The quantum state cannot be interpreted statistically?

[bohm2]

Here's another good blog by a physicist (Steve Hsu) that does a good job of discussing the implications of PBR:

Technically, the (lambda, q) formalization describes a model in which

(i) there is an underlying reality (some Mysterians apparently do not actually believe this) and
(ii) the state vector Psi does not describe the underlying reality but rather an observer's knowledge about it.

The fact that a given underlying reality lambda has probability q of being consistent with two different preparations of a state, which each yield different pure states phi_0 and phi_1 (their notation), is meant to capture (i) and (ii) above. Remember that to a Mysterian the pure state is a description of a state of knowledge, not of reality. So nonzero q means that two different states of knowledge (preparations) are consistent with the same underlying state of reality.

http://infoproc.blogspot.com/2011/11/is-wavefunction-real.html

I don't understand why he says in his comments:

I think it means wavefunctions don't collapse.

He must be joking?

 

[akhmeteli]

Here's another good blog by a physicist (Steve Hsu) that does a good job of discussing the implications of PBR:



http://infoproc.blogspot.com/2011/11/is-wavefunction-real.html

I don't understand why he says in his comments:

I think it means wavefunctions don't collapse.

He must be joking?

I have no idea if he is joking or not, but if he is not, he is not alone - see the quote from Schlosshauer's review (M. Schlosshauer, Annals of Physics, 321 (2006) 112-149) at https://www.physicsforums.com/showpost.php?p=2534950&postcount=41

 

[qsa]

Here's another good blog by a physicist (Steve Hsu) that does a good job of discussing the implications of PBR:

thanks for the link

here is one of his comments



They explicitly note in the paper (for the really clueless) that they aren't trying to show that qm is really deterministic. In fact they entertain much more general classes of theories than ordinary qm, including stochastic hidden variables.

and another from other posters

Guess it's time to take Weinberg's advice and rethink the entire QM


I say yes to both. You know why, lines!

 

[bohm2]

I have no idea if he is joking or not, but if he is not, he is not alone - see the quote from Schlosshauer's review (M. Schlosshauer, Annals of Physics, 321 (2006) 112-149) at https://www.physicsforums.com/showpost.php?p=2534950&postcount=41

I was hoping that there was some argument in PBR that can eliminate spontaneous collapse theories like GRW. Anything that narrows down interpretations is a good thing. I really don't care which other interpretation gets shut down. The more the merrier. Let's just hope we reach that ONE interpretation before we reach our graves

 

[DevilsAvocado]

The quote above is not from a philosopher and either am I (just for the record). But as you get older there's a natural tendency to reflect on what you were doing in your field, when you were younger, I think? Not that there's anything wrong with pure philosophy as long as they meet Friedman's quote below (in my opinion):

And that's what posters are doing on here, for the most part, I think.

I’m sorry for that sentence, it was over the line. And it should have been in singular, not plurals. (I you know what I mean...)

I have no problem with philosophy, it’s cool, especially when put under the "Friedman restriction" in your quote; "Their problem is not so much to justify this knowledge from some 'higher' standpoint so as to articulate the new philosophical conceptions that are forced upon us by the new science. In Kant's words, mathematics and the science of nature stand in no need of philosophical inquiry for themselves, but for the sake of another science: metaphysics".

This perfectly okay, and I think everybody agrees on that.

IMHO the problem starts when a "philosopher" (and it’s not you I’m talking about) wants to bring down the "firewall" between science and philosophy, and then (naturally) what 'sets the rules' in a situation like this is the "philosopher" and his "philosophy".

This can never be right (and I think many of the hundred of posts in this thread is an example of this failure and confusion).

Another thing that could cause severe trouble is the fact the metaphysics is a "blurry thing", if not specified exactly, and could mean Ontology, Natural Theology/Religion* or Universal science.

In this place we’re supposed to stick to the facts, and if I claim something 'extraordinary', like; "Bertrand Russell started out as a High energy physicist, but he failed and there were no answers for him there, and he therefore shifted to philosophy", I need a source to backup this preposterous claim!

This particular attack on Steven Weinberg is extremely dull-witted, since he’s known for being an down-to-earth atheist and a hardnosed scientific realist, sticking to the facts, and a strong opponent of postmodernists questioning scientific objectivity. There are probably very few "metaphysical molecules" in this body... if you know what I mean. And the claim that the Nobel laureate Steven Weinberg is just a "personal guesser" is a full-blown disgrace, and just on the edge to being reported!


*This is not place or the time to deal with the following, but jfyi: I have seen "the subject" advocating for a position where it’s not okay to refute a claim that the Earth is only 6000 years old, if the (creationist) opponent is referring to "a belief" and not scientific facts – "this is a religious statement about which science is of course completely moot"... I hope you agree that this 100% crap and has nothing to do with science or philosophy of science.

 

[qsa]

IMHO the problem starts when a "philosopher" (and it’s not you I’m talking about) wants to bring down the "firewall" between science and philosophy, and then (naturally) what 'sets the rules' in a situation like this is the "philosopher" and his "philosophy".

This can never be right (and I think many of the hundred of posts in this thread is an example of this failure and confusion).

Another thing that could cause severe trouble is the fact the metaphysics is a "blurry thing", if not specified exactly, and could mean Ontology, Natural Theology/Religion* or Universal science.

I agree, please check your PM.

 

[apeiron]

I’m sorry for that sentence, it was over the line.

But mysteriously you always seem to get away with it. Need we mention Netanyahu's eyes?

I enjoy your contributions but do you need to get into these personal feuds based on misunderstandings and misinterpretations? They are fun for a while, then sour badly.

...just on the edge to being reported!

If you are looking for reportable comments in this thread, no need to look much further than multiple instances of this kind of stuff...https://www.physicsforums.com/showpost.php?p=3657619&postcount=380

If you are looking for some amusement, ask the semi-intellectual Professor Gobbledygook

 

[ThomasT]

Let's just hope we reach that ONE interpretation before we reach our graves

My guess is that most working physicists operate with a minimalist interpretation of qm -- which essentially entails not taking the formalism, the formal mathematical maps ... literally (ie., as necessarily referring to the underlying territory) , but still appreciating that certain inferences about the underlying reality might reasonably be made, based on the notion that there's no particular reason to believe that the underlying reality is essentially different from the reality of our sensory experience.

Wrt the OP, I was taught not to think of quantum states as depictions of reality. The qm formalism as a whole involves classical conceptions as well as mathematical abstractions which obviously are not descriptions of reality but are calculational tools.

Can the quantum state be interpreted statistically? Well, the quantum theory is a statistical/probabilistic theory. The precise relationship between the mathematical formalism and the underlying reality is, and will remain, a matter of speculative conjecture.

It's been an interesting/entertaining thread, but I think that it's probably run its course. The unsatisfying answer, imo, to the question of the meaning of the quantum theory is that there can't be any definitive answer to that question.

 

[bohm2]

I’m sorry for that sentence, it was over the line. And it should have been in singular, not plurals. (I you know what I mean...)

No problem. It wasn't over the line. I just might be that I'm a bit of a whimp/sensitive. It's my anxiety/ASD? I feel like people are screaming at me even when they're not even talking/referring to me.

 

[apeiron]

No problem. It wasn't over the line. I just might be that I'm a bit of a whimp/sensitive. It's my anxiety/ASD? I feel like people are screaming at me even when they're not even talking/referring to me.

Avocado wasn't referring to you. The clue is in: "it should have been in singular, not plurals. (I you know what I mean...)"

 

[Ken G]

Indeed, he was referring to himself, or more correctly a caricature that he has created. He thinks he's referring to me, but he has no idea what I'm saying, so he is referring to something he sees in the mirror. As it has nothing to do with me, I take no offense, it's rather amusing.

For those who want to know what I'm actually saying, they should also ignore DevilsAvocdo's fantasy version, and consider this: my point can be summarized by noting the error in what was said by Steve Hsu quoted above:

Technically, the (lambda, q) formalization describes a model in which

(i) there is an underlying reality (some Mysterians apparently do not actually believe this) and
(ii) the state vector Psi does not describe the underlying reality but rather an observer's knowledge about it.

