Bell's Theorem Correlations Velocity

[Rodsw]

The observable universe is about 92 billion light years in diameter. It would take 80 years for us just to reach the edge of our galaxy traveling at the speed of light. And there are a magnitude billions of galaxies with the space between them even more distant than within a galaxy.

Does it make sense Bell's Theorem still work for two entangled particles at say between 92 billion light years separation between them?

What is more logical is Bell's Theorem correlations have speed limit, such that they are near instantaneous in between say the edge to edge of a galaxy. This means the correlations need to have speed.

Aspect experiments have not proven the correlation is instantaneous.. just that it would be at least 10 times faster than the speed of light.

This means for separations of billions of light years. The correlations couldn't be instantaneous but needs to have speed limit. Would this be possible? What law forbid it to be even possible?

 

[ThomasT]

Does it make sense Bell's Theorem still work for two entangled particles at say between 92 billion light years separation between them?

It's not clear to me what this question is asking. But it seems that as long as you have channels that are able to transmit entangled particles, undisturbed, to detectors that are 92 billion light years apart, then Bell's theorem should still hold.

My understanding is that Bell's theorem is about whether a local realistic hidden variable (LRHV) formalism is compatible with the formalism of standard QM. Afaik, Bell showed, definitively, that it isn't. Subsequent experiments have demonstrated (not definitively because of some remaining experimental loopholes, but convincingly enough for most) that Bell-type LRHV models/theories of quantum entanglement are not viable.

Whether Bell's LRHV formulation should be considered the general LRHV formulation is something of an open question.

What is more logical is Bell's Theorem correlations have speed limit, such that they are near instantaneous in between say the edge to edge of a galaxy. This means the correlations need to have speed.

It seems that you're assuming some sort communication/transmission/propagation between entangled particles. This isn't what Bell's theorem is about. What Bell said was that if you assume some sort of communication/transmission/propagation between entangled particles, then that communication/transmission/propagation would have to be instantaneous. But, wrt ordinary language, that's a semantic contradiction. Another way of saying it is that these effects are happening (or might be recorded by a god's view observer) as happening simultaneously.

"Bell's theorem correlations", or, perhaps more appropriately, Bell test correlations, are statistical correlations, and there's no speed limit, afaik, on those. So, no, the correlations don't need to have a speed. But if you're assuming propagations between entangled particles, then, yes, those would be amenable to statements regarding their speed, and a limit on that speed.

But, as noted above, that's not what Bell's theorem is about.

Aspect experiments have not proven the correlation is instantaneous.. just that it would be at least 10 times faster than the speed of light.

Aspect et al.'s experiments haven't proven anything. They have demonstrated, ie., provided one example of, the nonviability of Bell-type LRHV models of quantum entanglement, and the viability of the standard QM formalism.

If you want to assume some sort of communication/transmission/propagation between entangled particles, then it seems that it would have to be traveling quite a bit faster than light. But there's absolutely no physical evidence that anything like that is happening. And, as mentioned, it isn't what Bell's theorem is about.

 

[Rodsw]

It's not clear to me what this question is asking. But it seems that as long as you have channels that are able to transmit entangled particles, undisturbed, to detectors that are 92 billion light years apart, then Bell's theorem should still hold.

My understanding is that Bell's theorem is about whether a local realistic hidden variable (LRHV) formalism is compatible with the formalism of standard QM. Afaik, Bell showed, definitively, that it isn't. Subsequent experiments have demonstrated (not definitively because of some remaining experimental loopholes, but convincingly enough for most) that Bell-type LRHV models/theories of quantum entanglement are not viable.

Whether Bell's LRHV formulation should be considered the general LRHV formulation is something of an open question.

It seems that you're assuming some sort communication/transmission/propagation between entangled particles. This isn't what Bell's theorem is about. What Bell said was that if you assume some sort of communication/transmission/propagation between entangled particles, then that communication/transmission/propagation would have to be instantaneous. But, wrt ordinary language, that's a semantic contradiction. Another way of saying it is that these effects are happening (or might be recorded by a god's view observer) as happening simultaneously.

"Bell's theorem correlations", or, perhaps more appropriately, Bell test correlations, are statistical correlations, and there's no speed limit, afaik, on those. So, no, the correlations don't need to have a speed. But if you're assuming propagations between entangled particles, then, yes, those would be amenable to statements regarding their speed, and a limit on that speed.

But, as noted above, that's not what Bell's theorem is about.

Aspect et al.'s experiments haven't proven anything. They have demonstrated, ie., provided one example of, the nonviability of Bell-type LRHV models of quantum entanglement, and the viability of the standard QM formalism.

If you want to assume some sort of communication/transmission/propagation between entangled particles, then it seems that it would have to be traveling quite a bit faster than light. But there's absolutely no physical evidence that anything like that is happening. And, as mentioned, it isn't what Bell's theorem is about.

But even if there were no communication/transmission/propagation between the entangled particles themselves, something behind the scene communication/transmission/propagation is occurring in order to conspire to make the entangled pairs correlated. So I wonder if this behind the scene "thing" has velocity limit.. it would be a stretch to think they can handle 92 Billion Light years instantaneously hence I wonder if there is a speed limit to the correlation information sychronizer (what it is)?

 

[ThomasT]

But even if there were no communication/transmission/propagation between the entangled particles themselves, something behind the scene communication/transmission/propagation is occurring in order to conspire to make the entangled pairs correlated.

The way I've learned to think about it is in terms of a relationship between measurable properties of the entangled particles. And that wouldn't necessarily have anything to do with communications/transmissions/propagations between the separated particles. If the particles have interacted with each other, or have been emitted from the same atom, etc., then they're related -- and that relationship can be measured by global instrumental variables (such as the angular difference between crossed polarizers in optical Bell tests).

So I wonder if this behind the scene "thing" has velocity limit ...

Well, you can assume that the entangled particles are communicating in some way. That's not ruled out. Just not the most parsimonious way to approach understanding quantum entanglement, imho. And if you assume that they're communicating, then I think it's been demonstrated that that would have a lower bound. Not sure about an upper bound.

... it would be a stretch to think they can handle 92 Billion Light years instantaneously hence I wonder if there is a speed limit to the correlation information sychronizer (what it is)?

Afaik, the "correlation information synchronizer" would refer to the coincidence circuitry and the post experimental data processing which doesn't per se, afaik, imply any sort of communication between entangled particles.

But, as mentioned, you can assume that the particles are communicating with each other and then from any particular experimental preparation you can calculate at least a lower bound for such communications.

If you approach quantum entanglement in terms of relationships between entangled particles, then the distance between them isn't a consideration insofar as you're able to preserve the entanglement relationship.

