Superdeterminism and the Mermin Device: A New Perspective on Bell's Inequality

[malawi_glenn]

https://www.nobelprize.org/prizes/physics/2022/popular-information/

Using groundbreaking experiments, Alain Aspect, John Clauser and Anton Zeilinger have demonstrated the potential to investigate and control particles that are in entangled states. What happens to one particle in an entangled pair determines what happens to the other, even if they are really too far apart to affect each other. The laureates’ development of experimental tools has laid the foundation for a new era of quantum technology.

Thoughts? :)

EDIT:
Veratisiums explanation


Feel free to post other videos/lectures regarding the topic of this years Nobel Prize in physics :)

 

[atyy]

Fantastic! I'm sure @DrChinese must be happy, given his citation of Bell's theorem as "the most profound result in science", which I'm inclined to agree with :)
https://www.drchinese.com/Bells_Theorem.htm

 

[DrClaude]

Good one!

 

[malawi_glenn]

There is a really nice Aspect in this prize

Spoiler

Alain Aspect

 

[Cthugha]

There is a really nice Aspect in this prize

Spoiler

Alain Aspect

Indeed. I must admit that an Aspect ratio of 1:3 sounds a bit unusual to me, but I like it.

 

[pinball1970]

The video, press sat on the floor!

https://www.nobelprize.org/prizes/physics/2022/prize-announcement/

 

[mfb]

Finally, a comprehensive prize from A to Z!

It was about time. Zeilinger was a candidate for 20+ years, Aspect and Clauser for even longer.

 

[DrChinese]

Fantastic! I'm sure @DrChinese must be happy, given his citation of Bell's theorem as "the most profound result in science", which I'm inclined to agree with :)
https://www.drchinese.com/Bells_Theorem.htm

You know it! Long overdue as far as I'm concerned!

 

[DrClaude]

I am still surprised that Haroche and Wineland won it before Aspect and Clauser.

 

[Demystifier]

Clauser, Aspect and Zeilinger certainly deserved the prize, but the Nobel Committee did a sloppy job. Their text
https://www.nobelprize.org/uploads/2022/10/advanced-physicsprize2022.pdf
is self-contradictory, as the following two quotes from it demonstrate.

"Yet another alternative to the Copenhagen interpretation was the ‘Bohmian’ or pilot-wave version of quantum mechanics [6]. This is a fully deterministic theory that reproduces the results of non-relativistic quantum mechanics, but at the price of non-locality."

"Using a special version of the Bohmian-EPR thought experiment, [Bell] showed mathematically that no hidden variable theory would be able to reproduce all the results of quantum mechanics."

 

[martinbn]

Clauser, Aspect and Zeilinger certainly deserved the prize, but the Nobel Committee did a sloppy job. Their text
https://www.nobelprize.org/uploads/2022/10/advanced-physicsprize2022.pdf
is self-contradictory, as the following two quotes from it demonstrate.

"Yet another alternative to the Copenhagen interpretation was the ‘Bohmian’ or pilot-wave version of quantum mechanics [6]. This is a fully deterministic theory that reproduces the results of non-relativistic quantum mechanics, but at the price of non-locality."

"Using a special version of the Bohmian-EPR thought experiment, [Bell] showed mathematically that no hidden variable theory would be able to reproduce all the results of quantum mechanics."

They may be wrong, but technically the two quotes do not contradict each other. In the first they do not say that Bohmian Mechanics has hidden variables.

 

[mfb]

Well, we know it has, and the second quote is simply wrong because it's missing "local".

 

[Demystifier]

Jean Bricmont wrote on facebook a more detailed critique of the Nobel Committee text. Here I copy-paste the Bricmont's writing:

For my physics colleagues.

Like most people interested in foundations of quantum mechanics, I am very happy that a well deserved Nobel prize is awarded to three outstanding experimentalists interested in those foundations. However, I would like to make a few comments on the Press release on the Nobel Prize in Physics (https://www.nobelprize.org/.../physics/2022/press-release/):

Press release: One key factor in this development is how quantum mechanics allows two or more particles to exist in what is called an entangled state. What happens to one of the particles in an entangled pair determines what happens to the other particle, even if they are far apart.

Comment: That is correct. To be more precise, whenever some experiment is performed on one particle of the pair being in an entangled state, knowing the result of that experiment immediately foretells what the result of a similar experiment done on the other particle will be. And that is true no matter how far apart the particles are.

Press release: For a long time, the question was whether the correlation was because the particles in an entangled pair contained hidden variables, instructions that tell them which result they should give in an experiment.

