The right reason to doubt the simulation hypothesis

This weekend, Sabine Hossenfelder did a video and post about the simulation hypothesis, the idea that we might be living in a computer simulation. She dismisses the notion that consciousness can’t be a computational simulation, which I think is correct, but then settles on the idea that physics itself can’t be simulated, because we have no idea how to do it, apparently not noticing that her objections about physics are very similar to the objections many make about consciousness.

To be clear, I’m not a fan of the simulation hypothesis. However I don’t think it’s as easy to dismiss as Hossenfelder implies. But when thinking about it, I think we have to distinguish between two varieties. One involves simulating an entire universe that we just happen to be part of. The other involves simulating us and our reactions within a version of the existing universe.

The first kind requires that the simulation be running within an outer universe that is more complex than the one we’re in. You can’t simulate a universe that is as complex or more complex than the reality the simulation is running in, at least not without the simulation executing far more slowly than the outer universe. That means the reality we’re in is either very different from that outer reality, or is a more coarse grained version of it. But that doesn’t mean that outer universe isn’t there, just that it can’t work exactly as our universe does. So dismissing the idea because we can’t simulate our own universe with fidelity from within our own universe is unjustified.

I do agree with Hossenfelder that this type of simulation has religious overtones. If we are in a simulated universe, then the aliens running the simulation are effectively our God, or gods. But a simulation proponent would likely argue that there’s nothing about the hypothesis that implies those beings are even aware of our existence, or if they are, that they care about us one way or another. We might be an unforeseen side effect, one that could eventually gum up their desired results.

The second type of simulation is very different. It’s not an attempt to simulate an entire universe, only an attempt to simulate us. In this type of simulation, reproducing the physics of the universe is not necessary. The only thing that is necessary is giving us the conscious impression of those physics. In other words, there’s no need to simulate quantum physics or general relativity, only to simulate our reaction to those physics. Indeed, there’s no reason to assume the entire human race is being simulated. It might only include you, or me, or you, I, and a few other people.

Why would someone create a simulation like this? Who can say. They might want to simulate our reaction to a particular situation. Maybe we’re prisoners being probed. Or maybe we went to Rekall to pay for a simulated vacation. (If so, customer support needs to drop in right now so I can demand an exit and refund.) Or maybe our AI overlords are testing our loyalty.

The key thing here is none of Hossenfelder’s objections apply to this more limited type of simulation.

My own issue with the simulation hypothesis is that there’s no particular reason to think it’s true. We might live in a reality, or we might live in a simulated reality. Straight reality seems like a simpler model than simulated reality, at least given the evidence we have so far. But this is a far less polemical stance than Hossenfelder’s position that it’s pseudoscience.

Personally, I’m not a fan of flinging the pseudoscience label at something unless it’s a clear case of fake science. The simulation hypothesis is speculative metaphysical guessing, but I don’t think it rises (falls?) to that level. The increasing trend of people calling anything they find implausible “pseudoscience” cheapens the bite of that label, which I think should be reserved for things like astrology, creationism, homeopathy, and similar notions that are clearly contradicted by science. Using it against ideas we just find implausible is simply pushing our own views in a sanctimonious manner.

Unless of course I’m missing something?

62 thoughts on “The right reason to doubt the simulation hypothesis

  1. I have said a number of times that we cannot rule out creationism because all of this could have been created 15 minutes ago with all of us being given false memories. This would, in effect, be a simulated universe, although not the type you are discussing.

    Re “I do agree with Hossenfelder that this type of simulation has religious overtones. If we are in a simulated universe, then the aliens running the simulation are effectively our God, or gods.” So, the owner of an ant farm is a god to the ants? I do not think you can infer the relationship between the creator and the created. We are stuck in a rut in thinking that the creator must be a god, rather than an entity with the power to pull off the act of creation.

    Why would we confer god status upon such a being, with all of the baggage that entails. Would we worship that creator? Why? What is we found out that our creator is an elementary student taking universe creation studies?

    I think we are projecting when we make such inferences, and doing so for no good reason other than to suck up to the religious (See, you were right all along!)

    Liked by 2 people

    1. I guess it depends on how you define “god”. But if they created us and controlled our fate, it seems hard to avoid that label. Although as I noted in the post, it doesn’t mean they’d be a benign or wise god. Worshipping or praying to them might be pointless.

      Liked by 1 person

  2. Very much agree about the pseudoscience label. One more aspect of our general cultural disconnect from facts.

    I’ve long floated the idea that reality as we know it could end somewhere out beyond the orbit of Pluto. Maybe once we get out far enough we run into the end of reality. (Ever seen the movie, The Thirteenth Floor?) Astronomy software already simulates the Solar system and beyond. Could be the Earth is just a Sim Earth or Sim Solar system.