 

[bohm2]

You might find this paper interesting:

Yet, it is always possible, in principle, to explain such experimental violations through models based on hidden influences propagating at a finite speed v > c, provided v is large enough. Here, we show that for any finite speed v > c, such models predict correlations that can be exploited for faster-than-light communication. This superluminal communication does not require access to any hidden physical quantities, but only the manipulation of measurement devices at the level of our present-day description of quantum experiments. Hence, assuming the impossibility of using quantum non-locality for superluminal communication, we exclude any possible explanation of quantum correlations in term of finite-speed influences.

The authors then conclude:

This work illustrates the difficulty to modify quantum physics while maintaining no-signaling. If we want to keep no-signalling, it shows that quantum non-locality must necessarily relate discontinuously parts of the universe that are arbitrarily distant. This gives further weight to the idea that quantum correlations somehow arise from outside spacetime, in the sense that no story in space and time can describe how they occur.

Quantum nonlocality based on finite-speed causal influences leads to superluminal signaling
http://lanl.arxiv.org/PS_cache/arxiv/pdf/1110/1110.3795v1.pdf

 

[Nugatory]

it would be a stretch to think they can handle 92 Billion Light years instantaneously

Yes, but it's also a stretch to think that they can handle 92 billion light-years in any time less than 92 billion years :-)

And kidding aside... When you speak in terms of an influence that propagates at some finite speed, you're speaking in realistic terms. If that finite speed is greater than the speed of light, then your realistic model is incompatible with relativity and therefore not local (as the term is generally used). I don't find "faster than light but finite" to be any more digestible than "infinite".

 

[ThomasT]

You might find this paper interesting:
Quantum nonlocality based on finite-speed causal influences leads to superluminal signaling
http://lanl.arxiv.org/PS_cache/arxiv/pdf/1110/1110.3795v1.pdf

So, if communication between entangled particles is assumed, and if the speed of that communication is assumed to be finite (ie., not instantaneous), then superluminal signalling is possible? Is that what the paper is saying? Haven't read it yet.

It would seem that either the paper is wrong, or the 'no signalling theorems' are wrong, or the assumption of communication between entangled particles is wrong, or maybe it's just that the technology hasn't gotten 'up to speed' yet. And I have no idea at this time which it might be because I don't assume that separated entangled particles are communicating. As I mentioned, I just think about quantum entanglement in terms of relationships between entangled particles.

The understanding of experimental violations of Bell inequalities has an explanation in terms of how LRHV formalism relates to Bell test preparations. It doesn't inform wrt what's going on in the reality underlying instrumental behavior. At least that's my current assessment/understanding.

 

[bohm2]

So, if communication between entangled particles is assumed, and if the speed of that communication is assumed to be finite (ie., not instantaneous), then superluminal signalling is possible? Is that what the paper is saying? Haven't read it yet.

Yes, that's how I interpreted it. One of the authors (Gisin) was involved in testing Bell's (although it doesn't close all loopholes):

Experimental demonstration of quantum correlations over more than 10 km
http://arxiv.org/abs/quant-ph/9707042

 

[Rodsw]

The way I've learned to think about it is in terms of a relationship between measurable properties of the entangled particles. And that wouldn't necessarily have anything to do with communications/transmissions/propagations between the separated particles. If the particles have interacted with each other, or have been emitted from the same atom, etc., then they're related -- and that relationship can be measured by global instrumental variables (such as the angular difference between crossed polarizers in optical Bell tests).

Well, you can assume that the entangled particles are communicating in some way. That's not ruled out. Just not the most parsimonious way to approach understanding quantum entanglement, imho. And if you assume that they're communicating, then I think it's been demonstrated that that would have a lower bound. Not sure about an upper bound.

Afaik, the "correlation information synchronizer" would refer to the coincidence circuitry and the post experimental data processing which doesn't per se, afaik, imply any sort of communication between entangled particles.

But, as mentioned, you can assume that the particles are communicating with each other and then from any particular experimental preparation you can calculate at least a lower bound for such communications.

If you approach quantum entanglement in terms of relationships between entangled particles, then the distance between them isn't a consideration insofar as you're able to preserve the entanglement relationship.

You misunderstood my statements above. When I mentioned behind the scene communications/transmissions/propagations, I was referring to the wave functions. So the communications is not in between the particles, but somehow the wave function has to communicate.

Or we can put it in the following statement. It would be a stretch to think that the wave function can be maintained 92 Billion Light years instantaneously hence I wonder if there is a speed limit to the wave function speed?

Of course this is assuming the wave function was physical.

But supposed the wave function was not physical. The correlations on paper still has to be maintained 92 Billion light years. And again. It would be a stretch to think that the wave function on paper can be maintained 92 Billion Light years instantaneously hence I wonder if there is a speed limit to the wave function on paper. (?)

 

[ThomasT]

You misunderstood my statements above. When I mentioned behind the scene communications/transmissions/propagations, I was referring to the wave functions. So the communications is not in between the particles, but somehow the wave function has to communicate.

Wavefunctions are just mathematical entities. If you want to assume that they actually describe propagating particles, then the communication you suggest is between entangled particles. Isn't it?

Afaik, QM doesn't describe any communication between entangled particles.

Or we can put it in the following statement. It would be a stretch to think that the wave function can be maintained 92 Billion Light years instantaneously ...

Not if the wavefunction is just a mathematical entity. As I mentioned, if you think of quantum entanglement in terms of relationships between separarated entangled particles, then the distance between those particles isn't important insofar as you're able to maintain the relationship between them.

... hence I wonder if there is a speed limit to the wave function speed?

Wavefunctions are mathematical entities. I don't know what else to say.

Of course this is assuming the wave function was physical.

Ok. But there's no particular reason to assume that.

But supposed the wave function was not physical.

Well, it isn't physical, it's mathematical. You can assume that it corresponds to the physical world, but that's just an assumption. All that's known is that it's mathematical.

The correlations on paper still has to be maintained 92 Billion light years.

They are maintained 92 billion light years -- provided that the relationships between quantum entangled particles can be maintained for that distance/period.

And again. It would be a stretch to think that the wave function on paper can be maintained 92 Billion Light years ...

Well, I think it's a stretch also.
And, in any case, it can't be tested. So why worry about it?

My honest opinion is that you're thinking about this in the wrong way, based on assumptions that have no support wrt empirical science.

Are quantum entangled particles communicating with each other? I have no idea. Is there any reason to assume that they are? Afaik, no.

 

[Rodsw]

Wavefunctions are just mathematical entities. If you want to assume that they actually describe propagating particles, then the communication you suggest is between entangled particles. Isn't it?

