In the 1950s, it was unusual for television programs to address the topic of sex. Lucy and Ricky Ricardo slept in separate beds on I Love Lucy. Both were forbidden by network standards to even use the word pregnant. (For all viewers knew, Little Ricky was the product of an immaculate conception.) Teens on sitcoms rarely investigated anything other than chaste dating.

But for the juvenile audience of Watch Mr. Wizard, viewers got what may have been television’s earliest widespread discussion of sex. More specifically, the gestation period of hamsters.

Watch Mr. Wizard, which aired on NBC from 1951 to 1965, featured host Don Herbert performing a series of science experiments using everyday objects—glass bottles, cans, aquariums, matches—to illustrate the amazing world of physics. Eggs were sucked into bottles; water was boiled using an ice cube. They were pseudo-magic tricks, but instead of obscuring his method, Herbert satisfied the audience’s curiosity by explaining how science made them all possible. A revolving cast of kid assistants, none of them particularly interested in science, stood at Herbert's side and marveled at how Newtonian laws influenced their day-to-day existence.

Hebert was so popular that NBC gave him free rein to blow things up or discuss hamster sex. And then, nearly 20 years after Watch Mr. Wizard's cancellation in 1965, Herbert was given the opportunity to captivate a brand-new generation of kids with Mr. Wizard's World, which made its debut on the fledging Nickelodeon cable channel in 1983. Forget Bill Nye: For millions of viewers, Herbert was the original "science guy."

Don Herbert Kemske was born July 10, 1917 in Waconia, Minnesota. He developed an interest in science while in the Boy Scouts and later obtained a degree in English and general science from the University of Wisconsin–La Crosse (then known as La Crosse State Teachers College) in 1940. But Herbert didn’t pursue a teaching career. Instead, he followed his interest in drama and theater to New York City, where he worked as a pageboy for NBC, acted opposite future First Lady Nancy Reagan, and was cast in a Broadway show.

But acting, while promising, wasn’t foremost on Herbert's mind. He enrolled in the Army Air Forces in 1942, eventually piloting a B-24 bomber in 56 bombing missions over Europe. He was also involved in the invasion of Italy. Herbert was awarded a Distinguished Flying Cross and Air Medal for his contributions. (His dual role as war hero and kid show host may have been the origin of the infamous myth about Fred Rogers being a sniper.)

After arriving back home, Herbert's love of the arts led him to Chicago, where he felt he might be able to find a way back into the entertainment industry.

Eventually, he did.

Herbert agreed to begin hosting a science-oriented show for WMAQ-TV, Chicago's NBC affiliate. Just a few years after the introduction of the atom bomb and with Americans troubled by reports of Soviet space technology like Sputnik, the time seemed right for a series that focused on the scientific laws governing the world. An ad executive thinking of sponsoring the program wanted to call him “the Wizard.” Herbert, feeling that was perhaps too pretentious, added a “Mr.” to the title.

Watch Mr. Wizard premiered in 1951. Like a lot of television of the era, it was live, not taped. The pace was leisurely, with Herbert walking through general principles over the course of a half-hour. Crucially, he refused to wear a lab coat or conduct his experiments in a laboratory setting. Instead, he wore short-sleeved shirts and used common household items while broadcasting from a garage or kitchen. His first assistant was 11-year-old Willy, Herbert’s real-life next-door neighbor.

Herbert was adamant that science not be confined to sterile lab settings. He reasoned that by using everyday household items to conduct his experiments, kids would be able to replicate them at home.

“Milk bottles are your flasks,” Herbert said. “Glasses your beakers, and the whole house your laboratory.”

There was no barrier between a child and their curiosity. Herbert would present situations—a rising cake, blowing wind—and then explain the “trick.” He considered entertaining his audience to be his primary job, not educating them, but was thrilled if he could succeed at doing both.

“I do a kind of educational television but the difference between what I do and educational television is like night and day,” Herbert told the St. Louis Post-Dispatch in 1961. “The primary purchase of educational television is to teach and the primary purpose of Mr. Wizard is to entertain, to stimulate, to intrigue.”

Within a few years, Watch Mr. Wizard was being carried in more than 100 markets and was reaching between 1 and 3 million weekly viewers [PDF]. While the audience was not as sizable as a primetime hit, it was a substantial number for an educational program. (Though it was ostensibly for kids, half of Watch Mr. Wizard's viewers were adults.) His audience was also devoted, with 5000 fan clubs springing up across the country that eventually claimed 100,000 members. Herbert’s notoriety helped him sell 200,000 copies of various science books.

In 1965, NBC announced it would be canceling Watch Mr. Wizard. The show had run its course, the network claimed, and audiences were increasingly looking at television as an empty-calorie prospect—not an educational tool. Even so, a 14-year run was something only a handful of shows had ever achieved. But Herbert wasn’t done.

Though NBC briefly revived Watch Mr. Wizard in 1971, Herbert felt his skills were best-suited to areas outside of weekly half-hour television. He produced 18 films that were meant to be screened in classrooms; the National Science Foundation helped fund a series of 80-second segments titled How About for local newscasts across the country. Though most of the footage didn’t use the “Mr. Wizard” name, Herbert was often introduced with that moniker regardless.

The news spots led to renewed interest in Mr. Wizard. After viewing a pilot, Nickelodeon agreed to fund 26 half-hour episodes of Mr. Wizard’s World for a 1983 premiere. More than 30 years after his television debut, Herbert was back, once again dispensing with the confines of laboratory settings.

For Herbert's Nickelodeon series, the pace was much quicker, with eight to 10 segments per episode. The kid assistants, he later said, were savvier about molecules and computers than their 1950s counterparts. But most everything else remained the same.

In both incarnations of the show, Herbert refused to cater to gender stereotypes. Girls were by his side as frequently as boys, and Herbert remarked they were probably better equipped to get into the sciences. He had a cutoff age of 13 for the boys. After that, he said, they “became know-it-alls.”

Mr. Wizard’s World ran through 1990, at which point Herbert largely disappeared from public view. Though he had never expressly set out to teach science and even believed television was a poor fit for educational purposes, his relaxed approach to the subject proved to be a huge inspiration nonetheless.

Following Herbert's death at age 89 in 2007, a National Science Foundation official claimed that, more than anyone, Herbert may have been the person most responsible for getting people interested in science. In the 1960s and 1970s, applicants to The Rockefeller University—a science research center based in New York City—were asked what inspired them to get into science. In the space allotted for an answer, half of them wrote: "Mr. Wizard."