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.
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.