Roger Penrose´s OR theory, Consiousness is a QM phenomenon?

[rolnor]

TL;DR Summary

Is consiousness a QM phenomenon?

I read a summary about the OR theory by Penrose, the problem is; why would QM has anything to do with consiousness? It seems now that when scientists cant explain something, the say its a QM phenomenon. QM theory has replaced philosophy and religion. Its a little more scientific so they don have to be ashamed that they have spiritual thoughts about life and the soul etc.

I can not list the scientists that have these tendencies, but I think you agree with me. It all sounds a little like "Midichlorians" that Star Wars movies say are responsible for "The Force". When I read this I see that he talks a lot about the areas he has competens in, but the chemistry/biochemistry part is quickly scrolled through.

I am a pharmaceutical chemist and I am not impressed. The part about amino-acid residues in microtubules is very short, and it needs to be much more closely reviewed. Why these microtubules would act as quantum computers is not explained, its assumed. What do you guys think about this, is it discussed among you or is it more like popular science?

https://www.tandfonline.com/doi/full/10.1080/17588928.2020.1839037

 

[Lord Jestocost]

The difficulty which some physicists and philosophers have with quantum theory is that it seems “to introduce the consciousness of the observer” in the theory, because the quantum theory gives only probabilities that one will find a certain measured value at a certain time. But the consciousness is not the subject of the quantum theory. It is an explicit precondition to apply the theory. The theory of measurement needs the recourse to consciousness in order to be able to say what it is talking about.

 

[rolnor]

And it would be very impossible to say anything about anything if you dont read the instrument you are using to observe, so its hard to disprove that this old idea about the necessity of a consious observer. A bacteria can not read the instrument, and if it could the bacteria would still need to tell us about its findings, and then we have the same problem again. Its fun for the fantasy, imagination, to believe this kind of thing, but something so extremely super-natural need very strong evidence to be believable, I have seen nothing of that sort, its just an idéa. If we apply a measurement and dont look at the instruments reading, its probably the same result as if we did look at the intruments reading. We can never know this.

 

[PeroK]

And it would be very impossible to say anything about anything if you dont read the instrument you are using to observe, so its hard to disprove that this old idea about the necessity of a consious observer.

In fact, it has been disproved. See, for example:

Https://en.m.wikipedia.org/wiki/Observer_effect_(physics)

A bacteria can not read the instrument, and if it could the bacteria would still need to tell us about its findings, and then we have the same problem again. Its fun for the fantasy, imagination, to believe this kind of thing, but something so extremely super-natural need very strong evidence to be believable, I have seen nothing of that sort, its just an idéa. If we apply a measurement and dont look at the instruments reading, its probably the same result as if we did look at the intruments reading. We can never know this.

It may be fantasy, but it's not physics.

 

[rolnor]

 

[Motore]

Yes:

However, the need for the "observer" to be conscious (versus merely existent, as in a unicellular microorganism) is not supported by scientific research, and has been pointed out as a misconception rooted in a poor understanding of the quantum wave function ψ and the quantum measurement process.

So do you have a question or...?

 

[PeterDonis]

The theory of measurement needs the recourse to consciousness in order to be able to say what it is talking about.

This used to be the case, but it isn't now with the development of decoherence theory. Decoherence gives a criterion for when a "measurement" (or more generally an irreversible change) takes place that does not require consciousness.

 

[PeterDonis]

If we apply a measurement and dont look at the instruments reading, its probably the same result as if we did look at the intruments reading. We can never know this.

Yes, we can. We have strong evidence that classical physics is a very good approximation for macroscopic objects, including macroscopic objects that existed for billions of years before humans came along, such as the sun and planets in our solar system, the galaxies in the universe, etc. This evidence would make no sense if it took a conscious observer to make a measurement, or more generally an irreversible change, happen. Fortunately, with decoherence theory, as I noted in my previous post just now, we have a criterion for when such events happen that doesn't involve consciousness, so we can be perfectly comfortable with saying that the macroscopic objects in the universe were decohering each other (and indeed themselves) for billions of years before any human observers came along.

 

[PeterDonis]

@rolnor your post #5 consists of just a quote. Where is it from?

 

[rolnor]

Yes:

So do you have a question or...?

No, not really, I just wanted to show the content of the link I was given. Roger Penrose talks a lot on youtube about the need for a consious observer, its strange that the new research does not seem to reach him.

 

[rolnor]

@rolnor your post #5 consists of just a quote. Where is it from?

