The problem with time travel is that there are so many paradoxes. Like 'the time machine didnt exist in the past so you cant go back further than when it was created. Etc etc.
I think that it might be possible for particles to travel back in time, through the use of worm holes/ black holes etc. Again I dont know if this is true or has been disproven but from what I know of space time and its concept it would be possible to travel anywhere in to (back and forward) the space time matrix. Hmmmmmm (:
Interesting fact, we can slow down times effect on us. And therefore in relative terms travel through time.
You have two twins. You take one and put him on Earth. The other lives in a satellite circling the Earth at lets say 25000 km/h.
After 80 years you bring them together and the one that was in space travelling at a higher speed will be around a nano second younger than his other twin.
(i.e. time has less effect on you the faster you are travelling)
The longer you travel for the younger you are. And the faster you travel to the speed of light the younger you are. All relative to what time frame/ speed you live in.
If I was to travel 3 light years away at the speed of light (impossible but lets say 99.99999999999% the speed of light) It would take me just over 3 years to get to my destination. Then I turn around and come back to Earth.
So just over 6 years have past, relative to my speed.
On Earth 80 million years have passed. omfg \o/
Its crazy how it works but it does (:
Thank you Einstein.