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What is the default position in the mind-body problem?

Nous

Well-Known Member
Premium Member
Quantum mechanics.
Quantum mechanics is a theory, not a mechanism.

My question was in response to your claim that it seems undeniable to you "that the world is physical (i.e. composed of matter/energy) in nature." Obviously "matter/energy" do not account for the correlations found in the tests of Bell and Legget-Garg inequalities, in which the postulates of local realism are violated.
 

siti

Well-Known Member
Quantum mechanics is a theory...
...that explains how physical reality works at sub-atomic levels. But the position you seem to be taking here is philosophically unsound on at least two grounds:

1. You are committing a cum hoc ergo propter hoc fallacy of the exact kind you railed against in another thread recently. You are making the assumption that correlation implies causality by claiming that the experimenter's 'choice' IS the cause of the correlation between "Alice" and "Bob's" observations. There is correlation and that is very intriguing. It does appear that there is a non-local collapse of the wavefunction that simultaneously manifests in instruments in spatially separated 'labs'. It is not possible to explain this in terms of classical models of physical reality - that is true - and is the point of the experiment in fact. The results correspond to the predictions of quantum mechanics, but exactly how that works (in this kind of experiment) nobody knows and that brings us to the second ground...

2...You are also arguing ad ignorantium... you are suggesting that because we (currently) know of no physical model of reality that can explain this, there must be a non-physical explanation. But it may simply be that there is an as yet unknown physical model that will ultimately provide a perfectly good explanation. It may not be "classical", "local" or "determined" - but does that mean it is not "real" or "physical"?

Just because our predefined limits of "real" and "physical" are "violated" doesn't mean we have entered an entirely new realm of a-physical unreality. Its like the old maps - where it used to say "here be dragons" or when that naughty little pup "Toto" pulled back the curtain on the Wizard of Oz - well - there weren't really dragons or wizards after all - it was just more of the same only different.
 

Nous

Well-Known Member
Premium Member
...that explains how physical reality works at sub-atomic levels. But the position you seem to be taking here is philosophically unsound on at least two grounds:

1. You are committing a cum hoc ergo propter hoc fallacy of the exact kind you railed against in another thread recently. You are making the assumption that correlation implies causality by claiming that the experimenter's 'choice' IS the cause of the correlation between "Alice" and "Bob's" observations. There is correlation and that is very intriguing. It does appear that there is a non-local collapse of the wavefunction that simultaneously manifests in instruments in spatially separated 'labs'. It is not possible to explain this in terms of classical models of physical reality - that is true - and is the point of the experiment in fact. The results correspond to the predictions of quantum mechanics, but exactly how that works (in this kind of experiment) nobody knows and that brings us to the second ground...

2...You are also arguing ad ignorantium... you are suggesting that because we (currently) know of no physical model of reality that can explain this, there must be a non-physical explanation. But it may simply be that there is an as yet unknown physical model that will ultimately provide a perfectly good explanation. It may not be "classical", "local" or "determined" - but does that mean it is not "real" or "physical"?

Just because our predefined limits of "real" and "physical" are "violated" doesn't mean we have entered an entirely new realm of a-physical unreality. Its like the old maps - where it used to say "here be dragons" or when that naughty little pup "Toto" pulled back the curtain on the Wizard of Oz - well - there weren't really dragons or wizards after all - it was just more of the same only different.
How ridiculous. I did not perpetrate any logical fallacy by pointing out the fact that what you define as "physical" ("matter/energy") does not account for the correlations that violate the postulates of local realism.
 

siti

Well-Known Member
I did not perpetrate any logical fallacy by pointing out the fact that what you define as "physical" ("matter/energy") does not account for the correlations that violate the postulates of local realism.
The fallacy is in the underlying assumption that just because there is a gap in our understanding of physical reality, reality must be unreal or non-physical. You were arguing against the idea that physicalism should be the default position in the search for a solution to the "mind-body problem". If that is not what you meant then your comments are irrelevant to this discussion, it that is what you meant then they are fallacious in the context of this discussion. If my comment is "ridiculous" feel free to demonstrate that - by ridicule if you must - I have a thick skin - I shan't be offended.
 

