Arthur Jeffries, Ph.D.—a.k.a. Professor Proton— was a down-on-his-luck former children's science show host who's hired by Sheldon and Leonard to entertain them. Professor Proton was known for demonstrating scientific principles using everyday objects. Proton often would dispense the aphorism, "There is no problem you can't solve, if you use your noggin’.” The Professor Proton theme song lyrics read, "Grab your goggles, put your lab coat on. Here he comes, Professor Proton." His beloved puppet sidekick – Gino The Neutrino – was a blue, anthropomorphized elementary particle with an Italian accent, a mustache, and gondolier costume under a lab coat. It is later revealed that Jeffries hated the puppet after his puppeteer slept with his then wife.