I How To Experimentally Confirm the Wigner-Von Neumann Interpretation

[ChadGPT]

Ok. But then any claim that this interpretation makes different experimental predictions from "Standard Quantum Theory" cannot be right, because the only thing that makes "consciousness causes collapse" viable at all is that it does not make any different experimental predictions--it just puts "collapse" at the furthest possible point, so to speak, in the Von Neumann chain. So your claims that this interpretation does make different experimental predictions (for example that it allows interference under conditions where "Standard Quantum Theory" does not) cannot be right--or else you are using some other interpretation.

Consider a double slit experiment with detectors at each slit but which have no memory of their own, and which each relay the w-w information to a recording device that stores the information in a readable way to a conscious observer. Now run the experiment with the detectors on and the recorders off. Standard Quantum Theory says that the detection events resolve the which way information, and regardless of whether or not it is made available to any conscious observers there will be no interference pattern. The information exists *in principle* in the universe, and that is enough. Yet Von Nuemann-Wigner says that if the recorders are not recording the w-w information, such that it will be impossible for any conscious observer to ever read it, then we should see an interference pattern despite the fact that the detectors have resolved the which way information. Turn the recorders on and the interference pattern disappears. There is a definite contradiction, and different experimental predictions.

No. The math is the same for any intepretation of QM. If the math is different, you don't have an interpretation of QM: you have a different theory. "Consciousness causes collapse", at least as it appears in the literature I am familiar with, is not a different theory; it's just an interpretation of QM and uses the same math.

If I am right and it indeed makes different experimental predictions, then it would require different math I would think.

 

[ChadGPT]

Thanks fellas, I have two more questions and then I think I'm tapped out:

1) Why isn't an absorber considered an eraser? Is it theoretically possible to recover which-path information from an absorber in some way that is not possible using a diagonal polarizer as an eraser? For instance, the position that the photon hits the absorber might theoretically reveal the path it took to get there. But then again, the position the photon hit the diagonal polarizer, (the atoms that make it up) might also reveal which path information *in principle* or even the air molecules it interfered with on the way might reveal w-w information...

2) What is the accepted explanation for why coincidence counters reveal that the photons distributed themselves in a fringe interference pattern when correlated to one path and an anti-fringe when correlated to the other? Is there some non-miraculous explanation for this?

 

[PeroK]

Is there some non-miraculous explanation for this?

This is the question that prehistorical people asked about thunderstorms, the sun and moon, crops, birth and life. Because they lacked the scientific knowldege to explain them otherwise. In the modern world, QM may appear miraculous to those who are reluctant to study it, but who merely wonder at experimental results.

 

[ChadGPT]

This is the question that prehistorical people asked about thunderstorms, the sun and moon, crops, birth and life. Because they lacked the scientific knowldege to explain them otherwise. In the modern world, QM may appear miraculous to those who are reluctant to study it, but who merely wonder at experimental results.

Hyperbole.

 

[PeroK]

Hyperbole.

More parabolic than hyperbolic, I would have said.

 

[PeterDonis]

Von Nuemann-Wigner says that if the recorders are not recording the w-w information, such that it will be impossible for any conscious observer to ever read it, then we should see an interference pattern

You keep making claims about what Von-Neumann Wigner "says" with no support. I have already asked you for a reference to back up your claims, and I have also pointed out to you that any valid interpretation of QM must make the same experimental predictions as "standard QM", whereas you are claiming that Von-Neumann Wigner does not.

At this point you are going to have to either give a reference to back up your claims, or retract them.

 

[PeterDonis]

1) Why isn't an absorber considered an eraser?

Um, because it isn't?

Is it theoretically possible to recover which-path information from an absorber in some way that is not possible using a diagonal polarizer as an eraser? For instance, the position that the photon hits the absorber might theoretically reveal the path it took to get there. But then again, the position the photon hit the diagonal polarizer, (the atoms that make it up) might also reveal which path information *in principle* or even the air molecules it interfered with on the way might reveal w-w information...

It was already pointed out, way back in post #2 of this thread, that "which-path information" is a "lazy heuristic". The fact that it is telling you things that appear to contradict "standard QM" is not a problem with "standard QM"; it's a problem with you using a lazy heuristic.

