Originally Posted by LuigiHann
this is a great site for that sort of thing. Essays exist for most of the things discussed in this thread. Some may argue that it's unfair for him to enforce his own "rules" on all time travel movies, even though different movies seem to present different models of time travel, but he does a good job justifying it for the most part.
Sorry to dismiss it this early dude but I haven't even read it. There's basically 2 main time travel theories; pre destination and post destination
pre destination implies there's only been one timeline (see the 12 monkeys, terminator 1, or the time travelers wife) which has already had all time travel entrenched in it and thus makes it impossible to change the timeline.
post desitnation implies that the timeline CAN be changed as time travel is not entrenched in the timeline as we see in BTTF.