Its a part from the wiki-link I was given, I thought this was easy to understand, I was unclear about this, sorry.

 

[PeroK]

No, not really, I just wanted to show the content of the link I was given. Roger Penrose talks a lot on youtube about the need for a consious observer, its strange that the new research does not seem to reach him.

Penrose has developed a few maverick theories in the past few years. His views on QM and consciousness may not be mainstream.

 

[Filip Larsen]

As I understand it the precise link between QM models of anesthetic molecules and the obvious effect anesthesia has on consciousness is still very much ongoing, see e.g. https://www.nature.com/articles/s41598-017-09992-7 and https://www.nature.com/articles/s41598-019-47651-1. While the precise link is still baffeling researchers I also understand that some link in the realm of QM is still strongly suspected.

 

[rolnor]

Thanx, I checked the first link and they use molecular dynamics to measure the binding of very small molecules like ether to microtubules, I question this, when a molecule is so small you can make it fit in almost any pocket in a proteine, its not specifik binding. But of course there can be something to this, but to suggest that these microtubules are quantum computers need a lot of support before I take it seriously, a whole lot of experimenting is needed.

 

[rolnor]

Yes, we can. We have strong evidence that classical physics is a very good approximation for macroscopic objects, including macroscopic objects that existed for billions of years before humans came along, such as the sun and planets in our solar system, the galaxies in the universe, etc. This evidence would make no sense if it took a conscious observer to make a measurement, or more generally an irreversible change, happen. Fortunately, with decoherence theory, as I noted in my previous post just now, we have a criterion for when such events happen that doesn't involve consciousness, so we can be perfectly comfortable with saying that the macroscopic objects in the universe were decohering each other (and indeed themselves) for billions of years before any human observers came along.

I agree, But I am talking about the quantum world, not the macroscopic world? But I think the same apply on the QM world, there is no need for a consiouss observer, the instruments will read the same thing anyway

 

[mitchell porter]

I know quite a lot about the "Orch OR" theory (at least, compared to most people). But let me start with some generalities.

There is a conception of quantum theory, popular among the spiritually inclined, according to which mind is separate from matter, and is responsible for "collapsing the wavefunction". This is NOT Penrose's conception. His philosophy of mind is actually materialistic (or at least monistic, I haven't seen his recent interviews). He posits that wavefunctions are the objective mathematical description of reality, and that there is a quantum-gravitational process which causes them to collapse out of superposition into particular eigenfunctions.

So in his theory, the observer is not playing a role in fundamental physical dynamics. Physical reality is just this intricate texture of entanglement in which localized wavefunctions alternate between smooth unitary evolution of superpositions, and discontinuous collapses onto eigenfunctions.

The connection to consciousness is as follows. Penrose interprets the famous results of Godel, Turing and others, on the limitations of computational systems, to imply that metamathematical reasoning, and perhaps other forms of metacognition, involve dynamics in the brain that are not Turing-computable; and he thinks that quantum gravity presents the best mathematical opportunity for noncomputable dynamics.

He thereby arrived at this hypothesis: The physical substrate of consciousness in the brain must be some kind of wavefunction, and the quantum gravitational determination of eigenfunctions must correspond to certain kinds of cognitive process.

As you can see, this is a 100% physical theory of consciousness, albeit an eccentric one.

After believing this privately for years, he published a book about it in 1989, which came to the attention of the anesthesiologist Stuart Hameroff, who had long held that microtubules in neurons perform some kind of information processing. So they combined their ideas, to propose that the tubulin subunits of microtubules are in entangled superpositions that are constantly being pruned by Penrose's "orchestrated objective reduction" of wavefunctions.

At this point, the hypothesis is still 100% physical, but now it is also biophysical - the proposal is that these particular molecules in the brain are the primary locus of the quantum dynamics relevant to consciousness.

Meanwhile, after a long period in which scientific psychology first focused only on behavior, and then began to allow for internal information processing as well (i.e. cognitive psychology), the notion of consciousness began to return to center stage in philosophy of mind. People began to ask, what are the "neural correlates of consciousness", i.e. exactly which parts of the brain are the conscious parts; and what exactly are the relationships, between the entities and properties of the natural sciences, and the entities and properties of subjective experience?

Penrose and Hameroff make a few proposals here too, but I have less of a grasp on this side of the theory, which would be tied to further speculations about interactions between quantum states of microtubules and e.g. the different brain waves that electrophysiologists have learned to correlate with particular states of mind.

