The 'Big Bang Theory' Geeks Meet Stephen Hawking [Exclusive Photo and Video]

Over the past five seasons, the cast of CBS's hit nerd-com "The Big Bang Theory" have welcomed a host of super-dorky guest stars (Wil Wheaton, anyone?), but this week's visitor might top them all. Renowned theoretical physicist Stephen Hawking stops by on Thursday's installment, and we have two exclusives for you: this behind-the-scenes photo of Hawking with the "Big Bang" cast, and a sneak-peek clip from the episode.

This week's plot finds Wolowitz getting the chance of a lifetime: to work with Hawking. Sheldon is a huge Hawking fan and is willing to do anything to meet his idol. And he's not alone; in fact, the whole "Big Bang" crew is a little bewildered that Hawking would agree to do their show. Executive producer Bill Prady says, "We're not exactly sure how we got him. It's the kind of mystery that could only be understood by, say, a Stephen Hawking."

[Video: Watch More Clips From 'The Big Bang Theory' Right Here]

In this exclusive clip, Sheldon is eager to do whatever Wolowitz wants for the chance to spend time with Hawking. But Wolowitz takes advantage of Sheldon's enthusiasm -- and gives him some serious dirty work to do. We won't spoil it, but here's a hint: Ever wonder how Howard's belt buckles stay so shiny?

"The Big Bang Theory" airs Thursdays at 8 PM on CBS.