Rather than relating consciousness and quantum physics at a “macroscopic” perspective, Penrose starts at the molecular level. From here, you can read a paper by Hameroff and Penrose or click Download PDF for a printable version. (I haven’t read this paper though I intend to.)
Although it may not connect to OP’s thesis, it’s impressive how much chemistry essential to life requires quantum effects. Photosynthesis achieves its huge efficiency due to quantum tunneling; olfactory sensors measure precise electron orbital gaps by the quantum tunneling facilitated; feeble magnetic forces are apparently detected by their effect on pairs of entangled electrons. Quantum effects may also play important roles in DNA processes or Penrose’s microtubules.
No, you are using it correctly; qualia is the subjective experience of consciousness. There is observational evidence of a sort (I view my experience of being conscious, and I assume others feel the same), but it is a subjective observation by definition.
There is, however, zero evidence for any external field or universal psyche that is somehow accessed by the physical brain, whereas we can directly observe electrochemical reactions relating to specific types of inputs and impulses which tends to indicate that cognition is a function of normal, explicable biochemical reactions in the brain. The whole of cognition and memory (the two are inextricably linked) is really complex, to the point that we can’t even begin to replicate or synthesize it artificially but the individual aspects are strightforward enough that we can observe them directly in animals with very simple nervous systems.
Consciousness is an emergent phenomena of incredibly complex and layered processes that run with massive simultaneity within the highly networked human brain. It’s a really, really, really hard problem to describe, much less begin to simulate, but there is nothing about cognition that requires invoking supernatural or undetectable physical fields.
I’m surprised that there’s any dopers who believe in free will. There isn’t a single good argument for it and physics and chemistry pretty clearly argue against it. If consciousness does take into account quantum effects then our behavior is seeded by something random and we don’t have free will anyway. Those quantum consciousness people always say that a particle is indeterminate until it is “observed.” That’s a really bad term because it leads people to believe that consciousness has some exclusive part in the creation of reality. The truth is the wave function collapses when a particle interacts with another particle.
I do. I seriously doubt that every facet of human behavior is governed by the laws of physics. Granted, there are some inherent limitations imposed by biology and other sciences, but I choose how I educate myself (based on what’s available to me, of course). In my formative years, information was a lot less readily available than it is today, but I still chose my interests, especially in terms of reading. I programmed myself on top of a set of ‘system software,’ if you will. Nor, if everything is determined by quantum-level interactions, would experience have nearly as much influence as it does on the human psyche.
I also find it difficult to believe that my discovery of the general hypocrisy and misanthropy of conservatism wasn’t responsible for a good part of my leftward drift. I began as a true-believer Reaganite when I really became involved politically, and I’ve pretty much always had libertarian tendencies. I don’t think that any of that was a result of random particles interacting in my neurons, or some sort of cellular decay.
I believe in “free will” (defined simply as human volitional agency, and our ability to make conscious choices) but for almost exactly the opposite reason from Johnny Ace. I think that every facet of human behavior is governed by the laws of physics…and that the laws of physics in no way contradict the fact that we make choices in our lives.
(The trouble with the term “free will” is that it has theological connotations. I do not believe in religious free will.)
A very basic problem in quantum mechanics is that it is postulates that wavefunction collapse occurs when “a measurement is made”. Now to me there isn’t a huge difference between a “measurement” and an “observation” and the problem is whatever you call it, quantum mechanics doesn’t define what it is nor is it easy to define. This problem is still very much outstanding.
The idea that collapse occurs when one particle interacts with another I would say is a mistake as its not consistent with QM. More complicated ideas of describing collapse as a purely physical process have been tried such as non-linear wavefunctions, but such ideas have never had much success and though they are more successful at re-creating the predictions of QM they are also testably different from QM.
These days because collapse is seen as suspect as a physical process, many physicists prefer interpretations without collapse such as the many worlds interpretation or Bohmian mechanics. It must be said though that doing away with collapse does not necessarily solve the QM measurement problem (e.g. many worlds) or that it can introduce ideas/elements that are seen as problematic (e.g. Bohmian mechanics or just about any interpretation of QM to someone tbh).
I’m not sure how there can be any factually grounded dispute that the answer is “little to inform each other and folks are barking up a stupid tree”. Quantum mechanics describes the behavior of particles that are sufficiently small that quantum phenomena are dominant and descriptions in terms of wave functions instead of classical mechanics apply. The brain fairly obviously operates on a macro scale. Any similarity to quantum physics is not just metaphorical, but a metaphor stretched pretty thin.
What other laws would you propose? Since “the laws of physics” describe the observed natural world, the only alternative is “magic”. I seriously doubt that human behavior is governed by magic.
I’d say physicists are fairly confident these days that there is not a mystical dividing line between quantum mechanics and the macroscopic that might be suggested by gedanken experiments like Schrodinger’s cat. A more modern pov on that thought experiment is that it is possible the cat is both dead and alive in some respect, depending on your interpretation, but practicalities of such large systems means that you can’t distinguish it from the situation where it is definitely dead or alive but it is unknown which it is.
It is fair to say the brain processes don’t seem to need quantum descriptions though and this is where I think most people disagree with Penrose. However for me knowledge and observation are important ideas in QM or at least important in arriving at a description which fits with what we observe. I wouldn’t suggest anything spiritual or mystical, but I feel it is important to accept that you may not be able to divorce observation from the observer.
