The Pseudoscientific Philosophy of Source Code

Warning: Spoilers for the new Duncan Jones / Jake Gyllenhall film Source Code. The ending is far from the best part, and the good stuff is clear early on, so spoiling it isn’t all that bad.

[I]ts science is preposterous. Does that matter, as long as everyone treats it with the greatest urgency? After all, space travel beyond the solar system is preposterous, and yet we couldn’t do without ‘Star Trek.'”

– Roger Ebert on Source Code

Does that matter? Does that matter? At Overthinking It, it always matters!

Source Code is a solid movie with a lot going for it and a few issues. The most obvious problem – and, sure, the least important, but we’re talking about it anyway – is its pseudoscience. While other sci-fi movies give you a comforting drone of nonsense words that frame what is going on in just the right combination of sensibility and implausibility, Source Code not only leans on science that can’t reasonably work the way they say it does, it also relies on very complicated stuff that is explained multiple times through different implausible phenomena. It can all be a lot to take.

Never fear though, Overthinking It is here to parse the pseudoscience, and, perhaps start a conversation about the best way to either fix the pseudoscience so it works or determine what kernel of reality or insight may lie at the heard of it.

So, after the jump, let’s do to the drivers whatever it is people do to the drivers and get cracking!

What We Are Told is Happening

I’m going to base this off a combination of what is outright explained and how characters react in context – in Source Code not only is the pseudoscience described in different ways at different times, and not only is the explanation not always consistent, but it is sometimes mumbled or breezed through, as if they don’t have confidence in the audience’s ability to suspend disbelief. This is unfortunate, because every Lieutenant Commander Data fan knows that the key to good technobabble is to pronounce it clearly and with the utmost confidence – that if you have that, the audience will follow you everywhere.

So, admittedly, there’s going to be a certain amount of patchwork involved in my reconstruction. If I am off on anything, sound off in the comments.

Adding to the confusion, the people running the source code program think the source code is one thing, but, as we eventually find out from Captain Colter Stevens (that’s Mr. Gyllenhaal), it is something else entirely. Let’s start with what The Man tells us.

(This, by the way, is where we start in with big spoilers. You have been warned.)

We are told by Collen Goodwin and Dr. Rutledge – a.k.a. “Good Cop” and “Bad Cop,” a.k.a. “Attractive, Dutiful Soldier” and “Grumpy, Handicapped Project Manager” a.k.a. “Motherly Female Character” and “Unfeeling Scientist,” that the source code is based on a computer program that works through quantum physics.

Now you start to see why this is getting its own post.

According to Dr. Rutledge – a.k.a. “The Black Guy” – a human being’s short-term memory stores 8 minutes worth of experience – the source code project retrieves this experience from a dead person and plugs another person into it to relive those 8 minutes – and not just to passively notice details or perceive the sensory information of the dead person, but to exist within that time – to have feelings and perspective, to look around the environment, even play out those 8 minutes in different ways, like going places the deceased person didn’t go or changing the course of events, to see what might have happened and gather more information. Then, after the 8 minutes, the operative “dies,” returns to an intermediary space, and can communicate findings back to the people running the project through a computer interface.

The source code project uses this technology to fight terrorism by sending special mentally programmed/trained operatives into the memories of people killed in terrorist attacks to identify the terrorists and prevent them from killing again. Dr. Rutledge is very excited about its prospects as a weapon in the War on Terror, but its suitability in fighting crimes where the perpetrator often either commits suicide or publicly claims responsibility is not discussed.

Goodwinn – a.k.a. “The Blonde Lady” – tells us it’s “just a computer program.” That it works off the exchange of information and doesn’t itself constitute an experience in reality. It’s like a simulation.

By this explanation, it’s the ultimate extension of those b.s. “enhance… enhance…” scenes in movies and CSIsh television shows, where computers let you get information from an old photograph that it can’t possibly have captured because of silly things like resolution. It doesn’t make sense that source code operatives can interrogate people in the memory of the deceased. If the dead person didn’t perceive something, it wouldn’t be in his memory. It’s like this great scene from the legendary British sci-fi show Red Dwarf:

Oh, and the last big wrinkle? The source code operatives are all themselves dead people. The government keeps dead people hooked up to computers to investigate the memories of other dead people. Apparently, only dead people can do it, perhaps of some quality of their brains, perhaps because the procedures to hook somebody up to the source code devices are so invasive and harmful it would not be legal or ethical to do it to a living human being (it’s also probably not ethical to do it to a dead one, but the movie addresses that adequately, and it’s not pseudoscience, so I won’t get into it). Source Code is Quantum Leap meets Groundhog Day meets The Sixth Sense! Stay classy, government.

