Is Time Travel possible, according to Einsteins Theory?
You need to actually read the basis for, and explanations of Relativity. Supraluminal (faster than light) travel is not possible. At the sped of light time stops, not for the universe at large, but for the thing traveling at light speed. As an object approaches light speed, it ages more slowly than objects traveling at non-relativistic speeds. This has been demonstrated many many times experimentally. Light does not age and therefore does not decay. If you could travel at light speed you would not age even a fraction of a second. So you would cross the entire universe in an instant based on your reckoning. The rest of the universe would continue to age, so 13 billion years would pass for the rest of the universe while no time passed for you. Now go read a book on relativity.
