I Does a "physically real" quantum interpretation exist?

[A. Neumaier]

To me its weird to identify a mathematical expression with physical properties. Physical properties are due to measurements.

All physical properties we talk about in physics have both a mathematical expression and a meaning in terms of measurements.

But measurements have no priority. Forces have been felt by people long before they were first measured by Galilei.

 

[timmdeeg]

All physical properties we talk about in physics have both a mathematical expression and a meaning in terms of measurements.

So leaving aside whether measurable or not which physical properties are described by the wave function?

 

[A. Neumaier]

So leaving aside whether measurable or not which physical properties are described by the wave function?

Scattering probabilities under all kinds of scattering experiments, and detection probabilities for certain kinds of measurements. These are physical properties of the sources and detectors in the experiments.

 

[martinbn]

So leaving aside whether measurable or not which physical properties are described by the wave function?

Different people may have different opinions, and different interpretations may say all kinds of things, but QM says that there isn't anything in addition to the wave function. So all properties are described by it.

 

[A. Neumaier]

Different people may have different opinions, and different interpretations may say all kinds of things, but QM says that there isn't anything in addition to the wave function. So all properties are described by it.

In addition to wave functions there must at least be measurements, since Born's rule is about them.

And we need much more to 'be there' to be able to relate wave functions to our everyday reality. We don't see, hear, or touch wave functions....

 

[timmdeeg]

Scattering probabilities under all kinds of scattering experiments, and detection probabilities for certain kinds of measurements. These are physical properties of the sources and detectors in the experiments.

If we leave everything in the context of the the probability density aside are there still other physical properties?

 

[martinbn]

In addition to wave functions there must at least be measurements, since Born's rule is about them.

And we need much more to 'be there' to be able to relate wave functions to our everyday reality. We don't see, hear, or touch wave functions....

Yes, but this is not the question! His question was what properties are described by the wave function. The fact that one needs measurments and that the particles and fields are there is somthing different.

 

[WernerQH]

So we are still pondering the question: How does the wave function relate to the real world?

 

[A. Neumaier]

So leaving aside whether measurable or not which physical properties are described by the wave function?

QM says that there isn't anything in addition to the wave function. So all properties are described by it.

Yes, but this is not the question! His question was what properties are described by the wave function. The fact that one needs measurments and that the particles and fields are there is somthing different.

???

If there isn't anything in addition to the wave function then, since there are measurements, meansurements must be described by it.

But if the only property of a wave function is the wave function itself, and nothing of it refers to reality then the wave function is irrelevant to reality, hence to physics.

 

[A. Neumaier]

If we leave everything in the context of the probability density aside are there still other physical properties?

Beyond the probabilistic properties, everything is controversial. What else is physical about it depends on the interpretation of quantum mechanics assumed.

My thermal interpretation claims that all quantum expectation values computable from it are potentially physical properties.

Bohmians think that wave functions guide particles along their paths, and therefore exert physical forces.

Those who think the wave function encode only subjective knowledge presumably have to conclude that the wave function describes certain properties of observer brains.

 

[timmdeeg]

Beyond the probabilistic properties, everything is controversial. What else is physical about it depends on the interpretation of quantum mechanics assumed.

Like MWI, thanks.

My thermal interpretation claims that all quantum expectation values computable from it are potentially physical properties.

I've been following partly a long Thread some time ago, where you explained your TI. If I remember correctly it concern mainly the measurement problem, not physical properties prior to measurement. - Perhaps my memory is wrong.

Those who think the wave function encode only subjective knowledge presumably have to conclude that the wave function describes certain properties of observer brains.

 

[A. Neumaier]

I've been following partly a long Thread some time ago, where you explained your TI. If I remember correctly it concern mainly the measurement problem, not physical properties prior to measurement. - Perhaps my memory is wrong.

Since the TI is a realistic theory, quantum systems have definite physical properties all the time, determined by their state (in general a mixed state). Measurements produce limited accuracy approximations to these physical properties, just like in classical physics.

