Is Consciousness involved in wave function collapse?

[Varon]

I'm not sure one can answer that, one can only speak of what they mean by the words. If we did program a robot to be able to conceive of and experience a single outcome, then for the purposes of everything I've said above, that robot would be conscious. Whether or not it is possible to actually program a robot to be conscious is a question that is debated ad nauseum in the artificial intelligence community, and no one strikes me as being terribly close to a definitive answer, nor does it matter at all to anything I've said because the "robots" I talked about were ones that we could actually imagine programming with existing technology.

You said the lifeless robot can only perceive mixed state in the double slit experiment. Can you please be clear what is the equivalent of mixed state in the double slit. I think it has to do with the fact that we don't know which slit the photon would enter. But won't this produce detection events? I guess not. So what does it mean the robot can only perceive mixed state when nothing in the detector got any photon hits?

 

[Ken G]

You said the lifeless robot can only perceive mixed state in the double slit experiment. Can you please be clear what is the equivalent of mixed state in the double slit. I think it has to do with the fact that we don't know which slit the photon would enter. But won't this produce detection events? I guess not. So what does it mean the robot can only perceive mixed state when nothing in the detector got any photon hits?

The robot doesn't perceive at all, that's the point. What we are talking about is a program and a machine running that program, and its job is to test quantum mechanical predictions. Quantum mechanical predictions are mixed states, that's it, that's all you get from quantum mechanics. So the robot must be set up to test the mixed-state predictions, and this is always done in the classical limit. That's the ultimate irony of doing quantum science, all the predictions of the quantum theory are tested in the classical limit of many events, but they can be done one at a time and tested with outcomes that are quantum in nature. However, the outcomes that come from quantum mechanics are mixed states, so a robot set up to test quantum mechanics in a universe with no perception and no concept of a unique outcome would have to test quantum mixed states. The tests come out the same as classical ensembles, so rarely are the quanta sent through one at a time. Instead, the robot would be programmed to recognize the superposition principle, and would send a vast ensemble through their instrument, and test the mixed-state predictions in the classical limit, and find that quantum mechanics works with flying colors. All without ever having a concept of a single unique outcome for a single quantum.

Now, a robot might also be set up to test if the classical limit also holds if the quanta are sent through one at a time. Again quantum mechanical predictions look like probabilities of certain quantized events occurring when you project onto the quantum, but when you think in terms of the whole system making the measurement, it is still a pure state. You can't test the pure state of the whole system, it's too complicated, so you have to test the mixed state of the quantum subsystem, and that's where the probability distribution comes in. But there's still no concept of a single outcome here, if we believe the prediction of the theory, there is a probability distribution of outcomes. That's a very bizarre ontological entity, our minds can only handle it by replacing it with an ensemble of single outcomes that divide up according to the probability fractions (the old "one thing happened by I don't know which" construct). But the predicted outcome of the theory, with no intelligences there, is not actually that, instead it is a superposition of the instrument registering single outcomes, but no single global outcome in the reality, those single outcomes are not actualized individually, they are part of a superposition.

At first when you just have a single run of the apparatus, the terms in the superposition look very different, but when you run it over and over and aggregate the results, they all start to look the same. A superposition of things that are all the same is just one thing, and so in the classical limit, the "single reality" is recovered, and that single reality is a robot attesting to the success of the prediction. Never is there a need for any artificial imposition of a single global reality, until one gets to the classical limit where the theory can really be tested accurately. Unless there are consciousnesses at those intermediate stages.

 

[Varon]

That's simply because the phrase "consciousness causes collapse" can mean about 100 different things, many of which have been carefully delineated on this thread. Indeed that was the initial disconnect between myself and G01, if you care to review that discussion. Nothing that I am saying is what that Wiki means by consciousness causing collapse, but what I do mean is completely consistent with both the Wiki I quoted for you, and what G01 just said above.

All covered in the thread, you're not telling me anything I haven't already discussed in detail.
Now I'm just repeating, but I will go through it yet again because this is the crux of the whole business right here.

A measurement made by a lifeless computer creates what is called a mixed state for the quantum system. That is because the quantum system is, at this point, a subspace of a larger apparatus. The larger apparatus, as G01 just explained, is still in a pure state according to the unitary evolution of quantum mechanics theory. The mixed state is the projection from the whole system onto the subspace of the quantum system. Nothing there creates any difficulties, nor requires any interpretations of quantum mechanics-- the full system is in a pure state so is still unitary, the projection onto the subspace is not supposed to be unitary, it's a projection from a joint wave function to a single-particle state, and that does not lead to a single-particle wavefunction at all (let alone an eigenstate of the measurable), it leads to a mixed state.

After your last message, it was clearer that the "lifeless robot" can only see the mixed state after numerous runs of the single photon emission forming an ensemble. Realizing this. I went back and forth in this thread over an hour reading old messages to get the whole context. So let me go back to this. When exactly is a double slit in pure state? I understand well that when a quantum system is completely isolated, it is in pure state, and anytime a subspace or region is focus due to decoherence, it is in mixed state. How do you apply this to the double slit setup? This is because you are talking of ensemble of many million single photon emission. Where is the pure state here? When only one photon is sent a time? But you said mixed state is equal to numerous single photon experiments, so is pure state related only to one photon at a time or can you consider pure state in some scenerio of the numerous runs?

Now back to the "lifeless robot", you said it can't perceive single or definite outcome, but note that each hit in the detector is composed of single outcome. Even though the lifeless robot can only detect the ensemble, but an ensemble is made up of each one photon at a time emission. So you can't say that a "lifeless robot" or as you put it below "measuring devices should not "cause a non unitary process to occur." Remember each photon at a time emission and detection is already a non unitary process. The lifeless robot or measuring device can detect ensemble of them.. in other words, it can detect ensemble of millions of single non-unitary process... although only human consciousness can perceive the intermediate and know it is because of the single non-unitary process. Pls. be precise in your language, then BruceW may completely understand you too because I feel he gives up understanding it because of the critical issues I mentioned above. Thanks.