There need not be any mystical or bright line between the quantum and the macroscopic and indeed I believe it’s commonly accepted that the differences are only ones of degree. One merely posits that the wave function associated with macroscopic objects can be treated as irrelevant, whereas as one approaches the subatomic scale it becomes fundamentally crucial.
That certainly true for many important aspects of QM, but there is no reason to believe (i.e.- not a shred of evidence) that the brain cannot be described in classical mechanistic terms, and indeed actually in computational terms according to widely accepted theories in cognitive science, with intelligence and consciousness arising as emergent properties of suitable systems that are physically unremarkable, completely deterministic, and entirely non-mystical. For if not, then what pertinent physical laws apply to such systems that we are unaware of?
Many early quantum physicists took a similiar view that we could merely posit QM is irrelevant for macroscopic objects, but this is worryingly close to making a dividing line between the two. If QM is fundamental is something that really needs to be explained.
We now know a lot more than we did then and we can see that a macroscopic object like a cat is heavily entangled with its environment and hence its state is not pure such as would be described by a wavefunction, but instead behaves like a statistical ensemble which is why we can never observe interference phenomena in the cat that would show it is both alive and dead. It is important to realize though that the cat+environment state is pure and corresponds to both the cat being alive and dead.
As I made clear above I don’t see any evidence that brains cannot be described classically less than any other macroscopic object can. However the fact that our brain can be described classically I would also say is important in itself - for example looking at the kind of information it processes.
So you believe that, somewhere in our brain, the laws of chemistry (forget physics for now) are being violated by consciousness? At what point in our evolutionary chain did the brain get the ability to violate these laws? I think there is a strong selective evolutionary pressure for a social being to believe in its own agency. Those who didn’t feel responsible for their actions couldn’t feel guilt and shame - all group cohesion emotions.
The only reason the term “measurement” is used is because we’ve found the limitations of what we can known through refining our measurement methods. You don’t need to measure the speed or position of a particle to collapse it’s wave function. The collapse is caused by the particle interacting with the detector. It’s really unfortunate that popularizers don’t point this out.
The biggest problem with determinism is…where does the information come from?
This is a flaw with absolute Newtonian determinism: all of the information in the whole world had to have existed, in some form, at the beginning of the cosmos.
Maybe not so big a problem with a more modern, quantum-compatible form of determinism, but it’s still not really answered. If every state depends on the previous state…how can there be growth of complexity?
I’m far more comfortable with a more statistical form of change, where information can increase thermodynamically, without depending (too much) on prior states.
No disagreement on either of those points, but nor do I think they present any difficulties. On the first one, one could make the same statement about the difference between classical Newtonian physics and relativity – that they are “worrying close to making a dividing line” between two different physical realities. But of course there is no difficulty because we can explain how and why each applies, which one is fundamental, and the limits of the approximate classical one.
On the second one, your description of the cat as a statistical ensemble is a good one and helps elucidate the apparent QM-macroscopic dichotomy. In the final analysis, it’s the only reason macroscopic objects have the deterministic behaviors they do instead of doing mysterious things like flowing through each other or unpredictably vanishing like the Cheshire Cat. But I think that Shroedinger’s thought experiment has sometimes been greatly overblown. It seems like nothing more than a tongue-in-cheek attempt to show that there’s some kind of basic contradiction between QM and the real world, when we know that clearly there is not.
This may sound like a nice solution to the measurement problem, but it’s a common mistake as this idea is still problematic in QM.
In quantum mechanics the time evolution of the wavefunction described by a wave equation like the Schrodinger equation is unitary, but collapse is non-unitary. I won’t elaborate on what “unitary” means as it is unlikely to illuminating and for the sake of understanding the measurement problem it is only sufficient to understand that the time evolution of the wavefunction via the wave equation and collapse are two irreconcilably different forms of time evolution.
Now let’s say we have a particle that is in a superposition of states and we are performing a measurement which will either give a 0 or a 1 as the result. We might try to solve the measurement problem by instead of describing just the particle itself, describing the system of the particle+detector. We might think that in reality such a system is so complex we couldn’t hope to describe it properly and that in such a complicated system somewhere something happens that mimics the behavior of wavefunction collapse in a single particle system. Whilst such a system is very complex, the principles at stake are fairly basic and when we describe the particle+detector system in such a way what happens is that after a time we get the system in a superposition of states of the detector reading “0” and the detector reading “1”. This comes down to the irreconcilability of unitary and non-unitary processes.
Now let’s say we come and read the detector, we will only read a “0” or a “1” and we certainly don’t observe the detector to be in a superposition of such states, which is why it is tempting to think consciousness plays a role in QM, particularly if you have collapse as a real physical process. However this is a matter of interpretation.
Why is that a problem? Or to put it a different way, why is it any more of a problem than saying that all the total matter+energy in the universe must have existed in some form at the Beginning? Where did that come from? It’s no different.
If you want to impute some concept of true randomness in the QM sense to the evolution of the universe, fine, but that solves nothing. The universe as presently constituted has a specific state, and that state contains an incredibly vast amount of information. The map of the cosmic microwave background radiation alone is patchy and uneven and resembles a vast cosmic bitmap. It wouldn’t be if it was completely uniform, or systematically repetitive, but it’s none of those things. Just the CMB alone is a universe full of data. Where did that data come from?
Another historian observation in answer to the now bolded question:
It isn’t that they both “need models based on emergence.” It’s that both sets of ideas were developed by people who were already working within an emergence-based paradigm.