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Starting from the answers to this question, even people not familiar with the interpretations of quantum mechanics can understand that physicists are not interested in substance metaphysics. This is understandable, as the scientific method requires experimentally verifiable predictions. But the result is a quite unsatisfying lack of answers to the "why" and "how" questions inherent to our nature.

I was attracted to science from an early age, because I had seen that countless key questions could be answered unequivocally. I was initially surprised to discover the limits in understanding we had hit with QM. But I was actually annoyed to see that the people most qualified to provide answers that could help make sense of the quantum weirdness had given up for decades. I now understand the reasoning, but will never accept that "x just is and doesn't make sense" or that "y can never be understood". It sounds too much like religion's cheap cop-out that our minds can't hope to understand God.

So who does the task of tackling these hard questions fall to? Scientists who dabble in philosophy and aren't afraid to publish unscientific theories? Philosophers who dabble in physics or read popularized versions of experimental results and interpretations of QM? Or has the academic community overall decided to give up on substance metaphysics? So we leave it to journalists to take interpretations like multiple worlds and present them as reasonable explanations of how the universe works? (I know the math for MWI works out, but I personally find it a ridiculous theory, that took Occam's razor and used it to shear sheep)

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    "But the result is a quite unsatisfying lack of answers to the "why" and "how" questions inherent to our nature." FWIW, this problem started with Newton's theory of gravity. His famous gravitational equation described how gravity worked, but he was totally unable to explain how or why it worked. He took a lot of criticism for that at the time. Ever since then, it's been understood that science describes, but does not necessarily explain, natural phenomena. Sean Carroll is one physicist interested in interpretations, particularly Many Worlds. He has Youtube videos of great interest.
    – user4894
    Jun 1 at 21:42
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    MWI is an interpretation, not a theory.
    – Sandejo
    Jun 1 at 22:21
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    It is one thing to ask "why" and "how" questions about quantum mechanics, but it is another to insist that the answers must adhere to substance metaphysics, or that it is inherent to our nature. One lesson of quantum mechanics is that substance metaphysics is not the only option, and that its presuppositions are too tightly linked to our experience with macroscopic objects, and likely too naive when it comes to the fabric of the world. It is not that people gave up on answering "what is a quantum particle like?", it is that they moved on to more sophisticated answers than classical analogies.
    – Conifold
    Jun 1 at 22:36
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    What you call "an idea that makes sense" is exactly a classical analogy, a mechanical model or something like it, a peek "behind the curtain" but in familiar terms. That is exactly the limitation of substance metaphysics, object permanence that we learn in early childhood when navigating a room, which underpins the concept of substance. Quantum objects lack this permanence, they do not stay there when "we" (interacting system) look away, they are creatures of interaction manifested in discrete events. Substance interpretations exist (Bohmianism), but they are at best awkward and unwieldy.
    – Conifold
    Jun 2 at 4:54
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    "Copenhagen interpretation" is not really an interpretation, it is a cloud where each can discern their own shapes with minimal constraints. And "real" wave functions, multidimensional and non-local, Bohmian particles, etc., still cling to the stereotype of object permanence, ideas that make sense need not. Mathematics simply resists permanence interpretations, they break symmetries and equivalences of the theory in arbitrary ways to fit a preconceived idea. Metaphysics based on events, transactions or some other primitives instead of substances produces more organic interpretations.
    – Conifold
    Jun 2 at 6:23
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I agree with Conifold; here are my perspectives.

The general position of physicists on the "x just is and doesn't make sense" issue (also known as the shut up and calculate paradigm) is not that we have given up all hope of making sense of QM's predictions, but that 1) QM is under no obligation to "make sense" to even an extremely clever human mind which occupies a macroscopic, non-QM world, and 2) at the present moment we have no good candidates in hand for a brand new interpretation or mathematical conception of QM which "makes sense" (this is known as the foundational problem of quantum mechanics).

What constitutes a "quite unsatisfying lack of answers" is entirely a matter of opinion and in this context, those best qualified by actual experience to offer opinions on that are the practitioners themselves i.e., those who write down the equations and mathematically solve them for a living. If you can't do the math, whatever you might think about whether or not the "lack of answers" is in fact real and whether or not that is quite unsatisfying isn't relevant. I furnish here an analogy:

Imagine you have a new conception of the meaning and significance of the classic ancient Greek plays. Now, anyone who wants so can come up with any interpretation of those plays they wish, without justifying that interpretation to anyone at all. But if someone from the community of ancient Greek scholars then asks you if you 1) know how to read ancient Greek and 2) have used that skill to read the plays in their original form and you answer "no" to both questions, the chance that you will add anything of value to the body of knowledge on ancient Greek plays is so small that no one in the community is going to spend their time reading your thesis- especially when there is no shortage of unsolved problems in the field to work on.

