So how does time travel work?
...the speed of light in a vacuum is constant and an absolute physical boundary for motion. This does not have a major impact on a person's day to day life since we travel at speeds much slower than light speed. For objects traveling near light speed, however, the theory of relativity states that objects will move slower and shorten in length from the point of view of an observer on Earth. Einstein also derived the famous equation, E = mc2, which reveals the equivalence of mass and energy. When Einstein applied his theory to gravitational fields, he derived the "curved space-time continuum" which depicts the dimensions of space and time as a two-dimensional surface where massive objects create valleys and dips in the surface. This aspect of relativity explained the phenomena of light bending around the sun, predicted black holes as well as the background radiation left from the Big Bang. For his work on relativity, the photoelectric effect and blackbody radiation, Einstein received the Nobel Prize in 1921.
In simple words...if we can travel at the speed of light, we can break the time barrier.
One simple question which should be taken into consideration is that if some sort of vehicle is created can the human body withstand that kind of speed???
It is just a theory though :)