To be more specific, the person who gets put into the source code to do the investigating has to be really really badly wounded – arguably to the point of death, depending on how you define death (it is clearly not information theoretic death – be warned before clicking, though, Wikipedia pages on death are pretty depressing). The operative also has to match certain arbitrary qualities with the deceased from whom the source code has been retrieved, like size, body type, brainwave patterns, etc. – presumably so that when the soldier is quantum leaping into a body to go hunt down the criminal, that person doesn’t fall over out of inability to pass information back and forth to his illusory legs. Dr. Sam Beckett never had this problem.

This dead-but-not-technically dead person, who in this movie is a military helicopter pilot killed in Afghanistan, is kept in a vague-science-pod in a sort-of-secret lab – where his (or her, but there is no her example in this movie, so I’m just going to say his) body is kept “activated” by electrodes hooked up to his brain that enable the source code project to work. In the movie, we see that the body sure does look barely alive – it even breathes. That’s Captain Colter Stevens.

The whole process involves memory wipes between cases and a degree of traumatic mental reprogramming, which, we are told, has only ever worked once, with Captain Stevens. It isn’t entirely clear how much the project has messed with Captain Steven’s brain (or mind). He is conditioned to respond to certain cues (namely a specific passage about a woman and a bunch of playing cards, which help him recover from mental disruptions and memory wipes). He appears to retain most of his own memory of his own life and sense of self, except the part about being killed in Afghanistan, but his relationship with reality is frayed. At times (especially before we see his physical body) it seems possible that some manner of mental degradation might collapse the project and erase him from existence (“kill him,” although for most of the movie the word would seem too vague to apply appropriately).

While wrestling with all this between trips into the memories of the deceased – and communicating findings back to “Beleaguered Castle,” the source code project’s home base, this dead-but-not-technically dead person perceives himself in a form of Plato’s Cave:

In this space, which is depicted as a vaguely military escape pod or crashed aircraft cockpit, Captain Stevens, we are told, manifests his surroundings, and even his body, as familiar enough to him that he can cope with his situation. The government communicates with him by viewscreens – those are the “shadows on the wall” that Gyllenhaal perceives as real, but which offer only a distorted idea of what his situation in the world really is.

The prisoners in Plato’s allegory of the cave have been in there long enough to not have a memory of what the “real world” was like. This raises the question of what the “real world” actually is for Captain Stevens – and this isn’t a question the movie answers easily (we never, for example, see any of Captain Stevens’s “real life”).

Obvious Problems

One obvious problem is that, within the source code, the “operative” doesn’t have access to any of the “subject’s” memories about himself. The investigator doesn’t know who he is supposed to be when he arrives, doesn’t know how the subject is feeling or reacting to stuff – doesn’t even have a record of what the subject did (one of the avenues the movie could have gone down and didn’t was that the subject was himself the bomber) and there’s no Ziggy-toting Al to give him the instant exposition after the “Oh boy” take.

This makes sense in Quantum Leap, where there’s a certain amount of Deus In Machina going on, but given this explanation of how source code works – that it is based in the 8-minutes of short-term memory from a dead person – this falls a bit short. Sure, core information about identity might be in long-term memory and thus not captured by the program (although this isn’t really how that works, but that’s adequate), but there’s a lot in your short-term memory about how you react emotionally to things which is just totally thrown aside in the movie. The things you looked at would be in focus, and little else would be visible. Looking at it all through the eyes of the person who lived it would be very restricting, but it would also be useful information to have.

Furthermore, the information source code gets from the 8-minute sample is just too much to be believable. In the source code, at one point, Captain Stevens leaves the train where the deceased was for the whole trip and follows some random guy into a public bathroom in a random suburban train station. It doesn’t make sense that this information would be in the memory of the guy who died. It would be possible to do this movie such that the discrepancies between what the deceased perceived and what the operative discovered could be chalked up to looking again at forgotten details or playing with mental manifestations, but source code goes far enough that this can’t be the case.

