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Consciousness and Quantum Mechanics: What's the Link?
🕑 Added 2022-11-19 16:00:10 +0000 UTC[This is a transcript of the video.]
Physicists have debated the role of consciousness in quantum mechanics for more than 100 years. Some podcast episodes will soon reach that length, but I have a dentist appointment in 2 hours, so we’ll have to wrap it up a little more quickly. Why did some physicists like von Neumann and Wigner think that consciousness is necessary to make sense of quantum mechanics, and can consciousness influence the outcome of a quantum experiment? That’s what we’ll talk about today.
In quantum mechanics, everything is described by a wave-function. There’s for example a wave-function for a particle going left, and one for a particle going right which sounds about as exciting as you expect physics to be. But the weird bit is that there’s also a wave-function for a particle that goes both left and right. This is called a superposition.
According to the standard interpretation of quantum mechanics such a superposition means that the particle is indeed neither left nor right, but both, until you make a measurement. The moment you measure the particle, you know whether it went left or right, and the wave-function “collapses” to one that fits to your observation.
Albert Einstein didn’t like this at all. Yes, that guy again. Einstein said, this collapse happens faster than light, that’s a “spooky action at a distance”, so it has to be wrong. But Bohr said, there’s nothing wrong with that, because the wave-function isn’t real. It just describes what we *know. And you can update knowledge faster than the speed of light. John Bell used the following example: “When the Queen dies in London, the Prince of Wales becomes instantaneously king.” No matter where he is.
So why wasn’t the speed of light limit broken when the queen died? Because we can update our *knowledge about what happened elsewhere without causing any event elsewhere. And this is how Bohr thought about the collapse of the wave-function. You can update it instantaneously because it just describes what we know.
Einstein wasn’t convinced, but Bohr won the argument. So, if you believe Bohr, then the wave-function has something to do with knowing. But who or what knows? Well, the observer does. By this logic, the update of the wave-function becomes linked to the thing that can know something, which is the human brain.
Bohr didn’t actually explain what this all means. He was quite content with being incomprehensible, and a lot of physicists have since followed his example. But Eugene Wigner was bothered. He thought the idea that the wave-function describes knowledge has a big problem. To illustrate this, he came up with what is now called the “Wigner’s friend experiment”.
He said, suppose you have created a particle in a superposition of left and right and you measure it. But you’re inside a laboratory and have a friend waiting outside, in front of the closed door, because that’s how physicists treat their friends. Your friend doesn’t know the outcome of the measurement until you open the door to tell her what you measured. Wigner said that for her, you are in a superposition of having measured the particle left and right, until she collapses your wavefunction. He then argued that it would be “absurd” if consciousness was in a superposition. And since no one knew just what caused a wave-function to collapse, he postulated that it was consciousness.
Most physicists think today that a measurement is an interaction with some apparatus. It has nothing to do with whether you or someone else looks at the result, or whether you tell someone about it. But in the early days of quantum mechanics, it was unclear what the mathematics means.
A similar interpretation of quantum mechanics as Wigner’s had been put forward earlier by John von Neumann. Despite the German-sounding name, von Neumann was Hungarian, like Eugene Wigner. Both later emigrated to the United States.
Von Neumann’s argument was that a particle in a superposition can cause superpositions of the things it interacts with. This leads to superpositions of entire measurement apparatus, and everything that follows from that. Say, you use the measurement outcome to decide whether to blow up a bomb or not, then get a superposition of superposition of a bomb that’s blown up and one that didn’t. And that leads to a superposition of a world in which you died and one in which you didn’t. And a superposition of worlds in which you go on to win the Nobel Prize and one in which you didn’t, and so on.
Von Neuman said that this chain of events needs to be cut somehow, and since everything *in physics seemed to keep the superpositions alive, he thought the collapse had to be caused by something “extra-physical” or “psychophysical”. It had to be the conscious perception of an observer. The observer either sees a bomb explode or not. That’s the end of that chain of superpositions, and maybe also the end of the observer.
This idea of Wigner and von Neumann that consciousness causes the collapse of the wave-function is an interpretation of quantum mechanics rather than a new theory because mathematically it doesn’t make any difference. That’s because the only observations we can make any statements about are those which were eventually registered in our brain. Though you might argue that really there’s only one brain which is your own and everything else is your imagination, in which case, thanks for imagining me.
