That’s right, but it doesn’t add up to what you said about spacetime being saturated with ‘world-branching’ events.
While the decay wave is propagating, for instance, nothing’s decohering. It’s only when it reaches the critically unstable system of the detector that that happens.
It’s only when it reaches the critically unstable system of the detector that that happens.
There is no single moment like that. if the distance from the atom to the detector is r and we prepare the atom at time 0, the interaction between the atom/field states and the detector states (i.e. decoherence) starts at the time c/r and continues on.
interaction between the atom/field states and the detector states (i.e. decoherence) starts at the time c/r and continues on
Depends on your framework, but it will actually start even earlier than that in a general QFT. The expectation will be non-zero for all times t. I suppose the physical interpretation is something like a local-fluctuation trips the detector.
Of course, commutators will be non-zero as locality requires.
That’s right, but it doesn’t add up to what you said about spacetime being saturated with ‘world-branching’ events.
While the decay wave is propagating, for instance, nothing’s decohering. It’s only when it reaches the critically unstable system of the detector that that happens.
There is no single moment like that. if the distance from the atom to the detector is r and we prepare the atom at time 0, the interaction between the atom/field states and the detector states (i.e. decoherence) starts at the time c/r and continues on.
Depends on your framework, but it will actually start even earlier than that in a general QFT. The expectation will be non-zero for all times t. I suppose the physical interpretation is something like a local-fluctuation trips the detector.
Of course, commutators will be non-zero as locality requires.
Right, good point. Still, there are rarely just a few distinct branches in almost any measurement process, it’s a continuum of states, isn’t it?