Don Herbert, who explained the wonderful world of science to millions of young baby boomers on television in the 1950s and '60s as "Mr. Wizard" and did the same for another generation of youngsters on the Nickelodeon cable TV channel in the 1980s, died Tuesday. He was 89.

Herbert died at his home in Bell Canyon after a long battle with multiple myeloma, said Tom Nikosey, Herbert's son-in-law.

A low-key, avuncular presence who wore a tie and white dress shirt with the sleeves rolled up, Herbert launched his weekly half-hour science show for children on NBC in 1951.

Broadcast live from Chicago on Saturdays the first few years and then from New York City, "Watch Mr. Wizard" ran for 14 years.

Herbert used basic experiments to teach scientific principles to his TV audience via an in-studio guest boy or girl who assisted in the experiments.

"I was a grade school kid in the '50s and watched 'Mr. Wizard' Saturday mornings and was just glued to the television," said Nikosey, president of Mr. Wizard Studios, which sells Herbert's science books and TV shows on DVD.

"The show just heightened my curiosity about science and the way things worked," Nikosey said. "I learned an awful lot from him, as did millions of other kids."

By 1955, there were about 5,000 Mr. Wizard Science Clubs nationwide, with more than 100,000 members.

And as Mr. Wizard, Herbert was a true TV star, featured in an array of magazines, including TV Guide, Life, Time, Newsweek, Science Digest, Boy's Life and even Glamour.

Herbert was taken aback by the show's success.

"What really did it for us was the inclusion of a child," he told the St. Louis Post-Dispatch in 2004. "When we started out, it was just me up there alone. That was too much like having a professor give a lecture. We cast a boy and girl to come in and talk with me about science. That's when it took off.

"The children watching could identify with someone like them."

In explaining how he brought a sense of wonder to elementary scientific experiments, Herbert told the New York Times in 2004 that he "would perform the trick, as it were, to hook the kids, and then explain the science later.

"We thought we needed it to seem like magic to hook the audience, but then we realized that viewers would be engaged with just a simple scientific question, like, why do birds fly and not humans? A lot of scientists criticized us for using the words 'magic' and 'mystery' in the show's subtitle, but they came around eventually."

"Watch Mr. Wizard" garnered numerous honors, including a Peabody Award, four Ohio State awards and the Thomas Alva Edison Foundation Award for "Best Science TV Program for Youth."

And Herbert had a lasting effect.

"Over the years, Don has been personally responsible for more people going into the sciences than any other single person in this country," George Tressel, a National Science Foundation official, said in 1989.

"I fully realize the number is virtually endless when I talk to scientists," he said. "They all say that Mr. Wizard taught them to think."

Herbert's experiments on the show typically used household items.