Bob Newhart is a noted comedian who won an Emmy for his performance on The Big Bang Theory as Arthur Jefferies, also known as Professor Proton who appeared as the former children's science show host or as Sheldon's ghostly Jedi advisor. Bob started out in stand up comedy in the 1950s and went on to television and movies. He is best known for his television series, The Bob Newhart Show and Newhart. He also appeared in the movies Catch-22, Cold Turkey, The Rescuers, First Family (film)|First Family, Legally Blonde 2 and Elf (film)|Elf. He appeared on six episodes of The Big Bang Theory. "The Planetarium Collision" (2018), "The Proton Regeneration" (2017), "The Opening Night Excitation" (2015), "The Proton Transmogrification" (2014), "The Proton Displacement" (2013) and "The Proton Resurgence" (2013).