    It got especially poignant in 2016 when it sure seemed like we lived in some bizarre political “what if” experiment. Given that all we know is from received data, there’s no real proof anything much beyond our local environment actually exists.

    Liked by 2 people

    1. The Thirteenth Floor, now that was a good movie. It kind of got lost in the wake of The Matrix as an also ran, but in many ways it was far edgier. Imagine driving to the edge of town and discovering…an edge of reality!

      Yeah, it seems like in the last few years my reaction has often been, are we really doing this? Where’s the reset button? This game is a loss. If only reality paid any attention to my desires.

      Liked by 1 person

    2. BTW, just got back from outside making sure my outside faucets were insulated or covered. It’s supposed to not break freezing tomorrow and drop to 15 F the next night, after a day of freezing rain. Work just sent a text saying we’re off tomorrow. Yay?


      1. Freezing rain is the worst. I read about that huge pile up in Texas recently. When that happens here, sometimes the ice ends up hanging around under the snow all winter, and that makes for… interesting times.

        Up here in the frozen north, plumbers often put an inside value in the pipes that feed the outside faucets. The procedure is to close that value and open the valves on the faucets themselves to release any pressure from frozen water inside the line.

        We’re headed for -20 tonight, so it’s something to worry about!


        1. Yeah, they don’t do that for our faucets down here. Your only options are to cut off the entire house, which is big time inconvenient, cover and insulate the faucets, or set them dripping, but that last is risky since it could lead to the whole thing freezing up.

          I already have my inside faucets dripping though, hoping that’s enough to keep things good for the pipes in the walls. It’s been a long time since it got below 20 F down here.

          Best of luck with -20! I’m pretty sure we’d be dead down here.


    3. If Trump were fiction, he would be rejected by any reasonable editor, publisher, director or producer. “This script is too outlandish. The bad guy’s lies are just too blatant and obvious, no real politician would do this, or if they did their career would be mercifully short. Come on, you gotta give a little realism to get the audience to buy into your premise! Go back to writing school.”

      Liked by 1 person

  3. An ancient alien intelligence built an uber-advanced simulation environment and then died away leaving this artificial(?) system to run on its merry own. And my (not yours) consciousness grew like a computational fungus within this environment. Nobody’s in charge and the mold is growing to encompass the entire system. Fun thought. I rather like this one.

    Regarding complexity simulation, what if the outer Uni-Sim runs at a much faster pace but treats the simulation environment’s internal “time” constant as a function of its own processing performance. A billion time units tick by outside, which equals a single nanosecond inside. Tick, start over. The inner complexity could be vastly more involved than the outer one, and we’d never know it.

    Intentionally designed Uni-Sims are less compelling to me.

    Liked by 2 people

    1. The idea that we’re an unexpected fungus, or vermin in someone’s carefully crafted mechanisms has its appeal.

      I like your take. If someone’s going to create a simulation, this was the best they could come up with? Of course, that’s assuming they themselves aren’t reaching the same conclusion and about to pull the plug, but that’s just cra

      Liked by 2 people

  4. My feeling is that the simulation hypothesis is an untestable hypothesis. What I mean is, let’s say you run an experiment that finds evidence that we are in a simulation. Well, that evidence could also, just as easily, mean that the natural laws of physics don’t work the way we previously thought they did. Or, if you run an experiment that supposedly proves we are not in a simulation, you could simply hypothesize that the simulation must be good enough to fool our experiment.

    So in my mind, I’m not convinced that the simulation hypothesis is really science. It’s an interesting idea to think about, and it’s great fodder for writing science fiction. At the same time, calling it pseudoscience feels wrong to me, too. That word implies to me that someone’s playing a con game, and I don’t think the people who talk about the simulation hypothesis are trying to con anybody.

    Liked by 1 person

    1. One of the things I sometimes wonder about quantum physics is if it isn’t just us reaching the limitations of the simulation, scratching our head, and saying, “Wow, reality is bizarre.” Of course, there’s no way to know that isn’t true, but as you noted, there’s no particular reason to believe it either.

      I agree the simulation hypothesis isn’t science. It’s more philosophy, particularly metaphysics. But good point about the motives. The people talking about it aren’t trying to fake anyone out.

      Although there are quacks who engage in pseudoscience, not as a con game, but because they really think they’re doing science. But I think we should save labels like “quack” and “pseudoscience” for the cases which clearly contradict empirical evidence.

      Liked by 1 person

      1. I’ve had the same thought. Maybe us puzzling over quantum physics is like video game characters trying to figure out why they’re pixelated. And I believe SMBC did a cartoon a while back where our universe turns out to be somebody’s homework assignment, and quantum physics is the part they did the night before the assignment was due. I think about that one a lot too.

