a serious plot hole

Rating: 9/10 (18 August 2006)

I do really like this film and it is from an era when I was a teenager. It definitely captures the mood of the eighties and also the nostalgia for the fifties which was prevalent in the seventies and eighties. I'm not really one for picking holes in movies as the whole point of going to the cinema is that you are entering a fantasy realm. However when watching BTTF recently I noticed a serious plot hole. There has to be a suspension of logic when time travel is involved but usually time travel films make their own internal cock eyed sense if you accept that time travel is possible. In BTTF though there is a lack of internal consistency which I will explain. When Marty travels back in time he alters history and returns to his own time to discover things have changed. This means though that there are in effect two Marty's. The one who we follow through out the film and the one who grew up in the history in which his father punched biff and lives a much better life. When Marty returns at the end he see's "himself", a different Marty, being chased by the terrorists and going back in time. The problem is, what happens to this Marty? Where does he go? The Marty at the end is the same one who grew up in the original history where his Father was run over by the car. If the second Marty went back to 1955 he would find the other Marty there with him. Also when the musician calls Chuck Berry to let him hear Marty playing Chuck Berry on the guitar we are supposed to accept that this is a case of effect before cause. But even in this context it doesn't make sense because Marty grew up in a different history in which Chuck Berry hadn't heard him play guitar and so wouldn't have developed that sound. Anyway, it's a fantastic film despite this or perhaps even because of this crazy paradoxical plot.