Interpretation of quantum theories through the interpretation of classical ones

[bayakiv]

TL;DR

Why does classical mechanics or classical field theory do not need interpretation, while quantum theories require interpretation?

Perhaps the reason is that the principle of least action is elevated to a divine principle that does not require materialistic interpretation. If so, then the solution to the "secrets" of quantum theories lies in the solution of the materialistic essence of the physical magnitude of action.

 

[PeterDonis]

Why does classical mechanics or classical field theory do not need interpretation, while quantum theories require interpretation?

It's not that classical theories don't require interpretation. It's that everyone agrees on what that interpretation is, so nobody bothers to belabor the point.

Whereas everyone does not agree on the interpretation of QM; there are different, mutually inconsistent interpretations and no consensus on which one is right. (It's even possible that none of the ones we currently have are right.) So there is a lot of discussion about QM interpretation, whereas there isn't about the interpretation of classical physics.

 

[Demystifier]

Summary:: Why does classical mechanics or classical field theory do not need interpretation, while quantum theories require interpretation?

Because classical theories have a clear ontology, while quantum theories do not. Ontology is the thing supposed to exist in nature irrespective of observation. For instance, the Moon has a position even if nobody observers it according to classical mechanics, but it's not so obvious in quantum mechanics. For a large molecule it is even less obvious, and for a single atom or an electron it is even less less obvious.

 

[EPR]

I always question the common sense interpretation of classical mechanics. I think many physicists do.

 

[PeterDonis]

I always question the common sense interpretation of classical mechanics.

On what grounds?

I think many physicists do.

Can you give any references?

 

[EPR]

On what grounds?
Can you give any references?

On the grounds that realism fails in the quantum world.
There's also a theorem that rules out local realism per se.
https://www.nature.com/articles/nature15631

 

[Vanadium 50]

Why does classical mechanics or classical field theory do not need interpretation

I would consider "image charges" to fall into that category.

while quantum theories require interpretation?

Perhaps the reason is that the principle of least action is elevated to a divine principle

That's incorrect and hostile.

 

[StevieTNZ]

On the grounds that realism fails in the quantum world.
There's also a theorem that rules out local realism per se.
https://www.nature.com/articles/nature15631

Do note:

Some almost metaphysical loopholes remain open — if the results can be replicated with humans, rather than machines, freely choosing the measurement settings and consciously registering the outcomes, then the coffin will have been interred and buried.

from the article

 

[PeterDonis]

On the grounds that realism fails in the quantum world.

The fact that the Bell inequalities are violated (which is what "realism fails" refers to in the paper you linked to) does not, IMO, pose any problem for the interpretation of classical mechanics. After all, the very physicists who wonder about "realism failing in the quantum world" have no issue at all with applying straightforward classical interpretations to things like the readings of experimental devices or the records of results as published in physics papers. So I think the idea that whatever issues with "realism" might exist in "the quantum world" poses a problem for the interpretation of classical mechanics is self-defeating.

 

[Jarek 31]

Perhaps the reason is that the principle of least action is elevated to a divine principle that does not require materialistic interpretation.

While classically we have single action optimizing trajectory/history, in QM we have Feynman ensemble among them instead ... in which mathematically dominate variations around classical trajectory (van Vleck formula etc.).

There is similar analogy in thermodynamics - naively we say that system is in minimal energy configuration ... which should be rather seen as approximation of Boltzmann ensemble of configuration, e.g. in Ising model (also getting e.g. Born rule: https://www.physicsforums.com/threa...sing-model-feynman-boltzmann-ensemble.995234/ ).

 

[bayakiv]

While classically we have single action optimizing trajectory/history, in QM we have Feynman ensemble among them instead ... in which mathematically dominate variations around classical trajectory (van Vleck formula etc.).

Well, even if the classical action is unique, and the quantum action is multiple, but would the materialistic interpretation of action be superfluous for understanding?

 

[bayakiv]

That's incorrect and hostile.

I do not understand.

 

[Jarek 31]

Imagine a jello - attaching forces, it deforms to "to minimize tension", energy.
Going to Lorentz invariant field theories like EM, this "jello" is in 4D spacetime - this time minimizing action.

But generally action is only our mathematical description of such "tension minimizing jello".

 

[bayakiv]

The interpretation of action by the stress of the environment seems to be not new, but it did not add anything new to understanding. I prefer the interpretation of the action as a distance traveled in a space with a neutral metric (in a doublet of Minkowski spaces).

 

[Jarek 31]

Indeed for trajectories we can use Fermat's principle of least time, e.g. for geodesics.
But for fields we need some tension optimization intuition - formalized in Lagrangian, action optimization.

 

[bayakiv]

If you look at post #10 in thread Geometry of matrix Dirac algebra , you will understand that the action for the field of accelerations of matter is interpreted there as the distance traveled by a particle of matter on the surface of a seven-dimensional sphere. This is how the action for fields is determined, and in the case of particles, the action is measured by the distance traveled by the feature of the vector field of accelerations of matter over the surface of the seven-dimensional sphere.

 

[PeterDonis]

I do not understand.

He means that terms like "divine principle" are inappropriate for a scientific discussion.

 

[bayakiv]

He means that terms like "divine principle" are inappropriate for a scientific discussion.

If this is so, then it is possible to change the wording to assert the need for a philosophical and mathematical understanding of the principle of least action. In general, the materialistic interpretation of action is the key to the correct interpretation of quantum theory.

 

[PeterDonis]

If this is so, then it is possible to change the wording to assert the need for a philosophical and mathematical understanding of the principle of least action. In general, the materialistic interpretation of action is the key to the correct interpretation of quantum theory.

Please give a reference for the QM interpretation you are describing here. Even though this is a forum about interpretations, discussion still needs to be based on valid references; it is not for discussion of people's personal opinions about QM.

 

[PeterDonis]

You insist on a link, but do not trust https://www.researchgate.net/

You either provide a reference, which we evaluate, or your thread gets closed. Claiming that PF does not "trust" the site your reference is from does not relieve you from that requirement. You provided no reference, so this thread is now closed.