I have been at pains to emphasize that, in a way, this is a fundamentally materialistic hypothesis. It is an observer-independent theory of physics, and a biophysical theory of consciousness in the brain. Nonetheless, it can be elaborated in other philosophical directions, e.g. do all wavefunctions in all substances have some kind of associated consciousness, should one regard consciousness as the "thing in itself", the fundamental reality, and wavefunctions as merely a mathematical formalism, and so forth.

 

[Lord Jestocost]

Maybe, the following might be of help to understand the role of the observer in quantum physics.

Ĉaslav Brukner and Anton Zeilinger in “Information and fundamental elements of the structure of quantum theory”, section “Measurement – The Update of Information”/1/:

“In this section it will be argued that identifying the quantum state with the catalog of our knowledge leads to the resolution of many of the seemingly paradoxical features of quantum mechanics connected to the so-called measurement problem.

In a quantum measurement, we find the system to be in one of the eigenstates of the observable defined by the measurement apparatus. A specific example is the case when we are considering a wave packet as being composed of a superposition of plane waves. Such a wave packet is more or less well-localized, but we can always perform a position measurement on a wave packet which is better localized than the dimension of the packet itself. This, sometimes called "reduction of the wave packet" or "collapse of the wave function", can only be seen as a "measurement paradox" if one views this change of the quantum state as a real physical process. In the extreme case it is often even related to an instant collapse of some physical wave in space.

There is no basis for any such assumption. In contrast, there is never a paradox if we realize that the wave function is just an encoded mathematical representation of our knowledge of the system. When the state of a quantum system has a non-zero value at some position in space at some particular time, it does not mean that the system is physically present at that point, but only that our knowledge (or lack of knowledge) of the system allows the particle a possibility of being present at that point at that instant.

What can be more natural than to change the representation of our knowledge if we gain new knowledge from a measurement performed on the system? When a measurement is performed, our knowledge of the system changes, and therefore its representation, the quantum state, also changes. In agreement with the new knowledge, it instantaneously changes all its components, even those which describe our knowledge concerning regions of space quite distant from the site of the measurement. Then no need whatsoever arises to allude to notions like superluminal or instantaneous transmission of information.
..........

With the only exception of the system being in an eigenstate of the measured observable, a quantum measurement changes the system into one of the possible new states (these being defined by the measurement apparatus) in a fundamentally unpredictable20 way. Thus it cannot be claimed to reveal a property existing before the measurement is performed. The reason for this is again the fact that a quantum system cannot, not even in principle, carry enough information to specify observation-independent properties corresponding to all possible measurements. After the measurement the state therefore must appear to be changed in accord with the new information, if any, acquired about the system together with unavoidable and irrecoverable loss of complementary information. Unlike a classical measurement, a quantum measurement thus does not just add (if any) some knowledge, it changes our knowledge in agreement with a fundamental finiteness of the total information content of the system. We will now bring the role of the observer in a quantum measurement to the center of our discussion. In classical physics we can assume that an observation reveals some property already existing in the outside world. For example, if we look at the moon, we just find out where it is and it is certainly safe to assume that the property of the moon to be there is independent of whether anyone looks or not. The situation is drastically different in quantum mechanics and it is just the very attitude of the Copenhagen interpretation giving a fundamental role to observation which is a major intellectual step forward over this naive classical realism.” [Bold by LJ]

/1/ in “Time, Quantum and Information” (A collection of research papers written in commemo-ration of the 90th birthday of C. F. von Weizsäcker), eds. Lutz Castell and Otfried Ischebeck, 2003

 

[rolnor]

Maybe, the following might be of help to understand the role of the observer in quantum physics.

Ĉaslav Brukner and Anton Zeilinger in “Information and fundamental elements of the structure of quantum theory”, section “Measurement – The Update of Information”/1/:

“In this section it will be argued that identifying the quantum state with the catalog of our knowledge leads to the resolution of many of the seemingly paradoxical features of quantum mechanics connected to the so-called measurement problem.

In a quantum measurement, we find the system to be in one of the eigenstates of the observable defined by the measurement apparatus. A specific example is the case when we are considering a wave packet as being composed of a superposition of plane waves. Such a wave packet is more or less well-localized, but we can always perform a position measurement on a wave packet which is better localized than the dimension of the packet itself. This, sometimes called "reduction of the wave packet" or "collapse of the wave function", can only be seen as a "measurement paradox" if one views this change of the quantum state as a real physical process. In the extreme case it is often even related to an instant collapse of some physical wave in space.

