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Only 3.14 More Shopping Days Until Pi Day.


The "Giant Pi drop" attracts thousands of math fanatics as they celebrate the calendar representation of pi, 3.14159, at at 1:59 on March 14 at (


Larry Shaw, the father of Pi Day, leads a pi parade at the Exploratorium science museum in San Francisco on March 14, 2008. (Photo by Amy Snyder/Exploratoriu)

At precisely 1:59 p.m. on March 14, thousands of people all over the world will pause before their computer screens to watch the Giant Pi—a talking pi symbol with facial features—drop, much like the crystal ball that falls at midnight in Times Square on New Year’s Eve.

What’s the fuss? Why, it is Pi Day, of course. For centuries, mathematicians and elementary school students have contemplated the famous ratio that is the circumference of a circle divided by its diameter. The result turns out to be—so far at least—an infinite number known by the Greek letter pi. The first six digits of pi are 3.14159, so naturally the Giant Pi drops on March 14 (3/14) at 1:59 p.m.

Since its humble beginning two decades ago, Pi Day has developed into a major holiday, supercharged by the growth of the Internet, which unites aficionados of the never-ending number worldwide. Tens of thousands of people are expected to tune in this year to the annual drop of the Giant Pi at, says Allan Green, a spokesman for the Web site. Parties are held at schools, labs and offices. Actual pie—the round kind with a flaky crust—is the obvious fare of choice.

“It’s the Christmas of cyberspace,” Green says. “There are math nerds and geeks in all walks of life, not just in schools. There are some math wonks on Wall Street too.”

For hard-core mathematicians, pi, which is central to many equations, represents a numerical marvel that is similar to the famous conundrum, Which came first, the chicken or the egg? To the math world, the question is, Which came first, the circle or the ratio?

Mathematicians have calculated and recalculated pi for millennia looking for repetition or an end. Thinkers from Archimedes to Isaac Newton to Leonhard Euler spent countless hours unraveling the numbers. Newton is quoted as saying that he would be “embarrassed” if people knew how much time he had devoted to calculating pi. Albert Einstein, arguably history’s most famous mathematician, was born on March 14.

The advent of computers has only fueled the mystique. As of 2002, pi had been calculated to more than 1.2 trillion decimal places. Nevertheless, many people do not tire of trying to remember hundreds of its endless digits. Akira Haraguchi, a retired engineer from Japan and the reputed world-record holder, memorized 100,000 digits of pi in 2006. It took him about 16 hours to recite them.

“Pi, in and of itself, describes the way the world looks to us—like the curviness of a circle,” says Tanoy Sinha, an associate at a financial-consulting firm in New York, who was also born on March 14. “We’re never going to know exactly what it is,” he adds.

The festivities for pi apparently began in the late 1980s when Larry Shaw, a physicist at the Exploratorium, an interactive science museum in San Francisco, started a celebration for the museum staff. Now the museum hosts an annual extravaganza in which visitors can eat pie (pizza or dessert), watch a Pi Day parade and add to a long string of color-coded beads in which each bead corresponds to a number representing a single decimal place.

From these humble terrestrial beginnings, Pi Day has evolved into a major cyberspace event. Web sites now hawk T-shirts, buttons, Pi Day cards and coffee mugs. There are pi raps posted on YouTube. One avid pi-ster from the Netherlands sells pi-shaped baking pans, so people can literally take a bite out of π.

Some celebrants are so ardent that they choose to marry on the day. Melissa Stramel, 34, and her fiancé, Andre Lamoureux, a 25-year-old Ph.D. candidate in mathematics education at Washington State University in Pullman, Wash., met when Stramel, a history major, went for tutoring after scoring a dismal 23 on her first math test. Love blossomed. The two hoped to marry this March 14 but have decided to wait a year. One thing is for certain: They will serve pie, not cake, at the wedding.

“When we were talking about getting married, he said, ‘We should have the symbol pi on top of the pie,’ ” Stramel recalls, adding that she has gotten into math and pi “a little more” since dating Lamoureux.

As an 11-year-old, Alex Pagels, now a freshman astrophysics major at the University of Minnesota in Minneapolis, memorized pi to 200 digits. These days he can only remember 150 decimal places, but his Facebook profile picture is of a lime-green pi symbol. Last year Pagels and a friend pooled their money to carry pie to school on March 14. This year, he hopes he can grab a slice of his favorite, rhubarb-peach.

Green, of, home of the talking pi, says that officially the Giant Pi prefers strawberry pie. But he quickly adds that the filling doesn’t really matter as long as the circumference of the pie can be measured with the equation C=2πr.