaw led a procession to circumambulate the Exploratorium's Pi shrine approximately 3.14 times while singing the happy birthday song to Albert Einstein who was born130 years ago. "It's an international geek holiday to perform Pi-related rites, sing Pi songs and eat ritual food, be it apple pie or pizza pie in honor of this special number," said Shaw.

Seven-year-old, Noah Battaglia, claims he can recite Pi up 194 digits. "It's my favorite number in the whole world and I wrote it out to 440 digits," said Battaglia. His parents said he has been obsessed with the number ever since his Family Project Day at school, when he was assigned to give a presentation about Pi.

"There's beauty and elegance in the number because it makes everyone, mathematicians and non-mathematicians interested in how it relates to life," said Lambertson.

Most importantly on Pi Day, people got to actually eat pie.