What is incorrect here? Well, it certainly isn't "technically" true, because it leaves out a very important step in the logic. Hsu, and many others it would seem, have tacitly, and without even realizing, assumed this huge leap of faith:

(ia) the existence of an "underlying reality" requires that what happens in that reality be determined by the parameters in some theory!

Why else would assumption (i) amount to a hill of beans, what possible scientific meaning does assumption (i) have without assumption (ia)? So no, it is not "gobbledygook" to point out a simple yet crucial logical oversight. And it is certainly not "mysterion" to question (ia), on the grounds that it has never been true yet. The problem is that people keep confusing what realism should mean, belief in an underlying reality (as I've argued above it should mean), with what it actually means in the standard lexicon. "Realism" is not the belief in an underlying reality, it is the belief that the properties of our theoies are the properties of the reality. In short, realism involves committing a category error, which can also be called the mind projection fallacy, because that's what it is. If reality "underlies" (or overlies, or sideways-lies) our theories, then we certainly should not, in the very next breath, mistake our theories for that reality.

Some have tried to rescue realism with what has been termed "structural realism", which asserts that although the properties of reality are not the properties of our theories, still they share some basic structural similarity. I have no issue with that, except that it is really too vague to be saying anything important. I cannot see any meaning behind it, other than merely saying the obvious truth that scientific theories work to some high degree of usefulness, which I called effective truth. If there can be any other meaning to sharing structure then I'd call it a darn vague one, and nothing that science needs to care about. What's more, I've pointed out that the entire term "realism", though applied in the traditional way, is actually a misnomer, because believing that the properties of our theories are the properties of reality, when it is demonstrably true that theories are generated in and exist in our minds, requires associating a product of our mind with the fundamental truth of reality-- which is called idealism and is usually considered the opposite of realism. Throw in how completely counter to the historical evidence is the belief that the properties of theories are the properties of nature, and I cannot think of any view less realistic (and more like a "mysterion") than what is passed off as realism in science, as demonstrated by the above logical omission.

 

[Ken G]

More philosophers rambling out of their butt – Steven Weinberg is now an "ex philosopher"??

As this involves more than just your factual errors about what I said (I never said he was an ex-philosopher, for example), I will correct your factual errors about Weinberg because it is relevant to his mindset. I'm certainly glad to see you can read a Wiki bio, but unfortunately bios only tell part of the story. Better to actually know something about Weinberg, such as what he says about himself. Consider this quote from his well-known essay "Against Philosophy":
"It is only fair to admit my limitations and biases in making this judgment. After a few years' infatuation with philosophy as an undergraduate I became disenchanted. The insights of the philosophers I studied seemed murky and inconsequential compared with the dazzling successes of physics and mathematics."

So I took "years of infatuation" and, not having the quote in front of me, paraphrased it as "started out in philosophy." That was a bit of an overstatement, but I did not imply he was a professional philosopher, so could ever be an "ex philosopher", but it is certainly true that we considers himself an "ex enthusiast" of philosophy, having started out with a serious interest in it ("years of infatuation"). This is all that is required to make the logical step I used it to make: that his views on philosophy are informed by his own personal experience of disenchantment with it. Then I pointed out that for someone who claims to be disenchanted with philosophy, he certainly does not hesitate to wax philosophical about science, religion, metaphysics, and the anthropic principle. This was the point I was making.

On the other hand, the ridiculous interpretation you gave to my remarks above, claiming that I said Weinberg was an ex philosopher and citing his bio to refute what was never said, is certainly symptomatic of all your problems understanding plain English. I think you should look to that problem before you offer any more insights into what others are saying.

 

[bohm2]

"Realism" is not the belief in an underlying reality, it is the belief that the properties of our theories are the properties of the reality.

I think the authors do note the possibility in the PBR paper where they write:

The first (assumption) is that if a quantum system is prepared in isolation from the rest of the universe, such that quantum theory assigns a pure state, then after preparation the system has a well defined set of physical properties.This assumption is necessary for the question we address to make sense: if such physical properties don't exist, it is meaningless to ask whether or not the quantum state is among them...We have shown that this is only possible if one or more of the assumptions above is dropped. More radical approaches (e.g. Fuchs, yourself?) are careful to avoid associating quantum systems with any physical properties at all.

So that "more radical approach" is to drop the belief that quantum systems have any physical properties? It is this option that you and Fuchs (I think) refer to that I don't understand. To me, it seems to degenerate into instrumentalism and goes against the spirit of "scientific realism" even though you didn't believe that this is necessarily true since you wrote:

scientific realism is already more or less a given

I'm just a bit lost. Do you think that Leifer is correct that taking your position (or Fuchs's) is taking a position against scientific realism leading to instrumentalism and making physics "the science of meter readings"? At the least, it seems that there can be no in between stance; that is, you are either an anti-realist/Bohrian or a scientific realist so that you can't be both a Bohrian and a scientific realist? I think that's why Bell kept asking the question: Whose information? Information about what?

Here are three possible answers to this question:
1.Wavefunctions are epistemic and there is some underlying ontic state. Quantum mechanics is the statistical theory of these ontic states in analogy with Liouville mechanics. (Scientific realism)

2.Wavefunctions are epistemic, but there is no deeper underlying reality. (Instrumentalism/anti-realist)

3.Wavefunctions are ontic (there may also be additional ontic degrees of freedom, which is an important distinction but not relevant to the present discussion. (Scientific realism)

Options 1 and 3 share a conviction of scientific realism, which is the idea that there must be some description of what is going on in reality that is independent of our knowledge of it. Option 2 is broadly anti-realist, although there can be some subtleties here.

So your position is one of those subtleties as is Fuch's. I don't understand it at all. Leifer questions this subtlety also:

The subtlety is basically a person called Chris Fuchs. He is clearly in the option 2 camp, but claims to be a scientific realist. Whether he is successful at maintaining realism is a matter of debate.

I have the same problem understanding Chomsky's position noted in my quote. He considers himself a scientific realist and yet takes a similar position to you and Fuchs, I think? And I see all 3 of you are far more intelligent than myself, so I'm just trying to understand how that is possible.

 

[Maui]

And the claim that the Nobel laureate Steven Weinberg is just a "personal guesser" is a full-blown disgrace, and just on the edge to being reported!

Can you provide the exact quote where someone said that? Or are you going to report yourself for spreading misinformation?

 

[Ken G]

So that "more radical approach" is to drop the belief that quantum systems have any physical properties?

Quite so, and indeed I reject the label "radical" in favor of the label "consistent with everything we know about science."

To me, it seems to degenerate into instrumentalism and goes against the spirit of "scientific realism" even though you didn't believe that this is necessarily true since you wrote:

I think I can clear up the consistent thread here. I would like to distinguish three flavors of realism, which don't all officially get called realism but the one that does seems the least realistic to me. Let's call them:
1) naive realism-- the properties that our theories attribute to natural systems in order to predict and understand their behavior are actual properties those systems possesses independently of how we reason, perceive, and do science.
2) structural realism-- the properties of our theories are just what we can demonstrate them to be: properties of our theories. However, they must work for some reason, to whatever extent they do work, so we'll say that they work because they share some vague "structural similarity" to the actual reality, whatever that means.
3) instrumentalism-- actual reality is a meaningless scientific concept, what we are applying science to is the outcomes of observations so everything that is real is titrated through some kind of instrument, and all we ever do is predict the behaviors of those instruments.

Here are my criticisms of each:
1) It's ridiculous, ignores how the human mind works, and is oblivious to the entire history of the endeavor of physics. It's just obviously wrong. Random example: Newton's action at a distance, which for generations was adopted as one of these "true properties" of the universe (not by Newton, by the way).
2) This one is at least logically self-consistent, but is pretty vague. I view it as basically correct, but only because it is not saying much. It's main purpose is to reassure ourselves that we have good reason to speak in ontological language, but in fact the real reason for doing that is simply because it is convenient. This convenience is what I meant by it being "a given" that scientists are going to invoke ontological language, and hence adopt a form of scientific realism, the issue is merely how literally will they take themselves.
3) This one is on the most rock solid foundation, but is overly restrictive. It loses sight of the fact that we don't just do science to predict stuff, we also do it to gain a sense of understanding. We seek unifying principles and powerful idealizations, so if all we were doing was predicting our instruments we wouldn't need those conceptual tools, and we'd lose a lot of the aesthetic wonder.