Afaik, QM doesn't describe any communication between entangled particles.

Not if the wavefunction is just a mathematical entity. As I mentioned, if you think of quantum entanglement in terms of relationships between separarated entangled particles, then the distance between those particles isn't important insofar as you're able to maintain the relationship between them.

Wavefunctions are mathematical entities. I don't know what else to say.

Ok. But there's no particular reason to assume that.

Well, it isn't physical, it's mathematical. You can assume that it corresponds to the physical world, but that's just an assumption. All that's known is that it's mathematical.

They are maintained 92 billion light years -- provided that the relationships between quantum entangled particles can be maintained for that distance/period.

Well, I think it's a stretch also.
And, in any case, it can't be tested. So why worry about it?

My honest opinion is that you're thinking about this in the wrong way, based on assumptions that have no support wrt empirical science.

Are quantum entangled particles communicating with each other? I have no idea. Is there any reason to assume that they are? Afaik, no.

I think I heard arguments of the sort that for the entangled pairs to be compared. It has to be done conventionally. So you are saying that for Alice and Bob stationed 92 billion light years away. They can only compare the results by traveling for 92 billion years near light speed and it is only upon meeting at the common point that the past got created (hence explaining the correlations)? I'm not arguing anything but just need to know what is the conventional understanding of this.

 

[ThomasT]

I think I heard arguments of the sort that for the entangled pairs to be compared. It has to be done conventionally. So you are saying that for Alice and Bob stationed 92 billion light years away. They can only compare the results by traveling for 92 billion years near light speed and it is only upon meeting at the common point that the past got created (hence explaining the correlations)? I'm not arguing anything but just need to know what is the conventional understanding of this.

Ok, I don't understand your understanding of quantum entanglement correlations. There's nothing, afaik, particularly mysterious about them, but I don't know what the conventional or mainstream understanding is (except to say that the physicists that I know and have talked to about this regard entanglement as being due to relationships between entangled particles, and not due to ftl communications between entangled particles).

Afaik, it doesn't make any sense to say that "the past got created" when Alice and Bob meet to compare results. Bell tests are like any other experiments involving global measurement parameters in that results accumulated at separated detectors have to be combined and then analysed/correlated wrt the associated global instrumental variables in order to demonstrate the correlations -- and this is all done via local transmissons.

So, I guess that I'm really not sure what your concern is. This is not to criticize your questions (questions are always ok), because the meaning of Bell's theorem has been debated for a few decades. It's not an easy thing to explain, and it really has nothing to do with the popularizations of Bell's theorem, or with ftl communications.

 

[Rodsw]

Ok, I don't understand your understanding of quantum entanglement correlations. There's nothing, afaik, particularly mysterious about them, but I don't know what the conventional or mainstream understanding is (except to say that the physicists that I know and have talked to about this regard entanglement as being due to relationships between entangled particles, and not due to ftl communications between entangled particles).

Afaik, it doesn't make any sense to say that "the past got created" when Alice and Bob meet to compare results. Bell tests are like any other experiments involving global measurement parameters in that results accumulated at separated detectors have to be combined and then analysed/correlated wrt the associated global instrumental variables in order to demonstrate the correlations -- and this is all done via local transmissons.

So, I guess that I'm really not sure what your concern is. This is not to criticize your questions (questions are always ok), because the meaning of Bell's theorem has been debated for a few decades. It's not an easy thing to explain, and it really has nothing to do with the popularizations of Bell's theorem, or with ftl communications.

Have you seen this site?

http://quantumtantra.com/bell2.html

Do you understand all the arguments mentioned there?

In Aspect experiment, the angles were changed in between. For example. After the photons have reached say half or 42 billion light years of the 92 billion light years distance, the angles of the polarizers of both ends were changed, and the results violated Bell's Inequality.

 

[ThomasT]

Have you seen this site?

http://quantumtantra.com/bell2.html

Do you understand all the arguments mentioned there?

I took a quick look at it. It seems to be saying that the correlation between the angular difference of the polarizers and the rate of coincidental detection must be linear if nature is local. Which is, imho, wrong.

In Aspect experiment, the angles were changed in between. For example. After the photons have reached say half or 42 billion light years of the 92 billion light years distance, the angles of the polarizers of both ends were changed, and the results violated Bell's Inequality.

It doesn't matter how many times the angle is changed while the photons are in flight. Each photon of an entangled pair interacts with its polarizer being at some specific orientation, and the pair's detection attributes are associated with one and only one angular difference.

Randomly changing the polarizer settings while the photons are in flight just removes the possibility of the photons being 'attuned' to some particular setting(s) on emission, or for them to be communicating with each other via local signals.

So, you're left with three possibilities: 1) the separated photons are communicating with each other via ftl signals, 2) the separated photons are communicating with each other via action at a distance, or 3) the separated photons aren't communicating with each other.

None of those possibilities has been proven or disproven, and, imho, 3) is the most reasonable assumption.

 

[Edgardo]

The observable universe is about 92 billion light years in diameter. It would take 80 years for us just to reach the edge of our galaxy traveling at the speed of light. And there are a magnitude billions of galaxies with the space between them even more distant than within a galaxy.

Does it make sense Bell's Theorem still work for two entangled particles at say between 92 billion light years separation between them?

What is more logical is Bell's Theorem correlations have speed limit, such that they are near instantaneous in between say the edge to edge of a galaxy. This means the correlations need to have speed.

Aspect experiments have not proven the correlation is instantaneous.. just that it would be at least 10 times faster than the speed of light.

This means for separations of billions of light years. The correlations couldn't be instantaneous but needs to have speed limit. Would this be possible? What law forbid it to be even possible?

I think you are asking about nonlocality: There are two events A and B. Event A cannot influence event B if B is outside of A's light cone. The correlations though seem to imply a faster than light signal from A that influences B.

One explanation for nonlocality that avoids faster than light signals is backward causation:
From event A not only a forward light cone is emitted but also a backward light cone. This reaches the source and therefore the particle measured at B. So this backward light cone tells the other particle to have the opposite spin. I wrote more about this in another thread:
Help for a beginner...Bell's Theorem

Other explanations are offered by interpretations of quantum mechanics (I have to mention that I don't understand them):
1. Relational quantum mechanics:
- Nonlocality A Backreaction blogpost on a paper by Rovelli.
- There was a discussion on PF too

2. Many Worlds interpretation
- From what I understand there is no collapse in this interpretation, thus no instantaenous collapse of the entangled state.
I read about it here:
The Interpretation of Quantum Mechanics: Many Worlds or Many Words?
Many lives in many worlds
Both articles by Max Tegmark

 

[bohm2]

Wavefunctions are mathematical entities. I don't know what else to say.

