Bob Newhart Big Bang, Bob Newhart is heading to "The Big Bang Theory" to give Sheldon and the gang a science lesson. According to TVLine, the "Bob Newhart Show" and "Newhart" star is stopping by "The Big Bang Theory" play Professor Proton, the former host of Sheldon's (Jim Parsons) favorite childhood science show. The episode, set to air May 2, will center on Sheldon's online search for his favorite TV host, played by Newhart. Once he tracks Professor Proton down, Sheldon discovers he can be booked for events and invites him to his house. Newhart's "Big Bang Theory" stint will mark his first TV appearance in quite some time. The six-time Emmy winner was seen on "ER" in 2003 and "Desperate Housewives" in 2005. Despite Sheldon's excitement about Professor Proton, it's not unlikely that he'll offend him. In a January episode of the series, he managed to tick off someone in the Human Resources de