There is no basis for any such assumption. In contrast, there is never a paradox if we realize that the wave function is just an encoded mathematical representation of our knowledge of the system. When the state of a quantum system has a non-zero value at some position in space at some particular time, it does not mean that the system is physically present at that point, but only that our knowledge (or lack of knowledge) of the system allows the particle a possibility of being present at that point at that instant.

What can be more natural than to change the representation of our knowledge if we gain new knowledge from a measurement performed on the system? When a measurement is performed, our knowledge of the system changes, and therefore its representation, the quantum state, also changes. In agreement with the new knowledge, it instantaneously changes all its components, even those which describe our knowledge concerning regions of space quite distant from the site of the measurement. Then no need whatsoever arises to allude to notions like superluminal or instantaneous transmission of information.
..........

With the only exception of the system being in an eigenstate of the measured observable, a quantum measurement changes the system into one of the possible new states (these being defined by the measurement apparatus) in a fundamentally unpredictable20 way. Thus it cannot be claimed to reveal a property existing before the measurement is performed. The reason for this is again the fact that a quantum system cannot, not even in principle, carry enough information to specify observation-independent properties corresponding to all possible measurements. After the measurement the state therefore must appear to be changed in accord with the new information, if any, acquired about the system together with unavoidable and irrecoverable loss of complementary information. Unlike a classical measurement, a quantum measurement thus does not just add (if any) some knowledge, it changes our knowledge in agreement with a fundamental finiteness of the total information content of the system. We will now bring the role of the observer in a quantum measurement to the center of our discussion. In classical physics we can assume that an observation reveals some property already existing in the outside world. For example, if we look at the moon, we just find out where it is and it is certainly safe to assume that the property of the moon to be there is independent of whether anyone looks or not. The situation is drastically different in quantum mechanics and it is just the very attitude of the Copenhagen interpretation giving a fundamental role to observation which is a major intellectual step forward over this naive classical realism.” [Bold by LJ]

/1/ in “Time, Quantum and Information” (A collection of research papers written in commemo-ration of the 90th birthday of C. F. von Weizsäcker), eds. Lutz Castell and Otfried Ischebeck, 2003

Thanx! If we consider a measuring device that prints a result from a quantum measurement on a piece of paper, is there a change on the surface of that paper when I look at it compared to before I look at the data on the paper? If 5 people look at the exact same time on the paper will they all be a uniform consiouss observer or will they se different data on the same paper? I have discussed this here some time ago and most of you agree with me, the data does not suddenly appear or change because I look at it, its there directly when the device prints it. No hokus pokus.

 

[rolnor]

Maybe, the following might be of help to understand the role of the observer in quantum physics.

Ĉaslav Brukner and Anton Zeilinger in “Information and fundamental elements of the structure of quantum theory”, section “Measurement – The Update of Information”/1/:

“In this section it will be argued that identifying the quantum state with the catalog of our knowledge leads to the resolution of many of the seemingly paradoxical features of quantum mechanics connected to the so-called measurement problem.

In a quantum measurement, we find the system to be in one of the eigenstates of the observable defined by the measurement apparatus. A specific example is the case when we are considering a wave packet as being composed of a superposition of plane waves. Such a wave packet is more or less well-localized, but we can always perform a position measurement on a wave packet which is better localized than the dimension of the packet itself. This, sometimes called "reduction of the wave packet" or "collapse of the wave function", can only be seen as a "measurement paradox" if one views this change of the quantum state as a real physical process. In the extreme case it is often even related to an instant collapse of some physical wave in space.

There is no basis for any such assumption. In contrast, there is never a paradox if we realize that the wave function is just an encoded mathematical representation of our knowledge of the system. When the state of a quantum system has a non-zero value at some position in space at some particular time, it does not mean that the system is physically present at that point, but only that our knowledge (or lack of knowledge) of the system allows the particle a possibility of being present at that point at that instant.

What can be more natural than to change the representation of our knowledge if we gain new knowledge from a measurement performed on the system? When a measurement is performed, our knowledge of the system changes, and therefore its representation, the quantum state, also changes. In agreement with the new knowledge, it instantaneously changes all its components, even those which describe our knowledge concerning regions of space quite distant from the site of the measurement. Then no need whatsoever arises to allude to notions like superluminal or instantaneous transmission of information.
..........

