"Quantum Leap" is an American science fiction television series created by Donald P. Bellisario. It was originally broadcast on NBC for five seasons from March 25, 1989 to May 5, 1993. It is headed by Scott Bakula as the physicist Dr. Sam Beckett by temporarily replacing others to correct historical mistakes, skipping time and space in experiments that travel through time and space. Dean Stockwell co-starred in Sam’s feminine, cigar smoking companion, best friend, Admiral Al Calavicci, in his watch It's a holographic image. The show was ranked 19th in the 2007 "TV Guide" "Most Popular Show of All Time".