Sure, but what are those entities about? What are they describing/modelling? How does one explain double-slit type interference phenomena (e.g. using single photons)? Moreover, there are papers suggesting that the wave functions are more than just mathematical entities; that is, they are telling us something about the way nature is. And here, I'm not denying that our view of nature will always be somewhat veiled due to our own cognitive filters.

The quantum state cannot be interpreted statistically (this is the original paper)
http://lanl.arxiv.org/abs/1111.3328
Generalisations of the recent Pusey-Barrett-Rudolph theorem for statistical models of quantum phenomena
http://xxx.lanl.gov/abs/1111.6304
Completeness of quantum theory implies that wave functions are physical properties
http://arxiv.org/PS_cache/arxiv/pdf/1111/1111.6597v1.pdf
Quantum theorem shakes foundations
http://www.nature.com/news/quantum-theorem-shakes-foundations-1.9392
Can the quantum state be interpreted statistically?
http://mattleifer.info/2011/11/20/can-the-quantum-state-be-interpreted-statistically/
Direct Measurement of the Quantum Wavefunction
http://arxiv.org/PS_cache/arxiv/pdf/1112/1112.3575v1.pdf

 

[ThomasT]

I think you are asking about nonlocality: There are two events A and B. Event A cannot influence event B if B is outside of A's light cone. The correlations though seem to imply a faster than light signal from A that influences B.

I don't think that either the entanglement correlations or the formalism of QM implies ftl communication between A and B. It's just that QM doesn't explicitly forbid it, and the correlations themselves are in line with the way light has been observed to behave wrt crossed polarizers in both classical and quantum polariscopic setups.

What experimental violations of Bell inequalities do indicate is that Bell-type LRHV formalizations of quantum entanglement aren't viable, and that the standard QM formalization of quantum entanglement is viable. But the QM formalization of quantum entanglement is neither explicitly local nor nonlocal.

What quantum nonlocality has evolved to refer to (and I'm guessing that this is how most physicists think of it) is the nonseparability of the QM formalization of quantum entanglement.

So, nonlocality (insofar as it refers to ftl propagations or action at a distance) is just an assumption based on no physical evidence other than the inability to fully account for quantum entanglement correlations via Bell-type LRHV models.

But, while imo that sort of nonlocality is an unwarranted assumption, it isn't ruled out, and if one chooses to assume it, then one is faced with some problems (imho ... pseudo-problems) that have led to some, imo, unwarranted (and unfalsifiable) interpretations of standard QM.

 

[ThomasT]

Sure, but what are those entities about? What are they describing/modelling?

You mean wrt a reality underlying instrumental behavior? Well, there's no way to definitively ascertain that afaik. Is there?

How does one explain double-slit type interference phenomena (e.g. using single photons)?

In terms of a qualitative comprehension/understanding of what's happening in the underlying reality? One doesn't, afaik.

Moreover, there are papers suggesting that the wave functions are more than just mathematical entities; that is, they are telling us something about the way nature is.

What I take from it is that there's a good possibility that the underlying reality involves wave mechanics in a hierarchy of particulate media. But afaik there's no way to determine exactly how a particular wave function corresponds to the underlying reality.

Thanks for the links.

 

[Rodsw]

I took a quick look at it. It seems to be saying that the correlation between the angular difference of the polarizers and the rate of coincidental detection must be linear if nature is local. Which is, imho, wrong.

I found this old thread between you and Jesse about the Helbert website.

https://www.physicsforums.com/showthread.php?t=417173&page=2

You mentioned: "But, according to Malus Law the number of mismatches at 60 degrees should be greater than the number of mismatches at 30 degrees + the number of mismatches at 30 degrees."

Jesse (Science Advisor) declared:

"No, the classical Malus' law does not predict this, not in the setup that Bell and Herbert described. The fact that you can find a completely different setup where the classical Malus' law does predict mismatches at 60 is greater than the sum of mismatches at 30 is just a strawman argument, since Bell never argued that his inequalities should apply in any experiments other than ones meeting the conditions he specified. Since classical electromagnetism is a local realist theory, it would indeed be impossible to replicate the 0.5 cos^2 (a-b) in a classical optics experiment that actually matched Bell's setup."

Hence, you ThomasT as an amateur is refuted by the professional. That thread was written in July of 2010. You still haven't learned after all this months and time?

It doesn't matter how many times the angle is changed while the photons are in flight. Each photon of an entangled pair interacts with its polarizer being at some specific orientation, and the pair's detection attributes are associated with one and only one angular difference.

Randomly changing the polarizer settings while the photons are in flight just removes the possibility of the photons being 'attuned' to some particular setting(s) on emission, or for them to be communicating with each other via local signals.

So, you're left with three possibilities: 1) the separated photons are communicating with each other via ftl signals, 2) the separated photons are communicating with each other via action at a distance, or 3) the separated photons aren't communicating with each other.

None of those possibilities has been proven or disproven, and, imho, 3) is the most reasonable assumption.

 

[ThomasT]

Hence, you ThomasT as an amateur is refuted by the professional. That thread was written in July of 2010. You still haven't learned after all this months and time?

My understanding of the issues surrounding the interpretation of Bell's theorem (Bt) has improved since that thread, wherein I probably made a lot of incorrect statements.

I don't know for sure, but my guess would be that most physicists don't think that Bt (including experimental violation of Bell inequalities) implies that nature is nonlocal. But, iirc, Jesse is one who does.

Anyway, the analogy was intended to show that the restrictions (for the purpose of making the assumptions of locality and realism explicit) encoded in Bell-type LRHV models of quantum entanglement (applied to optical Bell tests) amount to requiring light to behave in a way contrary to the way that light has been observed to behave in other, imo similar (such as classical and quantum polariscopic), setups.

To illustrate, consider a simple optical Bell setup with an emitter flanked by polarizers (a and b) and detectors (A and B). Like this:

A <--------- a <------------Emitter----------> b ---------> B

An interesting thing is that polarizer a can be placed between the emitter and polarizer b. Like this:

A <-------------------------Emitter-----> a -----> b -----> B

And you get the same coincidental photon flux (which, in the ideal, is .5(cos^2Theta), with Theta=a-b) as when the polarizers are in the original configuration, except that in second setup, just considering the right hand wing, it's easy to see that the rate of photon flux at B, .5(cos^2Theta), corresponds to observed polariscopic behavior of light.

