Does consciousness cause Wave-Function collapse?

[bhobba]

I do not understand, in my post , you guys gave the certainty that consciousness has nothing to do with it, in this post you put me in doubt about consciousness `playing a role on the collapse of the wave ..

Don't be confused. There is a difference between science having an open mind and embracing nonsense. Strong claims (ie basically nonsense which conciousness causes collapse is) require strong evidence - but that strong evidence may eventually be forthcoming - although such is highly doubtful - but one never knows.

Thanks
Bill

 

[Rajkovic]

then let's suppose that consciousness collapses the wave, what changes we would have in reality we experience (macro-world)

 

[bhobba]

My concern about Ballentine's 'ensemble' approach is that it doesn't explain why certain objects (e.g. electrons) must be described only as a (quantum) ensemble while others (e.g. baseballs) may be described as a single (classical) system. That is, it still seems to suffer from a micro/macro or quantum/classical 'cut' that is not defined. In contrast, PTI can explain this transition between the two theories.

Its ambivalent to such an issue. It simply accepts it. Ballentine doesn't even believe decoherence has anything to say about interpretational issues. And you know what - within his interpretation he is correct. For example if you read his 1970 paper its really an interpretation like BM in disguise. He has modified it a bit in his textbook so that is no longer true - but still he simply considers issues others worry about as non issues.

I know philosophy types sometimes say don't bother with Ballentine - its not even an interpretation since its basically just the formalism. Its a view I disagree with - but really we are getting way off topic.

Thanks
Bill

 

[bhobba]

then let's suppose that consciousness collapses the wave, what changes we would have in reality we experience (macro-world)

None - that's why its called an interpretation.

Its just a very very weird one.

Its like solipsism it leads to no consequences we can test, at least currently anyway, yet most reject it as the nonsense it is.

I sense you are wanting out of science what it can't give.

Thanks
Bill

 

[vanhees71]

My concern about Ballentine's 'ensemble' approach is that it doesn't explain why certain objects (e.g. electrons) must be described only as a (quantum) ensemble while others (e.g. baseballs) may be described as a single (classical) system. That is, it still seems to suffer from a micro/macro or quantum/classical 'cut' that is not defined. In contrast, PTI can explain this transition between the two theories.

That's easy to understand from the minimal statistical interpretation. A baseball is well described as a classical system, because you are only interested in very coarse-grained observables and not on the microscopic details. You don't follow the quantum state of $\mathcal{O}(10^{24})$ molecules in detail, because this is not possible in practice and fortunately far from being necessary to understand the "relevant" "classical" degrees of freedom (the center of mass/momentum motion and the rotation if you are satisfied with the "rigid-body approximation"). For those very rough effective degrees of freedom it is enough to consider the expectectation values which follow with high accuracy the classical description in terms of Newtonian mechanics.

 

[Rajkovic]

I just hate pseudoscience, and I hate everything about "the secret" or "what the bleep" "mind creating reality", so I just want to remove all my doubts about it, and to be sure that reality is fixed and objective.

 

[bhobba]

Ok. Can you please elaborate on "Not all interactions and nothing to do with an observer" Thanks in advance.

I am not sure exactly what your issue is - hopefully the following helps. Here is the technical detail:
http://philsci-archive.pitt.edu/5439/1/Decoherence_Essay_arXiv_version.pdf

See section 2.3 and point 3 where system B is removed from our control.

Now not all interactions are like that eg the electron in an atom interacts with the nucleus and is entangled with it but the systems are not such that you can observe the electron as a separate system. The example I gave with photons is. Although it does tell you something about the electrons location since its in the region of the nucleus - but wouldn't generally count as an observation.

Thanks
Bill

 

[bhobba]

I just hate pseudoscience, and I hate everything about "the secret" or "what the bleep" "mind creating reality", so I just want to remove all my doubts about it, and to be sure that reality is fixed and objective.

Sorry, science will not allow you to do that. It shows the new age junk in the secret etc does not have to be true and leads to basically a nonsense view of the world - but proving it wrong is another matter. The best you can do is when people trot out this rubbish tell them that's not what science says, you are adopting a view very few scientists ascribe to and much more common-sense views exist without resorting to quackery.