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    I agree with everything you wrote, except for the "no good candidates" part. What I see is physicists not being concerned with it ever making sense. Without effort from the people who understand it to come up with models that will produce the same results but help us picture it a bit too, it's not going anywhere. Ex Jun 2 at 0:58
  • A question for you niels. I just stumbled on a paper that was written by the other option I mentioned, people working on philosophy of science. It contains references to a history of ideas that I was oblivious to, as they are not in the traditional list of interpretations. They are clearly not part of the community you mentioned in the analogy, but does that mean they don't add to the body of knowledge? Link: taylorfrancis.com/chapters/edit/10.4324/9781315713151-12/… Jun 2 at 3:01
  • @ChristopherAkritidis, I do not have access to the paper (unwilling to pay for a download), but all three authors are professional philosophers and not mathematical physicists. I am going to bet that while they may add to the body of philosophical knowledge, they aren't adding to that of physics. If you have a download perhaps you could share it to killowatt@gmail.com so I could have a look- NN Jun 2 at 6:15
  • Sorry, a PDF is available below, but are interpretations considered part of the body of knowledge of physics? I thought it's really metaphysics... philarchive.org/archive/NEYSLA Jun 2 at 18:41
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It is clear based on the discussions and links in the comments that the task has been picked up by non-physicists, with several modern attempts at providing different interpretations. Very few (if any) of the authors are able to do the math themselves, but they seem to be consulting the people who can, to ensure that their proposals are compatible with observations. Some of the interpretations may be quite difficult to grasp and others may be unsettling, but I was very happy to learn that work is ongoing and that we haven't given up. Special thanks to @Conifold for his pointers.

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There are physicists who approach the problem to satisfy their ontological needs. The are not content with just shutting up and calculating. David Bohm is one of them. If the by him repicked up version of de Broglie's pilot wave was taken seriously we would have been left with something less vacuuous than the now standard Copenhagen view. History decided not to take this path though and we are stuck with numerous interpretations to account for the collapse of the wave function. The many worlds being one of these outlandish attempts.

The hidden variable approach by Bohm is a viable version but because so little people pursue it it is not yet fully fledged. The main problem is agreement with special relativity but this problem can be surmounted by choosing the right hidden variables. It is often said that the Bell experiment contradicts the existence of these variables but it merely rules out local hidden variables and yiu can imagine that these are exactly the ones not needed. My country fellow man and Noble prize winner van 't Hooft tries to figure out a deterministic approach too. He is not happy shutting up. Or just to calculate, though his Noble Prize was awarded for his showing of the renormalizability of certain field theories. Of course hidden variables have their drawbacks too. They are hidden! But they at least offer an explanation devoid of empty probability.

So there are not just journalists trying to look for the meta stuff. There are also many physicists who consider the MWI to be the ultimate theory but they put to many emphasis on unitarity and serve us the most science fictional idea ever.

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    What is advantage of hidden variables (initial conditions) over probability?
    – Anixx
    Jul 6 at 1:03
  • @Alex That it explains the pronabilities. How can anything be inherently probabilistic? You can say that it is QM and that we just cant understtand its nature but I think hidden variables are more comprehensible than inherent probability. Of course will the nature of these variables stay, well, hidden. Jul 6 at 7:31
  • You will just make your initial variables random. That is, making random one variable instead of another.
    – Anixx
    Jul 6 at 10:40
  • @Anixx Exactly! Every time the wave function collapses the variables are reset. They give rise to a new probability distribution. Jul 6 at 11:00
  • The irony is Bohm himself didn't take his proposal seriously because it requires a metaphysical configuration space, he was only aiming to show that it was possible in principle to do something like that. See Hossenfelder on why the physics community was & is against it: backreaction.blogspot.com/2020/10/… KJ Bostrom identified the 'empty' pilot waves as implying the same situation as some takes on MWI. Eg Hawkings
    – CriglCragl
    Jul 6 at 12:31

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