Inception and Quantum Mechanics: Shared Dream, Shared Reality

Does Inception’s shared dream machine rely on the Many Worlds interpretation of Quantum Mechanics?

[Please enjoy this guest article by Ben Adams! —Ed.]

Science fiction blockbusters have a history of questioning reality. Total Recall, The Matrix, Inception and countless others show us a world where technology can create dream worlds indistinguishable from reality, raising the question that consumed the mind of Mal in Inception: What if your world is not real?

The existence of that technology would have profound implications for our understanding of the mind and of reality. The different implementations of that technology, though, can drastically change what these movies have to say about the mind and reality.

In The Matrix and Total Recall, the technology behind the dream world is industrial and direct – the machine is powered by banks of computers tended by skilled operators and the computer can interact directly with the brain. The implication is that the computer creates a perfect model of the brain and figures out how to manipulate the inputs to the brain to fool it.

Neo sees the Lady in Red because the Matrix calculated what his brain would see in the real world, and sends the appropriate electrical signals through the plug in his neck. Creating those signals and the world they come from takes computation—when Neo shoots his gun at Agent Smith, the Matrix has to do a calculation to decide if he hit anything. Just like in a computer game, every object requires constant computation to exist and every person requires constant attention to maintain the illusion – which is why the Matrix requires so much hardware to support it.

In stark contrast, Inception’s dream technology is minimalist. It fits in a briefcase, can be operated by a 14-year old kid on a moving train and is connected to the subjects via a tiny IV plugged into the arm. The filmmakers even posted a manual online, in which it’s apparent that the machine doesn’t do anything except distribute drugs, and has no power, cooling or electronic components. This strongly suggests that the computational heavy lifting is done outside the machine—and inside the brains of the participants. This is actually an efficient way of doing business—after all, the 7 billion most powerful supercomputers on Earth are walking around right now, eating Buffalo wings and watching Jersey Shore. Instead of creating the world from whole cloth and injecting it into your brain, Inception’s machine must modulate the natural dreaming process, and let the brain do most of the work.

But if the mind just is a meat-computer, it must be subject to all the same limits on time and energy that govern any electronic computer. The functional elements of a computing device need energy to change states, and can only change states so many times a second. Neurons use up energy when they fire and are chemically limited to firing at a certain speed. This presents no problem in The Matrix or Total Recall—the Rekall device just writes over the parts of memory it wants to encode and The Matrix runs at a 1:1 ratio with reality, so the brain functions at normal speed. Inception, though, allows for both nested dreams and time dilation—meaning it must work in a different way than the other two.

Yusef, the chemist, states explicitly that the sedative used for the Fisher job accelerates brain function to “20 times normal.” But this means the growth in activity is exponential—in the hotel, the brain is working 400 times normal. In the fortress, 8000 times faster. Yusef establishes this exponential ratio when he explains how the kick will work: 10 hours of flight time equals ten years at the third level (there are 8760 hours in a year). For whatever time they spend at that level, their rate of thought will have to sped up 8,000 times: in 1 second of flight time, their brain needs to be able to compute 8,000 seconds of information at the third level. This becomes even more problematic in the “limbo world,” since the precise ratio of time dilation in limbo is left somewhat murky, but the implication is that the time dilation there is even greater than it is on the other levels. Even assuming the ratio is only 20:1, the implication is that the brain is working 160,000 times normal rate while the subjects are in limbo.

That’s not just unlikely; it’s impossible. You can’t make neurons fire or chemical signals travel 160,000 times faster than normal. If it takes a single calorie per minute to dream under normal circumstances, that means the brain would have to consume 160,000 calories per minute in limbo. Sources differ, but most seem to agree that the brain working at normal speeds consumes about 20W of energy. Even assuming that the dreaming process is a small portion of that (say 1W of energy), that means that the brain in limbo would require 160 kilowatts of energy, and produce the corresponding amount of heat equivalent. The combination of nested dreams and time dilation makes the “brain as computer” description of the mind impossible.

All of this though, assumes that the brain is a conventional computer. In conventional computation, rigid limits are imposed by the need for a bit to be either a zero or one, and for an array of bits to have just a single state. If you have an array of 8 bits and you want to run a calculation on all possible combinations of those bits, you have to run each calculation separately – (0000000, 00000001, 00000010, etc., all the way up to 11111111, for a total of 256.  Worse, each added bit doubles the number of calculations you have to run – quickly outpacing the capabilities of a conventional computer.

