Bell's theorem refuted?
sciencex.com
sciencex.com
The paper itself has a sole author, a post-doc with a single paper on arXiv.org[0]. And the paper is being published in a low-impact rated journal[1]. That doesn't rule it out as a breakthrough, but it means more skepticism is warranted.
> For over 55 years, John Bell has misled the physicists community and made us believe...
The author makes this a personal, nefarious attack that has been played on us. Not a mistake or disagreement, but that John Bell knew he was wrong.
> Einstein said that ... Not many believed him but this was the starting point for me when I came in touch with Bell's theorem.
This feels to me like the author is saying "Well Einstein says I'm right".
Overall, this feels like something we'll not be talking about for long. (But I'd LOVE to be wrong!)
[0]https://arxiv.org/search/physics?searchtype=author&query=Muc...
If he has indeed 'refuted' Bell's Theorem (and thus undermined the foundations of large swaths of theoretical Quantum Mechanics), one might expect he'd have at least one collaborator, a current research affiliation, and the interest of a journal with an impact factor greater than 2. It's possible he is the mythical solitary untrained genius, shunned by the establishment and producing Nobel-prize caliber research in his basement. That's probably not the way to bet, though.
Sure. But it is not forbidden.
Besides the odd circumstances, what outs me off is that he tries to link himself with former (well known) universities. He may have attended them, but he is in no way affiliated with them anymore. Crackhead-alarm
The problem is that (ignoring MA3) until the section "Predicting measurement results for the initial context" (inclusive) it is totally trivial if you have a background in Physics and Quantum Mechanics. It's not the usual model because it uses one (or two?) hidden variables, but it's easy to understand.
But the next section "Predicting measurement results for an arbitrary context" is totally unintelligible.
My guess is that the unintelligible part is hiding that when you measure a photon with a polarizer with an angle alpha, the other photon gets that information with an implicit faster than light communication. I have read it three times and I gave up.
To convince the scientific community it will be good to implement this model and post it in github or something.
* One function that create a pair of entangled photons X and Y.
* One function f that takes the photon X and the angle alpha and says if it passed the filter.
* One function g that takes the photon Y and the angle beta and says if it passed the other filter.
Bonus points if f and g are the same functions (or the only change is a pi/2).
No cheating, like using alpha in g, or assuming that alpha is 0.
Run a Montecarlo simulation and show that it gets the expected result. It's like 30 lines of Python or Fortran or whatever.
Transforming this to an analytical calculation is easy, but in an analytical calculations is easier to hide a change of variables and another trick that "transmit" alpha from one detector to the other.
(Straight implementation of Kupczynski Marian Closing the Door on Quantum Nonlocality https://philarchive.org/archive/KUPCTDv1 )
(Note for others: This is not an implementation of the OP method, it's another paper with a somewhat similar topic.)
It's an interesting model, but I don't like some details.
It generates a pair of (not entangled) photons with the same polarization (actually, +pi/2). Then it has two detectors.
In each detector the first secret parameter is equivalent to the usual calculation of the probability that a photon that has a polarization that is not aligned with the polarizer pass. If you can buy perfect/magical detectors that has the second secret parameter equal to zero, then this is just equivalent to the usual model with non entangled photons. And it should not break the Bell inequality.
The second secret parameter of each detector tries to model that the detectors sometimes miss a photon. I still don't like the model they are using, but it's not my specialty. Anyway, usually noise and fluky detectors make the result look more like classic results, so I expect that this second parameter makes the result not break the Bell inequality.
The problem is that it is possible to make very careful experiments that break the Bell inequality, so I don't understand what their model tries to show.
>The problem is that it is possible to make very careful experiments that break the Bell inequality, so I don't understand what their model tries to show.
Their plausible and local model aim to (and does!) reproduce the QM probabilities observed by experimenters (for all alpha and beta settings) and therefore does violate Bell inequality.
>It generates a pair of (not entangled) photons with the same polarization (actually, +pi/2)
The photon pair is entangled. The polarization is definite (and with a pi/2 offset between the pair) but unknown to the observer which is therefore measuring a distribution, that the key point. It's proposing an explanation of what entanglement is.
If alpha=beta or alpha=beta+90°, then the number of coincidences is approximately 500,000 (of the 20,000,000 tries)
If alpha=beta+45°, then the number of coincidences is only 1,500. i.e. like 300 times smaller.
Such a difference is would be very easy to see experimentally, and it is not the case. The number of coincidences independent of the angle between the sensors (with some noise, as always).
This filter is picking only the photons that have an angle phi that is very close to (alpha+beta)/2 or (alpha+beta)/2+90°.
For example if you have V=9.0 for alpha=beta+90° you have nbselected = 5622861 and for alpha=beta+45° nbselected = 1527848 That's only 3.7 times smaller.
But the main point of the paper is to have a really simple model to highlight the pointlessness of Bell theorem rather than point to a specific mistakes by experimenters.
0.9536987797308330
0.9540514229678816
0.9534108516112525
0.9540204547111079
0.9535252821469831
0.9538811736228740
0.9541386030170054
0.9534090666514868
0.9538249532069655
0.9535418321159825
(It is weird, but if alpha=0, and V=9, and you change beta, then the error is very close to (45-beta)/1000, where beta is in degrees. It's probably not exactly 1000, because using a number in degrees is weird, but it's similar.)