I'm just a bit lost. Do you think that Leifer is correct that taking your position (or Fuchs's) is taking a position against scientific realism leading to instrumentalism and making physics "the science of meter readings"?

No, that's the excluded middle: he thinks we are either just reading meters, or else physical systems have to have actual properties that determine their behavior. Where's the logic there? How about the far more likely case that applies to neither of those extremes?

 

[bohm2]

I would like to distinguish three flavors of realism, which don't all officially get called realism but the one that does seems the least realistic to me. Let's call them: 2) structural realism-- the properties of our theories are just what we can demonstrate them to be: properties of our theories. However, they must work for some reason, to whatever extent they do work, so we'll say that they work because they share some vague "structural similarity" to the actual reality, whatever that means.

Here are my criticisms of each:
2) This one is at least logically self-consistent, but is pretty vague. I view it as basically correct, but only because it is not saying much. It's main purpose is to reassure ourselves that we have good reason to speak in ontological language, but in fact the real reason for doing that is simply because it is convenient. This convenience is what I meant by it being "a given" that scientists are going to invoke ontological language, and hence adopt a form of scientific realism, the issue is merely how literally will they take themselves.

No, that's the excluded middle: he thinks we are either just reading meters, or else physical systems have to have actual properties that determine their behavior. Where's the logic there? How about the far more likely case that applies to neither of those extremes?

Maybe everybody is just misunderstanding each other? Isn't Leifer’s scientific realism and PBR fully compatible with your structural realism? I actually felt that Leifer is arguing that Fuch’s position is somewhere in between instrumentalism and your structural (scientific) realism. He seems skeptical that this can be done. I also got the impression that PBR and Leifer don’t believe that there is some direct one-to-one mapping between the properties of the theory and mind-independent reality. In fact, I take this to be the case where PBR write:

Nevertheless most physicists and chemists concerned with pragmatic applications successfully treat the quantum state as a real object encoding all properties of microscopic systems

.

I think this is the same point that Norsen makes regarding the misinterpretation of Bell’s stuff:

Note that everything in the above discussion refers to some particular candidate physical theory. For example, there is a tendency for misplaced skepticism to arise from Bell’s use of the concept of “beables” in the formulation of local causality. This term strikes the ears of those influenced by orthodox quantum philosophy as having a metaphysical character and/or possibly committing one (already, in the very definition of what it means for a theory to respect relativistic local causality) to something unorthodox like “realism” or “hidden variables.” Such concerns, however, are based on the failure to appreciate that the concept “beable” is theory-relative. “Beable” refers not to what is physically real, but to what some candidate theory posits as being physically real. Bell writes: “I use the term ‘beable’ rather than some more committed term like ‘being’ or ‘beer’ to recall the essentially tentative nature of any physical theory. Such a theory is at best a candidate for the description of nature. Terms like ‘being’, ‘beer’, ‘existent’, etc., would seem to me lacking in humility. In fact ‘beable’ is short for ‘maybe-able’.”

A complete specification of beables in some spacetime region simply means a specification of everything (relevant) that is posited by the candidate theory in question. There is no presumption that such a full specification actually correspond to what really exists in the relevant spacetime region, i.e., no presumption that the candidate theory in question is true.

Local Causality and Completeness: Bell vs. Jarrett
http://philsci-archive.pitt.edu/4163/1/BvJ.pdf

 

[my_wan]

Here are my criticisms of each:
1) It's ridiculous, ignores how the human mind works, and is oblivious to the entire history of the endeavor of physics. It's just obviously wrong. Random example: Newton's action at a distance, which for generations was adopted as one of these "true properties" of the universe (not by Newton, by the way).
2) This one is at least logically self-consistent, but is pretty vague. I view it as basically correct, but only because it is not saying much. It's main purpose is to reassure ourselves that we have good reason to speak in ontological language, but in fact the real reason for doing that is simply because it is convenient. This convenience is what I meant by it being "a given" that scientists are going to invoke ontological language, and hence adopt a form of scientific realism, the issue is merely how literally will they take themselves.
3) This one is on the most rock solid foundation, but is overly restrictive. It loses sight of the fact that we don't just do science to predict stuff, we also do it to gain a sense of understanding. We seek unifying principles and powerful idealizations, so if all we were doing was predicting our instruments we wouldn't need those conceptual tools, and we'd lose a lot of the aesthetic wonder.

I see one shortcoming in these criticisms. That is that 2) can potentially, and has in the past, provided the instrumentalism of 3). First time was with Newton's laws. Then later with the development of statistical mechanics as a model of classical thermodynamics culminating in empirical verification with Brownian motion.

The instrumentalist is of course fully justified in sticking with their position. The instrumentalist take is in fact all that structural realism ever actually provided. It certainly never proved structural realism as a fact. Is was simply an instrumentalist tool that lead us to QM.

Now we are in the domain of QM with a lot of open questions left. The fact that QM is pretty immaculate in the predictions it provides says nothing about what it leaves out, such as GR. Even if you take that as fundamentally separable issue there are things like the vacuum catastrophe. The question about structural realism is not whether it is factual or not, but whether or not it can play an instrumentalist role in synthesizing and or expanding the value of our instrumental formalism. Just like statistical mechanics could not be derived from classical thermodynamics, but classical thermodynamics is easily derived from statistical mechanics structural realism may turn out to be the only way to move physics beyond a certain point today.

Maybe not to, but to throw 2) out on the grounds of what we do not, or even cannot, know is instrumentally absurd. Hence, taking 2) and 3) as entirely separable is invalid from either the perspective of 2) or 3).

 

[Ken G]

Maybe everybody is just misunderstanding each other? Isn't Leifer’s scientific realism and PBR fully compatible with your structural realism?

I would say not. Here's the key difference. In what I would call structural realism, properties are always attributes of a theory, but reality is never beholden to the theory-- it is the theory that is beholden to the reality. So we can say "here are the properties of theory X" and ask if reality behaves in accordance with the predictions of those properties, but one can never assume there must be some theory Y whose properties determine what happens in the reality. That's just backward logic, it's not even naive realism. In naive realism, we say that the properties of the theories we already have are the properties of reality, but there's no requirement to postulate some other theory that we don't have and apply realism to it in absentia. So we need yet another brand of realism, call it 'reductionist realism", that holds not only that our theories refer to true properties, but that true properties determine what happens, so some theory is possible that will describe exactly what nature is doing. I do not believe the PBR theorem goes through without that assumption.

I actually felt that Leifer is arguing that Fuch’s position is somewhere in between instrumentalism and your structural (scientific) realism. He seems skeptical of this. I also got the impression that PBR and Leifer don’t believe that there is a one-to-one mapping between the properties of the theory and mind-independent reality. In fact, I take this to be the case where PBR write:[/quote]Yet what PBR write there, and the assumptions that go into their theorem, are quite different.

I think this is the same point that Norsen makes regarding the misinterpretation of Bell’s stuff:

Indeed, Bell's words are quite clearly what constititutes anti-realism, the way the term is normally used. That's what I've been saying-- the narrow application of the term "realism" is actually not very realistic at all, and Bell's view would not qualify, nor would that staunchest of realists Bohm (when he starts talking about the electron as an information processor, that is not a property of any current theory of electrons, so is not a realist perspective).

 

[bohm2]

Indeed, Bell's words are quite clearly what constititutes anti-realism, the way the term is normally used. That's what I've been saying-- the narrow application of the term "realism" is actually not very realistic at all, and Bell's view would not qualify, nor would that staunchest of realists Bohm (when he starts talking about the electron as an information processor, that is not a property of any current theory of electrons, so is not a realist perspective).