At this point, where all we have is the "lifeless computer", we do not have a single measurement outcome, we have a mixture of outcomes. This is also called an "ensemble" in mainstream quantum mechanics, the only difference is that to resolve certain difficulties in picturing what this is, we imagine lots and lots of copies of the system, instead of just one system. This makes it easier to imagine what a mixed state is, but there's really only one system there, it doesn't have to be an ensemble.

Enter a consciousness/intelligence/perceiver who thinks classically. Only now do we encounter the concept of an "actual outcome", and this creates a huge problem for quantum mechanics theory. Where does that actual outcome come from? No one knows, but here is where each of the interpretations step into provide an untestable answer. I've already outlined what those answers are above, and GO1 mentioned some of the possibilities as well. The key thing to recognize at this point is that none of that difficult business even comes up, and there's no need for an interpretation, until we factor in the presence of a consciousness and its resulting "actual outcome" perception. The physics is perfectly happy just leaving the quantum in a mixed state, if all we have is a lifeless computer. It's all related to how a conscious entity does science, and this involves the perception of an actual outcome, even though the theory provides no such concept and forces us to inject a layer of randomness to get agreement with our experiences. Because we are conscious.

So this role of consciousness is much more subtle, yet much more fundamental to everything we do in science, than what that Wiki is talking about. I know that without even reading the context of the rest of that Wiki.

No. Measuring apparatuses are physical constructs, and so, should obey the laws of physics. Unitary evolution is one of the laws they should obey. Ergo, measuring devices should not "cause a non unitary process to occur." The whole measurement problem, as nicely described by G01 above, is the origin of the apparent non-unitarity, since it cannot come from the measuring device. Here are the answers of the main interpretations:

CI: it comes from how we do science, since the unitary evolution piece was just a tool we use at one stage of the calculation. (This is related to our consciousness/intelligence/classical processing in the "how we do science" part.)

Many-worlds: the non-unitary element is illusory, the full unitary result is there but we only see a tiny part of the real story. (This is related to our consciousness/intelligence/classical processing in the "what part of the whole we see".)

Bohm: the unitary evolution is the illusion-- it's just a cloak placed on top of the pilot-wave evolution, which is deterministic and non-unitary. The unitarity is "filled in" by physically irrelevant aspects of the wave function, and it is stripped away by the measurement. (This is the only interpretation that does not involve consciousness in a direct way, because it treats unique experimental outcomes as purely deterministic, but it cannot be tested.)

 

[BruceW]

If we were conscious but non-classical, would we need the non-unitary explanations? I would say yes we would, because if one can imagine a conscious electron, it still has to register a single outcome to an experiment. That is the fundamental nature of consciousness, its association with experience. I probably could have ducked a lot of this difficulty by just replacing "consciousness" with "experiential agent", because I'm using the terms synonymously.

No, an electron in quantum state superposition will not undergo a non-unitary process. Only classical objects can undergo a non-unitary process.
(This is why decoherence is important. Non-unitary process can only happen after decoherence, but a single electron cannot 'decohere'. Only a large system of many particles can decohere).

But anyway, back to the main subject,
The postulates of QM say that there is a superposition of quantum states, then measurement causes an outcome of one of those states to happen with a particular probability. Then after measurement, the wavefunction will be equal to the state corresponding to the outcome.
(This is a measurement of the first kind, aka strong von Neumann projection, aka full collapse, ie the non-unitary process has happened).
From this method, you don't have to set up the system so that a person is making the measurement. Any classical object can 'make a measurement'.
It is true that if we want to predict the outcome for a human, the thing making the measurement can always be chosen to be human (since this is always the last step in any experiment). But generally, we can choose the non-unitary process to happen at the lab equipment, instead of at the person.

I am going with the general case that any classical object can cause the non-unitary process.
Ken G's opinion (as far as I understand) is that since we only need to find predictions for what happens from a human's perspective, we can choose our definition of 'measurement' such that only a human can make a measurement.

Ultimately, you could go one step further and say that the only perspective I am interested in is my perspective. I can then define 'measurement' such that only I can make a measurement. Therefore, when my scientist friend does an experiment, the outcome of the experiment (and my friend) are all just a quantum superposition, until he comes to see me, and then by seeing him, I cause a measurement to happen. This interpretation would work equally well.

So when Ken G was saying 'conscious', in my words, I would say 'the perspectives which we are interested in finding predictions for'. Or more precisely, 'classical objects which we define to be able to make measurements'.

I had to think for a long time to get this far. You're right, Varon, I had great difficulty understanding what conscious meant in this context.

 

[Varon]

No, an electron in quantum state superposition will not undergo a non-unitary process. Only classical objects can undergo a non-unitary process.
(This is why decoherence is important. Non-unitary process can only happen after decoherence, but a single electron cannot 'decohere'. Only a large system of many particles can decohere).

But anyway, back to the main subject,
The postulates of QM say that there is a superposition of quantum states, then measurement causes an outcome of one of those states to happen with a particular probability. Then after measurement, the wavefunction will be equal to the state corresponding to the outcome.
(This is a measurement of the first kind, aka strong von Neumann projection, aka full collapse, ie the non-unitary process has happened).
From this method, you don't have to set up the system so that a person is making the measurement. Any classical object can 'make a measurement'.
It is true that if we want to predict the outcome for a human, the thing making the measurement can always be chosen to be human (since this is always the last step in any experiment). But generally, we can choose the non-unitary process to happen at the lab equipment, instead of at the person.

