“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.

Posted by:Billy Nilles