Personally I don't believe in Time Travel because to do so would mean having to change the state of matter for every particle in the Universe including the entire Universe back to a former state of interaction which based upon gravitational constants would cause the entire Universe to collapse in on itself and then release itself in another completely different form of existence.
If this were to happen then everything would be gone in an instant and no of else would be around.
....but he is the interesting reality of Time Travel that can and does prove that we are all moving in the same moment in time both foreword and reverse.
First you have a clock that has a see through face on it. The clock mechanics on the inside can clearly be seen. On the side of the clock that is facing you the hourly numbers are visible and are placed normally going clockwise. Now we turn the clock around to the other side and we have numbers measuring the time going clockwise as well. You'll notice that if you peer through the glass to the other side of the clock that the numbers are equally opposite of each other but both are traveling counter-clockwise and clock-wise at the same time.
The hour and minute hand are two single pieces that run between the space of both hourly measurements so as to precisely measure time with a single mechanism instead of having an out of tune mechanic.
Now lets turn the clock around to the first side and begin the clock at 12:00. As the hands begin to move clock-wise you will notice that on the other side that the clock is measuring time as flowing backwards. So when the clock reaches 1pm it has also reached 11 am on the opposite measurement proving that time does flow backwards and forwards at the same time while the clock hands find an equilibrium of measurement at its center.
If your able to adjust the clock hands so that 2 pm measured 2 pm on the opposite clock facing then you will have achieved time travel and most likely entered a segment of space called sub-space where species like 8472 live.