Stephen Hawking Kicks Off 'Big Bang Theory' Panel at Comic-Con

When Stephen Hawking isn't playing Words With Friends against The Big Bang Theory's Sheldon Cooper, he likes to speculate about the universe.

The iconic physicist and author started a panel featuring producers of the Emmy-nominated series on Friday at Comic-Con with a pre-recorded video segment. Hawking guest-starred in season five's "The Hawking Excitation" episode of the CBS sitcom.

During the video, filmed in his University of Cambridge office, Hawking clears up how the universe was formed, speaking the lyrics to the Big Bang's opening credits, while still plugging his soon-to-be-released book and movie, Hawking.