October 21, 2015 is the day that Marty McFly and Doc Brown arrived in a time traveling DeLorean in Back to the Future II. My wife and I had been married about two years when we saw the first Back to the Future movie. I had finished my graduate program at UCLA in Semitic languages and had a lecturer position at a small Christian college in southern California. She was just starting her fifth year in college working on her teaching credential; at the time, she was still working full time at the Jay Nolan Center for Autism as a behavior specialist where she cared for autistic adults in a residential care facility.
I recall how much we enjoyed the movie, and being young and science fiction fans that we were, we spent the time at the restaurant afterward discussing the possibility of time travel and if time travel were real, would what we’d seen in the movie even be possible. We concluded it depended on whether the many worlds hypothesis for interpreting quantum physics was true. If it were true, then any alterations you made in the past would simply create an alternate reality. If the many worlds hypothesis was not the way the universe worked, then it seemed to us that it was unlikely that the past could be changed in any way.From what I gather in the movies, especially from Back to the Future II and the blackboard scene with Marty and Doc Brown, the universe of the movie assumes that the many world’s hypothesis is true. Of course, if that’s the case, then the alternate realities they create as a consequence of the DeLorean trips do not cease to exist, except for those riding in the DeLorean, as they are cut off from them and wind up, not in the original universe from which they left, but instead in another alternate reality, albeit closer to the nature of the one from which they left.
It is, of course, improbable that time travel is even possible. But for my wife and I, we had great fun watching the movies and discussing their ins and outs. Chances are, we’ll be spending some time this week watching the three movies once again; we have the DVDs, after all.