Is Time Travel Possible? - Scientific American
Time traveling to the near future is easy: you’re doing it right now at a rate of one second per second, and physicists say that rate can change.
Going backward in time gets thorny, though (thornier than getting ripped to shreds inside a black hole). Scientists have come up with a few ways it might be possible, and they have been aware of time travel paradoxes in general relativity for decades.
I ask the same question about this that Hawking did... "If Time travel is possible, where are all the visitors from the future?" Personally, I don't believe it's possible. I do, however, believe that their may be multi-universes where Time and realities may range from very slightly different to our Universe to extremely different. Can we travel to these different realities? Dunno' about that, but it would be interesting; and it would also eliminate Time travel paradoxes because our presence in an alternate universe would not affect our home universe.
Another interesting thing to consider is Entropy, which is the ultimate power in our universe. Without Entropy, we would sense no Time. There would be no time arrow pointing in in any direction. Are there alternate universes where Entropy is not as potent?
We may never know... that's the mystery of existence. While it is amazing that an insignificant chemical reaction started on this rock billions of years ago and led to the appearance of a big brained primate who evolved enough to actually sit and contemplate its own existence; I tend to doubt the big brained monkey will ever solve all the mysteries.
