Time travel has had a lot of controversy due to paradoxes and such. People are always saying "Why is that there if it hasn't happened yet?" and such.
It all basically boils down to 2 main theories.
The "Timeline of Change" Theory:
Time travellers who meddle must fix their actions because they have changed time, and have memories of nonexistant alternate timelines, causing them to cease to exist. Their memories are proof of the fact that they come from a separate part of the timeline's timeline, and paradoxes cause people to nonexist, instead of the universe spazzing out and imploding.
The "Written in Stone" Theory:
The future or past cannot change, and anything you try to do to change an event will either do nothing, or, more plausibly, cause it to happen in an unpredicted way. Things cannot change.
Personally, I think (neither italicizing nor boldening the single letter I does any change, and underlines look just plain weird!) that the "Timeline of Change" Theory is bullsh*t. It doesn't work out. If that happened, since they came from a nonexisting timeline to alter it to the current one, wouldn't they have no recollection of the former, nonexistant timeline, because they were from the current, existing timeline?
The "Timelines of Change" Theory counts in when Marty gets back to a family he doesn't remember. There was also an almost-paradox on when Doc dies, and Marty writes the letter, but that paradox is healed when Doc looks like he's died until the moment when Marty travels to 1955.
The "Written in Stone" Theory counts in at parts like the song, or the Mayor.
Also, I think that the 5th through 10th dimentions being probability is full of bullsh*t as well.
Convince me that the "Timelines of Change" Theory is the more plausible one.