The difference between an absorber of photons and a diagonal polarizer is decoherence, and the difference between experiments that allow "erasure" and ones that don't is also decoherence.

2) What is the accepted explanation for why coincidence counters reveal that the photons distributed themselves in a fringe interference pattern when correlated to one path and an anti-fringe when correlated to the other? Is there some non-miraculous explanation for this?

Of course, the explanation is called "Standard QM". I have already referred you to an exercise in Ballentine that deals with this exact issue.

 

[gentzen]

Standard Quantum Theory says that the detection events resolve the which way information, and regardless of whether or not it is made available to any conscious observers there will be no interference pattern. The information exists *in principle* in the universe, and that is enough. Yet Von Nuemann-Wigner says that if the recorders are not recording the w-w information, such that it will be impossible for any conscious observer to read it, then we should see an interference pattern despite the fact that the detectors have resolved the which way information. There is a definite contradiction.

Your mistake is that you believe that "consciousness causes collapse" talks about a "collapse" that is equivalent to disappearance of interference. But this is incorrect. Appearance or disappearance of interference is already predicted by QM math alone, no help from interpretations is needed for that fact.

The thing that is troublesome for QM math alone is "uniqueness of results". This is the sort of "collapse" from a probability distribution for possible measurement outcomes, to knowing the actual measurement outcome.

 

[ChadGPT]

Okay, thank you all for your help. "Von Neumann-Wigner Interpretation" is just a way of denoting "conscious causes collapse." Come up with a different name if you like, but regardless there is an interpretation of QM that makes this claim. I don't think it matters what you call it, and I don't think pretending like it doesn't exist makes sense either. I also think it makes experimental predictions that are different than the predictions of Standard Quantum Theory. There will be situations where SQT predicts particle pattern and "conscious causes collapse" predicts interference pattern. Namely, the thought experiment I last proposed you all for consideration but which you all elected to ignore to focus on other things: Detectors on, recorders off.

Nevertheless, I think I have cleared up my understanding at least a little bit thanks to your help regarding some matters. I have a feeling I've maxed out the benefit of this conversation at this point, and it will only go down hill from here if we continue. So you can now close this thread. Thank you all again for your help. I really honestly do appreciate it. It's hard to find people to have such conversations with to work though things, for a layman like myself. @PeterDonis I am going to get a copy of Ballentine. :)

 

[gentzen]

a way of denoting "conscious causes collapse." Come up with a different name if you like, but regardless there is an interpretation of QM that makes this claim.

There are collapse theories, which make different predictions from pure QM math. Therefore, one tries to call them „theories“ instead of „interpretations“. But their collapse is „more gentle“, to avoid making different predictions also for situations that have already been experimentally tested.

There have occasionally been versions of „relational interpretation“ that „accidentally“ made different predictions (than pure QM math), but this has always been quickly pointed out by others, and the authors retracted or adjusted their „versions“.

 

[Morbert]

There does seem to be a contradiction though. Consider a double slit experiment with detectors at each slit but which have no memory of their own, and relay the w-w information to a recording device that stores the information in a readable way to a conscious observer. Now run the experiment with the detectors on and the recorders off. Standard Quantum Theory says that the detection events resolve the which way information, and regardless of whether or not it is made available to any conscious observers there will be no interference pattern. The information exists *in principle* in the universe, and that is enough. Yet Von Nuemann-Wigner says that if the recorders are not recording the w-w information, such that it will be impossible for any conscious observer to read it, then we should see an interference pattern despite the fact that the detectors have resolved the which way information. There is a definite contradiction.

The bit in bold is not true. Neither Wigner's nor von Neumann's accounts say or imply this.

 

[PeterDonis]

"Von Neumann-Wigner Interpretation" is just a way of denoting "conscious causes collapse."

Ok, then you need to give a reference for a "consciousness causes collapse" interpretation that supports the claims you are making for what such an interpretation says. Either that or you need to retract those claims.

there is an interpretation of QM that makes this claim.

Then you should have no problem giving a reference for it.

I also think it makes experimental predictions that are different than the predictions of Standard Quantum Theory.

You need to either back this up with a reference or retract it. If you cannot do one of those two things, this thread will be closed.

 

[PeterDonis]

you can now close this thread.

I can do that, but if you are unable to give a reference to back up your claim quoted in my previous post, and you do not retract it (either of which requires you to make another post in this thread), you will also get a misinformation warning.

