If you haven’t seen the movie Looper yet, stop reading now. Or rather SPOILER ALERT!!!
We good? Good.
As a refresher: the movie’s premise is that in the future, the mob controls time travel. The main character works as a hit man for them—people are sent back in time and he whacks them with a gun. He is what is known as a “Looper”. Eventually he knows that his future self will be sent back and it is his responsibility to kill future him—thus closing the loop*.
Time travel isn’t the point of the movie. There is even a scene in the movie that admits that the whole time travel thing is a bit wishy-washy. So what I’m about to say isn’t a critique of the film or the filmmakers—I enjoyed the movie quite a bit.
But the time travel is a bit wishy-washy.
For the purposes of this movie, let’s assume that time is linear**. I don’t have a problem with the time travel, but in how it’s done.
Here’s why: Energy cannot be destroyed; it can only be redistributed. That redistribution usually happens in one of two ways—slowly through degradation over time, like a decaying body, or violently through a sudden release, like an explosion. It doesn’t just disappear suddenly.
Therefore, if the mob sends a person—a mass of energy—backwards on the timeline, then they need to send an equivalent mass forward into the future***. That way the energy is balanced on the timeline and therefore you and your future self could exist in and at the same time—just like the mass sent into the future, let’s say a sack of potatoes, would co-exist with its future self (if it still existed). However, since your two selves now exist at the same time as individuals, the actions you take on yourself would unlikely have a bearing on your future self.
So the ending, to me, is a bit wishy-washy. Or maybe it’s this blog post that’s wishy-washy****?
*Got all that? Of course you did. You watched the movie or else you wouldn’t be reading this far.
**Maybe it is, maybe it isn’t.
***The movie doesn’t seem to have this mechanic in place, as far as I can tell.
****In the future, I will probably wish I could go back in time and change this post.