Science (Fiction?) / Fantasy

So there are all sorts of ideas of how time travel might be accomplished. For example, wormholes as discussed in FTL travel are believed to be able to accomplish time travel by moving one mouth of the wormhole relative to the other (or something like that). I don’t know. Not relevant to what I want to talk about. I want to talk about what actually happens when you time travel, and whether or not you can get back to your own time in your own universe.

Traveling to the past
Assuming you could actually perform some sort of time travel, when you travel to the past, is it possible to change your past? I think it isn’t. The way I look at it, there are infinite parallel universes / dimensions where if you make one choice, your dimension branches one way, whereas if you make another choice, it branches the other way. Consequently, if you go back in time to before you were born and kill your father, you would not cease to exist. You are the you from your own universe, and the you from the branched universe would never exist. That said, if you never traveled back to your own universe, space and time, then you would end up existing in the other university for the duration of your stay there. The act of actually going back in time causes the branch to begin with. In your own universe, you did not appear at what ever location at whatever time. It is a paradox. The chance of meeting yourself is impossible. You can’t meet you. You can only meet the version of you that exists in the other universe (if that version even exists).
Ok, my head hurts … A lot.

Traveling to the future
When you travel to the future, I don’t think you are really time traveling. I think that the time travel comes into play when you try to get back to the ‘present’ because I view that as the past (see above). For example. If you go to sleep, then from your point of reference, an instant has gone by, but to the rest of the world, eight hours have gone by. Did you really travel to the future? In a manner of speaking you did, but your body aged by eight hours so I guess you did not. If on the other hand you were frozen cryogenically, then your body did not age and so you really did travel to the future (of your own universe).
The other point of view to traveling through time is the whole concept of time as a river. You can plunge in where-ever you like. In this view, the paradox is harder to grasp. If you jump back and kill your father before you were born you would then instantly disappear, but would you be able to strike the killing blow? Would you not disappear before the blow was struck, therefore eliminating the killing blow such that you reappeared and were able to strike? (ouch, it hurts) This paradox is what prevents this from being feasible.

I guess what I am trying to say is that time travel is really hard on my noggin’. If it were possible then the paradox would get in the way. My first example of parallel universes is not really time travel, because you are not traveling through time in your own universe. It avoids the paradox, but does not accomplish the same thing. If a story utilizes time travel, then the more serious the author takes it, or the more the story focusses on time travel, the harder it will be for the time travel to make sense.