 

[ChadGPT]

Ok, then you need to give a reference for a "consciousness causes collapse" interpretation that supports the claims you are making for what such an interpretation says. Either that or you need to retract those claims.

I mean you can just look at all the material out there that proposes to refute the claims of the "consciousness causes collapse" interpretation:

http://www.danko-nikolic.com/wp-con...kolic-Qm-and-consciousness-Annalen-Physik.pdf

Such refutations agree with me that the "consciousness causes collapse" interpretation makes different experimental predictions than the standard theory does, and so it is a testable hypothesis:

Then you should have no problem giving a reference for it.

Von Neumann,John. "The Mathematical Foundations of Quantum Mechanics." 1932.

F. London and E. Bauer, "La théorie de l'observation en mécanique quantique" (1939), English translation in Quantum Theory and Measurement, edited by J. A. Wheeler and W. H. Zurek, Princeton University, Princeton New Jersey, 1983, pp. 217–259.

H. Stapp (2001). "Quantum Theory and the Role of Mind in Nature". Foundations of Physics 31 (10): 1465–1499.

 

[PeterDonis]

I mean you can just look at all the material out there that proposes to refute the claims of the "consciousness causes collapse" interpretation:

http://www.danko-nikolic.com/wp-con...kolic-Qm-and-consciousness-Annalen-Physik.pdf

Such refutations agree with me that the "consciousness causes collapse" interpretation makes different experimental predictions than the standard theory does, and so it is a testable hypothesis:

View attachment 341928

The paper claims that "consciousness causes collapse" (referring to a claimed recognized interpretation that was already in the literature) says this, but it has the same problem the rest of your post does:

Von Neumann,John. "The Mathematical Foundations of Quantum Mechanics." 1932.

F. London and E. Bauer, "La théorie de l'observation en mécanique quantique" (1939), English translation in Quantum Theory and Measurement, edited by J. A. Wheeler and W. H. Zurek, Princeton University, Princeton New Jersey, 1983, pp. 217–259.

H. Stapp (2001). "Quantum Theory and the Role of Mind in Nature". Foundations of Physics 31 (10): 1465–1499.

Where, specifically, in these references do they say the "consciousness causes collapse" interpretation says what you claim it says?

The paper you reference does have one useful feature: it explicitly formulates a "consciousness causes collapse" hypothesis, and then shows (or at least claims to show) how this hypothesis makes a different experimental prediction from standard QM, a prediction which (at least in versions i and ii as given on p. 934) was already experimentally falsified at the time the paper was published (the paper states this later on). But the very fact that this hypothesis makes a different experimental prediction from standard QM, means it isn't an interpretation of QM: it's a different physical theory, one which is falsified by experimental evidence.

So if you want to say that we have experimental evidence that shows, with high confidence, that the specific hypothesis stated in the paper is falsified, yes, that's true. But that still leaves me skeptical of the claim that people like Von Neumann seriously entertained that particular hypothesis, and the paper you reference gives no actual evidence for that claim. Indeed, Von Neumann, in the very work you reference, pointed out that as far as QM is concerned, you can put the collapse anywhere from the initial interaction with the macroscopic measurement device to the consciousness of the human observer, and the experimental results are the same.

 

[PeterDonis]

H. Stapp (2001). "Quantum Theory and the Role of Mind in Nature". Foundations of Physics 31 (10): 1465–1499.

On p. 21 of this paper appears the statement: "Von Neumann quantum theory is designed to yield all the predictions of Copenhagen quantum theory". In other words, whatever "interpretation" Von Neumann was using, it did not make different experimental predictions from standard QM.

 

[ChadGPT]

Where, specifically, in these references do they say the "consciousness causes collapse" interpretation says what you claim it says?

The "consciousness causes collapse" hypothesis logically follows from the "consciousness causes collapse" interpretation.

Given that a "consciousness causes collapse" interpretation exists, and given that the interpretation entails the hypothesis, I have therefore stated what I have stated in this thread. You don't need references, you just need reason.

So, here is my retraction:

1) Instead of saying the Von Neumann-Wigner Interpretation, you all want me to say the "conscious causes collapse" interpretation. So I will say the "consciousness causes collapse" interpretation in order not to receive a misinformation strike.

