The physics behind time travel
Saturday, August 15th, 2009
Slate takes a look at the physics of time travel and comes up with the following rules:
1) There are no "parallel universes"
2) You can't visit any time before your time machine was built.
3) You can't kill your own grandfather.
4) You can't actually do anything in the past to affect the future.
1) There are no "parallel universes"
2) You can't visit any time before your time machine was built.
3) You can't kill your own grandfather.
4) You can't actually do anything in the past to affect the future.
From 