Okay, I think I like the structural realist version of scientific realism (despite the criticisms given in the link) and I think this is the view Bell, Weinberg and Chomsky were arguing for but I didn't fully comprehend. I think I finally got it. I hope But note the part discussing that we shouldn't be anti-realists:

According to Worrall, we should not accept standard scientific realism, which asserts that the nature of the unobservable objects that cause the phenomena we observe is correctly described by our best theories. However, neither should we be antirealists about science. Rather, we should adopt structural realism and epistemically commit ourselves only to the mathematical or structural content of our theories. Since there is (says Worrall) retention of structure across theory change, structural realism both

(a) avoids the force of the pessimistic meta-induction (by not committing us to belief in the theory's description of the furniture of the world) and
(b) does not make the success of science (especially the novel predictions of mature physical theories) seem miraculous (by committing us to the claim that the theory's structure, over and above its empirical content, describes the world).

http://plato.stanford.edu/entries/structural-realism/

And now the interesting questions:

1. Does PBR support the spirit of this view?
2. Which interpretation of QM is most consistent with this view?

I would say not. Here's the key difference. In what I would call structural realism, properties are always attributes of a theory, but reality is never beholden to the theory-- it is the theory that is beholden to the reality. So we can say "here are the properties of theory X" and ask if reality behaves in accordance with the predictions of those properties, but one can never assume there must be some theory Y whose properties determine what happens in the reality. That's just backward logic...

But aren't all of the symbols introduced in PBR, "theory-relative" to use Norsen's term, just as in Bell's theorem? Again I'm referring to his paper:

Local Causality and Completeness: Bell vs. Jarrett
http://lanl.arxiv.org/PS_cache/arxiv/pdf/0808/0808.2178v1.pdf

 

[Ken G]

Maybe not to, but to throw 2) out on the grounds of what we do not, or even cannot, know is instrumentally absurd. Hence, taking 2) and 3) as entirely separable is invalid from either the perspective of 2) or 3).

I don't actually think that (2) and (3) are separable in terms of what claims we can scientifically substantiate, they are only different in terms of how we frame what science is about. There's a tradeoff between what we can demonstrate science is about, versus what we'd like to think science is about, and the order of the three goes from overly stressing the latter to perhaps overly stressing the former.

 

[Ken G]

And now the interesting questions:

1. Does PBR support the spirit of this view?
2. Which interpretation of QM is most consistent with this view?

1. I'd say the issue here is what is in a "structure." The structure of all theories is to afford systems with properties, and interpret those properties as determining the system behavior. The trouble is, there seems to neither a unique way, nor an exact way, to do that. Thus the structural realist becomes a naive realist as soon as they extrapolate their faith in structure beyond what is actually present in the theories. I cry "foul" as soon as anyone who purports to structural realism reverses the direction of the logic of that stance-- the stance says that our theories represent or mimic in some way the actual structure that is there, but it never says the converse, that reality represents or mimics our theories. So no matter how well the concept of a property does in making correct predictions and organizing our thinking, and no matter how well the structure of these properties can mimic or reflect in some way what is actually happening, it's never going to mean there really are any such properties, or indeed any such thing as properties, in a reality that does not have us in it.

As for which interpretation of QM is most consistent with structural realism, I'd say they are all equally consistent, because they all focus on some kind of successful structure in the interpretation. This is very much my point-- structures are not unique.

 

[Len M]

2) structural realism-- the properties of our theories are just what we can demonstrate them to be: properties of our theories. However, they must work for some reason, to whatever extent they do work, so we'll say that they work because they share some vague "structural similarity" to the actual reality, whatever that means.

2) This one is at least logically self-consistent, but is pretty vague. I view it as basically correct, but only because it is not saying much. It's main purpose is to reassure ourselves that we have good reason to speak in ontological language, but in fact the real reason for doing that is simply because it is convenient. This convenience is what I meant by it being "a given" that scientists are going to invoke ontological language, and hence adopt a form of scientific realism, the issue is merely how literally will they take themselves.

I’m in favour of (2). I agree the relationship to actual reality is vague (it has to be because the scientific method is not applicable to mind independent reality), but what the notion does is to place existence before knowledge. Pure idealism does not, it places knowledge before existence.

That’s just a philosophical point I know, but for me it’s important, because accepting the notion of mind independent reality as having a connection (however vague) with properties of our reality gives a plausible philosophical argument against pure/radical idealism

 

[Ken G]

Yes, I agree-- to me, the defining character of realism is just the idea that reality leads to our understanding, rather than the other way around. That's exactly why I argue that naive realism is actually much closer to idealism, because it involves imagining that the reality is very close to what is happening in our minds, but then it's a small step to idealism where the reality is what is happening in our minds. You just can't have it both ways, maintaining a wide berth from idealism means being skeptical of the connections between our theories and true reality. Unfortunately, that is not the way the term "realism" is normally applied, which I believe is the source of much of the difficulty around applying that term in a logically self-consistent way.

 

[bohm2]

So no matter how well the concept of a property does in making correct predictions and organizing our thinking, and no matter how well the structure of these properties can mimic or reflect in some way what is actually happening, it's never going to mean there really are any such properties, or indeed any such thing as properties, in a reality that does not have us in it.

I was reading through Leifer's comments section and I'm not sure if this is accurate but Norsen argues this point:

Psi being "ontic" doesn’t mean that psi is among the beables postulated by the theory; it just means that it is a function of the posited beables.

So Norsen, if I'm not misinterprerting him, is arguing that PBR is theory-relative and isn't making any metaphysical claims? By "properties" PBR mean with respect to theory not with respect to mind-independent reality (metaphysical claim)?

 

[Fredrik]

So Norsen, if I'm not misinterprerting him, is arguing that PBR is theory-relative and isn't making any metaphysical claims? By "properties" PBR mean with respect to theory not with respect to mind-independent reality (metaphysical claim)?

The mathematical part of the PBR argument certainly doesn't say anything about properties being a part of "mind-independent reality". But the statements the authors make on page 1 strongly suggest that they think of "properties" as the theory-independent reason why our theories work.

You have brought up the fact that different people interpret the PBR article differently a couple of times. I think this is perhaps the main reason. To me, the comments on page 1 are completely irrelevant. They might as well not be a part of the article. Only the statement that can be proved mathematically deserves to be called a "theorem" anyway, so I don't care how the authors (mis)interpret the significance of what they can prove. Ken G on the other hand seems to care only about the things they said in plain (non-mathematical) English.

 

[bohm2]

The mathematical part of the PBR argument certainly doesn't say anything about properties being a part of "mind-independent reality". But the statements the authors make on page 1 strongly suggest that they think of "properties" as the theory-independent reason why our theories work.

This is from page 1 of PBR:

Our main assumption is that after preparation, the quantum system has some set of physical properties. These may be completely described by quantum theory, but in order to be as general as possible, we allow that they are described by some other, perhaps undiscovered theory. Assume that a complete list of these physical properties corresponds to some mathematical object, λ.

Isn't this analogous to Bell's assumptions where Norsen writes:

But this attitude fails to appreciate one of Bell’s important advances – namely, that his formulation of local causality is a criterion for assessing the locality of candidate theories. As already discussed in Section II, Bell’s “complete specification of beables” simply does not mean a specification that captures everything which in fact really exists; rather, it means a specification which captures everything which is posited to exist by some candidate theory. There is thus nothing the least bit metaphysical or obscure about Bell’s requirement. For any unambiguously formulated candidate theory, there should be no question about what is being posited to exist...There will of course still be difficult questions about how to decide whether a given candidate theory is true, and hence whether the particular sort of non-local causation contained in it accurately describes some aspect of Nature. But the miracle of Bell’s argument is that we need not know which theory is true, in order to know that the true theory (whatever it turns out to be) will have to exhibit non-local, super-luminal causation

.

http://lanl.arxiv.org/PS_cache/arxiv/pdf/0808/0808.2178v1.pdf

So in both "theorems" the assumptions are talking about properties of theories?

 

[Fredrik]

In that page 1 quote, they assume that systems have properties, and then they say that those properties may be described by QM or by some other theory. To me that suggests that they consider the properties to be more fundamental than the theories.

Consider what I said about ontological models for quantum theories here:

...a set \Lambda whose members are called ontic states. The members of \Lambda are assumed to satisfy an equality like \sum_{\lambda\in\Lambda} P(\lambda|\psi)P(k|A,\lambda)=|\langle k|\psi\rangle|^2. This exact notation is only appropriate when \Lambda is finite, and the ontological model is non-contextual, but it's sufficient to illustrate the general idea. This requirement makes it convenient to think of

• \lambda as a complete specification of all the properties of the system,
• P(\lambda|\psi) as the probability that the system has properties λ, given that the preparation procedure is consistent with |\psi\rangle,
• P(k|A,\lambda) as the probability that the result will be k, given that the properties of the system are λ, and that the measurement procedure is consistent with A.

