Bob Newhart Had Two Conditions To Play The Big Bang Theory's Professor Proton

Comedian Bob Newhart passed away this week at the age of 94, leaving behind a legacy built on big laughs and heartwarming performances. While plenty of TV fans knew Newhart best for his self-titled sitcoms, "The Bob Newhart Show" and "Newhart," a younger generation got familiar with the comedic actor thanks to his roles in "Elf" and on the CBS show "The Big Bang Theory." The latter would ultimately pave the way for the actor's final on-screen appearance, in which he reprised his role of beloved kids' TV scientist Professor Proton in the show's prequel series, "Young Sheldon."

Newhart first joined "The Big Bang Theory" in season 6, playing a Mr. Wizard or Bill Nye-like science expert who shared his curiosity with the world, including kid versions of Sheldon and Leonard. Though the TV host turned party performer lands in the hospital during his first appearance, Newhart would go on to reprise the character five more times in the series, often in episodes with titles featuring his memorable nickname. Before he signed onto the show, though, Newhart once told The Hollywood Reporter that he gave series creator Chuck Lorre two terms of agreement to his proposal. First and foremost, he told the outlet, Newhart wanted a studio audience to work with.

"I had only two things that were paramount: No. 1, my scenes had to be taped live," the comedian recalled in a 2013 interview. He explained: "There's a tendency to pre-tape a lot of stuff and put a laugh track on it and you lose something. With 'Newhart,' 'Lucy,' 'Honeymooners,' 'Mary Tyler Moore,' and 'All in the Family' it was always done in front of live audience." It's a point that's tough to argue with, as Newhart name dropped some of the best sitcoms of all time. He also admitted that his own performance is fueled by the experience of working in front of a crowd. "I always felt that the live audience gives it adrenaline," he told THR. "That's the only way I function."

Luckily, "The Big Bang Theory” was one of a handful of shows still working with live studio audiences in the 2010s, making Newhart's request easy to accommodate. The actor's second request was that Professor Proton become a "semi-recurring role." While Newhart didn't clarify whether he was worried about appearing in too many episodes or not enough, he said that Lorre agreed, and called him up with the idea for his character soon after. The pair had actually known each other for years before the inception of Professor Proton, with Newhart saying he was "familiar with [Lorre's] work­­ going back to 'Roseanne' and 'Cybil.' In fact, the pair apparently knew each other from days spent on the studio lot when "The Bob Newhart Show" was filming.

"Chuck was on the lot when we were doing 'The Bob Newhart Show' and at lunch, he'd come to our stage and sit there," Newhart recalled. "We've been going back and forth, and we never could find a project that we could both agree on until 'The Big Bang Theory.'" Lorre asked what "it would take" for Newhart to come on one of his shows, and the question kick-started the conversation leading to Professor Proton. The actor-comedian cited the show's intelligence and quick, modern comedic rhythm as two reasons he was eager to get on board.

Newhart was able to play around with Professor Proton over the next several seasons of the series, at one point returning alongside Bill Nye (the professor's nemesis, naturally) and, in a later "Star Wars"-themed episode, appearing as a Force Ghost to Jim Parsons' Sheldon. One episode even featured a reference to the famous surprise ending of "Newhart." While Newhart appeared briefly in "Young Sheldon," his presence as the protagonist's inspiration loomed large even when he wasn't on screen. By that point, the "Big Bang Theory" role had already solidified a unique place in Newhart's filmography. Astonishingly, it marked the only time the comedian ever received a Primetime Emmy.