Time travel has always been intriguing to me—and to lots of other people as well, judging from the number of movies and books that have been written on the subject. I will not pretend to understand all of the theories that have been espoused so far. I won’t even pretend to know any of them, because honestly, I don’t. I did have three semesters of physics in college though, and some of it was on relativity, which is tangentially related to time travel, but that doesn’t really make me more qualified than any other random dude. Watching some Doctor Who episodes has piqued my interest again.
Before we go any further, I want to make it clear that my ideas are in no way based on firm scientific principles. I would have a hard time defending them beyond what I’m writing here. I’m only writing this because it’s interesting to me. I would almost admit to trolling for feedback…but that sounds a little harsh, so I won’t say it.
If time travel is possible, it is only possible one way: forward.
If backwards time travel were possible, we would know by now. Even if future knowledge and memories were somehow erased upon backwards travel through time (why would they be?), other people would still remember new people popping up out of nowhere and document it somewhere. Backwards travel through time also creates the opportunity for paradoxes, the simplest of which is known as the Grandfather paradox.
If you can travel only forward, then there are no more paradoxes. You can only disappear one moment and re-appear later, never earlier. It’s the same idea as teleportation, only with a gap between the start and end points in time.
I’m not saying that time travel is possible, but only that if it is, it makes sense that such a limitation would exist.