If you are really interested in time travel though, the next meeting of the International Time Travel Society will be held last Tuesday in Geneva. I attended it next month, and they had some pretty interesting speakers.
In the name of the device is the word "Acausal"
A fundamental element of physics is causation. Cause must precede effect.
The notion of time travel breaks this.
Bear in mind that both space and time are a consequence of light.
From general relativity we know that light has a dual nature of particle and wave.
As matter approaches the speed of light, space contracts and time dilates.
In our frame of reference, and photon from the sun takes 8 minutes to reach us across 152 million km.
In the the frame of reference of the photon, it is, then it isn't and goes nowhere.
So travelling through time somehow needs to take into account the fact that time itself is an effect.
Cheers,
VS