Time is nothing but the sequencing of events. There is no way to travel in time because it is not something you can travel in. We say that we are traveling in time but that's only because of how we defined time. If you travel very fast your perception of time slows down, but never goes in reverse. You cannot travel faster than light (through space) and even if you could how would you navigate? I believe you can travel without using time however. There is no known physical manipulation of matter that effects time, other than velocity.
Given that mass is related to time via energy and time can only be effected by velocity, it seems like mass is a form of velocity. The higher your velocity, the higher your mass, and your mass becomes infinite at the speed of light, which would rip a hole in space. I don't see anyone ripping holes in space. Time travel is great science fiction but it's not likely to ever happen.