Thanks
Bill

 

[Rajkovic]

What bothers me more is the fact that Isn't obvious that "consciousness' has nothing to do with the collapse, but the system doing the measurement , why do people insists in this matter?
But, I think I know what Stevie is talking, when he referred to consciousness, he means that the system doing the interaction to collapse the wave could be the "quantum consciousness" ? woo woo, god exist ..

 

[craigi]

Come again. There is nothing in MW that requires an observer.

The observation selection effect comes from the fact that you can only observe a world with an observer.

 

[bhobba]

The observation selection effect comes from the fact that you can only observe a world with an observer.

You are confused with observe and observer. In QM an observation does not require an observer - this has been discussed many many times on this forum with it being very clear its a poor choice of words historically. In modern times its when decoherence occurs which does not require an observer.

Thanks
Bill

 

[bhobba]

What bothers me more is the fact that Isn't obvious that "consciousness' has nothing to do with the collapse, but the system doing the measurement , why do people insists in this matter?

Its the nature of ideas. There are many silly positions that can't be disproved. They are still silly - but in science that is not the standard - correspondence with experiment is.

Thanks
Bill

 

[craigi]

The observation selection effect comes from the fact that you can only observe a world with an observer.

You are confused with observe and observer. In QM an observation does not require an observer - this has been discussed many many times on this forum with it being vary clear its a poor choice of words historically. In modern times its when decoherence occurs which does not require an observer.

Thanks
Bill

Not at all. In this conext I'm referring to an observation made by a conscious observer, rather than a quantum mechanical observation which occurs in worlds regardless of whether they contain conscious observers.

 

[atyy]

Seriously, it's not even clear that there is something like a collapse in nature. I'm a follower of the minimal statistical interpretation, and there's no collapse necessary, which avoids a lot of problems with Einstein causality etc. For me "Collapse" is just a word for adjusting the state after the interaction of the system under consideration with a preparation apparatus in the sense of an ideal von Neumann "filter measurement". However, such preparation procedures can be understood from quantum dynamics alone. In very simple cases, like the spin filter measurement with a Stern-Gerlach apparatus you can even semianalytically calculate it by solving the Schrödinger equation. See, e.g.,

PHYSICAL REVIEW A 71, 052106 (2005)
Quantum mechanical description of Stern-Gerlach experiments
G. Potel, F. Barranco, S. Cruz-Barrios and J. Gómez-Camacho

If collapse does not occur in nature, then it occurs presumably in your mind - so it would seem that consciousness is involved in collapse.

 

[craigi]

If collapse does not occur in nature, then it occurs presumably in your mind - so it would seem that consciousness is involved in collapse.

Alternatively, there is no collapse.

 

[atyy]

Its the nature of ideas. There are many silly positions that can't be disproved. They are still silly - but in science that is not the standard - correspondence with experiment is.

I don't think the consciousness causing collapse is that silly, especially if one considers the Bayesian view of probability. In Bayesian probability, probability is subjective, and Bayes's rule updates a state of knowledge. If the state is not necessarily real, but just a tool to update a Bayesian probability, then it is updating a state of knowledge. Now of course, consciousness is not defined, but it is fun shorthand for something that has a state of knowledge and that can do Bayesian updating.

 

[craigi]

I don't think the consciousness causing collapse is that silly, especially if one considers the Bayesian view of probability. In Bayesian probability, probability is subjective, and Bayes's rule updates a state of knowledge. If the state is not necessarily real, but just a tool to update a Bayesian probability, then it is updating a state of knowledge. Now of course, consciousness is not defined, but it is fun shorthand for something that has a state of knowledge and that can do Bayesian updating.

It is a valid interpretation. The real problem with consciousness causing collapse, is that it's not easy to do science with a subjective-realist world view. You can circumvent the problem, by adding axioms to define domains where all observers agree.

A lot depends upon what the intent for your interpretation is. I don't see any use for consciousness causing collapse interpretations, other than that they're fun for boggling the mind and that they prevent us from becoming too dogmatic.

If I were to make a bet, I'd say that the the MWI will be proven in the next century by quantum computing and/or AI, followed by the findings being retro-fitted into other interpretations.

 

[atyy]

I just hate pseudoscience, and I hate everything about "the secret" or "what the bleep" "mind creating reality", so I just want to remove all my doubts about it, and to be sure that reality is fixed and objective.