        Who knows? Maybe there’s truth to the simulation hypothesis. It is definitely fun to think about it, even if it’s not as scientific a hypothesis as other things might be.

        Liked by 1 person

        1. Something went wrong this is the correct one.

          Here is a great animation.
          Curious young alien experiments with world building device and the result is . . .
          It is called “Looking Planet”. You may like it.

          Subtitling in english can be switched on.

          Liked by 1 person

  5. So how would distinguish between:

    1- A entire simulated universe with physics
    2a- A simulation of your conscious experience that included your experience of physics and books/media of physicists who wrote about physics
    2b- A simulation of the conscious experience of yourself and physicists including a history of all experiments ever conducted by physicists

    Liked by 1 person

      1. If you can’t distinguish between how would you know one is easier than the other? You would only know from inside the simulation and the simulation could make you believe that the second type of simulation is easier than the first type.


    1. To expand the thought even more broadly. If we are inside a simulation, we have no way to know that laws of physics in our simulation have any applicability to the laws of physics in the outer universe. Conservation of matter or energy may not even be applicability outside of our simulation, for example.


  6. BTW when you state this:

    “The second type of simulation is very different. It’s not an attempt to simulate an entire universe, only an attempt to simulate us. In this type of simulation, reproducing the physics of the universe is not necessary. The only thing that is necessary is giving us the conscious impression of those physics.”.

    It seems like you have inadvertently argued, in the context of simulations, that the simplest or most parsimonious position would be that everything is consciousness, in other words idealism.

    Actually doing a simulation may not be as difficult as it might seem if we simply create the universe as a sort of machine learning algorithm with the training data coming from the outer universe.


    1. I’m not sure. Even in the more limited simulation, there would be things going on outside of our consciousness. The simulation itself and whatever it was running on for instance. That piece of dog poo I accidentally stepped in while outside earlier would still be outside of my consciousness, whether it be reality, a full universal simulation, or the more limited one.

      Liked by 1 person

        1. Maybe not, but something causes that perception. In most forms of idealism, it has to be some mind somewhere thinking about it. I was surprised it was there, so it would be strange to say I was thinking about it prior to the perception. The dog was long gone. We could say God was thinking about it, but it seems simpler to just say poo happens.


  7. I think Chalmers made the point that, even if our reality is simulated, it’s still our reality. What ever is fundamentally at bottom doesn’t matter, because in fact it is multiply-realizable (that last is my point, not Chalmers’). I assume you’ve seen the video of the Game of Life being simulated by the Game of Life. You could make that recursive, but that does not mean that any one level is more “complex” than any other level. The “physics” could be exactly the same at every level.


    Liked by 1 person

    1. I’ve made that Chalmers point myself for a full universe simulation.

      I haven’t seen that on the Game of Life. So a Game of Life simulation is completely contained within the Game of Life? It’s not getting anything for free? Memory, CPU, etc? The entire algorithm is within the Game of Life? If so, I’d be curious how it was done.

      The only way I could our whole universe simulated within our own universe would be doing what I mentioned in the post, running it very slowly. But then, what’s our purpose in running the simulation? There’s not a whole lot of value if the simulated universe doesn’t get much past the big bang before our sun dies in the host universe.


    1. It seems you’re thinking about a simulation running with one set of rules running another simulation with the same set of rules. If the rules are different, all bets are off about a simulation running in a universe, simulated or otherwise, with a different set of rules.

      In an universe that is infinite in time, energy, and space, any notion of time or something running slowly may be meaningless. There would be no limitation on speed if energy could be created at will. On the other hand, the universe performing the simulation could arbitrarily impose limitations in its simulations such as limiting the amount of matter or energy in the simulated universe and thereby create a universe with time


  8. Einstein is quoted as saying “The most incomprehensible thing about the world is that it is comprehensible.” But how did he know for certain that it was comprehensible, and to what degree? Along these lines, I wonder if it is even possible to determine whether we are living in a simulation or not.

    Liked by 1 person

    1. I think you’re right. There’s no way to know, short of the simulation giving us permission to know.

      That leaves us two theories:
      a) reality
      b) reality as simulation within another reality

      The first option seems more parsimonious, with the caveat that parsimony is only a reliable(ish) heuristic.


  9. It seems to me that simulations cannot exist unless there is first a real world. Furthermore in a real world there may be computers which can be used to model what happens in that real world, such as its weather, and so provide information to advanced beings who build them. Here “simulations” may be considered models, and therefore in this capacity no one should worry that their reality might actually be a simulation. As they say, a simulation of water will not produce wetness but rather would model it. Thus a simulation of you would not produce “you”, but rather would model your behavior.

