What is the name of the children's science show host Sheldon adored?

The children's science show host Sheldon adored was Professor Proton.

Professor Proton is the fictional television persona of Arthur Jeffries, played by Bob Newhart on The Big Bang Theory. Sheldon and Leonard watched his educational program as children, and Sheldon regarded him as an important early influence on his interest in science.

The character was designed as a warm but slightly eccentric parody of classic children's science presenters. Although Professor Proton's show had been cancelled, Jeffries continued appearing at children's parties in costume. Sheldon later meets him as an adult and seeks his advice, even after Jeffries dies; the character returns in Sheldon's dreams in a role resembling a Jedi mentor.

A common mix-up is Mr. Wizard, the real-life science educator who partly inspired the character. Beakman and Bill Nye are also real science-show presenters, but neither was the host Sheldon idolized.