Now that all loopholes are closed

[Collin237]

I've read rumors that the last remaining loopholes of the Bell experiments have been closed, such as:

https://uwaterloo.ca/institute-for-quantum-computing/blog/post/ask-not-which-local-hidden-variable-theory-bell-tolls-it

Is this for real? And what are the surviving nonlocal realism interpretations?

 

[mgkii]

David Bohm produced a non-local hidden variable theory. It was shown to be consistent with Quantum Mechanics so is presumably a surviving interpretation.

Just googled it... here you go.
https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory

the wiki article seems to give equal credit to De Broglie and Bohm, but I'm pretty sure De Broglie developed the pilot wave theory, and Bohm turned this into a non-local hidden variable model. At least I'm pretty sure that's what I read...

 

[bhobba]

And what are the surviving nonlocal realism interpretations?

There are plenty of those. The issue is local realistic interpretations:
http://www.drchinese.com/Bells_Theorem.htm

Its not the death of such theories - the out is they are not the same as QM, but QM emerges from such theories. Thats how Bell is bypassed.

Thanks
Bill

 

[Demystifier]

the wiki article seems to give equal credit to De Broglie and Bohm, but I'm pretty sure De Broglie developed the pilot wave theory, and Bohm turned this into a non-local hidden variable model.

The theory had a non-local form already in the De Broglie theory, but it was Bohm who has shown that the theory has the same measurable predictions as standard QM. To show this, Bohm has developed a general theory of quantum measurements, which can be thought of as a forerunner of the modern theory of decoherence.

 

[Collin237]

but QM emerges from such theories.

How does that work?

 

[bhobba]

How does that work?

That depends on the theory - pretty obviously.

Here is an example:
http://arxiv.org/pdf/quant-ph/9508021.pdf

Thanks
Bill

 

[akhmeteli]

I've read rumors that the last remaining loopholes of the Bell experiments have been closed, such as:

https://uwaterloo.ca/institute-for-quantum-computing/blog/post/ask-not-which-local-hidden-variable-theory-bell-tolls-it

Is this for real? And what are the surviving nonlocal realism interpretations?

I am not sure the recent experiments are loophole-free: all of them explicitly assume fixed outcomes at some point. Strictly speaking, this assumption is incompatible with unitary evolution. Therefore, the experiments seem to rule out local realistic theories under an assumption that rules out standard quantum mechanics. In my book, that's rich...

 

[bhobba]

all of them explicitly assume fixed outcomes at some point.

Of course - that's what an observation is. So?

Strictly speaking, this assumption is incompatible with unitary evolution.

I think Dechorence has somethin to say about that. But this thread is not yhe place to iwscuss it.

Therefore, the experiments seem to rule out local realistic theories under an assumption that rules out standard quantum mechanics. In my book, that's rich...

I have seen similar musings before. I recall Dr Chinese entered into a long discussion referencing some paper about it. I thought it was a waste of time personally - but each to their own.

Thanks
Bill

 

[Collin237]

That depends on the theory - pretty obviously.

Here is an example:
http://arxiv.org/pdf/quant-ph/9508021.pdf

Thanks
Bill

Wow! I've been looking for something like that theory for twenty years! How did you find it?

 

[bhobba]

Wow! I've been looking for something like that theory for twenty years! How did you find it?

Here:
http://www.hpl.hp.com/techreports/2001/HPL-2001-7.pdf

Thanks
Bill

 

[Collin237]

How does State Diffusion explain the Bell violation?

(If this can't be answered on Physics Forums, could you please direct me to another site and answer it there?)