2) Instead of saying the "consciousness causes collapse" interpretation makes different experimental predictions than the standard theory, you all want me to say it's actually the hypothesis which logically follows from the interpretation that makes the different predictions. So I will say "hypothesis" instead of "interpretation" when referring to what makes the predictions.

So: The "consciousness causes collapse" HYPOTHESIS says what I claim it does, as per your approved semantics.

If all of that is still unsatisfactory to you, then I'm sorry but I've done all I can to meet your demands. No further attempts by me will be made. If you deem me still worthy of misinformation strike or whatever else, then so be it. I'm not going to go searching for a specific quotation somewhere to satisfy some appeal to authority when anyone can see that what I'm saying is extremely uncontroversial. Here's what I'm saying one more time: 1) The "consciousness causes collapse" interpretation exists. 2) It entails a hypothesis which makes different experimental predictions than the standard theory. If that earns me misinformation, oh well I guess... Id say that's on you, not me.

 

[gentzen]

I mean you can just look at all the material out there that proposes to refute the claims of the "consciousness causes collapse" interpretation:

http://www.danko-nikolic.com/wp-con...kolic-Qm-and-consciousness-Annalen-Physik.pdf

Such refutations agree with me that the "consciousness causes collapse" interpretation makes different experimental predictions than the standard theory does, and so it is a testable hypothesis:

One "not so hidden" signal that the paper might not be completely free from mistakes is this:

Acknowledgements We thank Thomas Metzinger, Markus Arndt, Anton Zeilinger, Rajarshi Roy and Nick Herbert for helpful comments. We are especially grateful to Hrvoje Nikolić for the fruitful discussions at the early stages of this project.

Danko and Hrvoje Nikolić are brothers, and in 2011 Hrvoje was already an important name in the "foundations community". This sort of acknowledgement with "restriction of responsibility" can indicate a lack of unrestricted endorsement. Also note that Danko Nikolić is not a physicist, and neither is Shan Yu. But overall, the paper is not bad. And it appeared in Annalen der Physik, which is quite good and peer-reviewed.

The paper you reference does have one useful feature: it explicitly formulates a "consciousness causes collapse" hypothesis, and then shows how this hypothesis makes a different experimental prediction from standard QM, ...

I now studied the paper in some detail. I think the hypothesis is still fine:

First, let us formulate the hypothesis to be tested:
The event of forming, in the observer’s mind, an explicit phenomenal representation of the result of a
quantum measurement is necessary for the wave function (superposition state) of the system to collapse
into a single eigenstate.

The mistake happened later:

Now, we can derive the predictions for this experimental setup that follow from the previously formulated relation (2):
The interference pattern should be visible if “which-path” information has not been registered in consciousness of the observer (i.e., the experimenter).

This prediction can simply not be derived from the hypothesis (or from relation (2)).

 

[Morbert]

Von Neumann,John. "The Mathematical Foundations of Quantum Mechanics." 1932.

Von Neumann, in chapter VI, discusses psycho-physical parallelism -- "that it must be possible so to describe the extra-physical process of the subjective perception as if it were in reality in the physical world" -- as a fundamental requirement of the scientific viewpoint. He says the content of this principle is that there is an arbitrariness to the divide between observer and observed in any description of a measurement. He goes on to show that quantum theories do not violate psycho-physical parallelism.

You are referencing von Neumann as if he is saying the opposite: As if he is saying the divide must be placed at the site of consciousness to produce the right expectations.

 

[gentzen]

Von Neumann,John. "The Mathematical Foundations of Quantum Mechanics." 1932.

F. London and E. Bauer, "La théorie de l'observation en mécanique quantique" (1939), English translation in Quantum Theory and Measurement, edited by J. A. Wheeler and W. H. Zurek, Princeton University, Princeton New Jersey, 1983, pp. 217–259.

H. Stapp (2001). "Quantum Theory and the Role of Mind in Nature". Foundations of Physics 31 (10): 1465–1499.

Where, specifically, in these references do they say the "consciousness causes collapse" interpretation says what you claim it says?