    What if your body were hijacked such that input sensations were provided by a machine rather than the outside world, and what you thus perceived seemed perfectly real to you? I suppose that could constitute a possible “simulated world”. Furthermore observe that in such a world all that you perceive would essentially be imagined. So your friends and family there would be figments of this solipsistic realm incited through brain manipulation. Note that there’d be no need for your hosts to simulate anything more than what you experience itself.

    The popular simulation speculation that I have a problem with, and that I think Sabine was trying to address, concerns proposals where it’s thought that we exist by means of nothing more than disembodied computer code. It’s understandable why people consider this possible, since many popular consciousness theories propose consciousness as nothing more than processed information. If that’s the case then overlords might have coded you and could subjecting you to whatever world they like without the trouble of dealing with the physics based mechanisms associated with a body. I don’t quite call such proposals “pseudoscience” however, but rather “supernatural”. In a natural world it seems to me that all computer output, such as my subjective experience, should only exist by means of physics based output mechanisms of some kind.

    There’s just one thing that I think these consciousness proposals would need in order to become natural, or statements of agnosticism regarding what might mechanize such proposals. So instead of the information processing of a global workspace itself creating subjective experience, for example, such theorists would say that they don’t know what instantiation mechanisms such processing might animate to produce subjective experience. Under such proposals it would still be possible that what you experience is all just a complex dream, but somewhere there’d be something with the mechanics to create that experience.

    Liked by 1 person

    1. Eric,
      So suppose you were in the scenario where someone had hijacked your body and was feeding you sensory impressions. How would you know you were experiencing simulated wetness instead of real wetness? Is there anything you could do to establish it wasn’t real wetness? And if you encountered another person, how would you know whether they were a real or simulated person?

      Now, consider that the hijacker wanted to play a trick on you, and hooked your introspection capabilities to another person. Now, when you tried to self reflect, rather than accessing your own consciousness, you accessed theirs. Would there be any way you could tell the difference?

      Then let’s replace the other consciousness with a simulated version. Now when you self reflect, rather than accessing your own consciousness, you’re accessing a fake one. What would clue you in that this wasn’t the real one?

      Finally, we replace the introspection mechanism with a simulated one. So a simulated introspection mechanism accessing a simulated consciousness. How can you tell that you’re not this simulated consciousness?

      Suppose a sysadmin dropped in and told you that they were very sorry, but you’re not a real conscious being, just a simulated conscious being, that you’ve never experienced “real” consciousness. What could you do to assess the truth or falseness of this claim?

      On the flip side, suppose a simulation told you it was conscious and became upset and adamant when you told them they weren’t really conscious, just a model of consciousness. If they pounded the (virtual) table and insisted they were conscious, what could you tell the simulation to have them compute that they were wrong?

      Liked by 1 person

      1. Mike,
        If someone hijacked me and fed my brain input which produced what I’ve come to know as the qualia of wetness, then I wouldn’t know the difference. Theoretically this could be an amazingly realistic dream. Similarly I wouldn’t know the difference if provided qualia that someone was with me.

        On turning my consciousness into someone else’s, that essentially works too. As things stand I consider each moment of my consciousness to be an individual self, though the present iteration can be joined somewhat with past selves through memory, as well as foreseen future selves through hope and worry about the future. So if my qualia of reflection comes from someone else, that would be the new instantaneous me.

        When you talk about replacing a consciousness with a simulated version however, that’s where things start to seem fishy. If there is qualia here then fine, that would constitute me each instant (with any memory qualia joining me with a perceived past, and any anticipation qualia joining me with a perceived future). And if you say that such qualia would exist as information processing alone rather than through physics based mechanisms (such as EM fields or whatever), then I’d call this scenario “supernatural”, though not inherently false. Either way if qualia were to exist then that would constitute me, and regardless of whether or not I thought something fishy was happening.

        As I see it there can be no “fake consciousness”, but there either would or worldn’t be qualia / consciousness. So even a sysadmin wouldn’t be the authority on my own consciousness — either I would or wouldn’t have it, and determined by whether or not I personally had subjective experience, or there was something it is like to be me, or existence could be good/bad for me, or that sort of thing. I can at least determine that I do have this right now, and that’s the only ontological truth I can ever have about what ultimately exists. Thus here I shouldn’t say that someone talking with me isn’t conscious. If they merely seem able to play a good game of chess however, that wouldn’t be very good evidence since even our computers can do that. But if they could hold a good conversation with me, I suspect that they’d not only be consciousness, but educatedly so. (Of course in dreams we subliminally speak for who we perceive, so that might instead be the case.)