Anyway, the explanation we are told about how the source code works (computer program, electrodes, memory, fresh corpses, some sort of quantum thing) doesn’t turn out to be how it actually works, which is pretty interesting…

What We Discover the Source Code Really Is

Captain Stevens does something in the movie that wrecks this whole explanation of the Source Code – he contacts the “real world” independently (he sends a text message from inside the source code that one of the characters gets outside the source code). Through this, we learn that Captain Stevens isn’t “in” the source code in the sense of being inside a computer simulation – he’s living an actual reality. The source code isn’t a machine for reliving memory, it’s a machine for transposing consciousness… or at least sentience… into alternate universes.

This is where the “quantum physics” technobabble kicks in. One of the possible (and, believe it or not, one of the more widely accepted) explanations for a lot of the craziness that happens in quantum physics is many-worlds interpretation.

One of the big problems of quantum mechanics is that events that have not been observed often can’t be said to have definitively happened or not happened. Rather, they exist in a “waveform” – in a probabilistic state between different likelihoods of happening – technically both happening and not happening at the same time. This phenomenon isn’t guesswork or philosophy (although the explanations for it are, to an extent), it’s experimentally verifiable.

Okay, this part gets complicated, so I’ll allow the illustrious computer-generated Dr. Quantum to explain:

Okay, so, in line with the Heisenberg Uncertainty Principle, which says we can never know the position and velocity of an observed thing at the same time, observing a wave/particle appears to change it – wave/particles that appear to behave probabilistically instead begin behaving deterministically.

This “waveform collapse” is a counterintuitive result – people don’t generally think of their observing things as having an effect in itself on the fundamental nature of reality, but it sure appears to in experiments. So, yeah, if you’re one of the folks who tends to believe concepts like “common sense” and “what exists exists and doubting it or questioning the nature of reality is stupid and a waste of time” – it turns out that a lot of the things about reality that seem apparent from everyday observation and tradition are a lot stranger than they appear to be – and this is only the stuff we’ve figured out is weird – imagine the stuff we haven’t spotted yet…

Anyway, there are multiple current, somewhat credible explanations for results of the double slit experiment and the “quantum weirdness” it and other experiments detect in the world. Some of them claim that observers fundamentally change the way things work in some way. Some of them downplay that factor and come up with explanations that sounds a little less mystical.

In the many-worlds interpretation, the waveform collapse is explained a little differently – the waveform is seen to collapse – one outcome seems to emerge from a probabilistic outcome – but observing the waveform has not collapsed the quantum phenomenon, it has simply followed the waveform along one of its many concurrent outcomes into a possible universe where only one of them happened. At the same time, from each quantum event, uncountably many other possible universes branch out like a tree, with reality extending into a vast web of all the things that ever could have happened stretching across the oddly shaped loaf of spacetime.

In the movie, this explains how Captain Stevens can access the information outside of what the deceased perceived – he isn’t reviewing a memory record of what happened, he is actually experiencing those 8 minutes in a reality. It’s not the possible universe he has historically experienced up until this point (in that universe he wasn’t on the train and everybody on it died), and the time frame is a bit exotic for him, but it’s part of the fabric of reality – its own succession of universes, where he can free roam across different branches of the web (and create more himself) whilst getting in ill-advised fisticuffs and gunplay until he has three stars, the cops start sending helicopters and he needs to find a spray paint garage.

Except the “inside” of the source code project isn’t a computer program, it’s a reality, so it looks a bit more like this:

More Obvious Problems

So, the most obvious problem with this explanation is how does Captain Stevens move from one reality to another? Well, we have “drivers” to do that, which is enough explanation for me to get through the story if it is said confidently enough. But, more specifically, what is moving into the other reality? In the other reality, when Captain Stevens is in the body of the deceased teacher and does stuff, what is the physical matter inside his skull like?

Is Captain Stevens’s brain inside the dead teacher’s body in the train reality? How does that work? Is Captain Stevens’s consciousness extra-materially imprinted onto the dead teacher’s brain? How is that feasible – especially considering all the memory Captain Stevens brings with him, especially when he talks to his dad? What is happening inside his physical body in the secret lab when he is controlling hands that exist in some branch of the possible universes that are sending Goodwin a text message from an alternate reality?