The problem is not to find an alternative algorithm that predicts one of the results, the problem is finding one that predicts correctly all the results.
It smoothly deforms the distribution between classical and QM, and the results look less like theoretical QM, and more like a experimental QM (in practice it's hard to observe 2.0*sqrt(2.0) theoretical violation of BI).
There is quite a lot of modelling freedom, to hide the distribution into the noise.
The whole question is what's more likely between experimenters missing photon pairs to the noise due to a systemic misconception in a complex experimental setup, or have the universe be non-local.
>The problem is not to find an alternative algorithm that predicts one of the results, the problem is finding one that predicts correctly all the results.
A model which predict all the results (Hint : Fields), will be more complex and even less likely to convince anyone.
Bell's theorem is a mathematical version of those onceyouseeit images ( https://twitter.com/TimKietzmann/status/1390405523430850562 ) where you realize that there is in fact nothing to see.
It's not about what is more likely or which model I prefer. It's about which model gives accurate prediction that agree with the experimental results. (Or if you want to be more technical, which one has not been falsified.)
It's evidence of the reasoning bug.
A circular reasoning logical fallacy due to the definition of what measurement and entanglement is.
Assume you are a creature living in a simulated local universe which works according to the above code, you can make the same measurements QM did and you could be holding all the arguments that Bell did and conclude that the world is non-local. Which is false by definition.
Scientists who know their stuff don't need a who. They can go purely on what.
If many such scientists accept something, then I think the scientific community will be convinced.
In the absence of this judgement from more knowledgeable scientists, people like me need to rely on who.
The way this is phrased, and the topic itself, makes this strongly sound like a crackpot that somehow sneaked into a journal.
Also, having misled a community do not imply having done so voluntarily.
From the paper:
>It is definitely not the intention of this paper to question the derivation of Bell’s inequality. Bell’s proof is mathematically correct. The point is simply that the assumptions of Bell’s inequality —namely, the restriction to non-contextual models— do not comprehensively describe conceivable physical reality.
I am familiar with Bell's theorem and the early work of Aspect in this subject. I have no memory of what a 'contextual model' is! So I can't comment on how interesting the paper is.
The author doesn't define it either. Define your terms.
Edit: After reading the introduction (keep in mind I haven't read it through)...
> In this paper, a local realistic but contextual model is presented, where the measurement results are predetermined but the polarization or spin (respectively) of particles in the singlet state is not fixed.
So the argument is that you're not collapsing the wavefunction so much as you don't know what you're measuring until you measure it?.. How is this compatible with a Stern–Gerlach experiment?
This is amazing if it's real. Can an expert shed any light on it?
If you believe QM is true then you flat out cannot have a local hidden variable theory. One possible way to "salvage" Bell's inequality with a local hidden variable theory is to effectively cheat by tying the chance of detecting a particle to the detector parameter (like the angle of the polarizer) and then throwing out some detections (detector A found a particle but detector B didn't fire, say). This effectively inflates the numerator in the probability in favor of the correlation while deflating the denominator, effectively discarding uncorrelated pairs. From what I understand, physicists are well aware of this problem and a significant portion of the entanglement experiments are devoted to justify how they're overcoming this loophole though I'm in absolutely no position to understand or judge if they're doing it well.
Maybe this is what the paper is talking about when considering a "contextual model"? If so, they don't present it in a clear or digestible way, which makes me suspicious that they're using terminology to hide something.
Could a physicist chime in and tell me what to make of this paper?
• a quick search for "refuting bell's theorem" will turn up attempts in 2000, 2007, 2011, 2012, 2017, etc, so let's take this with a huge grain of salt
• Europhysics Letters is a reasonably old journal (1986) but an impact factor of ~2 is pretty low; I wouldn't consider this a major journal
• As the Reddit discussion notes: "Just because you call your model locally realistic doesn't mean it's actually locally realistic. Calling it "contextual" doesn't change that. ... That part where the "context" of photon 1 changes the polarization of photon 2? That's not local.": https://www.reddit.com/r/Physics/comments/nig8d5/bells_theor...
Strange no one is arguing the science.
But the next section "Predicting measurement results for an arbitrary context" is totally unintelligible.
My guess is that the unintelligible part is hiding that when you measure a photon with a polarizer with an angle alpha, the other photon gets that information with an implicit faster than light communication. I have to read it again a third time, and I guess I'll need a fourth or fifth before I can have a definitive answer.
No but if it's legit they'd take it. And yea, I expect a researcher to be passingly familiar with the most popular research journals that everyone reads. Don't you?
Wow, this is way over my pay grade, but it sounds like this result makes quantum computers much harder to justify?
> "It is definitely not the intention of this paper to question the derivation of Bell's inequality. Bell's proof is mathematically correct. The point is simply that the assumptions of Bell's inequality —namely, the restriction to non-contextual models—do not comprehensively describe conceivable physical reality.
> "The model should reproduce the QM predictions of polarization measurements of entangled photons. In doing so, it would describe measurement results violating Bell's inequality."
The paper will be a slog if you don't know much QM or math; if you know some, you can likely get a handle on it.
To be honest, I'd like to see it refuted.