"The Big Bang Theory" Season 7 took a week's break and will be back with a brand new episode this Thursday. The episode "The Proton Displacement" will see the return of Prof. Proton (Bob Newhart). This is something Sheldon (Jim Parsons) did not expect.

As reported earlier, Prof. Proton will approach Leonard (Johnny Galecki) and seek his advice, which will not please Sheldon. He will feel "slighted." Sheldon's jealously will lead him to Prof. Proton's rival, Bill Nye. In the preview video, Sheldon can be seen telling Prof. Proton, "Sorry, I replaced you with a newer model." And, Professor Proton is ready to share his turf with Nye, and screams "Back Off."

Bill Nye, appearing as himself, is a rival science host on television. Nye said to The Huffington post that he feels like he is a "logical guy" for "The Big Bang Theory."

The sneak peek of "The Big Bang Theory" Season 7, Episode 7, "The Proton Displacement," reveals that Sheldon introduces his girlfriend, Amy, to Prof. Proton. The professor looks surprised and amused that Sheldon has a girlfriend. But Amy soon provides him a good reason to believe that she is indeed Sheldon's girlfriend.

 [Youtube/thebigbangtheory]

Newhart, 84, won 2013 Emmy Award for Outstanding Guest Actor in a Comedy Series for "The Big Bang Theory." Working with Newhart, Nye said to Huffington Post: "The guy is just a consummate pro. I remember this one moment in the script where he's angry with me and he just scared the daylights out of me. He came at me, "Back off!" It was really cool. It was really exciting. Then I got into it. I had no trouble at all."

Nye added he never misses an episode of "The Big Bang Theory." However, he does not think that he was like Sheldon while growing up.

"The Proton Displacement": "Sheldon feels slighted when Professor Proton seeks advice from Leonard instead of him, and he seeks revenge by befriending a rival science TV Host Bill Nye. Meanwhile, Raj gets jealous when Howard crashes "girls' night," according to CBS official synopsis.

 [Youtube/thebigbangtheory]