Time slows the nearer you get to light speed. At light speed time stops. If you could continue and could go faster than light, time should reverse, allowing travel to the past(everything in universe should reverse in time). Then to go back into future(back to your normal time when you originally left) just travel fast again to travel back into future or sit near a black hole until your back in your normal time. Seems plausible if matter could travel faster than light. If time slows nearer you get to light speed, then time stops at light speed, why can't time start to reverse if you keep going faster than light(again only if matter could travel faster than light)? Maybe the faster than light speed you travel, the faster time reverses, just as the faster you travel to get to light speed the faster time slows down. Time slows, time stops, then time reverses, maybe.