A theoretical quantum computer isn’t subject to this restriction. In the world of quantum physics, it’s possible for a quantum bit or qubit to be both zero and one at the same time, in what’s called a superposition. An array of qubits can be entangled with one another in such a way that they are all in a single superposition—8 qubits can represent all possible arrays of 8 bits, from 00000000 to 11111111 and everything in between. If a quantum computer executes an operation on that array of qubits, it is in effect running that operation on all 256 possible inputs at once. A theoretical quantum computer could scale exponentially, solving problems a conventional computer never could.

If the brain could make use of quantum computing effects, the normal limits on computation would not necessarily apply, and it’s possible that our brains could generate and keep up with a reality moving exponentially faster than our own. This is the quantum theory of mind, which argues that quantum effects are at the root of the brain’s incredible power, and may be the cause of consciousness itself. This solution is hinted at by the unstable nature of Inception’s dream worlds—once the dreamer becomes aware of or “observes” the dream, it collapses.

The brain-as-quantum-computer idea solves the problem of creating the dream world, but doesn’t solve the problem of sharing it: there’s still only a tiny IV line connecting the participants. Quantum brains could theoretically handle the calculations needed to create a universe 160,000 times faster than our own, but the result of those calculations has to be distributed through the dream machine at 160,000 times the normal speed of brain activity, running into the same problem as before. For a solution to this dilemma, we have to dig deeper into the different interpretations of quantum theory.

7 Comments on “Inception and Quantum Mechanics: Shared Dream, Shared Reality”

  1. Erik #

    Great post! It went a little off the rails on the second page from physics into meta-physics, but who cares since this site is about thinking outside the box and having fun!

    I don’t want to ruin it, but if you have not already you must read Neal Stephenson’s “Anathem”. It’s a massive book, but I couldn’t put it down, and if you are as interested in this subject matter as you sound, you won’t be able to either.


  2. Kantarky #

    Nice calculations. I know understand quantum theory better.

    I accept the lady in the red dress as an example, but technically, she was created by a computer programmer(mouse) for a training program outside of and separate from the matrix.

    The Matrix does not run at a 1:1 ratio with reality during bullet time.

    If your dreams are real, then parents will no longer tell their children that they were just dreaming. All your worst fears will be true.

    While the brains in inception are used as meat-computers, I am aware of no link exists to connect the minds.


  3. Nick #

    Fascinating stuff, and a thoughtful meditation on an entertaining idea. Like Jack Donaghy, I don’t sleep on planes because I don’t want to get incepted.

    I would say that if the many worlds/minds theory is to hold up, we need to find an explanation for the very specific effects of movement in “higher” worlds on “lower” worlds, how the inhabitants of those worlds can be trained to defend the secrets of the “surface” world, and why our world (or perhaps the “surface world” of the movie) isn’t plagued by kinetic interference or murderous secret-snatchers from similar worlds for whom we are presumably a dream-scape.

    Also, regarding The Prestige – I always took it that Danton absolutely knows that he’s going to be the man in the box. He just also knows that he’s going to be the man on the balcony.


  4. Jesse M #

    Great post. A subtle but profound way to look at the logic of Inception — that it’s not an inner psychological architecture, but a cosmic metaphysical one, full of “reality nodes” that the machine bridges between.

    Also interesting: if you’re talking about the dream-spaces being multiple worlds, you don’t actually answer the question of “Why can a character experience a year in one universe, but only live for ten minutes in another?” The only plausible answer I can think of is that these multiple universes are chronologically unhinged from one another, and don’t have even remotely analagous timelines.

    TIME in this scenario would work like SPACE in the Narnia series — there’s a specific moment in time (or a “window,” if you will) that acts as an entry point. Once you enter that new universe, you have complete access to the parallel space, with no real physical or temporal boundaries. However, you have to return to the same entry-point… the same drug-induced 10-minute window… that you used to cross the threshold in the first place. So that very short window of source-time opens up a great deal of virtual time, just like the very small real-world space of The Wardrobe opens up the very large virtual space of the Land of Narnia.

