Stephen Hawking in ‘The Big Bang Theory’

”When people would ask us who a ‘dream guest star’ for the show would be, we would always joke and say Stephen Hawking - knowing that it was a long shot of astronomical proportions.

”In fact, 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,” said show’s producer Bill Prady.