Back in April — which was Mathematics Awareness Month — Wired magazine featured an interview with Cheryl Heuton. Together with husband Nick Falacci, she created CBS' Friday-night crime drama "Numb3rs," which stars David Krumholtz as Charlie Eppes, a mathematician who uses the wonder of numbers to help his FBI-agent brother, Don (Rob Morrow), solve crimes.

"One of the inspirations for this show," said Heuton to Wired, "was Bill Nye the Science Guy. He talks a lot about inspiring young people to study math and science. I used to be a journalist. I did a three-hour interview with him once and never forgot that."

Nye is a scientist and engineer (and former part-time comedian), whose "Bill Nye the Science Guy" show, which aired on PBS and in syndication, used humor and clever demonstrations to illustrate scientific principles.

Now he's returning the favor to Heuton and Falacci by appearing on "Numb3rs," in an episode called "Scorched," airing at 10 p.m. Friday on Channel 2.

While Don and his team track a serial arsonist, Charlie and his CalSci (the show's fictional version of CalTech) colleague Dr. Larry Fleinhardt (Peter MacNicol) turn to Professor Bill Waldie to recreate a backdraft in the university's combustion lab.

"It was such a stretch for me," says Nye of the character. "I took weeks, I studied under Stanislaus — what's his name? — Stanislavski's grandson for months. I starved myself. My character's name is Bill Waldie, but call me Bill, please. 'The chance to create the conditions of a backdraft, this is just way cool,' is what my character says."

And just in case you've seen the movie "Backdraft" and still aren't sure what one is, Nye explains: "It is a smoke explosion, where unburned fuel is carried in particles of smoke. When you add enough oxygen, and the situation is hot enough, the smoke burns. And, it being airborne, it gets a lot of oxygen very well, so it burns really fast and you get an explosion."

Told that does sound cool, Nye says, "Or hot. My character has built a replica, and we prove that it couldn't have been a backdraft. I'm the downer before the big payoff, which is what is so pleasing about the show."

Because, after all, Charlie isn't always right. "Especially at a quarter after 10," Nye says. "About 10:52, he's pretty dead-on."

As a scientist, Nye is pretty happy about "Numb3rs."

"I'm thrilled," he says. "People in the scientific community have talked for a long time, 'Why don't we get on television? Why don't they show us scientists?'

"I don't want to put words in his mouth or speak for him, but Leon Letterman — he won a Nobel Prize in physics, unlike a lot of us — his thing was 'L.A. Science,' back when 'L.A. Law' was a big deal. 'Numb3rs' is that kind of show. I think it's the coolest thing in the world."

Nye even got some input into the episode. "I pitched them on including a tiny backdraft at the beginning of the piece. Have you ever blown out a candle and brought a match into the smoke and the candle reignites? That's a backdraft. That's a smoke explosion.

"So we put that at the beginning of the piece. Cheryl and Nick must have sold it to the executives, who want to get rid of everything. I can tell the pressure — 'You want to have cars in the shot? That adds cost.'"

Apparently other scientists share Nye's opinion of the show.

"I'm on this Committee on Public Understanding of Science and Technology," Nye says, "for which the acronym is COPUST — God, how horrible. It was PEST, Public Engagement of Science and Technology. It's stupid. Come on, people.

"Anyway, they love it at COPUST, and at Triple A, American Association for the Advancement of Science."

As for the show's treatment of mathematics, Nye says, "They had these equations on the board during Bill Waldie's appearance, and they're perfect. They're exactly right. I was so impressed."

According to Nye, Waldie doesn't manage to blow himself up in the episode, so there's a chance he might be back.