'The Big Bang Theory' preview: Bob Newhart and Bill Nye face off - Watch
"The Big Bang Theory" is preparing for one heck of a showdown on Thursday (Nov. 7) when Bob Newhart returns as Professor Proton and squares off against the one and only Bill Nye.
In a preview clip of the episode, things get heated when Sheldon ( Jim Parsons) jabs back at his idol after a perceived slight by bringing in "a newer model." Newhart's Proton doesn't take this too well, bellowing at Nye, "Back off, bow tie!"
Nerd fights -- does it get any better than that?
Check out the clip above and let us know if you're psyched for the big episode.
"The Big Bang Theory" airs Thursdays at 8 p.m. ET on CBS.