Quantum Leap

Quantum Leap is an American science fiction television series, created by Donald P. Bellisario, that aired on NBC for five seasons, from March 26, 1989, to May 5, 1993. The series stars Scott Bakula as Dr. Sam Beckett, a physicist who, believing he has invented a way to travel through time, voluntarily subjects himself to an experiment that he believes will prove the validity of his controversial theories. Sam "leaps" into the fluid of spacetime and apparently disappears forever. However, it is soon revealed that Beckett's consciousness is alive and able to transfer to and appear to inhabit the bodies of other people existing on his timeline. The artificially intelligent computer he created, called Ziggy, operates with the assumption that in order to return home, Sam must change events in the past in order to "correct" the future course of events.

Synopsis: Wikipedia, CC BY-SA 4.0