Consistent histories particle positions prior to measurement

[nickv2423]

I’m having a tough time understanding the CH interpretation. Only one of the histories happens when a measurement is made, but it seems to me it is saying that even prior to measurement a particle (ie electron) has a position and trajectory that we just don’t know about unlike standard QM. Is this what CH posits?

 

[PeterDonis]

Moderator's note: Thread moved to the QM interpretations subforum.

 

[gentzen]

but it seems to me it is saying that even prior to measurement a particle (ie electron) has a position and trajectory that we just don’t know about unlike standard QM. Is this what CH posits?

At least CH does not reject this statement, if you limit the meaning of „trajectory“ to suitably coarse grained descriptions.

 

[gentzen]

I’m having a tough time understanding the CH interpretation.

Are you aware that CH also has a formalism? Is your tough time related to that formalism? Or more to boiling down CH to „some essence“ that can be easily compared with other interpretations?

 

[nickv2423]

Are you aware that CH also has a formalism? Is your tough time related to that formalism? Or more to boiling down CH to „some essence“ that can be easily compared with other interpretations?

yea I’m having a tough time trying to comprehend what the formalism is saying. Are the coarse grained descriptions supposed to be the path they actually took prior to measurement or just a probability distribution

 

[gentzen]

yea I’m having a tough time trying to comprehend what the formalism is saying.

The formalism offers a way to have coarse grained descriptions and their compatible refinements.

Are the coarse grained descriptions supposed to be the path they actually took prior to measurement or just a probability distribution

You are supposed to use those coarse grained description in a suitable way to allow reasonable stories for the experimental setup under discussion. In this sense, the path is one the system might have taken (in a reasonable story). Measurements provide information about the path taken "in a specific instance" of the experiment. If the experiment is repeated many times, the frequencies of the measured results are hopefully consistent with the predicted coarse grained probabilities.

If you use a coarse grained description that is unsuited for the experimental setup under discussion, you still won't get any contradictions, but all computations done with that description will be useless nevertheless. CH claims that this is not a problem of the formalism. Opponents of CH claim that it is a problem, because CH does not offer sufficiently good criteria to distinguish suitable from unsuitable descriptions.