        One thing that your post bring out is that my “natural / supernatural” distinction could be superior to “science / pseudoscience”, since it harbors no demarcation problem.

        Liked by 1 person

        1. Eric,
          I thought you might balk at the simulation step.

          So for you, consciousness is about the unique physics of the brain, and those physics are EM fields. Presumably not just any EM fields will do. I assume you wouldn’t say, for instance, that the EM fields of the Earth, Sun, or my laptop doesn’t make them conscious. So there must be something specific to the brain’s EM field. What would you say that is? If whatever it is showed up anywhere else, would you consider it to be conscious?

          On the natural vs supernatural thing, even using your particular version of natural (which I take to hinge on causal determinism), I don’t see how you conclude that information processing is supernatural. Every time I see that statement, I just see, “Boo information processing theories.” What makes me wrong?

          Liked by 1 person

          1. Mike,
            This stuff needs to be stated properly. In order for you to practically get me, you’d need to tell me what I think on a given issue (including how I’d answer various associated questions). So consciousness shouldn’t be about the unique physics of the brain, though it’s pretty clear that the brain is able to effectively employ this physics.

            EM fields may or may not be the substrate of consciousness, though it’s the only brain mechanism that I know of which could potentially do this job. Science should at some point tell us more, but if so then qualia shouldn’t be unique to the brain. It should happen wherever the proper EM fields happen to exist, whether in the sun or whatever. But in non-life qualia should not tend to be “functional”. There it should be more like a random event where something experiences its existence, whether it thus feels good or bad. Theoretically evolution’s non-conscious forms of life didn’t do that well under more open circumstances, and so this subjective dynamic evolved into something functional.

            If experimentally verified, what could I tell you about the reason that the proper EM fields might create qualia? I honestly have no idea why this physics would function as such. And it’s true that I could say that about all sorts of physics, but certainly this.

            I don’t consider information processing supernatural. I merely consider the proposition of qualia by means of information processing without animating the proper variety of mechanism, to be supernatural. Why? Because all computers seem to function this way. There’s always input, processing, and an output components in order for them to do what they do. So when we propose something strange like qualia to exist through input and processing elements, though without physics based instantiation mechanisms, I’m thus legitimately able to claim that a non-causal or supernatural proposal is being made. Furthermore this is why it’s so ridiculous that the right information on paper that’s properly processed into another set of information on paper, could in itself create something which experiences what you do when your thumb gets whacked. But if that second set of information were used to animate some sort of qualia producing mechanism, by means of EM fields or whatever, then this would not be a supernatural proposal, or ridiculous.

            Liked by 1 person

          2. Eric,
            Well, we always reach the same endpoint. You see consciousness as requiring some form of special physics. You’re not sure what those physics are, aside from thinking something about EM fields makes it plausible they’re involved. Yet you are sure information processing isn’t the answer.

            Ironically, I think you exclude the most likely answer to the thing you’re not sure about. When we look at the physics of the brain, the one thing that distinguishes it from everything else is the sheer amount of information it moves. Our current technological devices remain a pale imitation in comparison. Even if we find the brain uses EM fields, I feel pretty certain it would use them to move and transform information.

            One question I have for you. Suppose those special physics are never found. Would you consider information processing? Or incline toward panpsychism?

            Liked by 1 person

          3. Mike,
            I consider EM fields to be plausible as a qualia medium since they’re a mechanistic output of neuron firing which can effectively carry every bit of information associated with that firing right in those fields. (Not that they should need every bit of that information for that, but still.) So just as your computer screen is an output mechanism for images from your computer, these fields theoretically could be an output mechanism for qualia from your head. I don’t know of anything else associated with brain function which seems to have this potential.

            You may recall that I’ve always been skeptical of information processing alone existing as qualia. You and I went round and round about this for years, and long before I was introduced to the idea that EM fields might serve as such a medium. Back then you’d skeptically ask, “So where is this ‘second computer’ that you propose?” I’d tell you that I didn’t know where it was or how the brain might create it, but rightly noted that this qualia stuff had a more certain existence to me than my brain itself. You were unimpressed since you saw no need for such a mechanism — for whatever the reason information processing alone never seemed like a ghostly explanation to you. So you’d assert that yes, if the right information on paper were properly converted into other information on paper, then something would experience what you do when your thumb gets whacked.

            The wonderful thing about you is your integrity to not balk at the implications of a given position. Others seem hesitant, and even given how popular the information processing explanation happens to be. Would Anil Seth be as open as you? (You know that I consider Dennett more of a salesman than anything, so I think he’d probably offer a confused response that some would nevertheless interpret as genius.)

            I bet there are online services where I could have random people assert whether or not my thumb pain thought experiment seems like it creates a supernatural situation. This might be something to consider since few of us bloggers seem to weigh in.