The function \lambda\mapsto P(\lambda|\psi) is called the epistemic state associated with the equivalence class of preparation procedures that the quantum theory associates with |\psi\rangle.

The way I see it, there are two ways to think about this. Either that formula holds because λ represents properties, or that formula just makes it convenient to think about λ as representing properties. It seems to me that P, B & R have chosen the first option, while the person who wrote the Stanford quote in #419, and the person who wrote the stuff in your last quote, would choose the second.

 

[qsa]

Yes, I agree-- to me, the defining character of realism is just the idea that reality leads to our understanding, rather than the other way around. That's exactly why I argue that naive realism is actually much closer to idealism, because it involves imagining that the reality is very close to what is happening in our minds, but then it's a small step to idealism where the reality is what is happening in our minds. You just can't have it both ways, maintaining a wide berth from idealism means being skeptical of the connections between our theories and true reality. Unfortunately, that is not the way the term "realism" is normally applied, which I believe is the source of much of the difficulty around applying that term in a logically self-consistent way.

Are you denying that nature has ontic character, even if all we can do to describe it, is a mind-dependent description. And how do you prove that since you already limited yourself early on. Or maybe I am not interpreting you idea correctly.

 

[my_wan]

I don't actually think that (2) and (3) are separable in terms of what claims we can scientifically substantiate, they are only different in terms of how we frame what science is about. There's a tradeoff between what we can demonstrate science is about, versus what we'd like to think science is about, and the order of the three goes from overly stressing the latter to perhaps overly stressing the former.

What science is about is a synthesis of that which we can substantiate to maximize predictability and innovation. To a priori drop (2), on the grounds that (3) is ultimately what it constitutes, undermines the very thing science is given that definition.

Are you arguing that we should "frame" science as something which science then must ignore what it is defined to be in order to potentially gain breakthroughs in the maximization of predictability and innovation? What is the point in this?

 

[Ken G]

Are you denying that nature has ontic character, even if all we can do to describe it, is a mind-dependent description.

No. Asserting that nature has ontic character is all that I think "realism" should mean. However, the standard meaning of the term is much more-- it holds that the ontic character of our theories (the "beables" of the theory) correspond exactly (in the case of naive realism) or in some structural way (in the case of structural realism) to the ontic character of reality. The first I consider pretty silly (at best it forces us to tell the difference between a beable that is not real and one that is, and resorting to the time-honored approach of saying that yesterday's beables were not real, but today's are, is clearly unsatisfactory). The second is reasonable but doesn't say much because it's not clear just what "structure" we are even talking about. But my fundamental claim is that if there is something that is impossible to talk about scientifically, then that thing does not even exist scientifically. So if we say "we can only talk about the ontic character of nature in a mind-dependent way", then there just plain isn't any scientific meaning to the mind independent ontic character of nature. Bohr already said it-- physics is not about nature, it is about what we can say about nature.

 

[Ken G]

What science is about is a synthesis of that which we can substantiate to maximize predictability and innovation. To a priori drop (2), on the grounds that (3) is ultimately what it constitutes, undermines the very thing science is given that definition.

I agree, that's why I never said to drop (2) in favor of (3). I think instrumentalism goes too far, it strips science of too much of its meaning just to have the benefit of being completely concrete. I would say that (1) is what every scientist in effect does in their daily progress but cannot justify as anything but convenience, and (3) is the only thing any scientist can really justify as actually true, but (2) is the compromise that gets something of the best of both worlds without being internally inconsistent.

Are you arguing that we should "frame" science as something which science then must ignore what it is defined to be in order to potentially gain breakthroughs in the maximization of predictability and innovation? What is the point in this?

I'm saying we should frame science as just what science is, and stop pretending it is something else. In particular, we should stop pretending that because theories invoke properties to great advantage, this means that the ontology that properties invoke is anything but a pretend ontology that we use as a convenience for doing science. The connection to a real ontology, if any such thing even exists, is both vague, and unnecessary to specify, to do science, so why not just accept this truth? When one does accept this truth, the idea that a property could determine the outcome of an experiment is dubious. A property of a theory can determine the prediction of a theory, but the PBR theorem is not about how to use QM to make a prediction, it is about what kinds of backstories we can tell about quantum mechanics that will be consistent with whatever brand of realism we are trying to make consistent with quantum mechanics.

 

[Ken G]

The mathematical part of the PBR argument certainly doesn't say anything about properties being a part of "mind-independent reality". But the statements the authors make on page 1 strongly suggest that they think of "properties" as the theory-independent reason why our theories work.

Yes, I'm a bit unclear about the role of that thinking in making the proof go through, or if it is just the importance of the theorem that is relevant to their interpretation of what properties are. Certainly, the blogs about the importance of the theorem are all about the "plain English" part, not the mathematics of the theorem. Still, it seems to me that what rules out epistemic interpretations of psi have to do with their interpretation of how properties need to work in some general way, not just what are the properties of quantum mechanics as a theory. The state psi, and how it responds to measurements, are the properties of quantum mechanics, so if one is only asking what these properties imply, then all they imply are the predictions of the theory and nothing else. In other words, the pure mathematics connects only to the actual predictions-- everything else is plain English.

 

[my_wan]

I agree, that's why I never said to drop (2) in favor of (3). I think instrumentalism goes too far, it strips science of too much of its meaning just to have the benefit of being completely concrete. I would say that (1) is what every scientist in effect does in their daily progress but cannot justify as anything but convenience, and (3) is the only thing any scientist can really justify as actually true, but (2) is the compromise that gets something of the best of both worlds without being internally inconsistent.
I'm saying we should frame science as just what science is, and stop pretending it is something else. In particular, we should stop pretending that because theories invoke properties to great advantage, this means that the ontology that properties invoke is anything but a pretend ontology that we use as a convenience for doing science. The connection to a real ontology, if any such thing even exists, is both vague, and unnecessary to specify, to do science, so why not just accept this truth? When one does accept this truth, the idea that a property could determine the outcome of an experiment is dubious. A property of a theory can determine the prediction of a theory, but the PBR theorem is not about how to use QM to make a prediction, it is about what kinds of backstories we can tell about quantum mechanics that will be consistent with whatever brand of realism we are trying to make consistent with quantum mechanics.

Again, we are not so far apart in a pragmatic sense. Yet our perspectives on the attitudes of what scientist actually do appears to be at odds. Perhaps because I'm a bit older than you and the present set of attitudes have only really gotten embedded in the last 25 years or so. So perhaps a bit of recent history of attitudes is in order.

When Feynman first presented his now famous Feynman diagrams they were rejected outright by the most prominent of the then present established peers as plain silly. Why? Because they accused him of trying to visualize what was "really" going on. The scientist since the famous Einstein debates had deeply embedded the idea the notion that "pretend ontology" was ALL any ontological construct was. Hence anything that even smelled like a picture, rather than pure mathematics, was silly. Scientist generally took the extreme end of the very position you are advocating and even accusing them of taking the opposing view.

Now with Feynman's obvious success this opened up some gates. The stream of views leaving out of those gates has gained momentum ever since, and this hasn't been all good or all bad, but has lead to a lot of good research on questions that certainly does need asked. When the various flavors of quantum interpretations were posited, such as Schrodinger's cat they weren't meant as interpretations of what was really going on, they were merely meant as conceptual devices to articulate the differences in QM and classical physics. As these questions resurfaced following Feynman the so called Gurus began to appear. Yet the gates weren't really opened up till Bell started publishing on Bell's inequalities.

In the words of GianCarlo Ghirard:

Actually I remember well that, at the beginning of the sixties when I started my scientific carreer, to work on foundational issues was considered by a great part of the scientific community a loss of time, a choice to pay more attention to (irrelevant) philosophical issues than to precise scientific problems. Luckily enough, the sixties were also the years in which another deep thinker, John S Bell, by deriving the celebrated inequality that bears his name [1], has given a tremendous imput to our understanding of reality by making clear that nonlocal features characterize most natural processes.

Today even what Christopher Fuchs might call the Copenhagenist wouldn't even be recognized by the authors of the Copenhagen Interpretation (CI). The very notion that CI, as originally stated, entails a collapse of the wavefunction is absurd. It disavowed any real notion of a wavefuction to make any notion of a collapse at all meaningful. Bell's inequality and the Aspect experiment drew in a public attention which often had their own SyFy (Imagine it Stupider) perception of the situation. The media doesn't give a crap what scientist think but are all too willing to characterize their BS as "what scientist say".