Additionally, how does the 8-minute clip of short-term memory play into this? How has extracting this information from a dead person enabled this travel through multiple universes? Why is the 8 minutes significant, and why does Stevens so often die at the end of it in the alternate realities?

The Four One One

If I had to sew in a technobabble patch to fix up this discrepancy – and recommend your own in the comments – it’s that the story leans on information rather than matter as the essential fabric of reality. The material world is at least somewhat illusory. If you have enough information about a part of the universe configured in a certain way, it can be the same as being in that part of the universe. The same with a person – people can be transmitted by conferring or reconfiguring information – and the quantum observer with sentience or consciousness can be moved along tracks in possible universes, experiencing different branches of the waveform, by being exposed to this information in a specific way.

There are certain ideas in the philosophy of mind that rely on an interpretation of subjective experience  that is a little bit like this. In these ideas, consciousness, in its many definitions, “emerges” as a new property from smaller, more discrete properties, sometimes identified as properties of discrete calculations or pieces of information. If you are willing to believe in a “strong emergence” from an informational or computational root – that consciousness and subjective experience could arise from information alone – it’s not patently absurd that a person’s perspective and place in reality could be moved around the multiverse by moving around information related to a different consciousness in a different reality.

“Strong emergence” is a bit of a bridge too if you ask me. The slipperiness of ice may seem like a totally new, emergent property that can’t be derived from the properties of its parts, but that is because the mind is comfortable with that sort of scale and is uncomfortable with the realities of how it works on the micro-scale. In fact, ice can become slippery as an extension of the aggregate interaction of a lot of quantum masses, charges and spins – it seems to “emerge” – but really the emergence is more an act of the person identifying the property and setting it aside as new, rather than the property itself emerging irreduceably.

Subjective experience is a bit trickier than, say, the slipperiness of ice is as an emergent property – it doesn’t make nearly as much sense for the parts of a computer to be able to reconstruct and manipulate the location and experience of Captain Steven’s subjective frame of reference. Why are discrete computations special as interactions of matter and energy? What about computational systems that are performing computations randomly, like an abacus falling down a flight of stairs? What about chemical or nuclear reactions that could conceivably used to track information? Is any body with sufficient information in it capable of subjective experience? Do stars have subjective frames of reference? There’s a lot of math inside a star – but is there a space baby?

Our intuition would say no, but as we saw with the double slit experiment, our intuition isn’t necessarily all that great at answering the really weird questions.

And if it is a weak emergence, where we can reduce it to its parts, what is the part of a subjective experience that observes? What is the ghost in the machine made of? We can put aside free will, we can put aside cogitation, we can even put aside the “sum” in “cogito ergo sum,” but we are still left with the problem of the philosophical zombie:

This is still thoroughly implausible – the movie is at best an artistic riff that came out of some of these ideas – but it would at least offer a good pseudoscientific explanation.

A Little Bit Bleaker Now

This explanation – and I think the whole pseudoscientific grounding of the movie – would be considerably more robust if Captain Stevens’s body were gone – if his brain signature were being stored in a computer, and that information was retaining his consciousness and continuing to provide the dasein with qualia. Because who doesn’t need that?

If Captain Stevens were just reduced to information, then his experience interacting with the other information would be easier to comprehend, and it would make more sense for him to be able to travel the multiverse by interacting with and changing the information of the dead teacher’s experience.

Well, when I saw “easier to comprehend,” I mean as a story device. It still is in the realm of crazytown in terms of science.

But I think the way the movie becomes a bit more elegant is if it goes significantly darker – if instead of discovering that his experience is a reality rather than a simulation, the movie left out the second explanation and just challenged Captain Stevens with the existential problem of what to do as a basically dead man trapped with only 8 minutes of another man’s experience.

Ought Stevens to re-up for another tour of duty to prolong his life, whatever it is? If the train isn’t real, is it still meaningful to save the people and get the girl at the end? What does that say about the imperatives to do stuff and self-actualization strategies we use in our own lives, with their own dubious relationship with reality? Is there a good reason why Captain Stevens should care about counterterrorism missions when perched this close to the gaping maw of the abyss?

Sound off in the comments!