            Would I open up to qualia as information processing alone if I thought that science had looked really hard at EM fields and other such proposals, but could find no supporting evidence for any of them as the substrate for qualia? This would surly frustrate me though I doubt it would open me up to qualia as information processing alone in itself. I could however believe in a deity if there were good evidence for its existence, such as the verification of all sorts of funky things that a given priest says. So I guess I could also believe in qualia as information processing alone if this were adequately verified. And who knows, maybe in that case someone could even convince me that this explanation was not supernatural?

            On panpsychism, I don’t think I’d ever go that way. The inability of that group to deal with my anesthesia observation suggests that even if trendy today, they’ll never get far in science itself.

            I wonder if you have any thoughts on why you’re so adamant that information processing alone happens to be both a natural and plausible explanation for qualia?

            Liked by 1 person

          4. Eric,
            Adamant? Well, I go where the evidence points and that’s where all the actual neuroscientific evidence I’ve read about currently points. Or perhaps more accurately, with the theory that most coherently explains the data.

            I know the narratives from EM field theories, but I find the logic strained and convoluted, a desire to validate an intuition that consciousness is a cloud that permeates and floats around the brain rather than part of its functionality. Similar to quantum theories of consciousness, I think they’re a solution in search of a problem. Maybe we’ll discover that the brain uses EM fields in some manner, but if so, I’d anticipate it would include both conscious and non-conscious information processing.

            I find everything I need to explain the mind in information processing. But a lot of people seem adamant that there is something else there. As I’ve mentioned before, if I thought that was true, the fact that nothing about the brain’s physics have so far been shown to be special would likely incline me toward panpsychism. Which is why I asked you about it. BTW, I think a panpsychist would respond to your anesthesia argument by saying that it would be a different consciousness than the one normally there. But overall, I find the information view more productive.

            Liked by 1 person

          5. Eric: If EM fields were a “qualia medium” then one would expect some disruption in the contents of consciousness during a brain MRI, but no such side effects are reported. This complete lack of disruptive evidence would seem to indicate that any such EM fields theories are false. If belief in EM field theories explain your hesitation to accept a biological definition of consciousness, you might consider reevaluating.

            “Magnetic resonance imaging (MRI) of the brain is a safe and painless test that uses a magnetic field and radio waves to produce detailed images of the brain and the brain stem.” and “According to researchers at John’s Hopkins University, the magnet in MRI machines can stimulate the inner ear’s balance center, causing some patients to feel vertigo while they are inside the machine and in the minute or two after they’ve left it.”

            — So sayeth the Google.

            Liked by 1 person

          6. Stephen,
            I don’t think a physicist would say that the magnet resonance imaging most useful for giving us associated brain pictures, would inherently interfere with the electromagnetic radiation associated with neuron firing. Apparently to interfere we’d need to use the right EM radiation. Presumably standard MRI isn’t that.

            McFadden does discuss this in his 2002 paper “Synchronous Firing and It’s Influence on the Brain’s Electromagnetic Field”, stating that static fields shouldn’t have much effect:

            Magnetic fields do penetrate tissue much more readily than electric fields but most naturally encountered magnetic fields, and also those experienced dur- ing nuclear magnetic resonance (NMR) scanning, are static (changing only the direction of moving charges) and are thereby unlikely to have physiological effects. Changing magnetic fields will penetrate the skull and induce electric cur- rents in the brain. However, there is abundant evidence (from, e.g., TMS studies as outlined above) that these do modify brain activity.

            (I guess since 2002 they dropped the “nuclear” term for this kind of imaging since it freaked people out.) I don’t quickly see that McFadden went over this again in his recent paper (2020), but rather suggested that it’s uncontroversial that his theory hasn’t effectively been dismissed in this way. I’ll leave that for the experts.

            What I don’t understand Stephen, is how you can believe that consciousness involves worldly causal dynamics, and yet also believe that no technological machine could conceivably do what life does to create it. To me the first position contradicts the second. What does life use to create consciousness? We don’t have to know that, but surely naturalism mandates some sort of physics. Thus it seems to me that a conceivable technological system which employs that physics will inherently create something with qualia, mandated by causality. If you instead thought that a god created us for example then I could understand. You don’t however, so what am I missing?


          7. Mike, your comment “I think a panpsychist would respond to your anesthesia argument by saying that it would be a different consciousness than the one normally there.”

            A different consciousness? Since panpsychists never define the term ‘consciousness’ how would we know? Without their definition, I have no idea what they’re talking about, but it’s surely not my consciousness which I am certain is produced by my brain.


          8. Stephen, I have to admit I’m not sure myself. I’ve seen a variety of takes on it, ranging from interaction with the environment, to causality, to the intrinsic nature of matter.