It is a valid interpretation. Regardless of where one's dogma lies, the real problem with consciousness causing collapse, is that it's not easy to do science with a subjective-realist world view.

Why not? The standard interpretation is Copenhagen, with a subjective classical/quantum cut. The cut can be shifted, depending on which part of the universe one is interested in. So quantum experimenters doing local experiments in Texas and in Singapore will put their respective cuts in different places. Copenhagen does acknowledge objective reality. But it also acknowledges that it is an incomplete theory of the reality, and is only interested in predicting measurement outcomes. So there is no need for subjective cuts to conflict with objective reality.

 

[atyy]

It is a valid interpretation. The real problem with consciousness causing collapse, is that it's not easy to do science with a subjective-realist world view. You can circumvent the problem, by adding axioms to define domains where all observers agree.

Can one do that? It is often said that decoherence plus some additional axioms will do that. For example the probability sieve is proposed as one method of choosing the preferred basis, whereas in the Copenhagen interpretation the basis is chosen by the observer. However, I don't think an additional axiom can place the cut, because the cut is not unique. If Alice and Bob do local experiments and are only interested in local outcomes, they can place the cut in different places.

A similar point is made by Schlosshauer on p15 of http://arxiv.org/abs/quant-ph/0312059
"Finally, a fundamental conceptual difficulty of the decoherence-based approach to the preferred-basis problem is the lack of a general criterion for what defines the systems and the “unobserved” degrees of freedom of the environment (see the discussion in Sec. III.A). While in many laboratory-type situations, the division into system and environment might seem straightforward, it is not clear a priori how quasiclassical observables can be defined through environment-induced superselection on a larger and more general scale, when larger parts of the universe are considered where the split into subsystems is not suggested by some specific system-apparatus surroundings setup."

 

[bhobba]

Not at all. In this conext I'm referring to an observation made by a conscious observer

But QM is independent of that. We are going around in circles - I keep saying the theory is expressed in terms of things that are observer independent and you keep saying it is. I will leave it there - its got nothing to do with an observer.

Thanks
Bill

 

[atyy]

I have a letter accepted for publication in Physics Today pointing out that Zurek's argument, commonly referred to as 'Quantum Darwinism', is circular. MWI based only on 'decoherence' does not gain a classical splitting basis unless it is put in by hand at the beginning. (See http://arxiv.org/abs/1412.7950 and http://arxiv.org/abs/1406.4126 )
Thus the classical world of experience is not successfully explained in MWI. Publication of my letter, as well as another reply from someone else to Zurek's article, is currently being held up pending a reply from Zurek. At this time, I do not know when (or if) that will happen, since he has not replied to any of his critics in the literature (that I know of) to date.
Also, it's certainly not necessary to appeal to 'consciousness' for wave function collapse. (I discuss this in my new book, as well as in my 2012 CUP book.)

I think this is an open problem. Schlosshauer makes comments in his review http://arxiv.org/abs/quant-ph/0312059 that broadly agrees with you. He also says that Zurek acknowledged it as a problem in 1998. I don't know whether Zurek has made progress on this issue since then. Bolding below is mine.

p8: "Also, there exists no general criterion for how the total Hilbert space is to be divided into subsystems, while at the same time much of what is called a property of the system will depend on its correlation with other systems. This problem becomes particularly acute if one would like decoherence not only to motivate explanations for the subjective perception of classicality (as in Zurek’s “existential interpretation,” see Zurek, 1993, 1998, 2003b, and Sec. IV.C below), but moreover to allow for the definition of quasiclassical “macrofacts.” Zurek (1998, p. 1820) admits this severe conceptual difficulty: In particular, one issue which has been often taken for granted is looming big, as a foundation of the whole decoherence program. It is the question of what are the “systems” which play such a crucial role in all the discussions of the emergent classicality. (. . . ) [A] compelling explanation of what are the systems—how to define them given, say, the overall Hamiltonian in some suitably large Hilbert space—would be undoubtedly most useful."

p15: "Finally, a fundamental conceptual difficulty of the decoherence-based approach to the preferred-basis problem is the lack of a general criterion for what defines the systems and the “unobserved” degrees of freedom of the environment (see the discussion in Sec. III.A). While in many laboratory-type situations, the division into system and environment might seem straightforward, it is not clear a priori how quasiclassical observables can be defined through environment-induced superselection on a larger and more general scale, when larger parts of the universe are considered where the split into subsystems is not suggested by some specific system-apparatus surroundings setup."

