Timeline for What is the definitive evidence we have that quantum theory's probabilistic nature is physical and not epistemic?
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14 events
| when toggle format | what | by | license | comment | |
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| Apr 19, 2021 at 10:24 | vote | accept | Markoul11 | ||
| Feb 27, 2021 at 9:07 | comment | added | Ruslan | @cmaster-reinstatemonica no, it's not hard at all. For one, you have a local wavefunction (not the Schrödinger's one, but e.g. the solutions of Dirac equation, Maxwell's equations). From this we can calculate all the measurable quantities without actually thinking about interpretations (AKA "shut up and calculate"). Physics doesn't really depend on the interpretation: all the interpretations either have to be consistent with the core theory (QM/QFT), or else they have testable predictions that diverge from it and are potential discoveries. | |
| Feb 27, 2021 at 8:43 | comment | added | cmaster - reinstate monica | @Ruslan Isn't it a bit hard to do physics when you opt for non-realism? I'd have thought that physicists mostly accept the non-locality, even though grudgingly. | |
| Feb 27, 2021 at 8:20 | comment | added | Ruslan | @cmaster-reinstatemonica that's a matter of interpretation. The fact that a theory contains these non-local objects doesn't automatically make them belong to the physical world. Some people are more comfortable with non-realism, others with non-locality. You just seem to be of the latter type. | |
| Feb 27, 2021 at 0:21 | comment | added | cmaster - reinstate monica | @Ruslan Which means that the fact remains that our physical world actually has non-local parts. It doesn't matter whether those non-local parts are observable or hidden variables, the non-locality is the fact that we need to digest. It's precisely this non-locality which makes quantum mechanical effects like entanglement so counterintuitive (and cool, and powerful...). That is the key take-away from the Bell test, imho. | |
| Feb 26, 2021 at 19:27 | comment | added | Ruslan | @Markoul11 the Bell's inequalities haven't quite "disproved" the hidden variables: they only forbid local hidden variables. For nonlocal ones there's e.g. de Broglie–Bohm theory, which reproduces the predictions of QM, but also predicts (unobservable) trajectories. | |
| Feb 26, 2021 at 18:28 | comment | added | Andrew | @annav Yes, it's good very smart people are around who don't simply accept the status quo and try to challenge it. It may be that I am just not smart and bold enough to see how to make progress in this direction. | |
| Feb 26, 2021 at 18:08 | comment | added | anna v | G. 't Hooft is a user on this site, and he is working on trying to find a deterministic theory , and has had discussions on this site on this subject | |
| Feb 26, 2021 at 16:19 | comment | added | Andrew | @Markoul11 According to quantum mechanics, there are no hidden variables. Quantum mechanics is all you need to understand the behavior of entangled spins. Personally, given what we know experimentally and theoretically, I think it is overwhelmingly likely that quantum mechanics is a correct and complete description of Nature. | |
| Feb 26, 2021 at 16:08 | comment | added | Markoul11 | If assuming the "hidden variables" refer exactly to these physical mechanics and procedures which generate the specific values of these intrinsic properties of the particles, I find it very peculiar how a change of the spin of an entangled particle is not affected by these hidden mechanics? Maybe the hidden variables are entangled too? | |
| Feb 26, 2021 at 16:08 | comment | added | Andrew | @Markoul11 Well, for one thing, intrinsic properties of elementary particles like mass and charge are not hidden since we can measure them :) More seriously, the "hidden variables" idea is that quantum mechanics is only an approximation to the true theory. In the true theory, we would find that physics really is deterministic, not probabilistic. Quantum mechanics only appeared to be probabilistic because we didn't have all the information (kind of like thermodynamics). But this idea doesn't really work. Also I should clarify Bell's inequalities only disprove local hidden variables. | |
| Feb 26, 2021 at 16:01 | comment | added | Markoul11 | Thank you for your insightful answer and also bringing up the subject of "hidden variables" which was disproved by Bell's inequalities experiment. However, I never understood what the difference is between "hidden variables" and the intrinsic properties of elementary particles? It is my understanding that in the case of the intrinsic properties, these are fixed stable values, parameters, that can be measured but the mechanics of how these came to be is unknown. | |
| Feb 26, 2021 at 15:59 | history | edited | Andrew | CC BY-SA 4.0 |
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| Feb 26, 2021 at 15:14 | history | answered | Andrew | CC BY-SA 4.0 |