Nous

Well-Known Member
Premium Member
The fallacy is in the underlying assumption that just because there is a gap in our understanding of physical reality, reality must be unreal or non-physical.
The fact that the correlations of entangled particles violate the postulates of local realism is not due to some "gap in our understanding". It's an empirical fact. The scientific evidence consistently substantiates this fact. Neither matter nor energy propogates at superluminal speeds so as to account for these correlations. That's also a well established empirical fact, not a claim made based on a "gap in our understanding".

Indeed, as Popescu notes in the paper cited above, "recent research seems to suggest the possible existence of nonlocal correlations stronger than those predicted by [quantum mechanics]."

Physicalism is a false religion. God knows, it's time to give it up. Get a new one.
 

siti

Well-Known Member
The fact that the correlations of entangled particles violate the postulates of local realism is not due to some "gap in our understanding".
Correct - the gap in our understanding is our inability to explain the correlations.

Neither matter nor energy propogates at superluminal speeds so as to account for these correlations. That's also a well established empirical fact, not a claim made based on a "gap in our understanding".
Correct again - so does that suggest that reality is not physical or that we just don't understand physical reality well enough to explain it? Does it suggest that whatever it is that causes "information" (whatever that is) to manifest itself at the "other side of the universe" (as it were - as it is even a few meters away if we are talking about requiring superluminal velocity to get there in time) instantaneously is nothing to do with matter or energy at all even though there is no way (as far as we know) to initiate such an "event" that does not depend on the physical manipulation of matter/energy?
 

Nous

Well-Known Member
Premium Member
Correct - the gap in our understanding is our inability to explain the correlations.
What? The correlations found in the tests of Bell and Leggett-Garg inequalities are explained as the product of the quantum properties being entangled in a world that is nonlocal and nonrealistic.

Correct again - so does that suggest that reality is not physical or that we just don't understand physical reality well enough to explain it?
Nothing in any of those experiments or any other experiments suggests that either matter or energy causes effects nonlocally. Therefore the correlated properties are not explained as the effects of matter or energy.

Again, the thesis of physicalism that you describe was empirically refuted long ago. You need a new religion. You need to update it at least to the early part of the 20th century.
 

Polymath257

Think & Care
Staff member
Premium Member
Quantum mechanics is a theory, not a mechanism.

My question was in response to your claim that it seems undeniable to you "that the world is physical (i.e. composed of matter/energy) in nature." Obviously "matter/energy" do not account for the correlations found in the tests of Bell and Legget-Garg inequalities, in which the postulates of local realism are violated.

Of course matter and energy explain such correlations! But matter and energy don't have the properties of the classical viewpoint. Instead, they have the properties of the quantum viewpoint.So, instead of having definite properties at all times (realism), they have probabilities of different values being measured for different properties. The correlations are determined at the point of entanglement (usually the point of formation of the entangled pair). No action at a distance occurs (so, QM is a local theory).

So, yes, local realism is violated. Instead, QM describes these things as local but non-realistic.
 

Polymath257

Think & Care
Staff member
Premium Member
What? The correlations found in the tests of Bell and Leggett-Garg inequalities are explained as the product of the quantum properties being entangled in a world that is nonlocal and nonrealistic.
No, it is local but non-realistic. The correlations propagate in a local fashion.

Nothing in any of those experiments or any other experiments suggests that either matter or energy causes effects nonlocally. Therefore the correlated properties are not explained as the effects of matter or energy.

On he contrary, matter and energy are described via quantum mechanics, not via classical mechanics. And in quantum mechanics, the properties of matter and energy are probabilistic, not realistic. But the probabilities propagate locally.

Again, the thesis of physicalism that you describe was empirically refuted long ago. You need a new religion. You need to update it at least to the early part of the 20th century.

Well, physicalism *today* means that the quantum properties of matter and energy are included.
 

Nous

Well-Known Member
Premium Member
No, it is local but non-realistic. The correlations propagate in a local fashion.



On he contrary, matter and energy are described via quantum mechanics, not via classical mechanics. And in quantum mechanics, the properties of matter and energy are probabilistic, not realistic. But the probabilities propagate locally.



Well, physicalism *today* means that the quantum properties of matter and energy are included.
Be sure to prove all of your claims here.
 

Polymath257

Think & Care
Staff member
Premium Member
Correct - the gap in our understanding is our inability to explain the correlations.

