Most things come and go, but pi, for many, is forever

This is a story about love. About inscrutable complexity and remarkable simplicity, about the promise of forever. It is about obsession and devotion, and grand gestures and 4,000-word love letters.

It is about a curious group of people with an almost religious zeal for a mind-numbing string of numbers. Actually one number, made up of a chain that is known — so far — to be more than 1 trillion digits long.

They are the acolytes of the church of pi. And once a year many of them gather to talk about pi, rhapsodize about it, eat pi-themed foods (actual pie, sure, but so much more), have pi recitation contests and, just maybe, feel a little less sheepish about their unusual passion.

That day falls on Wednesday this year: March 14. Or 3.14. Obviously.

And if you ask the fans of pi why, a startling number of them will come back with the same question: "Why climb Mount Everest?" Because it's there.

But then they start talking about some very simple ideas. Like the beauty of a number that seems to go on forever and yet has no discernible pattern. Or about the valor of the memorization gymnastics. This is how Akira Haraguchi, a 60-year-old mental-health counselor in Japan, puts it: "What I am aiming at is not just memorizing figures. I am thrilled by seeking a story in pi."

He said this one day last fall after accurately reciting pi to 100,000 decimal places. It took him 16 hours. He does not hold the Guinness world record, only because he has not submitted the required documentation to Guinness. But he has his story.

(The official world record belongs to Chao Lu, a Chinese chemistry student, who rattled off 67,890 digits over 24 hours in 2005.)

A brief math refresher: Pi is a simple concept — the relationship between a circle's circumference and diameter. Multiply the diameter by pi — 3.14159, to use a crude approximation that would make many of the people in this story blanch — and you get the circumference.

Supercomputers have computed pi to more than a trillion decimal places, looking always for a pattern to unlock its mystery. And for centuries the number has fascinated mathematicians.

And then there are people like Marc Umile. Twelve years ago, while working as an usher at a Philadelphia opera house, he picked up a book on curiosities of math and read about pi's seemingly infinite, random string.

He wondered about applying the way we absorb music to the mystical number. An obsession was born. In 2004 Umile read the digits of pi into a tape recorder. He did it a thousand at a time and gave it a rhythm — some numbers high-toned, some low.

He listened to the tape constantly for two years.

"To and from work, in my quiet time, on my lunch break ... " he said. "Probably 40 percent of the time there was an earphone in my ear. I said, 'Oh my God, what have I created?' "

What he created was what is believed to be the U.S. record for pi memorization — 12,887 digits.

Mike Keith, a software engineer in Virginia, wrote a poem to pi, a "piem." It is nearly 4,000 words long — and the number of letters in each word corresponds to pi's digits.

"One: A Poem: A Raven," it begins (3-1-4-1-5). "Midnights so dreary, tired and weary, silently pondering volumes extolling all by-now obsolete lore. During my rather long nap — the weirdest tap! An ominous vibrating sound disturbing my chamber's antedoor."

Keith says he thinks of himself only as "an average pi nut." He figures he knows maybe 100 pi digits off the top of his head.

It may be a stretch to say that pi has achieved a kind of cultural cachet, but it is true that, as an obsession, it's not just for math geeks anymore. Givenchy makes a Pi perfume. Kate Bush sings out its digits in a song. And — of course — YouTube stocks videos of people reading pi into the camera.

Umile is already booked to appear on a local TV show on Wednesday. The other night he rattled off 10,000 pi digits, just to keep the gears oiled.

Funny thing, though: For the life of him, he can't remember the phone number he calls every month to make his mortgage payment. And the other day he got his own bank account number wrong.

"It starts with 6-1-4," he says. "And I wrote 3-1-4."