Is a classical universe (with a deterministic dynamics) compatible with assuming that experimental choices can be made arbitrarily?(adsbygoogle = window.adsbygoogle || []).push({});

This question arises from the following statement of Bell:

that I had cited (with a reference) in https://www.physicsforums.com/posts/5694545/, and commented with: J.T. Bell said:'It has been assumed that the settings of instruments are in some sense free variables ...'For me this means that the values of such variables have implications only in their future light cones. They are in no sense a record of, and do not give information about what has gone before.

There was also a related statement by ueit in the same thread, A. Neumaier said: ↑In a deterministic universe, this assumption is obviously violated. For it means that these values are independent of the values of all observables prior to the moment the settings are made. Indeed, if they would depend on the latter, fixing one of the values provides a nontrivial relation on the prior variables in their past light cone and hence provides information about the latter. Thus they give information about what was before, in direct contradiction to Bell's assumptions.

ueit said: ↑Once an initial condition (positions/velocities) is chosen everything becomes fixed. When the particles will be emitted by the source, what spin will they have, if and when they will be measured, what settings the detectors will have and what will be the result is a function of that particular initial condition. There is no need to use a "fine-tuned" initial condition. If you want the experimenters to "choose" a different setting you cannot implement that without changing the initial condition, and that change will also have an effect on the source and on the entangled particles themselves.

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# A Classical universe and experimental choices

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