Then there is of course the priest of the religions Christopher Fuchs spoke of, which are trying to sell their interpretations by pointing to what they claim is "real" (their God) when nobody is looking in the interpretation. All hogwash as far as science is concerned. If they can offer some real science instead of BS interpretations explicitly designed to avoid predictions maybe they could be of some value. But that is just too risky for these "priest" of interpretations.

---
Does all this stupidity mean I want things returned to what they were before Bell, the attitude you seem to be advocating? The same attitude that got the Feynman diagrams initially treated as naive mad ravings about actual reality. Absolutely not! Important questions are being explored. To me the whole argument over what science "is" is ever bit as silly as all the "priest" at the conventions claiming if we only believe in their God everything will make sense. That goes for (non)realist poo pooing (non)realist also. It takes the whole array to explore the space of possibilities and only nature has the final word when somebody figures out how to ask the right question(s).

 

[bohm2]

I e-mailed one of the authors for clarification and Matt (Matthew F. Pusey) was very kind to answer and I'm sure he doesn't mind me posting this. I hope not. But since this debate has driven some of us to feel like smashing our computer monitors and unable to study either, here is his response:

My question:

Regarding your recent paper when you write that "this work, however, proceeds on the assumption that quantum systems-like atoms and photons-exist, and have at least some physical properties."

Are you assuming that these physical properties are just "theory-relative" without any presumption that such properties actually correspond to what really exists or are the assumptions based on properties actually being physically real?

Matt's response:

The idea is that the physical properties are "real" in the sense that they are not merely calculation devices in our heads, and can therefore be the cause of measurement outcomes. I suppose it is difficult to talk about physical reality without being "theory-relative" at all - for example the very ideas of photon and electrons come from theory. The result doesn't really depend on your exact philosophical standpoint on the nature of physical reality - we simply show that if a "reality" of some sort exists and satisfies our assumptions then the quantum state is "real" in whatever sense of the word "reality" the assumptions hold.

 

[DevilsAvocado]

I e-mailed one of the authors for clarification and Matt (Matthew F. Pusey) was very kind to answer and I'm sure he doesn't mind me posting this. I hope not. But since this debate has driven some of us to feel like smashing our computer monitors and unable to study either, here is his response:

The idea is that the physical properties are "real" in the sense that they are not merely calculation devices in our heads, and can therefore be the cause of measurement outcomes. I suppose it is difficult to talk about physical reality without being "theory-relative" at all - for example the very ideas of photon and electrons come from theory. The result doesn't really depend on your exact philosophical standpoint on the nature of physical reality - we simply show that if a "reality" of some sort exists and satisfies our assumptions then the quantum state is "real" in whatever sense of the word "reality" the assumptions hold.

[my bolding]

Excellent! I love it! :!)

This is what I have been trying to say since post #152! ()

From my perspective, the discussion what "hidden variables" are, and what properties they might posses, and how they commute these properties, is interesting but maybe 'premature', because I could claim that "hidden variables" are "Little Green Men with Flashlights" representing on/off, |0⟩ or |1⟩, and it would be quite hard to prove me wrong...

Therefore, this is clearly a question on realism. Is there "something" there when no one is watching?

Now, the PBR theorem has clearly a strong connection to the standard Bell framework, and therefore we cannot talk about realism without the other strongly related concept locality (despite Ken G’s 'aversion').

Thanks bohm2!


P.S. And of course, another formulation (philosophical-mumbo-jumbo-bulletproof): Is the moon there when nobody looks?

 

[bohm2]

Not another interpretation!

In a recent paper, Pusey, Barrett and Rudolph claim to proof that statistical interpretations of quantum mechanics do not work. In fact, their proof assumes that all statistical interpretations must be based on hidden variable realism. Effectively, the authors demand from the start that reality must be decided by mathematics, and not by measurements. If this unjustified assumption is dropped, the quantum formalism has a natural statistical interpretation that fully explains the paradox presented by the authors. It is therefore possible to conclude that the paradox actually supports the statistical interpretation, demonstrating once more that quantum mechanics should not be explained by measurement independent realities that are never observed and therefore lie beyond the reach of empirical tests.

The explanations given by Bohr, Heisenberg, von Neumann and many others all assume that (a) quantum mechanics should be interpreted statistically, and (b) hidden variables do not work. Could it be, that the authors of meant this group of physicists, when thay state that “Some physicists claim that quantum systems do not have physical properties, or that the existence of quantum systems at all is a convenient fiction”? This statement is certainly a drastic misrepresentation of the empirical position that objects can only be known by their observable effects. The authors contrast this by professing a belief in the existence of “quantum systems - like atoms and photons.” However, this seems to contradict their own conclusions, since the reality of a quantum state represented by superpositions of atom or photon numbers should be hard to reconcile with the existence of atoms and photons as real objects. Obviously, the authors of [1] are unaware of the difficulties associated with terms like “existence”, otherwise they would not think that the conviction that objects must “exist” in some absolute form could justify their assumption of a measurement independent reality. The positions that collide here are the empirical tradition that assumes that the existence of an object is known by its observable effects (and nothing else) [2], and the idealist or dogmatic [3] position that we know about the existence of an object from an authoritative theory.

Somebody on this forum will love this paper, I think?

The quantum state should be interpreted statistically
http://lanl.arxiv.org/PS_cache/arxiv/pdf/1112/1112.2446v1.pdf

I think these authors are using a similar argument to the "flaw" that Demystifier pointed out in a previous post in this thread?

I believe I have found a flaw in the paper.
In short, they try to show that there is no lambda satisfying certain properties. The problem is that the CRUCIAL property they assume is not even stated as being one of the properties, probably because they thought that property was "obvious". And that "obvious" property is today known as non-contextuality. Indeed, today it is well known that QM is NOT non-contextual. But long time ago, it was not known. A long time ago von Neumann has found a "proof" that hidden variables (i.e., lambda) were impossible, but later it was realized that he tacitly assumed non-contextuality, so today it is known that his theorem only shows that non-contextual hidden variables are impossible. It seems that essentially the same mistake made long time ago by von Neumann is now repeated by those guys here.

 

[Fra]

The idea is that the physical properties are "real" in the sense that they are not merely calculation devices in our heads, and can therefore be the cause of measurement outcomes.

I assume that human heads are just a metaphor for the "memory of an observer" (which generically is a piece of matter).

Then as I tried to advocate before it's perfectly possible that the properties are "only in heads" YET they DO influence the measurement outcomes!

The key is that there is more than one head! And the behaviour of physical system can essentially be seen as "interacting heads". And here it really is not a far stretch that the EXPECTATIONS of the heads, really does determined the interactions if the action of any head is assume to follow a rational action upon it's own expectations. There you go, it's group dynamics of expectations.

The best analogy is the theory of expectations and rational actions in economical dynamics. So as a first step, one might have a hard time to grasp that expectations rules physical interactions, but the concept is easier to understand in economy. Try to predict the stock market for example.

My opinon is that expectations are "real" as oppose to just living in a mathematical realm, but not real in the sense of observer invariant or detached from empirism. I see it more as "real empirical records" but these records are observer dependent, and other observer can only establish some of kind "reality" of other observers records by implicitly noting that they influence(but not fully determine) their actions.

/Fredrik

 

[my_wan]

Fredrik makes a good point. People talk about what we imagine as if there is nothing in our head that determines what we imagine. Sociologist have a term for "group dynamics of expectations", it's called "http://www.enotes.com/oxsoc-encyclopedia/definition-situation". Even if you could predict the stock market, once you buy stock as a result of that prediction you change the stock market so the prediction is no longer valid. The more stock you buy the more you change what the stock market does. Here buying stock is a lot like making a measurement. In QM you can only find the price of a stock by purchasing the stock (perform a measurement).

The information centric approach of Fredrik appears perfectly valid to me, in spite of my own predispositions toward realism. I don't think the two are mutually exclusive. In some ways an information centric approach is superior, due to the unpredictability created through feedback like in the stock market analogy, but neither would it erase certain advantages of an empirically valid observer independent model. Especially with respect to defining general causal constraints on the system.

