In man's wildest fantasies and Hollywood's most outrageous adventures, time travel is the ultimate thrill ride. But The Terminator and Dr. Who aren't the only ones fascinated with the idea of revisiting the past. Inspired by Carl Sagan's novel Contact, scientist Kip Thorne has postulated how time travel might be possible. Join NOVA for this wonderfully head-spinning trip to see how one man has created a theoretical time machine that may turn dreams into reality.

Thorne believes that someday, if a civilization far more advanced than ours could harness and manipulate "wormholes"- theoretical tunnels through space and time- they might be able to go back in time to arrive at a place before departing. Discover the wicked paradoxes of his theory, and learn how the emergence of new "quantum gravity" laws are creating heated scientific debate. And see how Thorne and other top scientists from around the world- including physicist Stephen Hawking- are pushing physics to the limit in an attempt to "understand" the true nature of time and space.