Bob Newhart's force is still with 'The Big Bang Theory'

Bob Newhart has millions of fans: The longtime devotees of classic sitcoms The Bob Newhart Show and Newhart and more recent ones who enjoy his work as Professor Proton on TV's top comedy,The Big Bang Theory. 

Has he ever met one like Sheldon Cooper (Jim Parsons), the supercilious genius who conjures up Professor Proton in his dreams in Thursday’s Big Bang (8 ET/PT)? 

“Let me think,” the 88-year-old Newhart says, pausing in classic style during a phone interview to discuss his fifth appearance on the CBS comedy (The comedian’s phone-call routines spawned best-selling albums in the 1960s.). “No. No one comes to mind. I think Sheldon is more annoying than anybody.”

And that’s the secret to the Sheldon-Proton chemistry. Sheldon so admires Professor Proton — a Bill Nye-like TV scientist who inspired him to pursue a career as a physicist — that his subconscious won’t let him go, even after the death of Arthur Jeffries, portrayed by Newhart, who played the kids' show host.

That doesn’t mean the perpetually aggrieved Jeffries goes along willingly, even though he’s a product of Sheldon’s mind. “Even as a figment of his imagination, I can’t stand him,” Newhart says, laughing.

In Thursday’s episode, Sheldon finds himself competing with rival/friend Wil Wheaton for the chance to play Proton in a revival of the science show.

Unsurprisingly, the imperious physicist's not exactly kid-friendly audition leads to a return engagement with Arthur in dreamland, where Star Wars fan Sheldon once again imagines his TV hero as a robe-wearing Obi-Wan Kenobi.

“What part of Rest in Peace don’t you understand?” a clearly annoyed Arthur asks Sheldon. Newhart's signature reaction shots speak volumes about his character's aggravation.

Unlike Arthur, Newhart has fun spending time with Parsons, his castmates and Big Bang’s writers and crew. It probably doesn't hurt that he won an Emmy in 2013 for his work on the show.

“The people are so good. That had a lot to do with my decision to do it. And the writing was paramount,” he says .

Newhart, a master of the studio-audience comedy that once dominated TV, embraces that form.

He notices one difference between Big Bang and his earlier shows.

“When I was doing The Bob Newhart Show with (Suzanne Pleshette), we did a (scene) with an IQ test. It had to take a minute and a half to set up (the joke)," he says. "You don’t have that kind of time today. You’ve got 15 seconds, and then bang! You’d better have another line. That’s the dictates of the young audience. They want it and they want it now.”

Newhart recently played a younger version of Proton in the September premiere of Young Sheldon, a Big Bang prequel that follows nine-year-old Sheldon’s upbringing in Texas.  

“We adore Bob," says Steven Molaro, an executive producer of both series. "He is a permanent part of our family even though technically his character is dead. We've managed to keep him around as a spirit in Sheldon's mind.  Any time we find a story that makes sense to bring him back, we are thrilled."

Newhart, who also makes occasional appearances on TNT’s The Librarians, is open to returning to Big Bang, but his ambitions are modest.

“I’m 88,” he says. “I’m not looking for a career on television.”