With the only exception of the system being in an eigenstate of the measured observable, a quantum measurement changes the system into one of the possible new states (these being defined by the measurement apparatus) in a fundamentally unpredictable20 way. Thus it cannot be claimed to reveal a property existing before the measurement is performed. The reason for this is again the fact that a quantum system cannot, not even in principle, carry enough information to specify observation-independent properties corresponding to all possible measurements. After the measurement the state therefore must appear to be changed in accord with the new information, if any, acquired about the system together with unavoidable and irrecoverable loss of complementary information. Unlike a classical measurement, a quantum measurement thus does not just add (if any) some knowledge, it changes our knowledge in agreement with a fundamental finiteness of the total information content of the system. We will now bring the role of the observer in a quantum measurement to the center of our discussion. In classical physics we can assume that an observation reveals some property already existing in the outside world. For example, if we look at the moon, we just find out where it is and it is certainly safe to assume that the property of the moon to be there is independent of whether anyone looks or not. The situation is drastically different in quantum mechanics and it is just the very attitude of the Copenhagen interpretation giving a fundamental role to observation which is a major intellectual step forward over this naive classical realism.” [Bold by LJ]

/1/ in “Time, Quantum and Information” (A collection of research papers written in commemo-ration of the 90th birthday of C. F. von Weizsäcker), eds. Lutz Castell and Otfried Ischebeck, 2003

This paper is 20 years old...

 

[rolnor]

I know quite a lot about the "Orch OR" theory (at least, compared to most people). But let me start with some generalities.

There is a conception of quantum theory, popular among the spiritually inclined, according to which mind is separate from matter, and is responsible for "collapsing the wavefunction". This is NOT Penrose's conception. His philosophy of mind is actually materialistic (or at least monistic, I haven't seen his recent interviews). He posits that wavefunctions are the objective mathematical description of reality, and that there is a quantum-gravitational process which causes them to collapse out of superposition into particular eigenfunctions.

So in his theory, the observer is not playing a role in fundamental physical dynamics. Physical reality is just this intricate texture of entanglement in which localized wavefunctions alternate between smooth unitary evolution of superpositions, and discontinuous collapses onto eigenfunctions.

The connection to consciousness is as follows. Penrose interprets the famous results of Godel, Turing and others, on the limitations of computational systems, to imply that metamathematical reasoning, and perhaps other forms of metacognition, involve dynamics in the brain that are not Turing-computable; and he thinks that quantum gravity presents the best mathematical opportunity for noncomputable dynamics.

He thereby arrived at this hypothesis: The physical substrate of consciousness in the brain must be some kind of wavefunction, and the quantum gravitational determination of eigenfunctions must correspond to certain kinds of cognitive process.

As you can see, this is a 100% physical theory of consciousness, albeit an eccentric one.

After believing this privately for years, he published a book about it in 1989, which came to the attention of the anesthesiologist Stuart Hameroff, who had long held that microtubules in neurons perform some kind of information processing. So they combined their ideas, to propose that the tubulin subunits of microtubules are in entangled superpositions that are constantly being pruned by Penrose's "orchestrated objective reduction" of wavefunctions.

At this point, the hypothesis is still 100% physical, but now it is also biophysical - the proposal is that these particular molecules in the brain are the primary locus of the quantum dynamics relevant to consciousness.

Meanwhile, after a long period in which scientific psychology first focused only on behavior, and then began to allow for internal information processing as well (i.e. cognitive psychology), the notion of consciousness began to return to center stage in philosophy of mind. People began to ask, what are the "neural correlates of consciousness", i.e. exactly which parts of the brain are the conscious parts; and what exactly are the relationships, between the entities and properties of the natural sciences, and the entities and properties of subjective experience?

Penrose and Hameroff make a few proposals here too, but I have less of a grasp on this side of the theory, which would be tied to further speculations about interactions between quantum states of microtubules and e.g. the different brain waves that electrophysiologists have learned to correlate with particular states of mind.

I have been at pains to emphasize that, in a way, this is a fundamentally materialistic hypothesis. It is an observer-independent theory of physics, and a biophysical theory of consciousness in the brain. Nonetheless, it can be elaborated in other philosophical directions, e.g. do all wavefunctions in all substances have some kind of associated consciousness, should one regard consciousness as the "thing in itself", the fundamental reality, and wavefunctions as merely a mathematical formalism, and so forth.

Thanx! I dont really started the discussion of the consciouss observer, I just find it a flimsy theory, its one thing that microtubules are involved in consciousnes and a very different that this effect is QM-based.