The Wigner von Neumann interpretation has problems because all interpretations of quantum mechanics have problems. Reinterpreting maths just pushes problems around like bumps under the carpet. In the Wigner von Neumann interpretation the problems manifest themselves as conscious observers who have inconsistent knowledge about reality. If you take this seriously it would imply that reality itself depends on who’s observing what. I talked about this in an earlier video, but today I want to focus on the consciousness issue.
The interpretation from Wigner and von Neumann is weird but not wrong. Still, it never became widely accepted. I believe the major reason it’s never been popular with physicists is that it’s unnecessarily complicated. No one knows what consciousness is anyway and if you want to calculate the outcome of a measurement in quantum mechanics you don’t need to know. So introducing some psychophysical factors to induce the collapse of the wave-function is just unnecessary word salad.
Philosophers dislike this interpretation for a different reason, namely because it’s internally inconsistent. You start with assuming that consciousness is not subject to the same laws of nature as everything else because it’s “extra-physical”. But then consciousness interacts with the physical world and that means it’s itself physical because you can test its effects on our observations. It’s the same problem as dualism. If the mind is non-physical, then it doesn’t help you explain observations in the physical world – you can’t have your cake and eat it too.
But there are still people working on it. For example, just a few months ago, David Chalmers and Kelvin MacQueen wrote a paper about this. They proposed to address the issues of the Wigner von Neuman interpretation by using a particular mathematical model for consciousness, that is integrated information theory, IIT for short.
We briefly talked about IIT in an earlier video. The basic idea is that each system is assigned a quantity, big Psi, that you can calculate from how well-connected the system is, and how it processes information. The bigger Psi, the more conscious the system. In this theory, consciousness it’s not binary, it’s not on or off, it’s gradual. This is why Christof Koch, one of the proponents of Integrated Information Theory, thinks it’s a panpsychist theory. Everything is a little bit conscious, it’s just that humans are a little bit more conscious than carrots. I want to apologize to all carrots who are watching.
In their new paper, Chalmers and MacQueen use IIT to build a model for wave-function collapse that is induced by systems which are “sufficiently conscious” in this quantifiable sense. This is no longer an interpretation of quantum mechanics but a modification, and it leads to predictions that differ from those of quantum mechanics. For example, they propose that some states that a quantum computer could generate might be “sufficiently conscious” and thus induce a collapse, though the details depend on the model.
For a paper by two philosophers it isn’t bad. My major misgiving about their consciousness induced collapse model is that it’s unnecessarily complicated. If you’re building a model in which collapse is induced by a macroscopic thing, why use a brain. Why not use the measurement device? Or cheese. I would like to propose that it’s really cheese that collapses the wave-function. Prove me wrong.
Okay, so here we have people thinking that it’s somehow the amount of consciousness in a system that induces collapse, which is kind of weird already. But there are also people who think that deliberately focused attention actually influences *how* a system collapses.
This idea was also brought up by Wigner, though I think it wasn’t his intention. In 1967, Wigner published a very influential essay titled “remarks on the mind-body problem” in which he wrote “we do not know of any phenomenon in which one subject is influenced by another without exerting an influence thereupon.” It’s not a big step from there to conclude that if conscious knowledge can be influenced by the result of a quantum experiment, then your conscious knowledge can also influence the result of a quantum experiment.
Now add to this that back then scientists were still experimenting with telepathy. Some of them were also studying if concentrating on the outcome of a random number generator would change the outcome. It was just a small step from there to the idea that if you focus your attention on photons going through a double slit that affects the pattern on the screen.
I’m not making this up, this is literally how those experiments work. There have been a few of them since the 1990s. The most recent one was published in 2012. The idea is that when a conscious being concentrates on the light passing through a double slit, then that has a similar effect as if you had measured which slit the light went through, so the interference pattern should change.
The authors describes their experiment as follows “It was explained [to the participants] that they could try to mentally “see” or imagine which of the two slits the photons were passing through, to “become one with” the optical system in a contemplative way, to mentally block one of the two slits, or to mentally “bend” the laser beam so as to cause it to pass through one slit rather than both.”
They then statistically analyse the difference in the interference pattern between the cases where the participants were told to concentrate on the double slit and not. The authors claim to see a statistically significant difference. Their analysis method was later criticized by another group which argued that the method of analysis is unreliable and the results can’t be trusted. Similar criticisms have been raised about earlier experiments.
How difficult can it be you may ask, to figure out whether the pattern of a double slit changed? Well, the issue is that the common illustration with multiple stripes for the unobserved double slit and two thick bands for the observed one is so misleading I can only call it wrong. It’s because a single slit also makes an interference pattern, it just looks slightly different from that of a double slit. So if you don’t expect your conscious observes to affect really each photon it can actually be difficult to tell the difference. There’d be easier examples to look at but maybe they didn’t want that.
In any case the brief summary is that the results of experiments that claimed to find an influence of conscious thought on the outcome of quantum experiments have remained highly controversial and have not been reproduced. In addition, the idea that your conscious attention somehow influences what a wave-function collapses into doesn’t make sense. Wigner was right in saying that in physics, if one thing can affect another, then that influence can go both ways. But that doesn’t mean that the influence is equally relevant in both directions. If it rains, you’ll get wet. If you swear at the sky in response, then the pressure waves coming out of your mouth move some air molecules. So they indeed influence the rain. But for all practical purposes it doesn’t make any difference.
And your brain indeed has a physical influence on its environment. That’s because thinking generates electric and magnetic fields. But they’re too weak to collapse the light going through a double slit.
I believe this is where the idea of “quantum healing” comes from, that by focusing your attention you can somehow influence what processes happen in your own body. My major problem with this isn’t even that it’s pseudoscience, but that it blames patients for being ill. Hey, if you’re dying from cancer, that’s your own fault, should have learned more quantum mechanics when you still could.
Finally let me add a brief comment about Roger Penrose and Stuart Hamaroff, who are maybe most famous for claiming that consciousness has something to do with quantum mechanics. Their argument however is a completely different one. It’s that the collapse of the wave-function leads to consciousness, not that consciousness leads to the collapse.
They have this idea that in the human brain there are certain large molecules, the microtubules, that can form coherent quantum states, and their collapse is relevant for consciousness. There are several problems with this. First of all you wouldn’t expect such large molecules to remain in quantum superpositions for a sufficiently long time in the human brain. Second, all cells have microtubules, so how come my liver isn’t also conscious? And third, what’s this whole microtubule business got to do with consciousness anyway? By the way, in my book “Existential Physics” I have an interview with Roger Penrose about this.
So, in summary. A) That consciousness causes the collapse of the wave-function is a possible interpretation of the mathematics, but it’s as problematic as all other interpretations of quantum mechanics. B) One can formulate a collapse model based on this idea which is a testable modification of quantum mechanics. But in all honesty, I think if they test it, they’ll just rule it out. C) The idea that you can influence the collapse of the wave-function by thinking is pseudoscience. And D) none of that is what Penrose and Hamaroff are on about, which is another story entirely.
Comments
I'm not sure, if something has to be conscious for understanding, but disagree with scientists (including Bee?), that we see consciousness created on advanced computers, although I don't think, there's something magic or supernatural about. Two arguments: 1. The stuff, something is built of, is not unimportant for its functions. The pulpy thing called brain works very different from a machine made of chips, and has at least two different ways of information interaction, chemical and electric. How this works together is hardly understood, but even if, would it make sense to simulate it in a machine? An analogy: highway bridges are built of steel and concret. Would it be possible to build them of plastic? Ask an engineer and he/she will calculate and draw for a while, and perhaps will say it's possible, if you work it out in a special way. But will it really be constructed? Think, we never will observe such a thing in reality. 2. Consciousness needs development: About 20 years pass by from a fetus to an adult with all the functions of being conscious, like self-awarness, reflexion, anticipation. Can you compress that in a machine? I don't know, but even if, you had to simulate all the experiences a child makes in its environment with a sensitive and sensible body by growing up. Then may be you created human consciousness at the end, but think then the biological reproduction is the easier way.
Happy to be new member successfully
Well, I believed in Free Will when I believed in a Creator who made humans and gave them the choice to follow His will for us or not. The whole shebang basically stopped making sense when I found out more about life and the Universe Atheism isn't a form of theism or religion. It's the *lack thereof* (I like Sabine's description of herself in Existential Physics as 'an agnostic and a heathen'. I'm just a heathen.) I reckon that if someone's faith makes their life better and harms no-one I've got no business disabusing them of it. I've learnt a fair bit about how people think and act, and why; a fair bit of that is predicated on being in survival mode so has a fair bit of unconscious decision-making involved. It takes effort and practice to not act from those reactions, so in that case 'free will' isn't really in play either. I can't control all my thoughts and emotions before I have them, so that's another dent in 'free will'. It's hard to follow Sabine all the way with not believing that it exists but I'm working on it. I can't argue with not having free will to believe in free will or not. 😆 I think we do well to minimise unnecessary upset in life but too much positivity or negativity causes a lack of practicality. As for electrical signals from the brain being a cause of telepathy, I'm like 🤷🏻♀️ what else might cause ESP? I found this video rather helpful for putting science and religious faith in context: https://youtu.be/hgetGsnSMQ8 (yes, it's the German Physicist!)
Greggery Peccary
The question of "what complexity" seems to be a perspective of computational origin. There have been theories (before Newton) of mind simpliciter; that is, consciousness is not analyzable in a reductionist program. I think this is the point of the show, to move beyond reductive mechanics, but in as much as that QM aspires to deterministic/predictivistic ideals, it doesn't launch.
I couldn't believe in it too at first, but eventually I had to except harsh reality.
I couldn't believe in it too at first, but eventually I had to except harsh reality.
Consciousness generally emerges when any form of living organism creates a representation of the surrounding environment by the process of autopoietic complexity reduction. This representation includes a (much simplified) model of the organism itself, which in turn leads to the organism's self-awareness, or consciousness.
My hypothesis is that consciousness evolved as an arbiter between the lower level sensory subsystems. While we do not understand consciousness, keeping it to be exclusively "experiencing" versus "stimulus/response", as we are evolved animals we can be safe in saying that consciousness exists to some extent in everything with a brain, which is a collection of cells, but less safe in arguing that individual cells have consciousness. Yes, cells learn (https://www.cell.com/current-biology/fulltext/S0960-9822(18)31210-7), but I write a program that changes its behavior depending on the errors that it detects and that program, artificial intelligence, is not conscious. The same holds for cells, their programming, DNA, does allow for adjustment in responses to stimuli, but that is not necessarily consciousness. The question is at what complexity does consciousness, experience, arise? There is a line between sophisticated behavior that is not conscious, such as in a cell or software learning, and consciousness, experiencing.
A scientific fact is that you believe in these phenomena :) .. I would say that: - atheism is a kind of theism, paradoxically: you make claims about something you can't know. I am an agnostic, because I can't know whether there are gods, or no gods. - we make decisions the same way computers make decisions. We are just much more complicated machines. - brain signals are very weak... it is hard enough for state-of-the-art machines directly connected to the brain to get any reading. They can read some regions, but they don't know what that means, it's way too complex to interpret. I don't believe biological brains a few feet away could read anything, let alone anything useful. - it is of course a nice Gedankenexperiment! I can understand why we don't want to be mere machines, that is a depressing thought. But I can't think how it could be otherwise. - one phenomenon I find interesting: believing in the power of the mind may very well help you feel better. So there some effect; that could mean that people who didn't believe in the power of the mind didn't thrive as much, and cultures which promote that belief have prevailed. - and last: no one has control on whether they believe in free will - that's my belief. So I totally accept that you don't. :)
I thought that not having free will was horribly discombobulating and now worse, you're even questioning the existence of cheese, George. Why can't we have nice things?!
I am an atheist but I don't want to quash anyone's religious faith. I think free will not existing and extrasensory perception being possible are not exclusive. Sabine explains that we make choices like computers do, in addition I think we have knowledge of the possible outcomes and ramifications of our choices and actions that electronic devices and artificial intelligences do not and I believe won't possess on many different levels. We don't just send and receive data, we shape the delivery to our purposes and parse the words and actions of others in turn, often to a very fine degree. We also have brains that use electricity and chemicals to work, so I think that we either come to have the same or similar thoughts by coincidence when in conversation, and/or we can pick up bits of other people's brain signals, and understand them as if they were our own thoughts. I'm rambling a bit but that's how I think we also can function as sentient beings without 'free will.' I have some vague thoughts that if we don't have free will, and we live in a block space-time Universe with events happening relative to our positions in space-time perhaps our 'light-cones' of perception can touch parts of space and this gives some people clairvoyance, precognition, predictive dreams... I know that this is seriously abusing interpretations and explanations of physics and the Universe but consider it a Gedankenexperiment perhaps. 😉 I am interested in how people have attempted to read the future in different ways and how ancient practices of healing from different cultures attempt to manipulate energies as well as tissues, so I do wonder if there's something to our bodies and minds beyond the constraints of our skins. I am am interested in some forms of 'woo' although I firmly believe in science and medicine above any 'quantum' or 'energy healing', emotional vibrations, etc. as I would rather most of my thinking be coherent and rooted in known phenomena. As for consciousness collapsing the wave function, I doubt particles are influenced by mere attention.
OK, I'm going to be very stupid. Bohr states that the wave function is not real, it is merely a probability curve that, in my tiny brain, is required simply because the quantum world is too tiny to see. But they also extend to the macro world for things not within view that can be represented by wave functions, mental probability distributions as to where they might be and what they are doing as derived from experience. Wave functions collapse when certainty is reached, after a measurement, such as seeing a friend when looking for them. It seems that this "consciousness" thing with regards to wave function collapse is simply an extension that people create with certain things that they believe should have meaning but that have no meaning, such as learning the state of an electron. To Schrodinger's cat the wave function was about being let out of the box.
There's no reason to kill yourself and if you kill yourself that's not on Sabine's conscience. She is one of 8 billion people on Earth and as such not the only important person nor honestly even of much importance at all to your journey in life compared to everyone else who actually knows you. Please talk with someone who you matter to and don't try to manipulate people by telling them you'll die
Hi Armando. That's funny. What if even cheese doesn't exist?🤯 I mean doesn't cheese come from humans? And if we don't exist, how cheese can exist?
I went to a pulsar timing array gravitational waves talk a few weeks ago and the speaker teased that this result would be released shortly. They held onto it for a good long while to make sure that their detection was robust. It will be interesting to see how good their statistics are.
Armando Mistral
Buuuut... if we're non- existent, where does the *cheese* come from?
Rad Antonov
And on a totally unrelated note, there was a neat perspectives piece in last week’s Science on using those pulsar timing arrays you told me about to measure the gravitational wave background. https://www.science.org/doi/10.1126/science.abq1187
Rad Antonov
I should’ve known. They are notoriously hard to pin down. Maybe try to localize them in a Wigner crystal next time.
You’ll have to share the definition of “consciousness” you’re working with, as not everyone uses the same definition.
I tried asking some electrons about that W, but every time one of them slowed down enough to talk to, I couldn't figure out where they were at. Thus, the correct pronunciation of Wigner is uncertain.
“It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is also zero, and that any people you may meet from time to time are merely the products of a deranged imagination.” Douglas Adams, The Hitchhiker's Guide to the Galaxy Hello fellow non-existent beings. My imagination of you guys and this interaction is delightful.
Hi Thomas, you and Greggery below hit a big nail on the head -- what definition of consciousness is in play here? I did find a few days ago an article in Quanta magazine about tests of some objective collapse models. It seems that the experiments didn't go well for the models. https://www.quantamagazine.org/physics-experiments-spell-doom-for-quantum-collapse-theory-20221020/
Hi Colleen, to be clear: everything is possible. God is possible as well... I can't know that no god exists... But my point is, if you believe in free will, you believe in something metaphysical (at least, that is my belief, but it is based on what we know from physics; and you might not agree with me, but Einstein didn't believe in free will... yes, that guy again ;) ). So, from the moment you introduce something metaphysical, and if you believe our minds have special physical properties that no other entity has, then why wouldn't those properties apply to other things like telepathy or the collapse of the wave function? My main point this belief in free will is rooted in our culture, and in all existing cultures. This is something very deep, and it is a belief in something magical. I think it fosters a lot of incoherent thinking, because many of our daily discussions are based on that magical thing. If you have an idea of how telepathy or clairvoyance would work, I would be interested to know! That sounds fascinating; and a bit scary too.