I am going with the general case that any classical object can cause the non-unitary process.
Ken G's opinion (as far as I understand) is that since we only need to find predictions for what happens from a human's perspective, we can choose our definition of 'measurement' such that only a human can make a measurement.

Ultimately, you could go one step further and say that the only perspective I am interested in is my perspective. I can then define 'measurement' such that only I can make a measurement. Therefore, when my scientist friend does an experiment, the outcome of the experiment (and my friend) are all just a quantum superposition, until he comes to see me, and then by seeing him, I cause a measurement to happen. This interpretation would work equally well.

So when Ken G was saying 'conscious', in my words, I would say 'the perspectives which we are interested in finding predictions for'. Or more precisely, 'classical objects which we define to be able to make measurements'.

I had to think for a long time to get this far. You're right, Varon, I had great difficulty understanding what conscious meant in this context.

I think what Ken was saying was simply that both machines and human consciousness are similar in that wave function collapse behavior was similar in their presence. What differs is how we perceive it. Since the only way to create an ensemble to match the prediction of the equation is to run many one at a time photon emission. The machine can only see the interference pattern after millions of single photon emissions as ensemble. Intermediate. It can't perceive the pattern as cause by collapse because machines can only see ensemble because the equation output can only be demonstrated with ensemble. It is only human which can know that a single outcome or hit in the detector is because of non-unitary process in a single photon at a time run. I think this is what Ken was saying. If I'm wrong. Let me know.

 

[Ken G]

No, an electron in quantum state superposition will not undergo a non-unitary process. Only classical objects can undergo a non-unitary process.

That's only partially correct, and highly misleading at best. When you couple an electron to a classical system, the electron may be part of a classical system, but it's still an electron, so projecting onto the electron subspace is still projecting onto a quantum system. And when you project a decohered pure-state closed system wavefunction onto an electron subspace, you get a mixed state, as I have been stressing. The electron subspace was originally described as a pure wavefunction (let's say), but after the decohering interaction it is now in a mixed state. That is very non-unitary! But it's not a problem for quantum mechanics because it is not a closed system, it is just a subsystem. Projections are not supposed to be unitary, and an electron does not become a "classical object" just because it is coupled to a classical system, but we do lose the ability to give the electron a wavefunction until we take the next step of perceiving a unique outcome for the electron, and then manually asserting a new pure state for it (which is also a non-unitary step). These are all things happening to the quantum subspace, the electron.

From this method, you don't have to set up the system so that a person is making the measurement. Any classical object can 'make a measurement'.

Here you mean a measurement in terms of a full collapse to a single new state, and to that I can only ask you: what evidence do you have that any classical object can do that, without a perception to register that final state? Certainly you can draw no evidence from the formal structure of quantum mechanics, which has no such provision. So you must draw from experience of scientists to assert it-- and that is not a classical system free of perception. If we simply watch closely where the various issues crop up, it does indeed crop up when there is an "experiential agent" to register the single outcome, and as I said above, a mindless machine would never have any need or reason to register a single outcome rather than a probability distribution of single outcomes-- just as quantum mechanics predicts they would.

But generally, we can choose the non-unitary process to happen at the lab equipment, instead of at the person.

Well this is certainly the fundamental disconnect. You are simply asserting we can do that, but you cannot really give any good reason why we should think that is a reasonable thing to do. We cannot test it, we agree on that, so it becomes a matter of convention more than anything else. I am merely pointing out that there is simply no justification for your assertion, whereas the justification for mine is that it is what quantum mechanics formal theory predicts. I grant you that the predictions of a formal theory are not the same thing as the reality, but at least it is some justification. There's no perfect solution-- we either stick in the non-unitary step in an ad hoc way within the theory, or we say we are leaving the theory when a perceptive conscious agent enters. But I suppose it is not experimentally answerable, so must be classified as an issue of personal taste.

Ken G's opinion (as far as I understand) is that since we only need to find predictions for what happens from a human's perspective, we can choose our definition of 'measurement' such that only a human can make a measurement.

Yes, I think that's a fair characterization, though I'd put it in the way I did above.

Ultimately, you could go one step further and say that the only perspective I am interested in is my perspective.

Well, you certainly wouldn't want to do that, it would be terrible scientific epistemology. We rely on several key concepts in science that this program would not support: in particular, objectivity. The whole theory of relativity is predicated on a symmetry principle among observers, for example. So this would be a bad epistemology. The one I'm talking about suffers none of those problems, because it not only allows for other conscious agents, it even allows for hypothetical conscious agents, to help us form a useful scientific language about what is happening in classical systems. All I'm doing is pointing to where the shell went in the shell game of designing such a language.

So when Ken G was saying 'conscious', in my words, I would say 'the perspectives which we are interested in finding predictions for'. Or more precisely, 'classical objects which we define to be able to make measurements'.

Yes, this is a way to frame it where we are in agreement. It is useful to find the common ground, and recognize then that our only disagreement lies in what is the most logical way to identify what the ability to make a measurement actually entails. It seems like a smaller disagreement that way. I think my earlier discussion with GO1 followed a similar course, but that was a lot of thread ago!

 

[apeiron]

In classical physics, that seems like a perfectly normal thing for any material object to do, and even though in statistical mechanics the fundamental object is a probability distribution, we still imagine we have an ensemble of single outcomes. But in quantum systems, the formal mathematics of quantum mechanics makes no mention of single outcomes to experiments, and single outcomes are never predicted and never tested. So this is an important "disconnect" for conscious entities. I'm arguing it is more important than the quantum/classical gap that Bohr and co. tended to focus on, because the two are so easily mistaken for each other.

