Dr. Sam Beckett from the TV show, Quantum Leap, had a theory of time travel he referred to as his “string theory”. His theory borrowed heavily from van Strickum’s Closed Timelike Curve and his explanation can help one better understand the Closed Timelike Curve.
From the beginning of each episode of Quantum Leap:
“Theorizing that one could time travel within his own lifetime, Dr. Sam Beckett stepped into the Quantum Leap accelerator and vanished.... He awoke to find himself trapped in the past, facing mirror images that were not his own and driven by an unknown force to change history for the better. His only guide on this journey is Al, an observer from his own time, who appears in the form of a hologram that only Sam can see and hear. And so Dr. Beckett finds himself leaping from life to life, striving to put right what once went wrong and hoping each time that his next leap will be the leap home.”
Dr. Beckett’s theory described through a conversation in the episode “Future Boy”:
Moe: Time is like a piece of string. One end of the string is birth, the other is death. If you can put them together, then your life is a loop.
Al: Hey! Sam, that’s your theory!
Moe: If I can travel fast enough along the loop, I will eventually end up back at the beginning of my life.
Al: He – He’s got it!
Sam: Well, let me ask you what would happen if you would ball the string, right? And then each day of your life would touch another day. And then, you could travel from one place on the string to another, thus enabling you to move back and forth within your own lifetime. Maybe.
Moe: That’s it! That’s it! Then I could actually…
Sam: Quantum Leap.