My idea is more on the line of “in the future we are going to grasp a conceptual frame that would make sense of all interpretations” (or explain them away) rather than pointing to a specific interpretation.
If it doesn’t fundamentally change quantum mechanics as a theory, is the picture likely to turn out fundamentally different from MWI? Roger Penrose, a vocal MWI critic, seems to wholeheartedly agree that QM implies MWI; it’s just that he thinks that this means the theory is wrong. David Deutsch, I believe, has said that he’s not certain that quantum mechanics is correct; but any modification of the theory, according to him, is unlikely to do away with the parallel universes.
QBism, too, seems to me to essentially accept the MWI picture as the underlying ontology, but then says that we should only care about the worlds that we actually observe (Sean Carroll has presented criticism similar to this, and mentioned that it sounds more like therapy to him), although it could be that I’ve misunderstood something.
If it doesn’t fundamentally change quantum mechanics as a theory, is the picture likely to turn out fundamentally different from MWI?
CI/OR is a different picture to MWI, yet neither change QM as a number-crunching theory. You have hit on the fundamental problems of empiricism: the correct interpretation of a data is underdetermined by data, and interpretations can differ radically with small changes in data or no changes in data.
I’m not sure what you mean by OR, but if it refers to Penrose’s interpretation (my guess, because it sounds like Orch-OR), then I believe that it indeed changes QM as a theory.
These are difficult question because we are speculating about future mathematics / physics.
First of all, there’s the question of how much of the quantum framework will survive the unification with gravity. Up until now, all theories that worked inside it have failed; worse, they have introduced black-hole paradoxes: most notably, thunderbolts and the firewall problem. I’m totally in the dark if a future unification will require a modification of the fundamental mathematical structure of QM. Say, if ER = EPR, and entanglement can be explained with a modified geometry of space-time, does it mean that superposition is also a geometrical phoenomenon that doesn’t require multiple worlds? I don’t really know.
But more on the point, I think (hope?) that future explorations of the quantum framework will yield an expanded landscape, where interpretations will be seen as the surface phoenomenon of something deeper: for example, something akin to what happens in classical mechanics with the Hamiltonian / Lagrangian formulations.
On a side note, I’ve read only the Wikipedia article on QBism and my impression was that it had an epistemological leaning, not ontological: if you use only SIC-POVMs, you can explain all quantum quirks with the epistemology of probability distributions. I might be very wrong, though.
Fair enough. I feel like I have a fairly good intuitive understanding of quantum mechanics, but it’s still almost entirely intuitive, and so is probably entirely inadequate beyond this point. But I’ve read speculations like this, and it sounds like things can get interesting: it’s just that it’s unclear to me how seriously we should take them at this stage, and also some of them take MWI as a starting point, too.
Regarding QBism, my idea of it is mostly based on a very short presentation of it by Rüdiger Schack at a panel, and the thing that confuses me is that if quantum mechanics is entirely about probability, then what do those probabilities tell us about?
it’s just that it’s unclear to me how seriously we should take them at this stage
Well, categorical quantum mechanics is a program under developement since 2008, and it gives you a quantum framework in any computational theory with enough symmetries (databases, linguistics, etc). It spawned quantum programming languages and a graphical calculus. So I think it’s pretty succesful and has to be taken seriously, albeit it’s far from being complete (it lacks a unified treatment of infinite systems, for example).
Depends what you mean by “about”. The (strong) Qbist perspective is that probabilities, including those derived from quantum theory, represent an agents beliefs concerning his future interactions with the world. If you’re looking for what these probabilities tell us about the underlying “reality” then that’s an open question, which Fuchs et al are still exploring.
If you’re looking for what these probabilities tell us about the underlying “reality”
I am. It seems to me that if quantum mechanics is about probabilities, then those probabilities have to be about something: essentially, this seems to suggest that either the underlying reality is unknown, indicating that quantum mechanics needs to be modified somehow, or that Qbism is more like an “interpretation of MWI”, where one chooses to only care about the one world she finds herself in.
The QBist stance is that we “know” very little about the underlying reality. One of the only things that Chris Fuchs is willing to accept as an objective property of a quantum system is its Hilbert space dimension.
