Stephen Hawking
Stephen Hawking (January 8, 1942 — March 14, 2018) was a British theoretical physicist, known for his work on black holes, theoretical cosmology and quantum gravity. He was considered the world's smartest man. Due to his amyotrophic lateral sclerosis (ALS), Hawking was almost totally paralyzed, so he had had to use a wheelchair to move around, and used a voice synthesizer to talk. He made four appearances on the show as himself: "They Saved Lisa's Brain", "Don't Fear the Roofer", "Stop or My Dog Will Shoot!" and "Elementary School Musical".