            And your response is one I’ve given many times. I’m interested in how the consciousness with emotional feelings, memory, perception, attention, and self reflection work, and panpsychism doesn’t seem to address any of those things, except to say that’s not what they’re talking about. Apparently it’s whatever is left over after all the functionality is removed. I personally don’t think anything is left over at that point, but many are adamant that something is.


          9. Eric, then what about the changing magnetic fields that do “modify brain activity?” In that case there should be evidence that the fields effect the contents of consciousness if the EM fields as qualia medium theory is correct. The EM theory has other challenges common to cortical consciousness theories, first among them explaining the unified nature of the stream of consciousness that I believe implies a single localized production of consciousness itself.

            Regarding your suggestion that some sort of some sort of physics could produce consciousness, suppose that the generation of a feeling is accomplished by a particular physical configuration of interconnected brain cells. How would that configuration of flesh be reproduced in an inorganic substrate to create a feeling, an emergent characteristic of the cell configuration?

            Liked by 1 person

          10. Stephen,
            There’s no question that all varieties of wave (water, sound, EM, and so on) have the potential to be affected by what they encounter, and certainly other waves of the same variety. Of course this is why governments must regulate who is entitled to use various EM wave frequencies technologically. Since you mentioned MRI I only gave you that part of McFadden’s answer, though here’s the full thing:

            Prediction 6. The high conductivity of the cerebral fluid and fluid within the brain ventricles creates an effective ‘Faraday cage’ that insulates the brain from most natural exogenous electric fields. A constant external electric field will thereby induce almost no field at all in the brain (Adair, 1991). Alternating cur- rents from technological devices (power lines, mobile phones, etc.) will generate an alternating induced field, but its magnitude will be very weak. For example, a 60 Hz electrical field of 1000 V/m (typical of a powerline) will generate a tissue field of only 40 μV/m inside the head (Adair, 1991), clearly much weaker than either the endogenous em field or the field caused by thermal noise in cell mem- branes. Magnetic fields do penetrate tissue much more readily than electric fields but most naturally encountered magnetic fields, and also those experienced dur- ing nuclear magnetic resonance (NMR) scanning, are static (changing only the direction of moving charges) and are thereby unlikely to have physiological effects. Changing magnetic fields will penetrate the skull and induce electric cur- rents in the brain. However, there is abundant evidence (from, e.g., TMS studies as outlined above) that these do modify brain activity. Indeed, repetitive TMS is subject to strict safety guidelines to prevent inducing seizures in normal subjects (Hallett, 2000) through field effects.

            My take is that the brain seems to be relatively insulated from standard EM radiation, whereas the static nature of the MRI variety leaves that potential relatively benign, and then the non static nature associated with Transcranial Magnetic Stimulation will of course have physiological effects, since here electric current becomes inducted in specific parts of the brain. Apparently this has medical applications though must be used carefully since incorrectly juicing certain brain parts should be hazardous!

            In any case the sort of radiation which neuron firing tends to produce is well known and is monitored through EEG. But note that very little of this radiation is theorized as the substrate of consciousness. Theoretically only when certain neuron firing falls in synchrony does the right stuff get produced. And not all such synchrony, as in epileptic seizures, but some. If true this will of course need empirical determination.

            If scientists end up working this out then it seems to me that just as noise canceling headphones alter the sound waves which reach our ears, we should be able to produce the right radiation (perhaps transmitted from something implanted in the head) that directly alters an electromagnetic field which serves as qualia, and so subjective experience should be altered on this basis.

            This isn’t a cortical consciousness theory however. Given their behavior I personally suspect that “there is something it is like” to exist as a spider as well as a bee. (Neither have cortex right?) Neuron firing in general creates EM radiation, and theoretically the proper synchronized kind creates a qualia medium for bees, spiders, dogs, and so on.

            The unified nature of the stream of consciousness is actually a tremendous strength of McFadden’s theory. How do various parts of the brain that create subjective experience, come together as a single stream? It stands to reason that you’d need a single thing which is affected by various parts of the brain, somewhat like your computer screen may be affected by various parts of your computer. It could be that a standing EM field with astounding complexity serves as the single localized conscious self that you speak of. For this I like to imagine waves in a pond from thrown rocks, though the waves here would effectively serve as vision and all else that’s subjectively experienced.