On the left side of the second setup, A is recording the maximum photon flux. While on the right side the photon flux at B is .5(cos^2Theta). So, the coincidental photon flux goes from half the maximum (with the polarizers aligned) to zero (with the polarizers perpendicular).

This is one of the considerations that got me to thinking that requiring the number of mismatches at 60 degrees to be equal to or less than double the number of mismatches at 30 degrees might not be in line with the way light should be expected to behave in optical Bell tests (in a local universe), given the prior experimental literature on the behavior of light. And yet, this is the way that Bell-type LRHV models of entanglement require light to behave.

There's no argument that Bell's theorem rules out Bell-type LRHV models of quantum entanglement. But there's still some dispute about whether experimental violations of Bell inequalities demonstrate nonlocality. You're free to assume that nature is nonlocal, in the sense of entangled photons communicating with each other via ftl signals (it isn't ruled out, afaik ... but it might be an unfalsifiable assumption), and then proceed to solve the problems associated with that assumption.

Anyway, assuming that entangled particles are communicating with each other, then, afaik, there's a lower bound on the speed of such communication. As I mentioned, I don't know about an upper bound. According to the dBB interpretation it's instantaneous. Isn't it? Not sure. But if it is, then that means action at a distance. EPR showed that either there's instantaneous action at a distance, or standard QM is an incomplete description of physical reality. That the latter is the more reasonable assumption seems obvious to me. But it has to be qualified. Standard QM is complete in that it includes everything that's known that's pertinent to any particular experimental preparation.

 

[Rodsw]

My understanding of the issues surrounding the interpretation of Bell's theorem (Bt) has improved since that thread, wherein I probably made a lot of incorrect statements.

I don't know for sure, but my guess would be that most physicists don't think that Bt (including experimental violation of Bell inequalities) implies that nature is nonlocal. But, iirc, Jesse is one who does.

Anyway, the analogy was intended to show that the restrictions (for the purpose of making the assumptions of locality and realism explicit) encoded in Bell-type LRHV models of quantum entanglement (applied to optical Bell tests) amount to requiring light to behave in a way contrary to the way that light has been observed to behave in other, imo similar (such as classical and quantum polariscopic), setups.

To illustrate, consider a simple optical Bell setup with an emitter flanked by polarizers (a and b) and detectors (A and B). Like this:

A <--------- a <------------Emitter----------> b ---------> B

An interesting thing is that polarizer a can be placed between the emitter and polarizer b. Like this:

A <-------------------------Emitter-----> a -----> b -----> B

And you get the same coincidental photon flux (which, in the ideal, is .5(cos_2Theta), with Theta=a-b) as when the polarizers are in the original configuration, except that in second setup, just considering the right hand wing, it's easy to see that the rate of photon flux at B, .5(cos_2Theta), corresponds to observed polariscopic behavior of light.

On the left side of the second setup, A is recording the maximum photon flux. While on the right side the photon flux at B is .5(cos_2Theta). So, the coincidental photon flux goes from half the maximum (with the polarizers aligned) to zero (with the polarizers perpendicular).

This is one of the considerations that got me to thinking that requiring the number of mismatches at 60 degrees to be equal to or less than double the number of mismatches at 30 degrees might not be in line with the way light should be expected to behave in optical Bell tests (in a local universe), given the prior experimental literature on the behavior of light. And yet, this is the way that Bell-type LRHV models of entanglement require light to behave.

The arguments are for Jesse to comment (if he is reading this).

There's no argument that Bell's theorem rules out Bell-type LRHV models of quantum entanglement. But there's still some dispute about whether experimental violations of Bell inequalities demonstrate nonlocality. You're free to assume that nature is nonlocal, in the sense of entangled photons communicating with each other via ftl signals (it isn't ruled out, afaik ... but it might be an unfalsifiable assumption), and then proceed to solve the problems associated with that assumption.

Anyway, assuming that entangled particles are communicating with each other, then, afaik, there's a lower bound on the speed of such communication. As I mentioned, I don't know about an upper bound. According to the dBB interpretation it's instantaneous. Isn't it? Not sure. But if it is, then that means action at a distance. EPR showed that either there's instantaneous action at a distance, or standard QM is an incomplete description of physical reality. That the latter is the more reasonable assumption seems obvious to me. But it has to be qualified. Standard QM is complete in that it includes everything that's known that's pertinent to any particular experimental preparation.

You always focus on Polarizers. I forgot what other parameters can be used for Bell's Theorem testS. Can anyone familiar with this enumate what are all the parameters that are tested, for example, polarization, spin.. what else? I think those other parameters would be more obvious proof of the correlations.

I also heard of this argument where for Alice and Bob to compare the results. They must meet at a point in time. I forgot why exactly is this mentioned. I thought it had to do with something about realism and how the results would be consistent by some kind of consistent histories where the past of Alice and Bob got changed too. Not sure.. hope someone can point out the purpose of this reasoning that they had to meet at a point in time.. something about no experiments can prove the correlations occurring simultaneous at Alice and Bob ends.

 

[ThomasT]

The arguments are for Jesse to comment (if he is reading this).

Or any others more knowledgeable about this than us. Keep in mind that the consideration I mentioned, even if correct, doesn't diminish the fact that Bell's theorem definitively rules out Bell-type LRHV models of quantum entanglement. But it might cause one to consider a bit more carefully whether Bell's theorem and experiment violations of Bell inequalities should be taken to mean that nature is nonlocal.

You always focus on Polarizers.

Just trying to keep it simple (for myself ). Anyway, afaik, most Bell tests are optical Bell tests involving polarizers.

I forgot what other parameters can be used for Bell's Theorem testS. Can anyone familiar with this enumate what are all the parameters that are tested, for example, polarization, spin.. what else? I think those other parameters would be more obvious proof of the correlations.

There's no need to prove the entanglement correlations. They've been observed/recorded. They're real. But it's a bit of an unwarranted (imho) leap to go from those correlations to assuming that nature is nonlocal.

I also heard of this argument where for Alice and Bob to compare the results. They must meet at a point in time. I forgot why exactly is this mentioned.

Alice and Bob don't necessarily have to meet, but in order to correlate Theta to rate of coincidental detection you need the data streams from both A and B, and the data processing is done via local channels. The paired detection attributes at A and B don't have to be generated simultaneously.

You might want to start a new thread on some of your considerations that seem to be a bit off topic from your OP. If you phrase them well enough then maybe some of the PF science advisors will reply.

 

[Rodsw]

Or any others more knowledgeable about this than us. Keep in mind that the consideration I mentioned, even if correct, doesn't diminish the fact that Bell's theorem definitively rules out Bell-type LRHV models of quantum entanglement. But it might cause one to consider a bit more carefully whether Bell's theorem and experiment violations of Bell inequalities should be taken to mean that nature is nonlocal.