I have read von Neumann often and thorough enough to know that he didn't say this. And I also noticed that many papers are careful not to claim too much regarding von Neumann, by using words like "implicit proposal" or "hinted at". I now searched for F. London and E. Bauer on my computer, to check whether I understood them correctly, because papers use words like "suggested explicitly" or "later advocated" to describe their position. I found an interesting "misunderstanding" of von Neumann's point in a "famous" paper by van Kampen, but not the book/paper by London and Bauer. Online, I found at least an english translation. I read §11 again. I see why people feel that it advocates more explicitly for "consciousness causes collapse" than von Neumann. But for me, this is still just the standard interpretation, with a bit more focus on Heisenberg's "knowledge" interpretation of the quantum state than von Neumann's presentation.

Here is the interesting "misunderstanding" from "Ten theorems about quantum mechanical measurements" by N.G. van Kampen (1988):

And this process is repeated and gives rise to a chain of measurements, which can end only in the brain of the observer, where in some mysterious way it becomes a part of the “gedankliche Innerleben des Individuums”.
This is actually the conclusion of von Neumann and others [7,8]. I find it hard to understand that someone who arrives at such a conclusion does not seek the error in his argument. Quantum mechanics is not a theory of the mind of an observer, but of physical, objectively recorded phenomena, see theorem II.

This is interesting, because van Kampen didn't get the "uniqueness of results" point von Neumann was making. In turn, he presented a solution/position for the "uniqueness of results" point in this paper, but failed to express himself clearly enough. Later John Stewart Bell failed to understand van Kampen's position/argument, and tried to reconstruct it (i.e. make sense out of it), but failed completely. Bell's conclusion was that van Kampen made an error in his argument, just like van Kampen concluded that von Neumann should have sought the error in his argument.

 

[PeterDonis]

This prediction can simply not be derived from the hypothesis (or from relation (2)).

That's entirely possible since no math is given. I would be interested to see if there are any rebuttal papers to that one in the literature.

In any case, the experimental results make clear that even if such a prediction could be derived from the hypothesis, or one like it, it is falsified by the data.

 

[PeterDonis]

Given that a "consciousness causes collapse" interpretation exists

No, we don't even know that. So far we have only one paper that states a hypothesis--but as @gentzen points out, it's not even clear that the claimed experimental prediction being different from standard QM follows from that hypothesis.

here is my retraction

You aren't retracting the actual problematic claim you have made:

You claimed that Von Neumann and Wigner proposed a "consciousness causes collapse" interpretation, or something like it, which makes different experimental predictions from standard QM.

1) Instead of saying the Von Neumann-Wigner Interpretation, you all want me to say the "conscious causes collapse" interpretation.

No, I want you to either substantiate or retract your claim that Von Neumann and Wigner actually proposed such an interpretation that makes different experimental predictions from standard QM.

2) Instead of saying the "consciousness causes collapse" interpretation makes different experimental predictions than the standard theory, you all want me to say it's actually the hypothesis which logically follows from the interpretation that makes the different predictions.

You are misunderstanding the issue. See above.

anyone can see that what I'm saying is extremely uncontroversial.

This is obviously false since pretty much every other poster besides you in this thread has questioned what you are saying.

Here's what I'm saying one more time: 1) The "consciousness causes collapse" interpretation exists. 2) It entails a hypothesis which makes different experimental predictions than the standard theory. If that earns me misinformation, oh well I guess...

Indeed.

Id say that's on you, not me.

It's on me to moderate these forums. But making claims that you can't back up is on you.

Thread closed.

 

[PeterDonis]

For reference, here is information provided by @gentzen on rebuttal papers:

That's entirely possible since no math is given. I would be interested to see if there are any rebuttal papers to that one in the literature.

Here is the list of papers that cite "Quantum mechanics needs no consciousness":
https://scholar.google.com/scholar?oi=bibs&cites=1255182269027852700

The second item is "Can we Falsify the Consciousness-Causes-Collapse Hypothesis in Quantum Mechanics?" by J. Acacio de Barros, Gary Oas
https://arxiv.org/abs/1609.00614
https://link.springer.com/article/10.1007/s10701-017-0110-7
The abstract makes it clear that this is a rebuttal paper:

In this paper we examine some proposals to disprove the hypothesis that the interaction between mind and matter causes the collapse of the wave function, showing that such proposals are fundamentally flawed. ...

Also, reference 13 is the paper by Yu and Nikolic previously referred to, and is one of the proposals specifically stated to be refuted.