Outside view: This looks fairly legit on first glance, and Jonathan Oppenheim is a reputable physicist. The theory is experimentally testable, with numerous tests mentioned in the paper, and the tests don’t require reaching unrealistically high energies in a particle accelerator, which is good.
Inside view: Haven’t fully read the paper yet, so take with a grain of salt. Quantum mechanics already has a way of representing states with classical randomness, the density matrix, so having a partially classical and partially quantum theory certainly seems like it should be mathematically possible in the framework of QM. The paper addresses the obvious question of what happens to the gravitational field if we put a particle in a superposition of locations, and it seems the answer is that there is stochastic coupling between the quantum degrees of freedom and the classical gravitational field, and so particles don’t end up losing their coherence in double slit experiments, which would blatantly contradict existing observations.
Overall, I think there’s a high chance that this is a mathematically consistent theory that basically does what it says it does. Will it end up corresponding to the actual universe? That’s a question for experiment.
it seems the answer is that there is stochastic coupling between the quantum degrees of freedom and the classical gravitational field, and so particles don’t end up losing their coherence in double slit experiments, which would blatantly contradict existing observations
Yep, that’s the section I was looking at to get that information. Maybe I phrased it a bit unclearly. The thing that would contradict existing observations is if the interaction were not stochastic. Since it is stochastic in Oppenheim’s theory, the theory allows the interference patterns that we observe, so there’s no contradiction.
Outside view: This looks fairly legit on first glance, and Jonathan Oppenheim is a reputable physicist. The theory is experimentally testable, with numerous tests mentioned in the paper, and the tests don’t require reaching unrealistically high energies in a particle accelerator, which is good.
Inside view: Haven’t fully read the paper yet, so take with a grain of salt. Quantum mechanics already has a way of representing states with classical randomness, the density matrix, so having a partially classical and partially quantum theory certainly seems like it should be mathematically possible in the framework of QM. The paper addresses the obvious question of what happens to the gravitational field if we put a particle in a superposition of locations, and it seems the answer is that there is stochastic coupling between the quantum degrees of freedom and the classical gravitational field, and so particles don’t end up losing their coherence in double slit experiments, which would blatantly contradict existing observations.
Overall, I think there’s a high chance that this is a mathematically consistent theory that basically does what it says it does. Will it end up corresponding to the actual universe? That’s a question for experiment.
Isn’t that what he addresses in this section?
Yep, that’s the section I was looking at to get that information. Maybe I phrased it a bit unclearly. The thing that would contradict existing observations is if the interaction were not stochastic. Since it is stochastic in Oppenheim’s theory, the theory allows the interference patterns that we observe, so there’s no contradiction.