Just trying to keep it simple (for myself ). Anyway, afaik, most Bell tests are optical Bell tests involving polarizers.

There's no need to prove the entanglement correlations. They've been observed/recorded. They're real. But it's a bit of an unwarranted (imho) leap to go from those correlations to assuming that nature is nonlocal.

Let's first settle about this statement "assuming that nature is nonlocal" or the meaning of nonlocal. In the nitpicking world of convensional QM, Locality is untrue because in the absence of measurement to determine a particle position, there is no position. Hence no locality. There there is no such thing as quantum nonlocality because "nonlocality" is invalid since there is no locality. Is this your position or context when you mentioned "nonlocal"? Or is it in the context of Bohmiam Mechanics or Collapse Theories where locality exists, and hence "nonlocal" can be used as a word?

Alice and Bob don't necessarily have to meet, but in order to correlate Theta to rate of coincidental detection you need the data streams from both A and B, and the data processing is done via local channels. The paired detection attributes at A and B don't have to be generated simultaneously.

You might want to start a new thread on some of your considerations that seem to be a bit off topic from your OP. If you phrase them well enough then maybe some of the PF science advisors will reply.

I just want to know what is the orthodox accepted explanation of quantum correlations. First you agree there is a correlation? And if one change the settings when the photons or electrons are in mid flight, it can affect the result? But then you are arguing the correlations can be explained without resorting to long distant quantum correlations but just classical explanations? But this latter is refuted by experiments like Aspect's provided the loopholes were invalid. Or you are saying the loopholes could be true explaning the results? I'm still not clear of your position.

 

[bohm2]

There's no need to prove the entanglement correlations. They've been observed/recorded. They're real. But it's a bit of an unwarranted (imho) leap to go from those correlations to assuming that nature is nonlocal.

But that's exactly what Bell himself thought:

My own first paper (Physics 1, 195 (1965.) on this subject starts with a summary of the EPR argument from locality to deterministic hidden variables. But the commentators have almost universally reported that it begins with deterministic hidden variables.

J.S. Bell’s Concept of Local Causality
http://chaos.swarthmore.edu/courses/Physics113_2012/002.pdf

Similar arguments supporting this view are given in the following papers:

Although it has been clearly shown – from the original 1964 Bell paper right up to more recent instances (Maudlin (1996), Norsen (2007)) – that the Bell theorem does not include any ‘realism’ among its assumptions and that the non-locality established by the theorem holds for any theory that preserves quantum-mechanical predictions, be it ‘realistic’ or ‘non-realistic’, there seems to be a die-hard tendency to regard the Bell theorem as a result that does not establish non-locality but rather the impossibility of any objective (i.e. observer-independent in principle) account of the physical world, provided quantum mechanics is taken for granted.

Non-Local Realistic Theories and the Scope of the Bell Theorem
http://arxiv.org/ftp/arxiv/papers/0811/0811.2862.pdf

A crucial point that is usually overlooked is the fact that the existence of the hidden variables used in the deduction of Bell’s inequality is inferred from the assumption of locality using the EPR argument; it is not, as many physicists seem to think, an additional assumption that is necessary for proving the inequality. Therefore, violation of Bell’s inequality implies that locality has to be abandoned.

A Criticism of the article "An experimental test of non-local realism"
http://arxiv.org/abs/0809.4000

And this suggests that, if the ‘realism’ in ‘local realism’ is indeed Metaphysical Realism, the conversational implication noted by Maudlin–that we might save Locality by rejecting Realism–is patently false. We cannot choose between rejecting Locality and rejecting Metaphysical Realism (with the other being “saved”). We may reject Locality (and save Metaphysical Realism)–or we may reject Metaphysical Realism and with it any meaningful claims about Locality, the causal structure of the world, and literally everything else that every concept and theory in the entire history of physics has purported to be about. Faced with Bell’s Theorem and the empirical data showing violations of Bell’s inequalities, we must reject Locality–or turn solipsist, i.e., simply shut down cognitively and refrain from saying anything about anything.

Against ‘Realism’
http://lanl.arxiv.org/PS_cache/quant-ph/pdf/0607/0607057v2.pdf

There will of course still be difficult questions about how to decide whether a given candidate theory is true, and hence whether the particular sort of non-local causation contained in it accurately describes some aspect of Nature. But the miracle of Bell’s argument is that we need not know which theory is true, in order to know that the true theory (whatever it turns out to be) will have to exhibit non-local, super-luminal causation. There is thus no escaping Bell’s conclusion that some sort of non-local causation (in violation of the structure displayed in Fig- ure 1) exists in Nature–in apparent conflict with what most physicists take to be the requirements of SR.

Local Causality and Completeness: Bell vs. Jarrett
http://lanl.arxiv.org/PS_cache/arxiv/pdf/0808/0808.2178v1.pdf

 

[bohm2]

Let's first settle about this statement "assuming that nature is nonlocal" or the meaning of nonlocal. In the nitpicking world of convensional QM, Locality is untrue because in the absence of measurement to determine a particle position, there is no position. Hence no locality. There there is no such thing as quantum nonlocality because "nonlocality" is invalid since there is no locality. Is this your position or context when you mentioned "nonlocal"?

That's exactly why the whole idea of non-local vs local non-realism doesn't make sense to me. And I don't understand why there's this immense aversion to non-locality (especially since this doesn't imply instantaneous information transmission) or why there's this need to treat special relativity as sacrosanct. Sure, such instantaneous interactions among distantly separated systems do seem to call into question even our basic notions, that "physical" objects should be arranged in a space-time continuum; but so what. There's no necessary requirement that "external" reality should be mapped in any simple or direct fashion into the world of human ideas. As d'Espagnat points out,

...while space is indeed the arena where the phenomena are rightly viewed as taking place, it is not (nor is space-time) an arena in which independent reality evolves. Rather it (and time and space-time) are primarily allegorical, human modes of apprehension (as Kant might have said) of independent reality.

It then follows, that although we may be innately forced by our biologically-given mental structures to describe "empirical reality" (the subject-matter of physics proper) as if it evolves in a space-time manifold, "independent reality" may not actually evolve in such an arena. In fact,

...such 'data' as nonseparability, weak objectivity of all truly productive versions of quantum theory...seem to constitute quite strong arguments against an embedding of reality in space-time and/or cosmic time.

Rovelli, argues that,

in moving from theories of 'special objects', like...living beings, toward more general theories that include larger portions of Nature, we discover that these laws require, or admit, a progressively weaker notion of time...(and) considering the lowest level, we suggest that the very notion of time...is likely to disappear in a consistent theory that includes relativistic quantum-gravitational systems.