 

[Fredrik]

Effectively, the authors demand from the start that reality must be decided by mathematics, and not by measurements. If this unjustified assumption is dropped, the quantum formalism has a natural statistical interpretation that fully explains the paradox presented by the authors.

To be more specific, the authors (PBR) define the statistical interpretation of a quantum theory as "there's a ψ-epistemic ontological model for it", and if we ignore the possibility that there might be such a thing as an ontological model, and instead consider a way of looking at QM that involves negative probabilities, then we're not going to find a contradiction in the calculation that PBR did.

This guy is essentially just saying that if we don't make any of the assumptions that PBR did, then we also don't arrive at their conclusions. And then he let's us know that he knows a cool trick with negative probabilities. I find it hard to believe that this article will be published anywhere.

I think we started this discussion too soon. We still don't even know if the PBR article will be accepted for publication (I would at least demand massive rewrites if I was the reviewer), and I think comments about it will continue to appear, many of which will be garbage. I don't think I will bother to read anything else about this until someone has published a rigorous version of the mathematical argument.

 

[my_wan]

To be more specific, the authors (PBR) define the statistical interpretation of a quantum theory as "there's a ψ-epistemic ontological model for it", and if we ignore the possibility that there might be such a thing as an ontological model, and instead consider a way of looking at QM that involves negative probabilities, then we're not going to find a contradiction in the calculation that PBR did.

Funny thing is I still have no freaking clue what set of possible models ψ-epistemic ontological entail. Nor did the paper use any term or morph of those terms anywhere in the document. Nor does the notion that they somehow screwed up their own description but somehow you pieced it back together from a referenced articled that shared absolutely no common terminology.

So when you say "specifically" I'm still left with the vague notion that specifically you mean some "sort of electromagnetic phenomena". Sounds just as specific to me.

Now look at Matt's email response:

The result doesn't really depend on your exact philosophical standpoint on the nature of physical reality[...]

And he's absolutely right. It doesn't depend on your notion of ψ-epistemic or ψ-epistemic ontological either, which you offer no clues to the meaning outside the labels you placed in this singular context with no clarification on even that one context.

The authors did perfectly well and sensible with their own words. Figure out why their own words were perfectly sensible in the context they provided, even if the terminological was not unique to that context they explicitly provided. Else if you are going to throw their own word away as hogwash don't pretend you somehow can intuit what they meant from a reference paper using no common terminology, or variant thereof, whatsoever. Or explain the FULL context of how you intend the meaning of such terminology.

 

[Fra]

but neither would it erase certain advantages of an empirically valid observer independent model. Especially with respect to defining general causal constraints on the system.

Perhaps we can agree, if I get you right, "certain advantages" are indeed compatible, or even an integral part of my view:

Each observer, IMHO, has an empirically justified view of an "effective reality", and this contains the best match to observer invariants - to the extent that observer has inferred. And indeed, the concept of rational action means that THIS is definitely working as a constraint on the observer actions; in the sense that it's EXPECTATIONS of "invariants" with respect to OTHER observers, helps this observer to make place his bets - this is IMO the "certain advantage".

Interpreting in this way, I can agree on your last point as well. What I think is important though, is that we do not confuse OUR (or say MY OWN) view of "effective reality with invariants" with the concept that ANY observer (read any piece of matter) has it's potential OWN subjective view of another "effective reality".

The mind trap as I see it, that is easy to fall into, is the mental picture that there exists in some absolute timeless sense some "real reality" that connects all the "effective realities" by some master symmetry. One might first thinkg that "what's the difference" between effective reality and real reality? From the empirical point within the view of a GIVEN observer, there is no difference since the whole point is that there is no way to distinguish them!

But the real issue is when one expects the two "effective realities" of two INTERACTING observer to be the same. This is IMO an unjustified expectation that only makes sens in some mathematical realm, and insisting on it tend to result in other pathologies that I think are related to this simply becaue in mathematical realm there are no selection principles except inconsistencies. For example certain landscape problems or hard initial value and finetuning problems.

Still there is no denial that the "effective reality" is an essential to any given observe, and this of course INCLUDES *expectations* on how this observers observations relates to fellow observers etc. One can imagine semi-equilibriums, where a group of observers can actuall agree on observer invariants. But this presumes the group has equilibrated.

/Fredrik

 

[Fredrik]

Funny thing is...

Your refusal to accept that the PBR argument is an attempt to rule out what HS calls ψ-epistemic ontological models is quite bizarre. I have explained it lots of times, so I'm not going to do it again.

I have no idea why you think that the Pusey quote somehow means that I'm wrong about something.

 

[DevilsAvocado]

I assume that human heads are just a metaphor for the "memory of an observer" (which generically is a piece of matter).

Then as I tried to advocate before it's perfectly possible that the properties are "only in heads" YET they DO influence the measurement outcomes!

The key is that there is more than one head! And the behaviour of physical system can essentially be seen as "interacting heads". And here it really is not a far stretch that the EXPECTATIONS of the heads, really does determined the interactions if the action of any head is assume to follow a rational action upon it's own expectations. There you go, it's group dynamics of expectations.

The best analogy is the theory of expectations and rational actions in economical dynamics. So as a first step, one might have a hard time to grasp that expectations rules physical interactions, but the concept is easier to understand in economy. Try to predict the stock market for example.

My opinon is that expectations are "real" as oppose to just living in a mathematical realm, but not real in the sense of observer invariant or detached from empirism. I see it more as "real empirical records" but these records are observer dependent, and other observer can only establish some of kind "reality" of other observers records by implicitly noting that they influence(but not fully determine) their actions.

/Fredrik

Thanks Fredrik, interesting.

First let me say that I take yours and my_wan’s argumentation and 'search for knowledge' 100% serious, because to me you seem 100% sincere. Not like "the other guy", who build his own "personal reality" without any rules; creating whatever fits the personal divine worldview – a form of "semi-creationism".

Please forgive me if I’ve misunderstood your model, but afaict, you are saying that "our heads" are the only thing that matters, right? A group of scientists could/should be seen as "interacting heads"; examining the "reality", creating "the theory", setting up "the experiment", and finally examine "the data", correct?

This far, I think have no problem following the logic, but then I’m kinda lost... are you saying that the expectations (all the way from 'theory-making') is what finally decides the empirical data?? Then I must be missing something substantial, because afaict that would require some form of new "magical interaction" between thought/mind/consciousness and matter...?

Or did I get everything wrong from start...

Let’s skip my (hopefully temporal) ignorance and continue with your "EXPECTATIONS of the heads" model. This can only mean that we must trust "our heads" 100%; to always get everything right, and never hesitate, and always trust our senses 100% (carrying 'the information' to "our heads") – because if we cannot, we will get a chaotic and contradictory universe where the "laws of nature" breaks down.

Then the natural question arises:

– Can we do this? Are we "Gods" that get everything right all the time??​

To me, the answer is without doubt, No.

For example, take this simple illusion:

Stare at the center cross for at least 30 seconds to experience
the three phenomena of the illusion

When you stare at the cross for about 30 seconds or so, you will see three different things, in this sequence:

1. A gap running around the circle of lilac discs.
   
2. A green disc running around the circle of lilac discs in place of the gap.
   
3. The green disc running around on the grey background, with the lilac discs having disappeared in sequence.

If you do it 'right', you will see/"measure" three different and contradicting "data" from only "one reality". This will cause problems in "your model"... I think...

But I’m probably missing something... because this 'refutation' seems a little too simple...


Finally, I’ve seen users complaining about a badly souring atmosphere, so let’s lighten things up!

"If I am reading this graph correctly — I'd be very surprised!" -- Stephen Colbert

"You can always count on the Americans to do the right thing — after they have tried everything else." -- Winston Churchill​

P.S. Economics is not a branch of natural science, is it? More like psychology, right? The Nobel Prize in Economics is established by Sweden's central bank, not Alfred Nobel.

 

[DevilsAvocado]

... The mind trap as I see it, that is easy to fall into, is the mental picture that there exists in some absolute timeless sense some "real reality" that connects all the "effective realities" by some master symmetry. One might first thinkg that "what's the difference" between effective reality and real reality? From the empirical point within the view of a GIVEN observer, there is no difference since the whole point is that there is no way to distinguish them!