Section three of my new paper
https://www.physicsforums.com/threads/the-born-rule-100-years-ago-and-today.1078546/
and then part II of my book
https://www.physicsforums.com/threads/new-book-on-algebraic-quantum-physics.1065600/
would be a good introduction to the meaning of quantum mechanics (in general, and some touch of the TI).

 

[PeterDonis]

which physical properties are described by the wave function?

That depends on which QM interpretation you adopt; answers range from "none" to "all of them".

 

[physika]

And how would you describe "that what remains" using physical terms? The latter because we talk about a describable physical reality.

Describable or not, what there is.

Reality does not need to be describable (in principle) to exist/stay there.


......

 

[RUTA]

Does Fuchs reveal "the cause of this year-after-year sacrifice to the 'great mystery'"?

The religious analogy is perhaps amusing, but creating sects is not what scientists are striving for. And the number of interpretations (or what is passed off as such) has increased dramatically since I learnt quantum mechanics (half a century ago)! For me this is a symptom of an underlying unsolved problem. And it's only rationalization, or resignation to say that the interpretations are all equally "reasonable". It's unclear what quantum theory is about. Many people would like a better answer to the question than that it is about "wave functions", "quantum objects", or "measurements". (Of course there are also those who have given up and claim that the mathematical formalism is all that's needed.)

Maudlin wrote an entire book on the problem called "Quantum Non-Locality and Relativity" (I think it's in the third edition now). Essentially, he shows how any constructive (causal) account of entanglement must violate locality and/or statistical independence (SI). Physicists don't want to abandon causal explanation, locality or SI, thus the endless debate, i.e., "year-after-year sacrifice to the 'great mystery'"

 

[Lord Jestocost]

Maudlin wrote an entire book on the problem called "Quantum Non-Locality and Relativity" (I think it's in the third edition now). Essentially, he shows how any constructive (causal) account of entanglement must violate locality and/or statistical independence (SI). Physicists don't want to abandon causal explanation, locality or SI, thus the endless debate, i.e., "year-after-year sacrifice to the 'great mystery'"

Jan Faye, a Danish philosopher of science, points out to what physicists might be ‘infected with' so that they are ‘entangled’ in this endless debate. In his article “Complementarity and Human Nature” (in the book “Niels Bohr and the Philosophy of Physics: Twenty-First-Century Perspectives” (edited by Jan Faye and Henry J. Folse, published 2017)), he remarks:

By nature we are born realists. There is a world outside of ourselves, and it is more or less as we experience it. This kind of common-sense realism is included as a part of our innate cognitive understanding of the world. But it is the same instinct that drives many physicists to interpret their theories realistically. The disease which infects those physicists is not realism as such but representationalism, the view that "knowing" something means being able to "picture" what something looks like when nobody is looking at it, a canvas of reality painted by a ghost spectator. The realist instinct explains quite naturally their realistic tendencies. Yet, there are good reasons to believe that their realistic interpretation causes them to postulate a reality that we are completely unable to have knowledge about.

 

[DaddyCool]

Quantum physics has shown that all possible descriptions of an hypothetical underlying physical reality are incompatible with experimental data. Therefore, Idealism (essentially the view of the Irish philosopher George Berkeley) provides the only logically consistent interpretation of quantum mechanics. But most physicists do not accept idealism because it contradicts their personal beliefs, so they prefer an objectively wrong interpretation that gives them the illusion that quantum mechanics is compatible with realism.

 

[Nugatory]

but most physicists do not accept idealism because it contradicts their personal beliefs

There’s a selection effect at work here. Idealism is sufficiently incompatible with empirical science that those who accept the former are unlikely to be practitioners of the latter.

The forum rules include: “Philosophical discussions are permitted only at the discretion of the mentors and may be deleted or closed without warning or appeal”. You have made the point that Berkeley’s idealism sweeps away the foundational problems of quantum physics, and that’s as far as the discussion should go.

 

[PeterDonis]

Thread closed for moderation.