Quantum Spin: Is it Random? Alice & Bob's Test

[Demystifier]

In any case, discussion of it belongs in the relativity forum, not here.

I agree, but I have tried to anticipate what might be his next question.

 

[entropy1]

So when you talk about Alice's measurement giving a random result when that measurement occurs first, and then Bob's can't be random: you are talking AS IF the measurement outcomes were from completely separate and independent particles. You are in fact measuring a component/components of a combined system which is entangled.

Yes, but if you would assert that the latter (Bob's) measurement got collapsed, I figure we would have the same measurement result.

EDIT: I see you already pointed that out. So it is not decided whether B will collapse or not, which in my eyes suggests that QM will at this point realize both simultaneously!

 

[Nugatory]

Yes, but if you would assert that the latter (Bob's) measurement got collapsed, I figure we would have the same measurement result.

EDIT: I see you already pointed that out. So it is not decided whether B will collapse or not, which in my eyes suggests that QM will at this point realize both simultaneously!

You are choosing to use a collapse interpretation in a situation where it is known to work badly (because of the conflict between relativity and instantaneous collapse everywhere) and making the problem unnecessarily confusing. Just stop with this talk about collapse and look at what the math says.

(I feel as if I've said something similar before...)

 

[PeterDonis]

if you would assert that the latter (Bob's) measurement got collapsed

Then you would be having a discussion that belongs in the QM foundations and interpretations forum, not this one.