Yes, if I follow you right, this is a key point. Classical ontology believes that indeterminacy is merely epistemic. Reality must always be in some crisply definite state. And so the probability issue is just about not knowing in which of an ensemble of possible states reality happens to be at some moment.

But the "weirdness" of QM indeterminacy is that there is no ensemble that pre-exists the constraint towards some outcome. The indeterminacy is in fact ontic, not epistemic. But there is then a lack of "interpretation" for this view of reality. It is an unfamiliar metaphysical view.

What do you think of attempts to advance the metaphysics here by equating such indeterminacy to vagueness as in these two papers?

http://www.cfh.ufsc.br/~dkrause/Artigos/Vagueness.pdf

http://www.unicamp.br/~chibeni/public/vaguemicrophys-final.pdf

 

[Ken G]

Yes, if I follow you right, this is a key point. Classical ontology believes that indeterminacy is merely epistemic. Reality must always be in some crisply definite state. And so the probability issue is just about not knowing in which of an ensemble of possible states reality happens to be at some moment.

But the "weirdness" of QM indeterminacy is that there is no ensemble that pre-exists the constraint towards some outcome. The indeterminacy is in fact ontic, not epistemic. But there is then a lack of "interpretation" for this view of reality. It is an unfamiliar metaphysical view.

Yes, that's quite well put. The irony is, we used to think that reality had to be crisp, so indeterminacy is a kind of symptom of incomplete information, a mistake or failing of some kind. Now, we have the clear suggestion that it is crispness that is the mistake, that is the illusion of over-interpreted information that is in some sense a processing outcome more so than a real physical state independent of our perception. But the CI then steps into point out that we cannot epistemologically label the inevitable outcome of our processing a "mistake", because the entire endeavor from start to finish of understanding reality is an example of said processing. So it is better to call it a "disconnect" than a "mistake" or "illusion", the way many-worlds would.

What do you think of attempts to advance the metaphysics here by equating such indeterminacy to vagueness as in these two papers?

http://www.cfh.ufsc.br/~dkrause/Artigos/Vagueness.pdf

http://www.unicamp.br/~chibeni/public/vaguemicrophys-final.pdf

I think they will take significant effort to do justice to! But I like where they are going, I'm sympathetic to their argument and their program. What I would look for in a more critical examination is how they attribute the source of the connection between vagueness and indeterminacy. It would be tempting to say that the objects "really are vague" and reject the idea that "their vagueness stems from our incomplete knowledge of them or our indecision of how to define them", but my inclination would be to see that choice as a kind of false dichotomy. Knowledge is complete when it is all we can get, there is no "Platonic knowledge" of these things that we fall short of, because we have no definition of "knowledge" that is completely independent of how we think. So if we have complete knowledge and the thing is still vague, we can reject the second option. But does that require the first? I would be more comfortable with language like "the best knowledge we can get is both complete and vague, but this does not make any claims on some independent truth about the vagueness of the object."

In other words, we must be alert for a kind of category error here: inherent vagueness is not an attribute of an object, nor an attribute of the incomplete information we have about the object, it is an attribute of our inherent relationship to the object. The relationship is not provisional on the quality of our information, it is a fundamentally vague relationship. I believe this was Bohr's opinion, and I agree. The logic of the relationship is fuzzy, so we define fuzzy objects for it to act on, not the other way around.

 

[rodsika]

Dear Ken, I read you mentioned there was nothing wrong if the wave function were actually physical. If this were the case, then wave function was no longer just knowledge of the observer, then the argument that definite outcome can only be attributed to human consciousness becomes unnecessary. Or is there a counterpart problem for this case where the wave function were physical?

 

[Ken G]

Dear Ken, I read you mentioned there was nothing wrong if the wave function were actually physical. If this were the case, then wave function was no longer just knowledge of the observer, then the argument that definite outcome can only be attributed to human consciousness becomes unnecessary. Or is there a counterpart problem for this case where the wave function were physical?

That's pretty much the "many worlds" view, that our conscious experience is really only a tiny fraction of the full reality, and the full reality is that of the wave function of everything. The observer, us, is then just a kind of coherent ripple of processing in a vast river of incoherent happenings. The view has a certain rationalist appeal, but it certainly stretches what we can really use science to ascertain as true, because all of science must itself live in that coherent ripple of intelligent processing-- the rapids understanding the rest of the river, if we take the many-worlds story. It also doesn't completely sidestep the issue of consciousness, because the "ripples" of conscious processing are what we experience, so we still require our consciousness to be in the story that we tell about our experience. But the consciousness has a kind of passive role here, it controls what we experience, but not what "actually happens", as it is just a subprocess in what actually happens.

 

[rodsika]

That's pretty much the "many worlds" view, that our conscious experience is really only a tiny fraction of the full reality, and the full reality is that of the wave function of everything. The observer, us, is then just a kind of coherent ripple of processing in a vast river of incoherent happenings. The view has a certain rationalist appeal, but it certainly stretches what we can really use science to ascertain as true, because all of science must itself live in that coherent ripple of intelligent processing-- the rapids understanding the rest of the river, if we take the many-worlds story. It also doesn't completely sidestep the issue of consciousness, because the "ripples" of conscious processing are what we experience, so we still require our consciousness to be in the story that we tell about our experience. But the consciousness has a kind of passive role here, it controls what we experience, but not what "actually happens", as it is just a subprocess in what actually happens.

I'm not referring to Many Worlds but the wave function being physical and collapse still happens. Since it is objective, then your problem about consciosness and definite outcome vanish? Or what is the counterpart if the problem remains?

 

[Ken G]

I'm not referring to Many Worlds but the wave function being physical and collapse still happens.