 

[craigi]

But QM is independent of that. We are going around in circles - I keep saying the theory is expressed in terms of things that are observer independent and you keep saying it is. I will leave it there - its got nothing to do with an observer.

Thanks
Bill

Bill,

I'm not telling you that the MWI is expressed in terms of observer dependence. I'm saying that it results in an observation selection effect. In my first post in the thread, I mentioned quantum suicide, which I think you missed. I think if you review the thought experiment, then we'll understand each other perfectly well.

http://en.wikipedia.org/wiki/Quantum_suicide_and_immortality
http://wiki.lesswrong.com/wiki/Observation_selection_effect

Nevertheless, I've no interest in dragging out this misunderstanding either.

 

[bhobba]

I'm saying that it results in an observation selection effect.

I am saying because the interpretation doest even require conscious observers to exist its not possible for it to have such.

The quantum suicide effect is, to be blunt, simply philosophical dialectical sophistry of zero observational consequence:
http://en.wikipedia.org/wiki/Quantum_suicide_and_immortality
' it is not possible for the experimenter to experience having been killed, thus the only possible experience is one of having survived every iteration'

The worlds are all separate. You may just as easily conclude it is not possible for the experimenter to experience not having being killed as being alive. Indeed via that reasoning its not possible to experience anything. But since they are separate what goes on in other worlds has zero effect on what goes on in your world.

But then again you are talking about worlds with conscious observers - the interpretation doesn't require that.

Thanks
Bill

 

[craigi]

I am saying because the interpretation doest even require conscious observers to exist its not possible for it to have such.

The quantum suicide effect is, to be blunt, simply philosophical dialectical sophistry of zero observational consequence:
http://en.wikipedia.org/wiki/Quantum_suicide_and_immortality
' it is not possible for the experimenter to experience having been killed, thus the only possible experience is one of having survived every iteration'

The worlds are all separate. You may just as easily conclude it is not possible for the experimenter to experience not having being killed as being alive. Indeed via that reasoning its not possible to experience anything. But since they are separate what goes on in other worlds has zero effect on what goes on in your world.

But then again you are talking about worlds with conscious observers - the interpretation doesn't require that.

Thanks
Bill

It seems that you dislike the multiverse and anthropic principle that come along with the MWI. They're widely accepted features of the theory. At least we're on the same page now.

 

[bhobba]

It seems that you dislike the multiverse and anthropic principle that come along with the MWI.

The anthropic principle is not part of MW. I have zero Idea where you got that from. The multiverse is also different to MW.

The anthropic principle is the idea the many fundamental constants we see is explained because we happen to exist and they have to be that for that to occur. There are many alternate universes that are different. The problem here is that in MW each world has exactly the same fundamental laws and constants. The multiverse requires something like eternal inflation.

Have you actually studied MW from a book like the following:
http://users.ox.ac.uk/~mert0130/books-emergent.shtml

Thanks
Bill

 

[bhobba]

It is a valid interpretation. The real problem with consciousness causing collapse, is that it's not easy to do science with a subjective-realist world view. You can circumvent the problem, by adding axioms to define domains where all observers agree..

The real problem is, just like solipsism, is it leads to a world view most find far too weird to accept.

Thanks
Bill

 

[craigi]

The real problem is, just like solipsism, is it leads to a world view most find far too weird to accept.

Thanks
Bill

Sure. That's certainly a good objection, if you're choosing your interpretation based up aesthetics.

 

[craigi]

The anthropic principle is not part of MW. I have zero Idea where you got that from.

The anthropic principle is the idea the many fundamental constants we see is explained because we happen to exist and they have to be that for that to occur. There are many alternate universes that are different. The problem here is that in MW each world has exactly the same fundamental laws and constants. The multiverse requires something like eternal inflation.

Wat you're talking about is the fine tuning problem, which is relevant to the anthropic principle, but it isn't what the anthropic princple is.

