Thursday, April 27, 2006

Primer: what happens if this really works?

That is the title of an interesting if confusing movie about what happens to the relationship betwen a pair of friends when an invention they are striving to create actually works.

The movie is complicated by a bunch of jargon (early) and time travel (late). But I recommend it highly. The jargon you can ignore (although it is actually spot on if you know anything about the attempt to create superconductors, the development of which would be akin to the perpetual motion machine).

The time travel is a bit more central to the story. Suffice to say that it gets confusing because you are placed in a position of attempting to find out what has happened 'behind your back' as characters go back in time without your knowledge and revise events you had already witnessed thereby changing what you are presently witnessing.

Eventually this results in violating causality: changing something in the past that led to a future (that no longer exist) that is currently tampering in the past.

I posted the following to the topics forum so beware, SPOILERS AHEAD (it likely won't make any sense unless you've seen the movie anyway).


There are only two Aarons - meaning that there are only two permanent copies of Aaron. That does not prevent there from being three Aarons at a particular point in the movie, just as there only being one Abe prior to his failsafing does not mean that there are not two versions of Abe walking around (or hiding in a hotel) during previous portions of the movie.

People need to distinguish clearly between permanent copies that result from an interference by a future copy in causality (preventing their former self from entering the box) and 'looped copies' which resolve themselves into one by looping through the box.

Let me address the incident which most people take to be evidence for three separate Aarons: the fight that Aaron2 has with himself while Aaron1 is tied up in the attic. What happens is that Aaron2 is fighting with Aaron1 after Aaron1 has escaped the attic (which we know will happen) and then enters the failsafe to combat Aaron2. That is why Aaron1 (the fighter) is too tired to beat Aaron2: he has just escaped from the privations of the attic and spent a number of days traveling back in time to fight Aaron2.

Aaron1 (attic) will enter the box unless Aaron1 (fighter) prevents this. There is absolutely NO indication that this closure of the loop is prevented. In fact it seems that Aaron1 (fighter) has come back precisely to prevent himself from spawning a permanent double, but can't succeed in defeating Aaron2. So in the face of the evidence it seems reasonable to assume that Aaron1 (attic) will eventually escape - we know he does because we see it and we also see him fighting with Aaron2. After his escape he goes to the failsafe and vanishes, hence: there are only two Aarons: Aaron2 who wears the hoodie and goes to some French-speaking nation, and Aaron1, who will eventually successfully loop with his double and therefore does NOT spawn a third Aaron.

This interpretation is confirmed by the final conversation in the airport, where Aaron speaks of dividing the world into two hemispheres, one for each copy of Aaron and Abe (and jokingly, their wife and girlfriend).