What I want to share with you is how I think time travel effects time; history, future, present, and such. I have included some images, (that I have drawn myself, so be kind) that should help you understand my ideas. I recognize there are probably flaws in my logic. Should you find any, post a comment, and then I will think on it, and get back to you.
Think of an endless line of ants. (Weather or not ants really walk in a line I do not know, but lets pretend.) Now, unfortunately, this line needs a "lead" ant to make sense, but try to remember, really there is no beginning.
In this idea of ants, the "lead" ant chooses to go somewhere, and all the other ants follow blindly. If the lead ant runs into an obstacle, the other ants will also run into that obstacle. The lead ant makes his choice; around, over, under, and the like. The other ants follow.
So IF we could time travel, and just observe, not interfere (ignore the fact that even looking interferes) we would see exactly the same thing happen in every moment we look upon. Just like every ant that has to go around that rock, every moment has to pass through, or already has passed through, your birth, and your death. There are infinite moments in both directions and the exact same things will happen for each moment, no matter how far away they are on this line.
Now lets look at moments. A is long after your death. B is your death. C is your mid-life crisis. D is your birth. And E is long before your birth. A has been in every position on this line, and E will go through all those positions as well.
I hope you got that, because now we are moving on. Lets look at what time travel does to this model. Lets say the ants are walking on a stick.
Some one comes along and moves one end of the stick. The ant just on the end of that stick is going to be the new "lead" ant for all the ants behind him. There is no way for him to know how to get back to where he should be, so he starts his own line of ant and leads them forever.
This is a very simple model. Perhaps I will expand on it later in another post. Obviously there are lots of things that could come up to change how this works. If you have any questions about how this model works, or if you find holes in it, let me know, I would like nothing more than to perfect this model about time.