So did Bohm, he didn't interpret QM but introduced an entirely new concept, i.e., introducing a new description of microscopic phenomena and a new realization of uncertainty relations.vanhees71 said:Einstein didn't intepret Lorentz ether theory but introduced an entirely new concept, i.e., introducing a new description of space and time and a new realization of inertial frames.
You mean, something like Feynman path integrals in non-relativistic QM?vanhees71 said:Something that's no observable nor necessary to formulate the theory isn't needed and complicates the issues.
Really? Isn't it an unnecessary complication?vanhees71 said:I've nothing against Bohmian mechanics within non-relativistic 1st quantized QM.
We already discussed it. You didn't claim that it doesn't make the same predictions. You objected that it is not based on the same foundations. In particular, you couldn't accept that gauge potentials can be "real", even though there is no experiment that can't be interpreted by a "real" gauge potential. Is an interpretation with a "real" gauge potential more complicated? Probably is, but Bohmian interpretation of 1st quantized QM is also more complicated, and yet you have nothing against it.vanhees71 said:I've not seen a convincing realization for relativistic QFT. I know that you disagree with the latter.
Do you know any problem in non-relativistic QM that is easier to solve with path integrals, then with other methods? (I know that path integrals simplify a lot calculations in gauge field theories, but that's not what I'm asking about.)vanhees71 said:Path integrals are just another mathematical tool to formulate QM
Generally, for me at least: the merit of a competing theory, that may be built on different foundations, and have the same predictions in the current domain of corroboration, may offer a different paths forward when we try to generalize the theory to new predictive domains. It's like SR vs GR vs classical mechanics; for everyday physics or standard engineering on earth, classical mechanics is the BETTER effective theory in the sense that it is more efficient to use, to make computations with etc; even though it's "foundations" are questionable. But try to convince a construction engineer that he should use general relativity instead of newtons mechanics to check his construtions. Why would he?vanhees71 said:Yes, but it doesn't lead to any other prediction of observable facts than standard QM.
In my case, Bohmian way of thinking taught me that symmetries, especially space-time symmetries, may be emergent than fundamental. Then thinking of symmetries as emergent lead me to new ideas that do not depend on the Bohmian interpretation as such, see e.g. https://arxiv.org/abs/2301.04448Fra said:So for me, the main discriminator I use to choose between competing paradigms is; which of them you belive makes extending the theory unification of all forces easier to solve? And here we may have different ideas and noone can tell in advance what is the best one.
I don't know if anyone in the Bohmian program today has any such ambitions though. But not that I am aware of.
But earlier you said that if two theories are observationally equivalent, they are the same theory!vanhees71 said:Einstein didn't intepret Lorentz ether theory but introduced an entirely new concept, i.e., introducing a new description of space and time and a new realization of inertial frames.
This is a "insight" I share with you, even if I am not into Bohmian mechanics.Demystifier said:In my case, Bohmian way of thinking taught me that symmetries, especially space-time symmetries, may be emergent than fundamental. Then thinking of symmetries as emergent lead me to new ideas that do not depend on the Bohmian interpretation as such, see e.g. https://arxiv.org/abs/2301.04448
But simplicity is subjective. Personally I find the Bohmian QM simpler than the standard one, for many reasons. One of the reasons is that Bohmian QM does not need the measurement postulate, which standard QM does ("When an observable is measured, then the probability is such and such ...").vanhees71 said:True, but then usually one chooses the simpler one
Right, so I think then we can agree that it is a case of two theories, or interpretations of theories, with different foundations, where one eventually came to dominate, despite being observationally equivalent. That is, however, different from the description of shifts only happening because one theory matches the results better. Simplicity is kind of subjective (indeed many physicists at the time probably did not find the counterintuitive aspects of relativity to be "simpler"), what I think is much more indicative that this was the correct idea (which of course may be reappraised in the future) is that this shift in the metaphysics of the theory, despite being observationally equivalent, provided a new way of thought that allowed new breakthroughs, for instance general relativity. So I see this as an example where a change of interpretation led to radical increase in content and understanding, and discovering new properties of nature.vanhees71 said:True, but then usually one chooses the simpler one, i.e., one favors SRT against LET, because the latter makes unobservable additional assumptions (some "ether frame"), which doesn't add anything new, i.e., concerning observable facts about Nature they are otherwise equivalent. From a purely scientific point of view they are the same theory.
So?vanhees71 said:But Bohmian QM doesn't predict anything from that. All there is, also within BM, are the said probabilities.
There is no need to make the discussion of this whole thread, and yet we do. Why? Because we want to understand something conceptually. The same is with considering the fictitious trajectories.vanhees71 said:So, there's no need to consider these fictitious trajectories.
Not for using the term but for making a statement like this. It's off topic and adds nothing to the thread. If you have something to say, just say it. Don't speculate about what, if any, moderator response you will get.Fra said:Lets see if Peter Donis will slap my fingers for using the term
What does any of this (even assuming it's all valid) have to do with the topic of this thread?Fra said:its just a normal observer, but one with finite information capacity, to supposedly be more realistic. Otherwise its a normal observer.
But this limit meas thay cant entertain infinite repeats of experimenta to make perfect ensembles and timeless inferences.
In QFT or qm. Ensembles or arbitrarily large quantum systesm otherwise need to collect, process and represent so much data that its "fictious"
Also an internal observer does not need to be a classical or macro device. Its just tjat its inferencea would be extremely volatile.
Of course QM isnt desgine for internal observers.which is exactly MY problem with it. It is desigen for an ideal "fictive" asymptotic observer. But this fiction is reasonable for small systems.
It was an example of that different perspectives/interpretation yields different elements that are fictious. An example that i consider interesting especially for the view of spacetime and its symmetries.PeterDonis said:What does any of this (even assuming it's all valid) have to do with the topic of this thread?
Is it an example you just made up, or is it taken from something in the literature. Remember that personal speculation is off limits here.Fra said:It was an example of that different perspectives/interpretation yields different elements that are fictious.
