an interesting thought experiment

Rating: 7/10 (7 March 2017)

I really liked this movie, but more as a thought experiment than as straight science fiction. If I had one criticism of the film it would be that it sort of changes tone in the last act from a "hard" sci-fi to more of a fantasy, leaving part of me wishing they had seen the original theme thru to the end.
Both themes are well done enough that I enjoyed the film despite any incongruities I perceived. I should mention that I turned the spoiler tag on just to be safe, but I'm going to try and be a little vague anyway because I don't want to spoil a few big reveals that come together at the end of the film.
The basic plot: the world is stunned when twelve alien craft suddenly descend to earth and throw open their doors. As society begins to buckle a bit under the strain of this historic event, a talented professor of linguistics who had previously worked with the government as a translator is selected to join the US team attempting to establish communication with the aliens.
This first act is probably my favorite part of the movie. The alien physiology and method of communicating is very well designed, which gives a definite "this could really happen" vibe that is very engaging.
Likewise, the challenges and methods used by the team to try and understand an alien species that shares very little in common with us was fascinating. In a lesser film it would be easy to have the protagonists "realize" that they needed some trivial concept to communicate while the rest of the cast looks on in awe (e.g. "We just needed to realize that for the aliens, all of their conversation is done as stories!"). The reaction of the other characters is used to lead the audience to the idea that the protagonists are really smart, even if what they did isn't particularly brilliant. It's a common technique used by lazy writers to develop a sense of genius on screen when they don't really have any actual genius ideas to offer.
As the film progresses, a dangerous situation develops between the nations that has to do with each nations motivations and fears. And again it feels realistic and engaging as it unfolds, although here is where the fantasy ideas about to be revealed start to create some plot holes.
Without directly revealing any plot points, let me just make a couple of points about things that movies do that invariably create plot holes only solvable by "magic". The first is about anything having to do with traveling into the past or getting a book of horse race winners from the future or any other kind of "information from the future" scenario.
The basic problem here is that these situations always create paradoxes. If my crystal ball tells me that in five minutes some guy is going to punch me in the face I will invariably change my actions to avoid getting punched. But in doing so, I invalidate the "future" I saw. Information is, quite literally, energy, and by adding energy I am changing the conditions leading to the future and hence, the future. So knowing the future changes the past which changes the future which changes the past and so on. Movies that feature time travel have no choice but to gloss over this to keep the plot from becoming a confusing mess, and in so doing break with "realistic" story telling.
The second point I want to make is with what psychologists call magical thinking. This is where you make a mistaken connection between cause and affect, usually because you wish it were true. As in, "if I go stand by the fridge my team always makes the field goal!" Unless it's an X-men installment or whatever, movies don't usually have these plot elements in "realistic" movies because the writers know people will spot it and call them on it.
But there is an exception to this, which is when a writer takes a true piece of information and marries it to an unrelated but seemingly connected idea. Then the true fact becomes the justification for the made up thing. So for example, it's a proved fact that forcing yourself to smile even if you don't feel happy tricks the brain into actually feeling happier, something having to do with muscle memory or whatever. But if I tell you that and then tell you that learning to smile all the time can cure you of ever being depressed again, that is pure BS. The two ideas *seem* related, so knowing that the first one is true might let you believe the second one is too, but they're not and it isn't. The movie has a pretty big whopper in this category related to the true fact that immersing yourself in a foreign language actually changes the way you think.
"Arrival" sticks to the idea of "What would happen if aliens landed on earth tomorrow?" pretty well, and makes a stab at showing how people might react. In the last act it uses some of the issues I mentioned above to veer away from this into "What if space wizards gave us magic?" territory, but really only so that they could wrap up the plot and ask some interesting philosophical questions on their way out. Bottom line, I really enjoyed the film. I just think I might have enjoyed it a little more as a straight sci-fi flick than as a fantasy piece.