Back to the Paradox

[Peegee]

I don't think Back to the Future ever establishes if there are multiple timelines or if there is one continuous timeline that can be edited. My real vote is that when Marty 1 goes back and makes his parents successful and saves Doc Brown and Marty 2 leaves, Marty 2 ceases to exist because Marty 1 already exists.

EDIT: Also. Great Scott! This is heavy.

in BTTF2 doc brown tries to explain that modifying a different time will create a new timeline, thus making the previous timeline...something or other.

I'm wondering if the previous timeline still exists, despite not being able to get back there (except when cancelling the effects of the modification)



here's a facimile of what Doc Brown drew
we start BTTF at the top. the timeline was skewed and so travelling back to the past (to) before the modification point does not allow transit to the original timeline

the original timeline does not occur until the modification(s) is/are undone.



Since the original timeline no longer exists (or rather, never existed), how did it exist to begin with? And when you destroy the future timeline where you had to travel to in order to undo the change to go back to the original timeline, where does the changed timeline go?