I doubt it’s sensible to talk about an interpretation of MWI. MWI says that the wavefunction is a real physical object and wavefunction splitting is something that’s genuinely physically occurring. QBism denies that the wavefunction is a real physical object.
My idea is more on the line of “in the future we are going to grasp a conceptual frame that would make sense of all interpretations” (or explain them away) rather than pointing to a specific interpretation.
If it doesn’t fundamentally change quantum mechanics as a theory, is the picture likely to turn out fundamentally different from MWI? Roger Penrose, a vocal MWI critic, seems to wholeheartedly agree that QM implies MWI; it’s just that he thinks that this means the theory is wrong. David Deutsch, I believe, has said that he’s not certain that quantum mechanics is correct; but any modification of the theory, according to him, is unlikely to do away with the parallel universes.
QBism, too, seems to me to essentially accept the MWI picture as the underlying ontology, but then says that we should only care about the worlds that we actually observe (Sean Carroll has presented criticism similar to this, and mentioned that it sounds more like therapy to him), although it could be that I’ve misunderstood something.
CI/OR is a different picture to MWI, yet neither change QM as a number-crunching theory. You have hit on the fundamental problems of empiricism: the correct interpretation of a data is underdetermined by data, and interpretations can differ radically with small changes in data or no changes in data.
I’m not sure what you mean by OR, but if it refers to Penrose’s interpretation (my guess, because it sounds like Orch-OR), then I believe that it indeed changes QM as a theory.
These are difficult question because we are speculating about future mathematics / physics.
First of all, there’s the question of how much of the quantum framework will survive the unification with gravity. Up until now, all theories that worked inside it have failed; worse, they have introduced black-hole paradoxes: most notably, thunderbolts and the firewall problem. I’m totally in the dark if a future unification will require a modification of the fundamental mathematical structure of QM. Say, if ER = EPR, and entanglement can be explained with a modified geometry of space-time, does it mean that superposition is also a geometrical phoenomenon that doesn’t require multiple worlds? I don’t really know.
But more on the point, I think (hope?) that future explorations of the quantum framework will yield an expanded landscape, where interpretations will be seen as the surface phoenomenon of something deeper: for example, something akin to what happens in classical mechanics with the Hamiltonian / Lagrangian formulations.
On a side note, I’ve read only the Wikipedia article on QBism and my impression was that it had an epistemological leaning, not ontological: if you use only SIC-POVMs, you can explain all quantum quirks with the epistemology of probability distributions. I might be very wrong, though.
Fair enough. I feel like I have a fairly good intuitive understanding of quantum mechanics, but it’s still almost entirely intuitive, and so is probably entirely inadequate beyond this point. But I’ve read speculations like this, and it sounds like things can get interesting: it’s just that it’s unclear to me how seriously we should take them at this stage, and also some of them take MWI as a starting point, too.
Regarding QBism, my idea of it is mostly based on a very short presentation of it by Rüdiger Schack at a panel, and the thing that confuses me is that if quantum mechanics is entirely about probability, then what do those probabilities tell us about?
Well, categorical quantum mechanics is a program under developement since 2008, and it gives you a quantum framework in any computational theory with enough symmetries (databases, linguistics, etc).
It spawned quantum programming languages and a graphical calculus. So I think it’s pretty succesful and has to be taken seriously, albeit it’s far from being complete (it lacks a unified treatment of infinite systems, for example).
Depends what you mean by “about”. The (strong) Qbist perspective is that probabilities, including those derived from quantum theory, represent an agents beliefs concerning his future interactions with the world. If you’re looking for what these probabilities tell us about the underlying “reality” then that’s an open question, which Fuchs et al are still exploring.
I am. It seems to me that if quantum mechanics is about probabilities, then those probabilities have to be about something: essentially, this seems to suggest that either the underlying reality is unknown, indicating that quantum mechanics needs to be modified somehow, or that Qbism is more like an “interpretation of MWI”, where one chooses to only care about the one world she finds herself in.
The QBist stance is that we “know” very little about the underlying reality. One of the only things that Chris Fuchs is willing to accept as an objective property of a quantum system is its Hilbert space dimension.
I doubt it’s sensible to talk about an interpretation of MWI. MWI says that the wavefunction is a real physical object and wavefunction splitting is something that’s genuinely physically occurring. QBism denies that the wavefunction is a real physical object.