Time Travel Paradoxs' and Bad Headaches

The new Trek reboot has gotten me thinking about the nature of time. Here are my thoughts:

1) The past can be changed...sort of. The classic example is the Grandfather Paradox. How can one go back in time and kill their Grandfather. If they did, they would not exist in the future to go back in time to do the deed. HOWEVER, one can do this if you understand that it will create an ALTERNATE Time line that you will then be stuck in; whereas the old one (Prime One) will still exist. It has to do with the theory that when ever we have a choice to make, for every choice an alternate reality is created where each choice was made.

2) There is only one timeline and the past cannot be changed...sort of. Some believe that Time is aware, that it is a form of life with a beginning, middle and end. Whenever there is a major 9or even minor) change, Time will try to correct itself. So, if one goes back in time to kill their Grandfather, they may cease to exist; however, Time will repair itself by making it possible for the elements in this person will exist in others so that they would exist to go back and kill the Grandfather. It would, of course, create some kind of loop. However, it would still act as a repair mechanism so that Time is healed.

Thoughts?

GL

I think it's hilarious that every possible theory on time travel can co-exist within the Star Trek universe. Sometimes the present is immediately altered by interrupting events in the past, sometimes not, and sometimes the people involved are affected, sometimes not, etc.

My favorite time travel stories involve trying to change the past, but it turns out that everything works out the same, and the attempts to change things fall into place like pieces of a puzzle, having always been there.

So, what are your favorite time-travel movies?