Comment: this is correct but incomplete. That question was raised in 1935 paper by Einstein, Podolsky and Rosen in a widely misunderstood paper but in a different form: how do we explain those perfect corrections between results of experiments made on both particles, even when they are far apart from each other? There seems to be only two possibilities: either performing an experiment on one particle affects instantaneously the behavior of the other particle or both particles contain instructions that tell them which result they should give in those experiments.

But the first possibility means that there exist instantaneous actions at a distance in Nature, something that was inconceivable for Einstein, Podolsky and Rosen (and probably everybody else at that time). So, Einstein, Podolsky and Rosen thought that they had proven that particles do contain those instructions. Since those instructions are not part of the standard quantum mechanical formalism, they thought that they had proven that quantum mechanics is incomplete, which means that individual quantum system are characterized not only by their wave function or quantum state but also by those instructions, also called hidden variables.

Press release: In the 1960s, John Stewart Bell developed the mathematical inequality that is named after him. This states that if there are hidden variables, the correlation between the results of a large number of measurements will never exceed a certain value. However, quantum mechanics predicts that a certain type of experiment will violate Bell’s inequality, thus resulting in a stronger correlation than would otherwise be possible.

Comment: that is correct, but, if we remember the previous comment, it means that the only explanation for the perfect correlations between results of experiments made on both particles, even when they are far apart from each other, is that doing an experiment on one particle immediately affects the behavior of the other particle, i.e. that these « inconceivable » actions at a distance do exist in Nature.

Press release: John Clauser developed John Bell’s ideas, leading to a practical experiment. When he took the measurements, they supported quantum mechanics by clearly violating a Bell inequality. This means that quantum mechanics cannot be replaced by a theory that uses hidden variables.

Comment: That is rather wrong: the logic of the above remarks is that, if a Bell inequality is violated, then actions at a distance do exist in Nature. And concerning "hidden variables », it depends what one means: if, by that, one means the instructions whose existence Einstein, Podolsky and Rosen thought they had demonstrated, then indeed these variables do not exist. But the more standard meaning of that expression refers to any variables that characterize an individual quantum system on top of its wave function or quantum state.

And there exists a theory, the de Broglie-Bohm one, that does introduce such hidden variables, actually the most obvious ones, the particles’ positions. One should emphasize that the existence of those variables is not refuted by Bell’s arguments (or any other argument) and it would be very strange indeed if they were refuted by them, since Bell defended that theory almost through his entire life.

So, here is a paradox: Bell is credited for having refuted hidden variable theories, while he constantly defended and explained such a theory. Was he crazy? But then, why so much admiration for him?

It would be enough to read Bell’s collection of articles « Speakable and unspeakable in quantum mechanics » to notice his defense of the de Broglie-Bohm theory and his reasons for doing so. Unfortunately, very few physicists do that and, it seems, not even the members of the Nobel Committee.

 

[martinbn]

Why is their work viewed as work in the foundations of QM, not as work in experimental physics concerning entanglement?

 

[Demystifier]

Why is their work viewed as work in the foundations of QM, not as work in experimental physics concerning entanglement?

It's considered both.

 

[martinbn]

It's considered both.

Why?

 

[Demystifier]

Why?

Because it is. Experiments demonstrating violation of Bell inequalities are certainly very important for foundations of QM.

 

[martinbn]

Because it is. Experiments demonstrating violation of Bell inequalities are certainly very important for foundations of QM.

Of course they are important for the foundations, but they are not the foundations, they are experimental work not theoretical. What is meant by "foundations of QM"?

 

[Demystifier]

What is meant by "foundations of QM"?

It includes both theoretical and experimental work. Some experimentalists in the field even use the term "experimental metaphysics".

 

[RUTA]

From https://www.nobelprize.org/prizes/physics/2022/press-release/

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics 2022 to

Alain Aspect
Universite Paris-Saclay and École Polytechnique, Palaiseau, France

John F. Clauser
J.F. Clauser & Assoc., Walnut Creek, CA, USA

Anton Zeilinger
University of Vienna, Austria

``for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science''

 

[atyy]

Looking at Bricmont's Twitter after @Demystifier mentioned his FB post, I found this by Maudlin.

Maudlin, T. (2022, October 06). Einstein, God, and “Spooky Action-at-a-Distance”.IAI News.
https://iai.tv/articles/einstein-god-and-spooky-action-at-a-distance-auid-2255

 

[RUTA]

Looking at Bricmont's Twitter after @Demystifier mentioned his FB post, I found this by Maudlin.

Maudlin, T. (2022, October 06). Einstein, God, and “Spooky Action-at-a-Distance”.IAI News.
https://iai.tv/articles/einstein-god-and-spooky-action-at-a-distance-auid-2255

He's correct, assuming statistical independence. See this Insight: Superdeterminism and the Mermin Device for an explanation of how to violate Bell's inequality with instruction sets and locality, but in violation of statistical independence.