Non-local preparation in entanglement swapping experiments

[gentzen]

Consistent histories doesn't limit us to statistical interpretations if we adopt a Bayesian interpretation of probabilities.

Maybe ask yourself first what a realistic interpretation should provide. If that is missing, then Bayesian probabilities cannot fix that either.

Also note that not being able to provide this is not necessarily a drawback. It would even be incompatible with „Copenhagen done right“, if CH could provide this.

 

[DrChinese]

He doesn't reject Bell's theorem at all. He (and many others) reject the claim that Bell's theorem necessarily implies Einsteinian nonlocal influence.

Consistent histories rejects hidden variables. The point is without λ, you don't have to infer nonlocal influences.

My head is spinning.

I didn’t see the non-hidden variable mechanism that would then need to exist in CH. (We see that in MWI. We see that in retrocausal type explanations.) On the other hand, in your post #69: you say CH is realistic, but denies hidden variables. I am not sure how it can be realistic, which implies a pre-existing and determinate outcome for measurements at all angles independent of a setting elsewhere.

And he does accept a form of “proper” nonlocality. But I am very open to better understanding what is being presented, because it doesn’t seem to fit together as I read it.

 

[Morbert]

Maybe ask yourself first what a realistic interpretation should provide. If that is missing, then Bayesian probabilities cannot fix that either.

By realistic, Griffiths means measurements reveal pre-existing properties of the microscopic system. This would be in contrast with Roland Omnes's position, where macroscopic data is still ultimately what is real.

 

[gentzen]

By realistic, Griffiths means measurements reveal pre-existing properties of the microscopic system.

Griffiths only talks about statistical properties. This is not what most people (including me) mean by realistic. In fact, I claim that CH itself can only talk about statistical properties. This is a nontrivial claim, and it could be wrong. But not in the way Griffiths argues against it, by simply ignoring the issue.

(It could be wrong in Aharonov‘s way, where you actually get rid of the statistics.)

 

[DrChinese]

By realistic, Griffiths means measurements reveal pre-existing properties of the microscopic system. This would be in contrast with Roland Omnes's position, where CH logic is still ultimately only about macroscopic data.

OK, that is pretty much as good a definition as I could compose. The only think I might add is the caveat "the setting of one measuring device cannot influence the reading of another instrument".

So if it is realistic, according to Bell, there must be a nonlocal (instantaneous) mechanism of influence (per your quote of Bell). This is standard deduction from Bell, well-accepted and discussed in thousands of papers. If you deny this, you deny Bell. You can't say "I follow Bell" but then say Bell doesn't apply. If it doesn't apply, you simply don't follow Bell. You can't have your cake and eat it too.

In fact: We know there are no Alice/Bob datasets featuring pre-existing and immutable values in which a) there are perfect correlations at same angles; and b) Bell inequality violations at CHSH angles. I can't understand the point of asserting otherwise. And certainly not after decades of heavy study.

 

[DrChinese]

Griffiths only talks about statistical properties. This is not what most people (including me) mean by realistic.

Help me out: How does use of the word "statistical" change anything? (I am not arguing against you, just trying to understand how that can matter to Griffiths or anybody.)

We must also consider perfect correlations in Bell tests, so the "statistic" in these is 100%... i.e. an element of reality per EPR. There are no hypothetical datasets that reproduce this behavior. Any "realistic" explanation must be able to handle the cases of perfect correlation, as well as CHSH type correlation.

 

[gentzen]

We must also consider perfect correlations in Bell tests, so the "statistic" in these is 100%... i.e. an element of reality per EPR. There are no hypothetical datasets that reproduce this behavior. Any "realistic" explanation must be able to handle the cases of perfect correlation, as well as CHSH type correlation.

CH can handle this 100% case. It is the other cases where it only talks about statistics. And if it could reduce those other cases to 100% cases, then my claim would be wrong. But Griffiths does not even try, or acknowledge the issue.