 

[Lord Jestocost]

The realm of physics is the experiential reality – physics doesn’t delve into ideas about the ultimate reality. All one needs to carry out physics are observations that can be used to construct and test models – simply following the scientific method. What matters is not that the models match certain world-views or Weltanschauungen, but that the models make accurate predictions about what will happen next, i.e., fit into the experiential world.

World-views or Weltanschauungen comprise unfortunately a number of basic beliefs which cannot be proven at all. Physics can at least help to point out that some scientist – maybe based on some personal world-views or Weltanschauungen – might delve into the realm of ironic science. Ironic science – a term coined by John Horgan – resembles literature or philosophy or theology in that it offers points of view, opinions, which are, at best, "interesting" and which might provoke further comment. But ironic science, unfortunately, does not correspond to the scientific method.

 

[PeterDonis]

I think the same apply on the QM world, there is no need for a consiouss observer, the instruments will read the same thing anyway

That is correct.

 

[PeterDonis]

the data does not suddenly appear or change because I look at it, its there directly when the device prints it.

More precisely, the device printing the data involves decoherence, which makes an irreversible record that will be the same no matter who looks at it or how many people do so.

 

[Lord Jestocost]

Thanx! If we consider a measuring device that prints a result from a quantum measurement on a piece of paper, is there a change on the surface of that paper when I look at it compared to before I look at the data on the paper? If 5 people look at the exact same time on the paper will they all be a uniform consiouss observer or will they se different data on the same paper? I have discussed this here some time ago and most of you agree with me, the data does not suddenly appear or change because I look at it, its there directly when the device prints it. No hokus pokus.

When a measuring device prints a “result from a measurement” on a piece of paper, nothing changes - whether you would look at the paper or not. But when a "result" isn’t predictable, what do you learn when you don’t look at the paper?

 

[mitchell porter]

Thanx! I dont really started the discussion of the consciouss observer, I just find it a flimsy theory, its one thing that microtubules are involved in consciousnes and a very different that this effect is QM-based.

I consider the theory a kind of masterwork of bold speculation... People have very diverse reasons for being interested in "quantum mind theories"; in my case, it's because I think entanglement might have something to do with the subjectively unified nature of conscious experience. And if one is looking for cognitively relevant entanglement somewhere in the brain, I don't think you can beat the Penrose-Hameroff theory as a detailed speculation about how everything could be connected. Microtubules are relevant to neuronal function in various ways, along the axon they are exposed to the action potential, and there are various proposed mechanisms for how nontrivial entangled states could form and persist within the microtubules.

There is a quasi-mainstream precedent for this kind of quantum biology, and that is photosynthesis. There are a number of models of photosynthesis which suppose that some relatively exotic quantum processes - e.g. "quantum walks", "exciton condensates" - are part of the process whereby energy absorbed from solar photons, gets transferred within the photosynthetic complex. Similar things have been proposed for the microtubule. The debate over quantum photosynthesis has gone on for some years, so proving or disproving that something similar happens within the microtubule may also be a challenge, unless some lucky decisive breakthrough occurs.

 

[AndreasC]

This used to be the case, but it isn't now with the development of decoherence theory. Decoherence gives a criterion for when a "measurement" (or more generally an irreversible change) takes place that does not require consciousness.

Decoherence has nothing to do with consciousness and says nothing about the whole deal... Decoherence is a unitary process which results in the most likely outcomes of measurements coalescing very, very closely around the classically expected value. But collapse is a non unitary process, and it remains so. Whether that is due to a real, physical process generated by consciousness or one of the billion other ideas people have about interpreting measurement in QM, it is not related to decoherence. At any case the consciousness interpretation of QM has nothing to do with Penrose's theory, because that's not how he interprets QM. His theory is that quantum effects produce consciousness, not the other way around.

 

[PeterDonis]

Decoherence has nothing to do with consciousness

True. That's why using decoherence to explain what a "measurement" is removes the need to postulate that consciousness is required for a measurement.

Decoherence is a unitary process which results in the most likely outcomes of measurements coalescing very, very closely around the classically expected value. But collapse is a non unitary process, and it remains so.

All this is true; this is why decoherence by itself does not solve the measurement problem. But it does help to pin down exactly what the problem is--and part of that is removing the need for consciousness to be involved.

the consciousness interpretation of QM has nothing to do with Penrose's theory, because that's not how he interprets QM. His theory is that quantum effects produce consciousness, not the other way around

Yes, this is correct.