Question: In the first scene, Marty and Jennifer leave 1985 with Doc and arrive in 2015. How is it possible for their older selves to be present in the future when they left in 1985?
A nameless member
29th Sep 2023
Back to the Future Part II (1989)
1st Sep 2020
Back to the Future Part II (1989)
Question: In 1985-A, when Biff threatens to shoot Marty, Marty says that the police would match up the bullet with the gun. Biff mentions that he owns the police and that they couldn't match the bullet with Biff's gun. How could the police be unable to match the bullet that murdered George with Biff's gun?
Answer: Because he owns the police, and ensured the forensics were rigged.
Answer: Relates to the "branching timeline" interpretation of time travel. Basically they jump forwards to a future version of the timeline where they never left. When they return they make different choices and that branch doesn't happen any more, taking them on a new path. Alternatively (additionally), given that they do eventually return, that's all that matters. If they left somewhere at 10:00am, had time travelling adventures, but then returned at precisely the moment they left, at any point later they're still there like they never went anywhere.