"How old do you have to be to buy dry ice?" asks another lad.

"If you knew how to order it, I'd sell it to you," says Tyson, briefly and sincerely imagining himself as a dry-ice salesman. "I'd figure you were a kid interested in science, and I'm not going to stand in the way of that."

'There Were Noogies'



"I've got an idea for a future book project called 'How to Raise a Scientifically Literate Child,' " Tyson says, walking out of the school. "Not 'How to Raise a Scientist.' I don't care if my kids" -- Tyson and his wife, who has a PhD in mathematics, also have a son, named Travis -- "are scientists. But I want them to be literate about science."

He heads to the subway, which delivers him to the American Museum of Natural History, home to the Hayden Planetarium. His office is cluttered with certificates, photos, scientific journals, a bust of Newton with a "Jeopardy!" hat on it.

"I never got to be on the show," he says. "But I did record an Audio Daily Double for them recently."

Tyson is one of those rare scientists who seeks out TV appearances, and one of the few good enough on camera to get invited to places like "The Daily Show." Time magazine this year picked him as one of the 100 most influential people in the world -- a distinction, he points out, that makes more sense when you realize that the magazine anointed people by category. ("They're counting me as one of the most influential scientists," he says.) People magazine once named him "Sexiest Astrophysicist Alive," and though he wonders aloud about the depth of the competition, he is surely one of the few in his field who briefly considered exotic dancing as a part-time job.

At the time, he was a PhD candidate at the University of Texas, and several friends in a student dance troupe he had joined tipped him off about their part-time work at a Chippendales-style club.

"It seemed like a good idea, until I went to watch and they set their jockstraps on fire to the tune of 'Great Balls of Fire,' " he says. He knew that the lighter fluid burned out in an instant and that the jockstraps were lined with asbestos. But still. "I thought to myself: math tutor. I should be a math tutor."

Tyson started writing books after he transferred his PhD work to Columbia. The first, "Merlin's Tour of the Universe" in 1989, was illustrated by his older brother, an artist who lives in Upstate New York. Then came "Universe Down to Earth," "One Universe: At Home in the Cosmos" and "City of Stars: A New Yorker's Guide to the Cosmos," which included helpful hints about which days the sun sets directly over Manhattan's east-west streets.

When the Hayden Planetarium decided it needed to boost attendance, it went to the astrophysics departments at Columbia and Princeton and asked for ideas. Hire an astrophysicist to run the place, both universities suggested -- specifically, Tyson, by then a lecturer at Princeton.

"It took Neil about five minutes to win over his students," recalls Richard Gott, a former colleague. "I taught Astronomy 203 with him and [fellow heavy hitter] Michael Strauss. We were the Three Tenors -- and Neil was Pavarotti."

Tyson accepted the director's job after the planetarium agreed to add an academic research arm to the place, which he figured would keep it intellectually vibrant. Hayden also offers, as it long has, mini-courses to the public, and signing the certificates for completing those courses is a task Tyson enjoys. He had a collection of those certificates as a kid. To Tyson's parents, it was just part of the larger curriculum offered by the five boroughs.