The problem with the wavefunction being physical, yet collapsing, is that we can't identify any physical process that causes it to collapse to a single outcome, we can only identify a physical process that decoheres it into a mixed state of many happenings. You can still do it, but you have to resort to something pretty close to magic to get the wavefunction to behave that way as a physical entity, with no evidence of any physical process that can do that. You also have to take the physical embodiment of information pretty literally, and there doesn't seem to really be good reason to do that.

Since it is objective, then your problem about consciosness and definite outcome vanish? Or what is the counterpart if the problem remains?

Yes that particular problem does vanish, it just gets replaced by what seems a worse problem. At least if we put the problem at the doorstep of consciousness, we have some justification for expecting nonphysical behavior, since the whole subject/object dichotomy that runs through the concept of "physical behavior" breaks down there. But you can do it your way if you really want to, if you can live with such a totally unknown physical process that has no apparent reason to be so unknown.

 

[BruceW]

Yes, this is a way to frame it where we are in agreement. It is useful to find the common ground, and recognize then that our only disagreement lies in what is the most logical way to identify what the ability to make a measurement actually entails. It seems like a smaller disagreement that way. I think my earlier discussion with GO1 followed a similar course, but that was a lot of thread ago!

Yay! I agree. Glad we understand each other, although it took awhile!

I am merely pointing out that there is simply no justification for your assertion, whereas the justification for mine is that it is what quantum mechanics formal theory predicts. I grant you that the predictions of a formal theory are not the same thing as the reality, but at least it is some justification. There's no perfect solution-- we either stick in the non-unitary step in an ad hoc way within the theory, or we say we are leaving the theory when a perceptive conscious agent enters. But I suppose it is not experimentally answerable, so must be classified as an issue of personal taste.

Yes, I agree that its not experimentally answerable (unless QM has some kind of drastic revolution). This is my main justification for answering "consciousness is not involved in wave function collapse" - because experimentally we can't prove if its classical objects or conscious people that cause 'measurement'. I suppose I should have answered "If consciousness is involved in wavefunction collapse, then it would justify why we require collapse to happen (in CI), but there is no experimental support for consciousness to be involved in wave function collapse".

Well, you certainly wouldn't want to do that, it would be terrible scientific epistemology. We rely on several key concepts in science that this program would not support: in particular, objectivity. The whole theory of relativity is predicated on a symmetry principle among observers, for example. So this would be a bad epistemology.

Haha, yeah I guess you're right about that. The interpretation of "only I am allowed to make a measurement" Is like saying copenhagen interpretation for me, and many-worlds for everyone else. The theory would still work (assuming that CI and many-worlds are both viable interpretations), but it wouldn't have the nice symmetry among observers that physicists like to have in physical theories.

 

[BruceW]

I think what Ken was saying was simply that both machines and human consciousness are similar in that wave function collapse behavior was similar in their presence. What differs is how we perceive it. Since the only way to create an ensemble to match the prediction of the equation is to run many one at a time photon emission. The machine can only see the interference pattern after millions of single photon emissions as ensemble. Intermediate. It can't perceive the pattern as cause by collapse because machines can only see ensemble because the equation output can only be demonstrated with ensemble. It is only human which can know that a single outcome or hit in the detector is because of non-unitary process in a single photon at a time run. I think this is what Ken was saying. If I'm wrong. Let me know.

I think what Ken is saying is that the computer doesn't perceive anything. Therefore, the computer and particle are in a quantum superposition of possibilities. The computer appears to be able to measure a single outcome of one particle because the computer's quantum superposition collapses when a human looks at it. There have been no experiments which could determine whether the computer actually did measure a single collapse or whether the computer was in a quantum superposition until a human looked at it.

 

[Ken G]

Yay! I agree. Glad we understand each other, although it took awhile!

Always does-- communication is the hardest thing of all.

I suppose I should have answered "If consciousness is involved in wavefunction collapse, then it would justify why we require collapse to happen (in CI), but there is no experimental support for consciousness to be involved in wave function collapse".

And then I would probably have said "there is also no experimental support for saying that the non-unitary stage of collapse is a physical attribute of nature that exists independently of our mental processing of experimental outcomes, and our best formal theory certainly doesn't predict that it would be." But framing it with these two sentences, we see that it is truly a "tomato - tomahto" issue, as it all comes down to what untestable assumptions one cares to make. Which claim must stand to the burden of evidence? Since we now see it as a philosophical choice, you may reframe my comments on this thread not as "why the role of consciousness is crucial for interpreting quantum mechanics", but rather "why some choice about the role of consciousness must be made in order to interpret quantum mechanics, even if that choice is that it will not be regarded as important." Navigating these nuances is exactly why communication is so difficult-- but so important, so thank you for entering into the process with me.

 

[Ken G]

I think what Ken is saying is that the computer doesn't perceive anything. Therefore, the computer and particle are in a quantum superposition of possibilities. The computer appears to be able to measure a single outcome of one particle because the computer's quantum superposition collapses when a human looks at it. There have been no experiments which could determine whether the computer actually did measure a single collapse or whether the computer was in a quantum superposition until a human looked at it.

Right, I'm basically saying that I have no problem with the "many worlds" interpretation in any universe that doesn't have any conscious intelligences in it. But even when we contemplate what such a universe would be like, we can only do it by inserting hypothetical consciousnesses, to "make it talk our language." This is also what I don't like about many-worlds in the presence of consciousnesses-- the whole business is a language that is informed by consciousnesses, so to then remove those consciousnesses and imagine the language still means something seems disingenuous to me. Like telling nature "go about your conversation, pretend I'm not here-- oh, and could you please speak English?"

 

[Coldcall]

Thanks Ken G. Its always a pleasure reading your posts.

