Originally Posted by Chyron8472
So basically, my thoughts are that when Doc goes to the future by himself, he finds a future in which Marty and Jen are there but Doc's other self is not.
So, then why are 2015 Marty and Jennifer there when 1985 Marty and Jennifer go to the future? If future selves can exist when past/present selves visit the future, shouldn't a 2015 Doc be around, too (assuming he would still be alive, and even if he isn't, then in a grave somewhere), on his first future visit? Or am I just misunderstanding you? Because if 2015 Doc isn't there, then when 1985 Doc goes back to 2015 with Marty and Jennifer shouldn't there be two
1985 Docs there? And wouldn't Doc essentially be taking Marty and Jennifer into a "recording" of what he saw when he visited the first time?
It seems to me that the only way to account for both past/present selves and future selves to exist in the future simultaneously is the time ripple effect. If 1985 Marty, Doc and Jennifer were to stay in the future for more than the day they were there, their future selves would eventually
disappear, but not immediately
I lean more towards the 2015 visited by 1985 M/D/J being the actual
future, rather than some projection, which I think is what you're saying, right? But that doesn't mean it still can't be changed, just as 1985 is changed by visiting 1955 (since 1985 is 1955's future).
I'm sure I have something wrong in here. You seem to have a much better grasp on the logic of all this than I do, so please correct me. 2015 is by far the most confounding part of the trilogy, mainly because Gale and Zemeckis seem to have thrown several different theories about future time travel together which don't exactly jibe with each other. Figuring it all out is challenging, but fun.
Originally Posted by FaMzNeSS
So, it appears that one can travel to the future, a future where they still exist, so long as they do not do anything to endanger themselves to the point where they may alter the future, or risk not returning to the "present" at all.
Exactly. Which is why Old Biff disappears immediately upon returning to the future, but 2015 Marty and Jennifer don't disappear immediately just because 1985 Marty and Jennifer are there.