- #1

- 439

- 26

Bell demonstrated that there cannot be a local realistic theory that reproduces the expectation values of QM. I can see that a non-realistic theory is unsatisfactory, we would have to abandon the nice determinism we got so accustomed to in classical physics, from Newton to Maxwell to Einstein.

But what about non-locality? In non-relativistic QM, there are two different non-local processes:

1. The Schrödinger propagator is not Lorentz invariant. Allows faster-than-light communication.

2. Entanglement. Does not allow FTL communication.

If you fix the first by using the Dirac equation and Lorentz invariant propagators, you get amazingly successful theories as QFT. And you are at peace with SR.

So why do we even bother about 2.? Signalling is not possible using entanglement, so Einstein won't haunt us. Also with Bohmian mechanics, we already have a nice non-local realistic interpretation.