Doesn't this all boil down to the question of whether an independent reality exists without the presence of a "consciousness"? It seems to me that has always been the real argument involved in the measurement problem.

If reality is only a result of a certain threshold of information processing capacity being attained, then it seems logical (to me) that for reality to occur some sort of consciousness must be acting as the processor.

What else exists which can process very large amounts of information in such an arbritrary manner?

I can only think of a "brain", so if the "brain/s" are not present in the universe how does reality occur?

 

[Ken G]

Doesn't this all boil down to the question of whether an independent reality exists without the presence of a "consciousness"? It seems to me that has always been the real argument involved in the measurement problem.

I can't disagree with that, it is the place where our models of reality, and our models of our place in reality, bump heads. Is there any concept of "reality" at all that does not require we insert a concept of a perceptive intelligence into it to interpret what we even mean by that word?

If reality is only a result of a certain threshold of information processing capacity being attained, then it seems logical (to me) that for reality to occur some sort of consciousness must be acting as the processor.

I'm on your page.

I can only think of a "brain", so if the "brain/s" are not present in the universe how does reality occur?

Excellent question, I think the realisits would say that reality occurs anyway, but I think they have just tied themselves into an inextricable semantic knot if they try to tell me what they mean by reality occurring, if they are not allowed to avail themselves of the outputs of the kinds of processing you are talking about.

 

[yoda jedi]

I Wave function could be collapsed to definite outcome because of the existence of self-initiated volation.

this is called Subjective Dimanical Reduction

So it's like some kind of anthropic principle why nature has this capability to collapse wave function.

called Participatory Anthropic Principle

 

[Coldcall]

Ken G,

I can't disagree with that, it is the place where our models of reality, and our models of our place in reality, bump heads. Is there any concept of "reality" at all that does not require we insert a concept of a perceptive intelligence into it to interpret what we even mean by that word?

Exactly. I think at least "reality" is something easier for us to define as opposed to "consciousness" which usually leads to various viewpoints on what it really means. I got sort of tired of advocating the idea that our "consciousness" played some major role in the qm process because one usually gets labelled as being mystical :-)

However i think your way of arguing this point by using the notion of "reality" instead of the ambiguous "consciousness" is the right way to make the point.

yoda jedi,

"called Participatory Anthropic Principle"

IMO a great theory and the only "anthropic" theory which makes much sense to me. And i think one of the main reasons it has so few vocal advocates in the scientific community is that it more or less entails rejecting Copernican viewpoint re the place of man or other biology in the universe. It is more than a little heretical from the POV of realists and classical science.

 

[Ken G]

Exactly. I think at least "reality" is something easier for us to define as opposed to "consciousness" which usually leads to various viewpoints on what it really means. I got sort of tired of advocating the idea that our "consciousness" played some major role in the qm process because one usually gets labelled as being mystical :-)

I particularly like your characterization of reality as something that "occurs" rather than something that "is". That simple turn goes a long way toward refocusing the terms appropriately, because most people think consciousness "occurs" rather than "is" while reality "is" rather than "occurs", creating an almost uncrossable gap in the subsequent discussion. Since physics describes dynamics, not being, the standard language immediately makes consciousness something physics can describe, but reality as something that predates the physics, something the physics stems from. So if physics stems from reality, and consciousness stems from physics, consciousness can play no role in reality. However, if everything we describe using physics is a dynamical phenomenon (it "occurs"), and if we use physics to describe reality, why should we not confess to ourselves that anything we can conclude about reality using physics must necessarily be an "occurence" not a "being"? Ergo, physical reality occurs, just like consciousness occurs. And perhaps the two are closer than most recognize in the standard way of thinking.

IMO a great theory and the only "anthropic" theory which makes much sense to me. And i think one of the main reasons it has so few vocal advocates in the scientific community is that it more or less entails rejecting Copernican viewpoint re the place of man or other biology in the universe.

I'm not particularly wild about any variants of the AP, they all seem to represent, as someone once said, a puddle in the street wondering why it so miraculously fits to the shape of the pothole. Everything we know about the universe comes through the filter of our perception, so everything we know must be consistent with our ability to perceive. The AP only seems like something amazing if we imagine that the universe we perceive is the "actual universe", rather than just the universe we perceive. This is not necessarily a mystical viewpoint-- the pragmatist can say the universe we perceive is our definition of universe and the only one we will ever know anything about, but to them I say, "fine-- but note what happened to the AP the moment you defined universe to be that which we are capable of perceiving." Most versions of the AP involve embedding it in other universes we could perceive if we were there, but we can't be there so that explains why we aren't. It seems more rational to me to build an AP by embedding the universe we can perceive into a larger version of that same universe, the aspects of it that we cannot perceive. But this version of the AP makes the question go away without introducing anything predictive, because we are being more honest that the aspects we don't perceive have nothing to say about the ones we do. Whether they even exist as at all is "angels on a pin"-- but then, so is the AP.

 

[rodsika]

Ken, where did you particularly get this idea about definite outcomes needing consciousness to perceive and not in the equations of physics? I haven't heard of it before. What identical concepts did others use? Please enumerate them so we can relate to them. Thanks.

 

[Ken G]

Definite outcomes are not in the equations of quantum mechanics. That is quite well known, it's because the equations of quantum mechanics say that a closed system (like if we could put an experiment and everything involved with it inside a closed box) evolves unitarily. That means that if it starts out in a definite state, it remains always in a definite state. However, that definite state only applies to the whole closed system-- it includes various probabilities of outcomes for the states of its subspaces when those substates "decohere" (meaning they acquire randomized phase relationships with each other when you project from the full state of the closed system onto the subspaces). So a typical "subspace" would be the spin of a particle, say, and when you do a spin measurement you decohere the spin states from each other. But the closed system still has no way to pick out a particular spin state, they are all still there in the equations of quantum mechanics. The picking out of a particular spin state is, in practice, always done only one way: completely manually. That means the experimenter exits the theory of quantum mechanics and just asserts the outcome they perceive, manually throwing away the parts of the wavefunction of the whole system that don't show that outcome. No equation does that, because it is nonunitary. The reason this is necessary is that the perception requires it, and for no other reason, so I merely point out the reason that we have this step at all-- because we are conscious of a need for it.

