Source Code

I saw Source Code recently. It's one of those thinking-man's SF movies. 

i) Many SF movies invest lots of money and creativity in CGI, but forget to hire a decent screenwriter. But Source Code has a clever, and emotionally pleasing, plot. It also has an ingenious way to mask the incoherence of time-travel scenarios. So many SF films insult the intelligence of the audience by not even attempting to offer a reasonable explanation for time-travel.

The basic problem with retrocausation is that if someone changes the future by changing the past, then the future he originally came from never existed in the first place, in which case he was in no position to travel back into the past from that starting-point. Source Code tries to get around this in a couple of ways. First of all, Capt. Stevens isn't literally traveling back into the past. It's less about time than space. He's accessing an alternate universe. And he does so by piggybacking on someone else's memories of the event. So it's indirect.

Moreover, he doesn't change the future by changing the past in the same world. Rather, he communicates information from one alternate past to the present of a different world. So that introduces another buffer to insulate against retrocausal antinomies. 

Mind you, that creates a different problem. Is it possible to transmit information from one alternate universe to another? But even if that's impossible, it's not obviously incoherent. It's just a different kind of problem.

ii) However, having avoided or at least obscured retrocausal antinomies at the front-end of the picture, the screenwriter reintroduces the same problem at the back-end. That's because they wanted to make a movie with a happy ending. An alternate ending for Stevens. Where he doesn't die in theater. Where he's not a brain-in-a-vat. 

The problem, though, is that he lives on in the body of another passenger. That body-swap scenario was initially feasible because the passenger died in the bombing. So his body is available to be co-opted by Stevens. Since, however, Stevens preempts the bombing in that alternate universe, the passenger would continue to live–in which case he couldn't host the consciousness of a man from a different world. Presumably, Stevens also has a counterpart in this alternate universe, but he was killed in that world as well. 

The film also has alternate endings in alternate timelines. An epilogue. But the time lines seem to cross. There's the world in which he lives on as Sean, the world in which he was euthanized, and the world in which his truncated body continues on life-support. One timeline seems to affect another or pick up from where another left off. But that's illogical. 

Another question is how Stevens' mind remains attached to Sean after Goodwin pulls the plug. As I  understand the process, Stevens never had direct access to Sean's counterpart in the alternate universe. Rather, the last 8 minutes of Sean's memories were harvested from his dying brain in this world, and then fed into Stevens' brain. So how does Stevens' consciousness jump from this world to the parallel universe, and continue there after Sean's final memories are exhausted? It's a nifty plot device so long as you don't think about it too deeply. 

iii) There's a nice scene where Stevens his able to have a "postmortem" phone conversation with his father, in order to patch things up. Just the chance to hear the sound of his father's live voice one more time is an emotional jolt for Stevens. 

iv) The film raises bioethical conundra. Dr. Rutledge is a utilitarian. Better to exploit one individual to save millions of innocent lives. By contrast, Capt. Goodwin represents feminine compassion for the individual, as well as loyalty to a comrade. Both perspectives have moral merits.

The film also raises the issue of mercy-killing. Stevens is basically a brain-in-a-vat. To say he's kept artificially alive is an understatement. All that's left is his head and torso, with an exposed brain case connected to a neurointerface. Is it right to keep him artificially alive against his will just to use him as a guinea pig. In the end, Capt. Goodwin euthanizes him.  

v) I think Gyllenhaal performs well in the key lead role. I don't always care for Gyllenhaal. I think he looks a bit goofy. He was good in Donnie Darko and October Sky. 

vi) Despite their incoherence, time-travel stories have an irresistible appeal. That's because they tap into our sense of longing and regret. "If I knew then what I know now, what would I do differently"? Of course, that isn't realistic. It's a secular substitute for redemption.

Likewise, Stevens is able to rewrite his life to give himself a happy ending. That's nice, but it's a kind of ersatz heaven. In real life we don't get to hit the replay button, erase, and record a new message. Although that's what makes time-travel stories so appealing, that's also what makes them hollow and ultimately unsatisfying. In the long run, only the Gospel gives us real hope.