As a scientist (though not a physicist) I sometimes ask myself “is time travel possible?”. The answer is, clearly, I don’t know. Perhaps it is.
There are a large number of time travel theories. On one hand if it were possible to travel backwards in time, would we not be surrounded by millions of people from many centuries into the far future who have come to view us? Then again, why should they come this year when they have untold eras to visit instead.
Regardless, maybe they are in fact here? Maybe it is possible to visit us, but there are limitations? Time travel movies usually play a lot with these ideas, with the complex link between cause and effect, past and future.
One very good example is the movie Timecrimes. Although a large portion of it is unsurprising and can be said to fall into the standard time travel genre, at some stage during the middle of the movie it breaks from that and starts asking questions that aren’t normally investigated: what is cause and what is effect? It does so in a very effective and mesmerizing way, and when I left the cinema I couldn’t help but wonder why so few films deal with those fascinating issues.
In most films that are about time travel one of the following scenarios may occur:
(a) The protagonist may go back in time and alter something and cause a paradox (these movies often contradict themselves almost every single time).
(b) The hero may travel back in time only to discover he can’t change anything - he is a part of history.
(c) The hero may journey back in time only to explore an historical era (in a sense, this needn’t be a sci-fi movie).
(d) The hero may travel to the future - in many ways this is not a time travel movie but rather a futuristic movie (think ‘Buck Rogers’ - an astronaut gets frozen for 5 centuries and wakes up in the far future).
All these are intriguing alternatives. Until they are resolved by science, I will enjoy whatever movies and novels are written about the subject despite any (major) flaws.