            Regarding how we might use an inorganic substrate to function as an organic substrate, yeah that’s pretty ridiculous. But let’s let science get a bit closer figuring out how certain organic matter creates subjective experience before we decide that this can only exist biologically. We should avoid implying that biological stuff doesn’t ultimately reduce back to chemical stuff. Biology is so ridiculously far beyond technology that I commonly must simply smile and keep my mouth shut when people talk about how amazing our computers will become. 🙄

            You may have noticed that James Cross shares your skepticism that we could ever build something with phenomenal experience, though he’s also quite intrigued by consciousness as an EM field. In case you want to explore the concept a bit more, the following is a spot on McFadden’s homepage where he gives a general overview and then offers his two 2002 papers on the subject, a book chapter he wrote for a published 2006 consciousness book, two 2013 papers, and most recently his 2020 paper, all accessible from PhilPapers.

            One thing that I appreciate about him is that he speaks to be understood rather than to entrance people with cryptic word play. Maybe you’re familiar with Schwitzgebel’s October 2011 post which references three illegitimate benefits of obfuscation? Fortunately Johnjoe doesn’t take that path.


  10. The common assumption is that a simulation is running on a computer of some sort. But that isn’t the only possibility.

    One alternative is presented by Greg Egan in the story “Wang’s Carpets”. Read it online at

    Two excerpts:

    “… the carpets are more like an arbitrary number of different computers with overlapping data, all working in parallel. This is biology, not a designed machine—it’s as messy and wild as, say … a mammalian genome.”

    “’The squid has maps, not just of other squids’ bodies, but their minds as well. Right or wrong, it certainly tries to know what the others are thinking about. And’—he pointed out another set of links, leading to another, less crude, miniature squid mind—‘it thinks about its own thoughts as well. I’d call that consciousness, wouldn’t you?’”

    Better that you read “Wang’s Carpets” than I try—and fail—to accurately describe it.

    The second alternative is a complete dataset of a 4-dimensional universe composed of ‘snapshots,’ where entire 3-dimensional snapshots of the universe are arranged consecutively along a 4th dimension. Each snapshot is separated from the previous one by a unit of Planck time. Such a dataset is completely static—it does not and cannot change.

    Conscious beings are among the entities described within the unmoving and unchanging data. Importantly, consciousness is experienced, an emergent characteristic if you will, and the nature of the experience is that it’s a stream, or flow animating the successive snapshots in the dataset, very much like static frames in a movie reel create a moving picture. In this simulation scheme nothing is ever lost, so that all conscious experience is always being experienced, as opposed to a ‘running’ simulation where every instant is succeeded by the next computed one.

    This second alternative is, in fact, a description of our block universe. I have described this simulation—the one that we exist in—in “The Consequences of Eternalism” at:

    Of course, the origin of any simulation is unknowable from within, so the origin question has no answer and cannot legitimately be asked. Per Wittgenstein: “Whereof one cannot speak, thereof one must be silent.”

    Liked by 1 person

    1. Have you ever read Egan’s novel Diaspora? It includes the Wang’s Carpet story, but as part of a much larger arc that ends up spanning billions of years and universes. Pretty mind bending. One of these days I plan to dig it up and read it again.

      The problem with storing the complete dataset like that is the storage requirements. And if the simulation owners already know the full story, why bother to simulate it? Although I suppose some multidimensional being(s) may consider it a nice piece of art to have lying around.


    2. Yes I’ve read Diaspora … I’m a big fan of Egan’s work and I think I have all of his novels and short stories in both dead tree and EPUB versions.

      Your comments about storage, “simulation owners” and “multidimensional beings” steps into the block universe’s origin and implementation question which is the area “whereof one cannot speak …”. But even though knowledge is not possible, we can entertain ourselves with our sci-fi imaginings.

      Storage wouldn’t be a problem since the block universe is the storage. I’ve read somewhere (it escapes me at the moment) about a universe being finite from the “outside” but infinite to the observers inside.

      I’ve also had the thought that the block universe might be a Susskind Holographic Universe, a representation which I can’t imagine applying to a Presentist, evolving universe but it seems a good fit to a fixed and complete block conception.

      And the block universe might be a “Boltzmann universe,” one of a possibly infinite number of Boltzmann universes. Like a Boltzmann brain, it would appear fully formed—if an object with a brain’s complexity could just pop into existence, why not a universe?

      And in our imaginative musings, we shouldn’t ignore the “always was and always will be” possibility.


      1. The finite from the outside but infinite from the inside thing sounds like Brian Greene’s description of bubble universes. A bubble universe is a region of inflationary foam where inflation has stopped, and that stoppage condition spreads. So from the outside, it appears finite but expanding. However, the expansion will continue infinitely into the future.

        But from the inside, time is measured from the end of inflation and the big bang. However, from within the universe, that happens everywhere at the same time, so expansion into inflationary foam infinitely into the future becomes an infinite universe right from the beginning.

        Definitely that and all the black hole universe theories I’ve seen seem more consistent with an eternalist perspective.


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