Now, many-worlds says we shouldn't throw away the parts of the wave function we don't perceive, they are still there but we just don't perceive them. Our perception is seen to be less than the reality. However, this does not make the question of why we perceive what we perceive go away, because a universe with no perception would never need to assert what outcome was perceived to occur. So many-worlds still requires that perception enter the picture, it is the process that picks out one of the many worlds. The need for it is not gone, but the unitary evolution of the unperceived universe is salvaged, pretty much at the cost of empiricism as science's epistemological lychpin.

Another approach is deBroglie-Bohm, which holds that the equations of quantum mechanics cannot be the fundamental dynamical equations, expressly because they have this unpleasant feature of not connecting wiell with single outcomes. In DeBB, the one outcome is completely deterministic, nothing is thrown away and the "manual" step in quantum mechanics is there because quantum mechanics is incomplete. But to complete quantum mechanics, one must simply assume that there is information that is hidden from our view. It is essential to the dynamics that this information be hidden-- if it isn't, the dynamics is different (as in which-way information in a two-slit experiment). So behavior of the system depends on what we can know about it, even though the system is still evolving from a definite state (that we cannot know without changing the evolution) to another definite state. But note this still has not banished a role for perception, because defining what we can know about a system, which affects its evolution, is caught up in how we know things about systems, which relates to perception.

So I believe I have argued with simple logic that neither the equations of quantum mechanics, nor the popular interpretations of what those equations mean, has banished a role of conscious perception, they merely cause its role to crop up in different ways. The bottom line for me is, all of physics, all the language we use to talk about physics, requires that we insert a conscious perceiving agent somewhere in the story, even if that agent is inserted only hypothetically to give us a language we can use to talk about what is happening. So some role of a conscious perceiving agent is absolutely inescapable, even in systems that claim to have banished any need for it.

 

[rodsika]

Ken. This is because you are giving math too much apparent power that something outside it becomes mysterious. But if we would treat math as just a tool. Then the perceiving of definite outcome is natural. The math just models what occurs in superposition.

 

[Coldcall]

Ken G,

RE: "I'm not particularly wild about any variants of the AP, they all seem to represent, as someone once said, a puddle in the street wondering why it so miraculously fits to the shape of the pothole. Everything we know about the universe comes through the filter of our perception, so everything we know must be consistent with our ability to perceive..."

I think PAP is quite different than the other APs. If I'm not mistaken; Wheeler developed PAP as a derivative of his "delayed choice" experiment writ large on a cosmological scale. So in that sense it at least has some sort of experimental grounding even if one can argue that "delayed choice" cannot be scaled up to cosmological proportions. I think "delayed choice" is a demonstration of the (non-communicative) but still retrocausal nature of qm.
And for any version of AP to be even remotely plausible it seems to me one needs to demonstrate retrocausality.

I agree with you in that our understanding of the universe needs to be seen through the lens of our perceptions and not necessarily taken for granted.

Anyways thanks for taking the time; you always provide thought-provoking ideas, and there's nothing mystical about any of this, as far as i can tell :-)

 

[Ken G]

Ken. This is because you are giving math too much apparent power that something outside it becomes mysterious. But if we would treat math as just a tool. Then the perceiving of definite outcome is natural. The math just models what occurs in superposition.

That's more or less the Copenhagen approach, the math is a tool that needs not be taken seriously. Copenhagen is the most empirical of the interpretations, and it tends to attribute these strange effects to the fact that the perceiving agent is a classical object, so there is a "Heisenberg gap" between what we are observing and the instruments we are using to do so. But that doesn't completely escape a role of consciousness, because conscious perceiving agents presumably require classical complexity to function. A conscious atom, were that possible, would have no "Heisenberg gap", instead it would be the classical realm of trajectory and determinism that might seem bizarre to the atom-- but can we seriously imagine that an atom could be conscious? So even though it is classicality, not consciousness, that underpins the Copenhagen approach, we still must attribute our classicality to the fact that we need to be conscious to conceive of physics. The Heisenberg gap is then still a gap between that which can be a conscious perceiving agent, and that which cannot.

 

[rodsika]

That's more or less the Copenhagen approach, the math is a tool that needs not be taken seriously. Copenhagen is the most empirical of the interpretations, and it tends to attribute these strange effects to the fact that the perceiving agent is a classical object, so there is a "Heisenberg gap" between what we are observing and the instruments we are using to do so. But that doesn't completely escape a role of consciousness, because conscious perceiving agents presumably require classical complexity to function. A conscious atom, were that possible, would have no "Heisenberg gap", instead it would be the classical realm of trajectory and determinism that might seem bizarre to the atom-- but can we seriously imagine that an atom could be conscious? So even though it is classicality, not consciousness, that underpins the Copenhagen approach, we still must attribute our classicality to the fact that we need to be conscious to conceive of physics. The Heisenberg gap is then still a gap between that which can be a conscious perceiving agent, and that which cannot.

So it's not even a problem of quantum physics. The question becomes:

"For there to be something to be perceived, there must be a perceiver, why is there a perceiver?"

 

[Ferris_bg]

So it's not even a problem of quantum physics. The question becomes:

"For there to be something to be perceived, there must be a perceiver, why is there a perceiver?"