    I know that didn’t all fit together perfectly. The point is… there is no fixed quantitative ratio of “virtual time” to “real time”… just two universes, each working through its own timeline, linked by a narrow reference-point in the source universe, activated by the Pasiv Device.


  5. Patrick #

    Interesting read. Under the assumption that the “many minds” theory is true, in the sense that you describe it, what are the implications of death to people in the “real” world? When you are dreaming you have access to the multiverse through your subconscious in its dream state. However, you do not have access when you are awake. Perhaps this is the reason why those who have a natural death (old age, etc.) are asleep when they die. It is the consciousness’s fail-safe. It creates the bridge to the multiverse so that it can continue existing. However, if you die while awake (gun shot to the head, etc.) the fail-safe does not have the capability of activating, and the consciousness ends, this “soul” dies completely. The implications of this theory would be huge. If you were capable of mastering your mind in such a way that you could control the subconscious and consciously navigate through the multiverse, almost like lucid dreaming but control enough to become lucid at anytime not just after observing a dream, you could become immortal. It would be the meta-physical fountain of youth. You are awake in universe 1 and death is inevitable. Before the bullet strikes, you instantly put yourself into this lucid dreaming state and navigate to universe 2 via the multiverse connections established by the subconscious. The bullet strikes in Universe 1 and your body dies. However, your consciousness was locked in Universe 2 in the body it created as a means to interpret your presence there (i.e. your body in a dream). The ties to Universe 1 are severed the consciousness survives in Universe 2. You continue living as the person you were in Universe 1, however you are now living in an entirely different Universe. Repeat this at death in Universe 2 (and 3 and so-on) and you become immortal.

    A counter to this argument is what Jesse M brought up about Narnia. We can only perceive time and space as linear. However, if time and space is planar than it is very possible to the travel through a Narnian universe for years on end and return back to your universe without any time passing. Almost as if your connection between the original universe and Narnia were a portal locked at a specific time in the original universe once it is opened. To tie in to the the above example, we may be able to consciously navigate to universe 2 through a lucid state and we may return back to universe 1 only to be killed by the bullet because time never continued. But, if we tether the universes together by means of keeping a piece of our consciousness within Universe 1 so that both universe 1 and 2 can chronologically advance together, we then may be able to survive in universe 2 after the bullet strikes our body in Universe 1, but we may be diminished. However, the fragility of the consciousness is unknown, it may be able to continue in the diminished state, or it may be destroyed if it is not whole. But, since knowledge of, and memories of Universe 1 are the tether, it is possible that the consciousness will continue only without the piece that tied it to Universe 1. So, we will technically be immortal through the persistence of our consciousness, however everything that made that consciousness “ours” will be gone. (This is why there aren’t immortals walking around, you fall asleep before you die but the part of your consciousness that remained in Universe 1 was your memories. The consciousness exists, but you do not.) Thus, in order to become immortal, we would have to discover a way to tether the two universes together with something that does not define who we are. With that ability, true immortality would be possible.

    As for navigation through the multiverse, I believe this would be accomplished through brainwaves. In inception, the sedative may operate in such a way that those put under dream at the exact same brainwave pattern. And thus, matched with their proximity, are capable of sharing dreams. If this were real, then through music (binaural beats) and sedatives (tailored to the individuals normal brainwave states), we could precisely match the brainwaves of groups of people and allow them to navigate through the multiverse together and share dreams. I assume proximity would be necessary because the location of your bodies would create the portal to other universes. If people are close together, and operating at the same brainwave pattern, then they will enter the multiverse together, close to each other. The reason you don’t share dreams with your spouse when you sleep together is because you are not operating at the same brainwave pattern. The reason you don’t share dreams with strangers, whose brains are operating at the same brainwave pattern, is because you are not close enough to each other to meet in the dream multiverse. Thus, I believe that dream sharing is only possible if the two dreamers can create the exact same brainwave patterns and sleep in proximity to each other. This could be testable with the right equipment.


  6. Dan #

    I’ll just point out here that the vast majority of physicists spend very little time thinking about the “meaning” of quantum mechanics. It works, it makes testable predictions, and it allows us to do our jobs.

    This is in no way criticizing this interesting piece of overthinking, or overthinking in general, just reassuring anyone who doesn’t want to lose sleep over what quantum mechanics implies about the fundamental nature of human existence. Physicists aren’t laying awake at night, so you don’t have to either (unless you want to).


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