/Fredrik

I know that SR/GR, Evolutionary cosmology ΛCDM, Evolutionary biology, and Quantum Mechanics at the moment are in different parts of the "scientific universe", but how could ever hope to explain the evolution of Homo sapiens from Amœbas? You would need some form of "real reality" there... unless you are going to refer to "interacting amœbas"...? ()

And you still run into problems with the cosmological evolution...

 

[bohm2]

Now look at Matt's email response:

And he's absolutely right. It doesn't depend on your notion of ψ-epistemic or ψ-epistemic ontological either, which you offer no clues to the meaning outside the labels you placed in this singular context with no clarification on even that one context.The authors did perfectly well and sensible with their own words.

For some reason I have a feeling that you are right. It's just most of us including the authors of the most recent critical piece are just too dumb to figure it out. That kind of makes me feel better.

 

[Fredrik]

Not like "the other guy", who build his own "personal reality" without any rules; creating whatever fits the personal divine worldview – a form of "semi-creationism".

I have to say that your continued attacks on Ken G are kind of annoying. It's not the fact that you keep mentioning that you think he's wrong about something. It's the fact that you keep misrepresenting what he's been saying. I'm not interested enough to go look for evidence for this (other than the fact that I remember that I have several times thought it was obvious that you had misunderstood him), but it seems to me that you have many times claimed that he has views that he simply doesn't have. I thought about reporting you, but I decided that I don't want to force any moderator to read this thread.

If I was him, I would find it very offensive. I know how much it annoys me when people repeatedly claim that I believe something crazy just so they can attack some bizarre statement that I've never made and claim to have proved me wrong. This type of behavior is worse than direct insults in my opinion.

 

[Fra]

A group of scientists could/should be seen as "interacting heads"; examining the "reality", creating "the theory", setting up "the experiment", and finally examine "the data", correct?

Yes. (Except the case where head=piece of matter is more interesting)

This far, I think have no problem following the logic, but then I’m kinda lost... are you saying that the expectations (all the way from 'theory-making') is what finally decides the empirical data??

No, that's overstating it and missing the point.

One thing I've learned from PF about this is that it's extremely hard to convey this. Partly this is because this is more like a research program I describe, and the testable results are still not there to judge.

I'll try to explain more later. But the picture I describe is an evolution, in which the expectations of the future, actually influences the future. But I make an important distinction between determined (exactly) and influence. I think more of the expectations as defining the odds, but the cards are still played at random (but guided by the odds).

This means that my take on the laws of physics, is to understand them as equilibrium agreements in a larger generally open game.

This crazy game of "interacting expectations" can actually EXPLAIN certain equilibrium states that are observer in nature.

Again, the analogy I'm pulling here is NOT quite right (so don't overinterpret) but I think it's still a good hint in the right direction to understand my point.

In economy there is the concept of Nash equilibrium:
"If each player has chosen a strategy and no player can benefit by changing his or her strategy while the other players keep theirs unchanged, then the current set of strategy choices and the corresponding payoffs constitute a Nash equilibrium."
-- http://en.wikipedia.org/wiki/Nash_equilibrium (which btw is 1994 nobel winner in economy)

But here, replace "players" with "matter", and the "set of strategy choices" with the "naked" ( non-renormalized) physical actions of matter then the nash equilbrium corresponds to a situation where matter-matter interactions has reached a steady state and where stabel "observer-invariants" can be defined.

Now the idea behind all this, is to understand and predict WHICH observer invariants (symmetries) we have in nature, how the are related, and how they evolve.

My most remote by bold vision is this: To understand the standard model, as well as it's unification with gravity in terms of rational actions of matter onto other matter (the environment).

Another idea is that once you scale complexity down, there are not a lot of choices at all; and if you consider interacting systems of similar construction, predictions (in line with nash type guidelines) of WHICH stable symmetries that are expected once complexity is increased (=lowering the energy -> low energy limit) should be possible.

Ie. the standard model, is to be understood as an "equilibrium point" in an EVOLUTIONARY context. This should include many of the parameters. I'm crazy enough to think this is possible.

/Fredrik

 

[bohm2]

I have to say that your continued attacks on Ken G are kind of annoying...If I was him, I would find it very offensive. I know how much it annoys me when people repeatedly claim that I believe something crazy just so they can attack some bizarre statement that I've never made and claim to have proved me wrong. This type of behavior is worse than direct insults in my opinion.

I agree. I actually learn a lot from Ken G's posts even though I only recently started reading them. His position also seems pretty consistent and not that controversial among many scientists/philosophers. I'm just wondering if his arguments against PBR are similar to the ones advocated by the most recent article. If I recall he gave a somewhat similar criticism, I think?

 

[DevilsAvocado]

I have to say that your continued attacks on Ken G are kind of annoying. It's not the fact that you keep mentioning that you think he's wrong about something. It's the fact that you keep misrepresenting what he's been saying. I'm not interested enough to go look for evidence for this (other than the fact that I remember that I have several times thought it was obvious that you had misunderstood him), but it seems to me that you have many times claimed that he has views that he simply doesn't have. I thought about reporting you, but I decided that I don't want to force any moderator to read this thread.

If I was him, I would find it very offensive. I know how much it annoys me when people repeatedly claim that I believe something crazy just so they can attack some bizarre statement that I've never made and claim to have proved me wrong. This type of behavior is worse than direct insults in my opinion.

Go ahead, my friend, report me.

Then we could perhaps finally get an official name of the theory/interpretation/philosophy, or whatever, that have occupied almost 400+ posts in this thread. As a SA you are of course aware that personal theories/interpretations/philosophies are not allowed on PF.

"Not interested enough to go look for evidence", well, I can’t see how that makes your attack any different from what you think I’ve have done. You’re just guessing that I have no evidence at all.

I have evidence.

So please be my guest and push that button. If I get 'convicted', I have absolutely nothing to lose, since I’m not interested in spending time in a forum that support this kind of ideas, which according to the rules should not be supported.

Take care and good luck!

 

[DevilsAvocado]

Yes. (Except the case where head=piece of matter is more interesting)

No, that's overstating it and missing the point.

One thing I've learned from PF about this is that it's extremely hard to convey this. Partly this is because this is more like a research program I describe, and the testable results are still not there to judge.

I'll try to explain more later. But the picture I describe is an evolution, in which the expectations of the future, actually influences the future. But I make an important distinction between determined (exactly) and influence. I think more of the expectations as defining the odds, but the cards are still played at random (but guided by the odds).

This means that my take on the laws of physics, is to understand them as equilibrium agreements in a larger generally open game.

This crazy game of "interacting expectations" can actually EXPLAIN certain equilibrium states that are observer in nature.

Again, the analogy I'm pulling here is NOT quite right (so don't overinterpret) but I think it's still a good hint in the right direction to understand my point.

In economy there is the concept of Nash equilibrium:
"If each player has chosen a strategy and no player can benefit by changing his or her strategy while the other players keep theirs unchanged, then the current set of strategy choices and the corresponding payoffs constitute a Nash equilibrium."
-- http://en.wikipedia.org/wiki/Nash_equilibrium (which btw is 1994 nobel winner in economy)

But here, replace "players" with "matter", and the "set of strategy choices" with the "naked" ( non-renormalized) physical actions of matter then the nash equilbrium corresponds to a situation where matter-matter interactions has reached a steady state and where stabel "observer-invariants" can be defined.

Now the idea behind all this, is to understand and predict WHICH observer invariants (symmetries) we have in nature, how the are related, and how they evolve.

My most remote by bold vision is this: To understand the standard model, as well as it's unification with gravity in terms of rational actions of matter onto other matter (the environment).

Another idea is that once you scale complexity down, there are not a lot of choices at all; and if you consider interacting systems of similar construction, predictions (in line with nash type guidelines) of WHICH stable symmetries that are expected once complexity is increased (=lowering the energy -> low energy limit) should be possible.

Ie. the standard model, is to be understood as an "equilibrium point" in an EVOLUTIONARY context. This should include many of the parameters. I'm crazy enough to think this is possible.

/Fredrik

Thanks Fredrik, I don’t think it’s crazy at all, and the mere fact that you acknowledge that you are looking for a solution, instead of pretending to be the beholder of the TRUTH and the official spokesman of Niels Bohr, makes your ideas much more worth listen too.

I’ll get back when I’ve understood more (unless I’m not banned by then ).