 

[ThomasT]

That's exactly why the whole idea of non-local vs local non-realism doesn't make sense to me.

It doesn't make sense to me either, in the sense that labels like local or nonlocal wouldn't seem to me to pertain to a nonrealistic theory. But then, some seem to consider QFT to be nonrealistic but still local. Or one might consider certain models incorporated into QM to be somewhat realistic, and local, but the overall mathematical structure of QM to be nonrealistic, and therefore neither local nor nonlocal.

And I don't understand why there's this immense aversion to non-locality ...

Because it's just a hunch, an assumption based on an interpretation of an interpretation of standard QM.

... (especially since this doesn't imply instantaneous information transmission) ...

"Instantaneous information transmission" is just a contradiction in terms. Instantaneous action at a distance, or instantaneous distant effects depend on interpretation.

... or why there's this need to treat special relativity as sacrosanct.

Because nobody is going to scrap SR based on nonfalsifiable assumptions based on interpretations of interpretations. It's more reasonable and more parsimonious to suppose that there's something unwarranted (ie., wrong) about hunches that aren't supported by physical evidence than that there's something wrong with a century old theory that's passed thousands of empirical tests.

There's no necessary requirement that "external" reality should be mapped in any simple or direct fashion into the world of human ideas.

I agree. It seems reasonable to suppose that the world of our sensory apprehension is emergent. But that doesn't necessarily require that the underlying reality is essentially different from the reality that we experience. The two realms might be the same evolving 3D space (which we see in a certain way limited by our sensory capabilities) governed by the same fundamental mechanics.

... although we may be innately forced by our biologically-given mental structures to describe "empirical reality" (the subject-matter of physics proper) as if it evolves in a space-time manifold, "independent reality" may not actually evolve in such an arena.

Or ... it may.

Rovelli, argues that ...

I think Rovelli's talking about the form that a consistent unifying theory might have to take. Which might or might not correspond to the underlying reality. In any case, there's no way to determine that.

 

[ThomasT]

Rodsw, I see that you're logged in, so I'll reply to your questions below in an attempt to clarify things. But that's it. The only way you're going to be fully satisfied that you understand this stuff enough to ask clear and interesting questions is to search PF and other physics sites, Google, Wiki ... and do lots of reading.

Let's first settle about this statement "assuming that nature is nonlocal" or the meaning of nonlocal.

What I meant by it should be clear from my posts in this thread. The word nonlocal means different things in different contexts.

In the nitpicking world of convensional QM, Locality is untrue because in the absence of measurement to determine a particle position, there is no position. Hence no locality. Then there is no such thing as quantum nonlocality because "nonlocality" is invalid since there is no locality.

I guess that's one way of looking at it. But you can also think of it in terms that there's no "locality condition" explicitly encoded in standard QM and associated models (except of course for LRHV models).

Also, as mentioned, nonlocality means different things in different contexts. Quantum physicists use the term to mean ftl transmission, action at a distance, and the nonseparability of the QM formalism ... afaik.

Is this your position or context when you mentioned "nonlocal"?

As mentioned, if you've read my posts, then how I've used the term in a given context should be clear enough.

I just want to know what is the orthodox accepted explanation of quantum correlations.

Afaik, the orthodox position wrt quantum entanglement correlations is that they remain unexplained.

First you agree there is a correlation?

I'm wondering how you're thinking about, how you're using the word, "correlation". It's not a matter of whether I or anybody agrees that there are entanglement correlations. The correlations are just statistical comparisons of the data generated in Bell tests. They're recorded empirical facts.

"Entanglement correlations" doesn't refer to ftl transmissions or action at a distance, if that's how you're thinking about "the correlations".

And if one change the settings when the photons or electrons are in mid flight, it can affect the result?

The result, that is, the rate of coincidental detection, is dependent on the joint settings of the polarizers. Any unique joint setting is associated with a certain unique probability of coincidental detection.

But then you are arguing the correlations can be explained without resorting to long distant quantum correlations but just classical explanations?

I think there's a good possibility that entanglement correlations might eventually be understood (even if not being able to be modeled according to the requirements of a Bell-type LRHV) in a local framework involving an underlying parameter that doesn't determine individual detection and doesn't change from entangled pair to entangled pair. But the main reason I presented the consideration that I did was to illustrate one reason why I think it's a bit premature to be assuming that nature is nonlocal (in the sense that entangled particles are communicating with each other via ftl transmissions, or in the sense of action at a distance).

But this latter is refuted by experiments like Aspect's provided the loopholes were invalid.

What experimental violations of Bell inequalities refute are any and all Bell-type LRHV models of quantum entanglement.

Or you are saying the loopholes could be true explaning the results?

No, I don't think the experimental loopholes matter wrt the refutation of Bell-type LRHV models of quantum entanglement. Such models/theories are definitively refuted, afaik.

It should be noted that the more sophisticated LRHV models (that can clearly be called LRHV models) do reproduce basically the same angular dependence that QM does. But I don't know if closing all of the extant loopholes would result in a further convergence of the predictions of those models with the predictions of QM.

 

[Rodsw]

Rodsw, I see that you're logged in, so I'll reply to your questions below in an attempt to clarify things. But that's it. The only way you're going to be fully satisfied that you understand this stuff enough to ask clear and interesting questions is to search PF and other physics sites, Google, Wiki ... and do lots of reading.

What I meant by it should be clear from my posts in this thread. The word nonlocal means different things in different contexts.

I guess that's one way of looking at it. But you can also think of it in terms that there's no "locality condition" explicitly encoded in standard QM and associated models (except of course for LRHV models).

Also, as mentioned, nonlocality means different things in different contexts. Quantum physicists use the term to mean ftl transmission, action at a distance, and the nonseparability of the QM formalism ... afaik.

As mentioned, if you've read my posts, then how I've used the term in a given context should be clear enough.

Afaik, the orthodox position wrt quantum entanglement correlations is that they remain unexplained.

I'm wondering how you're thinking about, how you're using the word, "correlation". It's not a matter of whether I or anybody agrees that there are entanglement correlations. The correlations are just statistical comparisons of the data generated in Bell tests. They're recorded empirical facts. "Entanglement correlations" doesn't refer to ftl transmissions or action at a distance, if that's how you're thinking about "the correlations".

Gosh. Not only is "nonlocality" vague or even invalid.. so even the word "correlation". I thought quantum correlation automatically mean action at a distance correlation. So I guess we must use complete descriptions like "action at a distance correlation" to differentiate from "device correlation from initial condition"... but then since locality doesn't exist in orthodox QM, the word "distance" is invalid... so right now it seems they have almost made invalid even the words themselves so how would we even communicate.

