Originally posted by: JennyS1138
There's one major inconsistency: the fact that when Marty travels into the future, his older self is there. That's impossible! If someone goes in a time machine and travels ahead 30 years, then that means that they would be "missing" for those 30 years. THere can't be 2 Marty's. Flight of the Navigator got that right. The kid's in a time machine for a few minutes and is returned 8 years in the future. He hasn't aged but to the rest of his family he was gone 8 years. Duh.....
There's one major inconsistency: the fact that when Marty travels into the future, his older self is there. That's impossible! If someone goes in a time machine and travels ahead 30 years, then that means that they would be "missing" for those 30 years. THere can't be 2 Marty's. Flight of the Navigator got that right. The kid's in a time machine for a few minutes and is returned 8 years in the future. He hasn't aged but to the rest of his family he was gone 8 years. Duh.....
Yeah, the commentary addresses that, and YIYF's explanation is correct, that Marty and Jennifer will return to 1985, therefore the 2015 they go to is an extrapolation of the past. It doesn't quite mesh with their theory of time travel (except that since the future isn't written, the future they go to is an assumed future based on the events of the present, so it could work), and in, more or less, the words of Bob Gale, "It wouldn't be interesting if we went to the future, and Marty and Jennifer weren't there."