Because the perceiver WANTs to be there, otherwise there will be nothing.

 

[BruceW]

The philosophers of cosmology John Earman, Ernan McMullin and Jesús Mosterín contend that "in its weak version, the anthropic principle is a mere tautology, which does not allow us to explain anything or to predict anything that we did not already know. In its strong version, it is a gratuitous speculation".
I found this on wikipedia, with reference: Mosterín, Jesús. (2005). Op. cit.
I think I agree with these guys.

 

[Ken G]

Yes, I think they're right on target. Scientists often criticize the mental attitudes of others who do not ask for evidence to support attitudes that allow them to feel like they can make sense out of what is actually a mystery. We should not fall into the same pattern ourselves, it's downright hypocritical.

 

[G01]

The philosophers of cosmology John Earman, Ernan McMullin and Jesús Mosterín contend that "in its weak version, the anthropic principle is a mere tautology, which does not allow us to explain anything or to predict anything that we did not already know. In its strong version, it is a gratuitous speculation".
I found this on wikipedia, with reference: Mosterín, Jesús. (2005). Op. cit.
I think I agree with these guys.

Yes, I think they're right on target. Scientists often criticize the mental attitudes of others who do not ask for evidence to support attitudes that allow them to feel like they can make sense out of what is actually a mystery. We should not fall into the same pattern ourselves, it's downright hypocritical.

(Sorry I disappeared. Got busy with work, but I'm still following the conversation.)I agree with that statement as well. The anthropic principle is not a good scientific argument. It's not falsifiable, and basically amounts to begging the question in many instances.

Have any of you seen this article by Lee Smolin?

http://arxiv.org/abs/hep-th/0407213I don't like his alternative theory of cosmological natural selection, but I think his points about the anthropic principle are valid.

 

[yoda jedi]

The problem with the wavefunction being physical, yet collapsing, is that we can't identify any physical processthat causes it to collapse to a single outcome

nonlinear quantum mechanics.
there are various experiments planned to test that.


.

 

[rodsika]

Ken, you said without consciousness to perceive, there is no need to collapse and no measurement problem. But 13 billion years ago. What collapsed the wave function of the big bang in Copenhagen? Or are you saying our having evolved now is able go influence the past and collapse it? Or is if the possible the Big Bang and just prior to human evolution were always in superposition? But how could suns and galaxies even evolve without being in collapsed mode where things have positions?

 

[BruceW]

rodsika - just imagine that the universe followed many-worlds interpretation until humans came along to collapse the wavefunction. Also, collapse does happen retrospectively. That's what quantum eraser experiments have shown.
I personally think it is more likely that any classical object causes collapse. But the predictions of physics would work the same if only humans cause collapse.
(since we don't have any experiments that can distinguish between a human and a lump of organic matter).

 

[Ken G]

I don't like his alternative theory of cosmological natural selection, but I think his points about the anthropic principle are valid.

I concur. I've always said that arguments that go like "we already know X from observation, [and it seems X is needed for life], so I predict the universe will have attribute Y that allows X to be possible, because reliable theory A connects Y to X", is simply a statement of a test of theory A, so hinges on the reliability of theory A, not on any kind of "anthropic argument". This becomes clear if we simply strike out what I put in square brackets-- it has no part in the actual argument, it's just an add-on that makes it sound like we somehow have an example of an anthropic principle.

 

[Ken G]

nonlinear quantum mechanics.
there are various experiments planned to test that.

I'm not very familiar with nonlinear quantum mechanics, what is that?

 

[Ken G]

But how could suns and galaxies even evolve without being in collapsed mode where things have positions?

It seems to me there are 3 basic ways to address this issue. One is Wheeler's approach, explained by BruceW, that collapse happens retroactively when humans make a measurement. Before that, the universe was able to accommodate any of the outcomes, sort of like (in a macroscopic analogy) if you are playing bridge, you have to play in such a way as to accommodate any of the possible lays of the cards that are consistent with what you already know. We imagine that only one lay is the real one, but it wouldn't make any difference to how we play if all possibilities were equally real until we get more information. Another is BruceW's own approach, which is to say that some other process serves as the decider, whether or not there is consciousness present, so there's only one lay of the cards and we just don't know it yet.

I actually take a third approach. I don't think consciousness is doing anything physically active, such that it could "actively collapse" anything. Nor do I think that consciousness is a passive "fly on the wall" to what is physically happening. I think consciousness is part of what the word "physical" even means. All the language we use to do physics comes after we have already passed reality through the filter of our perception/consciousness, so it has left its mark even before we ask the question of what happened-- it is not something that we could point to and say "right there, that's when consciousness altered the outcome." Instead, what is a card, and what is a lay of the cards, are inextricably tied to how we perceive and interpret our reality, thereby making it what we mean by the reality. So when you imagine the Big Bang prior to any consciousnesses, it's not that the appearance of consciousness somehow changed the universe at later times, it's that you have to mentally insert hypothetical consciousnesses into the early Big Bang to even generate a language about what happened there. A "happening" is not an independent thing-- it is always a relationship to us. That's just the nature of intelligence.

 

[Maui]

This thread has been a very good read indeed. Consciousness just sits too close to souls, that seems to be the reason why 'çonsciousness' is often frowned upon, mocked or derided(or its existence is rejected) by neuroscientists, biologists and physicists(as if their unconscious, mechanistic framework were consistent with the observed evidence). But it might just be too early to talk about these issues in scientific terms on a science forum; that is until we get a firmer footing(congrats to the mods for allowing a bit of reasonable speculation to take place in the philosophy sub-forum).

 

[Evo]

Wow, this thread slipped through the cracks, it does not meet minimum criteria for posting.

Aha, this was moved here in error. Closed.