Predestination

I have a high threshold for great movies.  Predestination is not a great movie.  But it's interesting, well-acted, well-written, and technically proficient.  As J.F. remarked, "It is what Looper should have been."  I agree.  The film is based on a short story which I now have in my possession but have yet to finish reading.

More thoughts (and spoilers!) below the fold:


The time-travel looping was extremely complex and well thought out.  There are no obvious metaphysically impossible scenarios (unlike Looper which had some howlers) if one allows that time-travel into the past is metaphysically possible (along with backwards causation which seems logically entailed by time-travel into the past).  At least there are no obvious metaphysically impossible scenarios to me.  I would really need to watch the film again and take notes to see if there are any such inconsistencies.

The last scene with the Ethan Hawke character shooting his older self, the "Fizzle Bomber," is interesting and seems to allow for at least two interpretations.  If one goes with the "Predestination Paradox," he kills the Fizzle Bomber but doesn't change the past (time being linear and non-branching).  Nonetheless it's possible that a slightly younger Fizzle Bomber goes into the future and still blows up the building before he is killed.  Sure, the Fizzle Bomber is killed, but he's killed after he goes to the future at time T3, blows up the building at time T6, comes back at time T4 and is killed at time T5.  Clearly there is at least one timeline in which the building does blow up, otherwise there's no reason to go back after it happened to stop the Fizzle Bomber before it happens.  So, again, on one interpretation the Ethan Hawke character kills the Fizzle Bomber but doesn't prevent the building from exploding.  He grows older, becomes the Fizzle Bomber, and goes to the future to blow up the building before he is killed in the past.

On another interpretation, Ethan Hawke's character changes the past by creating a branching timeline (another world).  In one timeline (in one world) things play out as I described above.  But in one he shoots the Fizzle Bomber and does not become the Fizzle Bomber.  Since the film toys with the idea that the past can be changed, it appears open to this interpretation.

But then what would account for the branching timeline?  Both timelines seem identical at the point of the shooting of the Fizzle Bomber.  In both timelines, the Fizzle Bomber is shot.  Why, then, does he become the Fizzle Bomber in one but not in the other?   What accounts for the difference? 

It's hard to say.  Here is a scenario that is not possible: Time is linear and non-branching.  In 1975 the Fizzle Bomber blows up the building.  Ethan Hawke goes back in time, kills the Fizzle Bomber before 1975 and the building does not blow up in 1975.

That is a metaphysical impossibility.  The building cannot both blow up and not blow up, in the same world, at the same place, and at the same time. It's impossible to change the past in a world in which time is linear and time (and worlds) don't branch.

To follow the looping action, I found the following diagram here helpful: