This entire website is dedicated to quantum physics but also to the supposed relationship of quantum physics to consciousness. The immediate question of many will be about this relationship. I will try to explain that here. Another frequently asked question in this regard is whether quantum physics shows that consciousness exists independently of your physical brain. That is a question of great importance and has a lot to do with the fear of death. I want to answer that question as the physicist that I am. Before I make that attempt, I would like to quote a text from the preface to ‘Existential Physics‘ by physicist Sabine Hossenfelder.
Can I ask you something?" a young man inquired after learning that I am a physicist. "About quantum mechanics," he added, shyly. I was all ready to debate on the measurement postulate and the pitfalls of multipartite entanglement, but I was not prepared for the question that followed: "A shaman told me that my grandmother is still alive. Because of quantum mechanics. She is just not alive here and now? Is this right?"
Such a question would make me itchy – just like Sabine – especially as a physicist. The reason is that it is not a question to which I, as a physicist, can give a strictly physically substantiated affirmative or negative answer.
Can quantum physics demonstrate the survival of the consciousness after death?
From the position of modern physics, the short answer is no. I do have my ideas of course. But whether I, as a physicist, can provide a hard pure physics-based answer to questions about the survival of our consciousness after death, that would be far from the truth. Modern physics is not a very suitable tool to solve such a question. Physics is only concerned with evidential matter and force fields and everything it says must be confirmed experimentally. Think about that concerning the survival of your deceased grandmother. But there are clues that are very relevant.
Information is the key
There is an repeatedly experimentally demonstrated strong relationship between the information an experiment can provide and the behavior of the observed phenomena, such as where an object can or cannot be found. I think that is a strong indication that the observer plays an important role in quantum phenomena. I would like to emphasize here that the quantum world is not limited to phenomena on an atomic scale contrary to popular belief. As far as is known at the current state of physics, the world is quantum at every scale. So, it follows that information also plays an important role in the observed phenomena on the human scale.
Quantum physics does not prove that consciousness exists independently of the brain, but – not unimportantly – it certainly does not prove that it isn’t. When someone asserts the latter firmly, that is likely more an expression of his or her belief, the there-is-only-matter belief. In that respect it must be said that there are interpretations of quantum physics – and there are quite a few — that hold to there-is-only-matter and therefore want to exclude the influence of the observer. These interpretations fall short, on closer examination, of explaining observed phenomena or are so implausible and experimentally unverifiable that they also fall short. In contrast, an understandable and consistent interpretation of quantum phenomena advocated by many open-minded physicists is that the mind is primary and influences what we perceive. Mind manifests matter. As long as you won’t accept that, even as a possibility, the phenomena – such as the quantum collapse or the reduction of the quantum wave function – will remain incomprehensible and mysterious.
What is consciousness?
A definition of consciousness could be: consciousness is that which experiences. But that’s what it does and not what it is. We even experience our own consciousness but we do not know what it is. We process information that enters our consciousness and assign meaning to it. But we don’t actually get much further with the question what it ‘is’. Is our normal awareness our whole consciousness? Not likely, but we are not aware of our unconscious. By definition. It is quite possible that our awareness is only a small part of what I prefer to call the mind. Our consciousness is anyhow clearly an information processor that assigns meaning to information received. That should suffice here as useful definition. Useful because in contrast to the subject of consciousness, information is a very suitable subject to look at from a physics point of view.
The immaterial quantum wave
The quantum wave, also called the state wave, is a wave that cannot be observed directly with any material instrument. A state describes the behavior in time of an object. The quantum wave contains all possible states of the object we want to observe. That is is a wave, although not directly observable, we do infer from the behavior of the observed objects, such as the locations where they are detected and with what properties. On observation – detection – only one out of the infinite amount of all those possibilities in the state wave manifests itself. If necessary, read the page about the double slit before reading further here. The quantum wave is not material as it is not directly detectable with instruments, although there are many physicists who assume that this is a shortcoming of our instruments that will be solved in the future. This stance is called ‘promissory materialism‘.
Information influences the behavior of the quantum wave.
It turns out that the state wave adapts dynamically to the information that the experiment can provide. If I change the experimental set-up in terms of what information it will deliver, the state wave immediately changes. Even retroactively. Strangely enough, that information does not need to be observed immediately. Availability for future observation seems to be enough for the effect. You can read a good example of how the possibility of available information influences the quantum wave and how that has been determined experimentally in a recent post from me on this website: Decoherence and Information. The step from the influence of available information to the influence of the observer, the recipient of that information, seems obvious – what is information good for if not to inform someone? – but is difficult and perhaps even impossible to prove. So I won’t try that. But I want to try to make the idea of observer influence on the quantum wave plausible. That is feasible.
Does the observer’s consciousness play a role?
I personally think that the conclusion from the evidential influence of information on the state wave behavior that the consciousness of the observer influences the behavior of matter, is well defensible, although strictly speaking unprovable. There are physicists – such as Carlo Rovelli – who prefer to assume that objects only exist materially in their relationship with each other, thus explaining the observer effect. As far as I’m concerned, that’s an emergency jump, powered by cognitive dissonance, to avoid the existence of primary causal consciousness at all costs.
If you find it plausible that the consciousness of the observer causes the effect on the observed matter, the next logical step is justifiable and not so big. Consciousness cannot then be a product of the brain since it also is itself made of matter. I hope you understand that. Consciousness ‘is’ and it manifests matter. Consciousness is therefore primary, not matter. Unless you find it plausible that matter influences a non-material state wave and thereby manifests other matter that reversely influences another non-material state wave, as Rovelli supposes. Seen in its way, the material brain would thus constantly manifest its material self. As far as I’m concerned, that’s an impossible causal loop. But as I said before, I think Rovelli’s idea is an emergency measure to keep consciousness coûte que coûte out of physics.
So consciousness – the information processor – can not be a product of the brain. In that case, it can therefore exist separately from the brain – and actually the entire body. Then the next step towards the survival of consciousness at the death of the body is of course not so great anymore.
The Surviving Consciousness
The above is certainly not proof in a physical sense, but it is well defensible. Also remember that no physical theory can really be proven but only experimentally confirmed or falsified. So quantum physics really doesn’t prove that consciousness survives death, but it certainly doesn’t forbid it either. It even makes the survival possibility plausible. When you allow that as a possibility to consider seriously, you may start to see extraordinary experiences such as the near-death experience (NDE) in a different light. It could very well be true that those experiences are real experiences of an individual consciousness that is not or not very strongly linked to its body at that dramatic moment. Claiming that it is ‘just’ not possible and that these must be hallucinations is in any case unwise. Such a dismissal is even unkind considering that those who have experienced an NDE are strongly convinced that their experience was not a hallucination and have completely lost their fear of death. We are usually quite capable of recognizing a hallucination after the experience. Every time we wake up from a dream, we recognize it flawlessly as unreal. And then it’s unwise and heartless to dismiss those who see their personally experienced NDE as a true albeit extraordinary experience that turned their lives upside down, as sufferers of hallucinations.
“There may be many truths to which one cannot climb by one thread, but only by a rope woven of many strands.”, Iain McGilchrist.