ORIGINAL: RigoStar
I remember something...
How Marty was able to pay his coffee when just arrives in 1955, if the money is not the same? Right?
Cause you can see in BTTF 2, Doc has money change for different periods. So I guess, he will need different money for 1955.
I'm pretty sure this is addressed in an early draft of the script where Lou (the cafe owner) does say something to Marty about the money. However, for the actual film, they just decided to let it go. How often does one look at the year of money, especially when behind a cash register all day?
As for the question in the first post of this topic, the answer I have always heard (from many, many discussion on the
BttF.com Forum which I used to frequent more than this board) is that during the time that old Biff comes back from 1955, 2015 DOES change, but the only part of 2015 shown is Hill Dale, and from the description of the Officers Reese and Foley (the two female cops), Hill Dale is already a real shit-hole. Marty and Doc are just coming out of 2015 Marty's house, so they would not see the changes that are happening inside the house. And as previously stated in this thread, there is a deleted scene of Biff being erased from existence, which was
only cut because Zemeckis and Gale (and probably some of the crew) felt it would be too confusing for the casual viewer; therefore one can consider the deleted scene to be canon.
Another explanation is that the "ripple effect," a plot device to explain gradual and not hardly simultaneous changes in the future when the history is altered (remember the photo of Marty and his siblings in the first film? Marty was not immediately erased; his two siblings went before him one at a time), simply did not catch up immediately when Old Biff arrived. Just because Old Biff gets erased from existence does not mean that the rest of 2015 had to change along with him. It could take another few minutes or even hours before the ripple effect caught up to change 2015.
Or you could just say that parts II and III are nothing compared to the original. The original did not focus on time travel - it was simply a device to get Marty to interact with his parents while they were the same age as him. Parts II and III did try to focus on time travel, and therefore a helluva lot of plot holes open up. Personally, I think the original stands perfect on its own. Just think of how cool the ending is if we did not find out and NEVER found out what the future was like. That was the original intention of the ending; part II and III were never thought about until after the success of the first film.
Regardless, even though I'd prefer the original movie to stand on its own, I still consider myself to be the ultimate fan of the entire
Back to the Future trilogy on this section of Internet and on Long Island (and perhaps the entire tri-state area)