Recent content by flippiefanus

If I can translate the question into the language that I would understand, it would read: is there a physical process that can unentangle two entangled subsystems? That would be an interesting question, but I think the short answer is no. First, let me just say that I do not understand all the...

Yes, I'm trying to see if there are different possible mechanisms. There has been some experimental results that ruled out the basic Penrose-Diosi model. So something needs to be different. Not sure where this discussion will lead though. Perhaps it should be a new topic.

This topic intrigues me, and I think this approach to address the larger problem of quantum gravity is closer to the way physics works and therefore more likely to make progress in a scientific manner than other attempts. The idea of collapse due to an instability caused by gravity is in fact...

OK so it depends on what state you have. The expectation value of ##a## for a single Fock state is zero. But you get a nonzero value when you have for example a coherent state. So now you expand the state in a Fock basis and then consider the phase of off-diagonal terms in its density operator...

Why do you say this experiment can be analysed in flat spacetime? Earth's gravity does not represent flat spacetime.

The Wikipedia statement probably intended to explain how the one-particle Hilbert space is used as a basic element to build up multiple particle states as tensor products. The Fock basis includes states with multiple particles, for which the occupation number is larger than 1.

Then we are in agreement. Personally I also prefer to work on phase space, but one needs to work through the basics to have a good understanding.

Yes, I agree that off-diagonal terms carry the phase information, but not in the Fock basis. One needs a basis involving the other degrees of freedom, like the spatiotemporal degrees of freedom.

That quote is also significant for what it does not say: it does not say that one cannot use quantum theory for such scenarios.

No, go back and look at #7, #9 and #16 again. It is not a strawman.

OK but what is the reason why we want such a probability interpretation? It is not used in classical theory where we measure intensity. The underlying reason is because we work with quanta.

True, I've expressed myself poorly. Let me clarify. If ##|\psi\rangle## and ##|\phi\rangle## are single photon states, then we can have a superposition ##|\psi\rangle a+|\phi\rangle b## that can lead to interference. However, the tensor product ##|\psi\rangle|\phi\rangle## does not give us...

No that is not the case. See #7, #9, and #16 for example. Those are the replies that I started making comments to.

A laser produces a multi-photon state. Not sure what you were trying to say here. The state of two lasers that are coupled cannot be represented by a tensor product state. If you had a tensor product state you would not see interference. So clearly it becomes a multi-photon process. There is no...

One needs to have some force that can affect neutrinos to slow them down. (Gravity also affects them but that is not a force.) The only force that affects them is the weak force, which we don't know how to use yet.