Okay there are a couple parts to my theory. first im not talking about a time travel machine, I'm talking about moving faster then light and how doing this would make you travel backward into the past. this is all saying we can theoretically move faster then light through some kind of imaginary dark matter futuristic space ship.
I have a scenario where time travel would take place due to the space ship going faster then light. Now in my theory, two space ships are beside eachother talking with a sun shining light on them. One does a faster then light launch to a distance where it would take about 40 seconds to get to at light speed.
the space ship then turns around and moves left about 50 feet. Now looking back at the other space ship. the light that was reflecting off the ships is about 20 seconds in the past and the light is catchin up to him, and he would see himself talking to the other ship from the past. thus time travel has occured. because in the end time is really just how long something takes to reach our eyes. if u consider everything you see right now current, then that space ship would be current and you would be looking at the past.
this also would work for moving forward in time as if you looked in the other direction you just met the light coming from the other direction faster.
This is my theory, i may be missing alot of facts, but im only 17 and don't have alot of depth in science.
please give me feedback thanks