Photo: One of my favorite time travel devices is the DeLorean from Back To The Future (rendered in Lego by Legohaulic).
Sean Carroll has prepared this handy guide for filmmakers whose projects involve time travel. That means you, J.J. Abrams. Not that we didn’t enjoy your movie, but we may not be so indulgent in the future. Also Belle says stop ripping off your old TV shows (Alias, Lost, etc.) And McGâ€”Terminator Salvationâ€”we’re watching you.
0. There are no paradoxes.
1. Traveling into the future is easy.
2. Traveling into the past is hardâ€”but maybe not impossible.
3. Traveling through time is like traveling through space.
4. Things that travel together, age together.
5. Black holes are not time machines.
6. If something happened, it happened.
7. There is no meta-time.
8. You can’t travel back to before the time machine was built.
9. Unless you go to a parallel universe.
10. And even then, your old universe is still there.