No matter how far technology progresses, or what impossibilities science makes possible, one fact remains: a human being can't change the past. But that doesn't mean movies can't show what might happen if they could.
Over the years, the 'time travel' genre has swelled to include hundreds of films, ranging from adventure (Back to the Future) to psychological horror (The Jacket), with this week's About Time using the notion of time travel to put a spin on romantic comedy.
What better time to look back at the genre as a whole, highlighting not simply the most acclaimed films that happened to include the concept, but stories that added a new dimension to leaping backwards in time.
Here are Our 10 Favorite Time Travel Movies.