Rad Antonov
Let’s not knock electrons. They happen to be excitations of my favorite field. It’s better than having buddies you couldn’t possibly keep up with or ones that ghost you all the time. Did you happen to find out if his besties called him “V”-igner?
Hi David, how so?
Hi Nicolas, I don't think so. Free will is our ability to determine our own actions, nothing else. I do think that even without free will as Sabine describes that condition, there is a possibility of telepathy and clairvoyance.
Hi Mark, Freud has a lot to answer for, I think.
Hi George, that's a disconcerting way to think about myself. 😆
Both. 😄
If you write it here she might read it.
Consciousness emerges from autopoiesis. Every autopoietic system is conscious, therefore not only a carrot but even a single cell has consciousness, in the sense of self-awareness. This self-awareness emerges from the complexity reduction of the surrounding environment that happens at the cell membrane.
I spent a fair bit of time today trying to find out if Wigner was a "Copenhagen" guy or a "hidden variables" guy because this screams superdeterminism to me, specifically the measurement result being dependent on the detector setting. But then I wondered if Wigner was talking about macroscopic human thoughts and macroscopic "events" vs microscopic physics of particles in our brains and some sort of wave function interaction on that level with an emergent conscious phenomenon. On a macroscopic level, a mutual influence makes intuitive sense (even if free will is an illusion), but at the particle wave function level, I don't know -- it certainly leaves a bad taste in most physicists' mouths. Then again, some of Wigner's best friends were electrons.
Why not enlighten all of us? :) Surely we aren't as smart as Sabine, but how can you know that for sure?
The belief in free will is closely linked to such claims about the power of the mind... once we believe that we can decide what we think, we believe in a magical mind; and then anything is possible; we might as well be causing the collapse of the wave function.
Quantum healing is not the only medical theory that blame the patient for her disease. The psycho analysis of Freud for example blames the patient for her neurosis or psychosis.
That’s why full statistical independence does not exist. Omnia vicissim said Spinoza in the 17th century, all things influence each other.
Neils Bohr was right. We are confusing observation technology limitations with suppositions about reality. This is a natural result of trying to use something absolutely gigantic to probe details of something very tiny, which cannot be done without destroying the subject of investigation.
From the First Law of Thermodynamics perspective human doesn't exist. I mean there is no particle of us that can be isolated and studied under the microscope. And consequently whatever comes with human doesn't exist either; and since the consciousness comes with human it doesn't exist either. That's why it is confusing when scientist/s talk about things that don't even exist. To me It's virtually impossible to take flat-earthers seriously and scientist/s who talk about things that don't even exist aren't exception.
If Wigner's statement that “we do not know of any phenomenon in which one subject is influenced by another without exerting an influence thereupon" is true, isn't this a violation of statistical independence?
Dave Muth
How did her production team get a color picture of my dad as a baby, skeptically wondering about physical correlations? Color film wasn't invented yet! Now, that's SPOOKY!
Greggery Peccary
I am in a superposition of not being able to decide whether it seems odder to explain one thing you don't understand (collapse) by using another thing you don't understand (consciousness) or the other way around.
I LOVE this week's video, and I've honestly been thinking about this subject for several months. My question has been "What constitutes consciousness?". Has anyone tried to train a monkey, or a rat, or a dog, to observe quantum effects and see if that being's observation collapses the wave?
I've tried to outsource myself but it didn't work, so at least for now I'm totally real ;)
I appreciate your support but I cannot offer private consultations.
If Sabine is a manifestation of our collective imaginations, that's a pretty good effort on our part. Who is running her social media accounts then if she isn't real? 🙀 On telepathy and changing slit patterns, I think there is a possibility that the electrical activity of our brains might leak through our skulls and be picked up like interfering radio signals but maybe there's not a way for that to happen after all. Influencing photons would be telekinesis rather than telepathy. I am rather more doubtful about the existence of telekinesis.