Simply put, the anthropic principle is the requirement that a conscious observer must be present for an observation of the physical universe to be made.

In this context, the term observation, is used in the traditional sense and is not a quantum mechanical observation.

The multiverse is also different to MW.

Tegmark classifies the MWI universe as a level 3, multiverse.

Greene classifies the MWI universe as one of the nine types of multiverse.

 

[kith]

Now if you want to attack MW I think the quantum eraser experiment may prove difficult to handle - what happens to those worlds when decoherence is unscrambled?

I think that that if the splitting of worlds occurs whenever we have approximate decoherence, then it has to be possible for the worlds to remerge. Else, dynamics with periodic decoherence and recoherence don't fit in.

 

[rootone]

The real problem is, just like solipsism, is it leads to a world view most find far too weird to accept.
Bill

I think the comparison to solipsism is a good one.
It is an example of an assertion that may or may not be true, and which has zero possibility of either being proved or falsified.
Either way, it makes no difference in terms of explaining the observations which have actually been made,
The results of anyone given experiment are what they are, regardless of consciousness being present.
Just because a similar experiment could be done and the result could differ is to down to probability.
For me anyway, the notion that different results arising has a causal connection to whoever is doing the experiment sounds not only too weird to accept, it sounds plain daft.

 

[kith]

What bothers me more is the fact that Isn't obvious that "consciousness' has nothing to do with the collapse, but the system doing the measurement , why do people insists in this matter?

I think the whole thing is mostly a problem of terminology.

In my opinion, the terms "measurement" and "observer" should be reserved for science, i.e. we should use them only if someone actually performs an experiment on a system of his choice. If we do this, it is clear that consciousness has something to do with measurements but there's nothing mysterious: there's just a person doing science.

I would say that "collapse" refers to the perception of this person, while decoherence is an objective physical fact which looks the same for all external observers. I also think that "collapse" is a bad name because it sounds so objective.

 

[craigi]

I think that that if the splitting of worlds occurs whenever we have approximate decoherence, then it has to be possible for the worlds to remerge. Else, dynamics with periodic decoherence and recoherence don't fit in.

The definition of splitting is more deliberate than that. Worlds split during thermodynamically irreversible processes, which induce decoherence.

As we know from thermodynamics, irreversibility is a statisical property of a process in forward time, so theoretically, worlds could merge, in the same way that smashed glass could "magically" fix itself, but we feel comfortable saying that it's "never" going to happen.

 

[kith]

The definition of splitting is more deliberate than that. Worlds split during thermodynamically irreversible processes, which induce decoherence.

There are no exactly irreversible processes. If you model the dynamics of open quantum systems it doesn't matter whether something is truly irreversible or just has an astronomically large recurrence time but for the MWI this isn't enough. At least not unless you don'introduce something which says how long the recurrence time needs to be in order for a splitting to happen.

 

[rkastner]

Its ambivalent to such an issue. It simply accepts it. Ballentine doesn't even believe decoherence has anything to say about interpretational issues. And you know what - within his interpretation he is correct. For example if you read his 1970 paper its really an interpretation like BM in disguise. He has modified it a bit in his textbook so that is no longer true - but still he simply considers issues others worry about as non issues.

I know philosophy types sometimes say don't bother with Ballentine - its not even an interpretation since its basically just the formalism. Its a view I disagree with - but really we are getting way off topic.

Thanks
Bill

Thanks--I agree that he dismisses certain interpretational issues as non-issues. That's very convenient. But it puts him in a rather untenable position, since he introduced his interpretation ostensibly to solve interpretational issues. Apparently the ones his approach cannot solve, he declares them not in need of being solved--saying 'don't worry about it'. That's just a way of saying: I have given up on solving that and so should you." But another intepretations ( PTI) can solve them. So I would think that would count in their favor.

 

[craigi]

There are no exactly irreversible processes. If you model the dynamics of open quantum systems it doesn't matter whether something is truly irreversible or just has an astronomically large recurrence time but for the MWI this isn't enough. At least not unless you don't introduce something which says how long the recurrence time needs to be in order for a splitting to happen.

True.

Worlds merge almost never in the MWI, in the same way that a smashed object almost never "magically" reforms.

There isn't an exact definition for when splitting has taken place in the same way that there isn't an exact definition for an irreversible process.