I've always been a big fan of Stephen Hawking
Stephen Hawking
Stephen William Hawking (8 January 1942 – 14 March 2018) was an English theoretical physicist, cosmologist, and author who was director of research at the Centre for Theoretical Cosmology at the University of Cambridge at the time of his death. He was the Lucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009.
His scientific works included a collaboration with Roger Penrose on gravitational singularity theorems in the framework of general relativity and the theoretical prediction that black holes emit radiation, often called Hawking radiation.
always their "dream guest star" for the show, but that Hawking appearing was "a long shot of astronomical proportions". Hawking was a fan of "The Big Bang Theory" and requested to watch a rehearsal of the episode after filming his scene. Simon Helberg, who plays Howard, does an impression of Hawking's voice in the episode; he felt slightly uncomfortable mimicking Hawking, but Hawking seemed to enjoy the impression.
Hawking is the third high-profile guest star to appear in season 5, after