But we can and do explain those correlations! That is what quantum mechanics is all about! The entangled pair is formed in the decay (usually) of a previous symmetric state. The entanglement *means* that the properties are and will remain correlated. Those correlations propagate until the properties of the two particles are measured. There is no 'action at a distance'. The correlations are determined in the past light cone of both particles.

Correct again - so does that suggest that reality is not physical or that we just don't understand physical reality well enough to explain it? Does it suggest that whatever it is that causes "information" (whatever that is) to manifest itself at the "other side of the universe" (as it were - as it is even a few meters away if we are talking about requiring superluminal velocity to get there in time) instantaneously is nothing to do with matter or energy at all even though there is no way (as far as we know) to initiate such an "event" that does not depend on the physical manipulation of matter/energy?

And this is just false. The correlations we measure were predicted and explained long before they were measured. Some people thought of these correlations as counter-intuitive (which they are if you are fixated on a classical world view) and doubted they would show up in real-world experiments. But they did. And the details of those correlations are in perfect agreement with the predictions of QM.
 

Polymath257

Think & Care
Staff member
Premium Member
Prove it.

Prove it. What are "the properties of the classical viewpoint"? Provide references.

Prove it.

The classical viewpoint has matter made of particles with unique properties where the forces are propagated at finite speeds (although Newtonian gravity isn't local in this sense).

You ask me to prove that QM is a local theory. Well, what does that mean? It means, in this case, that the probabilities and correlations propagate at a finite speed that is less than the speed of light. And that is the case for quantum field theories. The difference between the quantum viewpoint and the classical one is that QM predicts the probabilities and correlations and not the specific events: everything is ultimately probabilistic. So, matter usually does NOT have definite properties, but rather probabilities.

I can only point you to proper treatments of QM for further support. But any good book on quantum field theory will answer your questions.
 

Polymath257

Think & Care
Staff member
Premium Member
Be sure to prove all of your claims here.

The very experiments you point do show that QM works to describe matter and energy. Remember that the correlations you rightly point to were predicted by QM.
 

Polymath257

Think & Care
Staff member
Premium Member
Be sure to prove all of your claims here.

What would you consider to be proof?

A reference to a quantum field theory book?
A quantum mechanical treatment of the Arrow experiment?
A specific equation that shows QM to be local?

The problem is that if you have ever *really* done QM, then you would know it isn't realistic (particles do not have specific properties at all times). And if you have done quantum field theory, you would know that it is local (no propagation faster than the speed of light).
 

Nous

Well-Known Member
Premium Member
The classical viewpoint has matter made of particles with unique properties where the forces are propagated at finite speeds
And you claim that "matter and energy don't have the properties of the classical viewpoint". Prove your claim that matter and energy do not propogate at finite speeds.

You ask me to prove that QM is a local theory. Well, what does that mean? It means, in this case, that the probabilities and correlations propagate at a finite speed that is less than the speed of light.
Then how do you account for the correlations that violate the postulates of locality and realism as defined by Bell and Leggett-Garg inequalities?

Above I noted what Bell said about the theorem that he proved: "If [a hidden variable theory] is local it will not agree with quantum mechanics, and if it agrees with quantum mechanics it will not be local. This is what the theorem says." So you're saying that Bell was just wrong about QM being a nonlocal theory?

And I linked to a paper on an experiment that found that the collapse of the wavefunction of a single photon is nonlocal. And you are saying that that is wrong?
 

siti

Well-Known Member
What? The correlations found in the tests of Bell and Leggett-Garg inequalities are explained as the product of the quantum properties being entangled in a world that is nonlocal and nonrealistic...Nothing in any of those experiments or any other experiments suggests that either matter or energy causes effects nonlocally. Therefore the correlated properties are not explained as the effects of matter or energy.
So what (if not matter or energy) was measured and how? How (without the physical manipulation of matter or energy) was the experiment - any experiment - performed? Can you cite a single experiment that has ever been done that did not depend on physical measurements?
 

Nous

Well-Known Member
Premium Member
So what (if not matter or energy) was measured and how?
What is measured in the tests of the Bell and Leggett-Garg inequalities is whether the results are consistent with or violate the inequalities.

How (without the physical manipulation of matter or energy) was the experiment - any experiment - performed? Can you cite a single experiment that has ever been done that did not depend on physical measurements?
Do you understand that the correlations between Alice's findings and Bob's findings are not the effect of matter or energy?
 
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