Have you seen the episode of Star Trek where Data plays poker with Stephen Hawking? How about the times he appeared on Futurama or the Simpsons? Or the absurd number of times he has come up in one way or another on The Big Bang Theory?
Stephen Hawking is probably the most recognizable theoretical physicist to laymen. Wheelchair-bound and speaking through a voice synthesizer, Hawking presents a very distinct image, while his work on black holes and the big bang, along with his popular treatments of science in books like A Brief History of Time, has made him synonymous in the public’s mind with genius.
He is not, however, the most recognizable theoretical physicist when talking to physicists. If Sheldon from The Big Bang Theory were a real string theorist he wouldn’t be obsessed with Hawking. He might, however, be obsessed with Edward Witten.
Edward Witten is tall and has an awkwardly high voice (for a sample, listen to the clip here). He’s also smart, smart enough to dabble in basically every subfield of theoretical physics and manage to make important contributions while doing so. He has a knack for digging up ideas from old papers and dredging out the solution to current questions of interest.
And far more than Hawking, he represents a clear target for parody, at least when that parody is crafted by physicists and mathematicians. Abstruse Goose has a nice take on his role in theoretical physics, while his collaboration with another physicist named Seiberg on what came to be known as Seiberg-Witten theory gave rise to the cyber-Witten pun.
So why hasn’t this guy appeared on Futurama? (After all, his dog does!)
Witten is famous among theorists, but he hasn’t done as much as Hawking to endear himself to the general public. He hasn’t written popular science books, and he almost never gives public talks. So when a well-researched show like The Big Bang Theory wants to mention a famous physicist, they go to Hawking, not to Witten, because people know about him. And unless Witten starts interfacing more with the public (or blog posts like this become more common), that’s not about to change.