Hope other quantumists can share because you have this somewhat biased thinking of the correlations being just a local influence via hidden variables. At least this word "hidden variable" can still be used. So in effect you are saying ThomasT that everything can be explained by hidden variables only or you see it this way?

Better yet. Try to define your words before you use them so we won't misunderstand especially in this vague topic. In your messages. You seem to jump from different contexts to maybe skip the issues or just to win the debate with Jesse by playing with words and his mind.

The result, that is, the rate of coincidental detection, is dependent on the joint settings of the polarizers. Any unique joint setting is associated with a certain unique probability of coincidental detection.

I think there's a good possibility that entanglement correlations might eventually be understood (even if not being able to be modeled according to the requirements of a Bell-type LRHV) in a local framework involving an underlying parameter that doesn't determine individual detection and doesn't change from entangled pair to entangled pair. But the main reason I presented the consideration that I did was to illustrate one reason why I think it's a bit premature to be assuming that nature is nonlocal (in the sense that entangled particles are communicating with each other via ftl transmissions, or in the sense of action at a distance).

What experimental violations of Bell inequalities refute are any and all Bell-type LRHV models of quantum entanglement.

No, I don't think the experimental loopholes matter wrt the refutation of Bell-type LRHV models of quantum entanglement. Such models/theories are definitively refuted, afaik.

It should be noted that the more sophisticated LRHV models (that can clearly be called LRHV models) do reproduce basically the same angular dependence that QM does. But I don't know if closing all of the extant loopholes would result in a further convergence of the predictions of those models with the predictions of QM.

 

[ThomasT]

@ Rodsw,
Look at your first post in this thread.
You asked:

Does it make sense Bell's Theorem still work for two entangled particles at say between 92 billion light years separation between them?

And the answer is, afaik, yes, if the entanglement can be maintained. But maybe you were really asking whether it makes sense to suppose that an experimentally produced entanglement could be maintained for that distance. To which the answer is, imho, no.

Then you said:

What is more logical is Bell's Theorem correlations have speed limit, such that they are near instantaneous in between say the edge to edge of a galaxy. This means the correlations need to have speed.

Which didn't make any sense to me, and it also seemed that you were using the word "correlations" when you actually meant ftl communication of some sort between entangled particles.

Imo, neither Bell's theorem nor quantum correlations implies ftl communication between entangled particles, but that you can assume ftl communication between entangled particles if you want to. In which case then, yes, I agree that it makes more sense to think of the communication between entangled particles as being ftl with some upper and lower bound, than it does to think in terms of instantaneous action at a distance.

You stated:

Aspect experiments have not proven the correlation is instantaneous.. just that it would be at least 10 times faster than the speed of light.

This means for separations of billions of light years. The correlations couldn't be instantaneous but needs to have speed limit.

Which seems to be saying that because Aspect experiments haven't proven that an assumed communication between entangled particles is instantaneous, but only that it must have a lower bound of at least 10c, then the assumed communication between entangled particles couldn't be instantaneous but must have an upper bound.

I agree that it makes no sense to speak of "instantaneous communication", but that's because the two terms "instantaneous" and "communication" are mutually contradictory, not because of what Aspect experiments didn't prove or because, wrt those experiments, one can calculate a lower bound on communication between entangled particles if one assumes that entangled particles are communicating.

Then you ask:

Would this be possible?

Afaik it's possible that entangled particles are communicating via ftl signals, and that those signals have an upper speed limit.

And you conclude with:

What law forbid it to be even possible?

No law that I know of, but then there's also no way (afaik) to empirically support the assumption that entangled particles are communicating with each other, and no way (afaik) to empirically falsify that assumption.

You're free to do calculations based on the assumption that entangled particles are communicating with each other. Ok?

 

[Rodsw]

@ Rodsw,
Look at your first post in this thread.
You asked:
And the answer is, afaik, yes, if the entanglement can be maintained. But maybe you were really asking whether it makes sense to suppose that an experimentally produced entanglement could be maintained for that distance. To which the answer is, imho, no.

Then you said:
Which didn't make any sense to me, and it also seemed that you were using the word "correlations" when you actually meant ftl communication of some sort between entangled particles.

Imo, neither Bell's theorem nor quantum correlations implies ftl communication between entangled particles, but that you can assume ftl communication between entangled particles if you want to. In which case then, yes, I agree that it makes more sense to think of the communication between entangled particles as being ftl with some upper and lower bound, than it does to think in terms of instantaneous action at a distance.

You stated:
Which seems to be saying that because Aspect experiments haven't proven that an assumed communication between entangled particles is instantaneous, but only that it must have a lower bound of at least 10c, then the assumed communication between entangled particles couldn't be instantaneous but must have an upper bound.

I agree that it makes no sense to speak of "instantaneous communication", but that's because the two terms "instantaneous" and "communication" are mutually contradictory, not because of what Aspect experiments didn't prove or because, wrt those experiments, one can calculate a lower bound on communication between entangled particles if one assumes that entangled particles are communicating.

Then you ask:
Afaik it's possible that entangled particles are communicating via ftl signals, and that those signals have an upper speed limit.

And you conclude with:
No law that I know of, but then there's also no way (afaik) to empirically support the assumption that entangled particles are communicating with each other, and no way (afaik) to empirically falsify that assumption.

You're free to do calculations based on the assumption that entangled particles are communicating with each other. Ok?

Actually when thinking of the orthodox Copenhagen line of thought. I'm thinking more in terms of programs. So when I mentioned correlations where the two ends can affect each other. It doesn't mean there is FTL or direct communication. This is because particles position don't exist before measurement. So I'm thinking in terms of programs which is made up of equations. Or take the computer analogy. You can simulate 92 billion light years inside the program. And the correlations can be explained by the fact the program or equations support it. It doesn't mean the two particles exist in space and time inside the program... only when they are measurement subroutine running that the program outputs it. I think this is how physicists look at the orthodox view. Now hope you get the context of what I meant by correlations which don't have to be FTL yet both ends are affected instantaneously (by the equations in the program).

 

[ThomasT]

Actually when thinking of the orthodox Copenhagen line of thought. I'm thinking more in terms of programs. So when I mentioned correlations where the two ends can affect each other. It doesn't mean there is FTL or direct communication. This is because particles position don't exist before measurement. So I'm thinking in terms of programs which is made up of equations. Or take the computer analogy. You can simulate 92 billion light years inside the program. And the correlations can be explained by the fact the program or equations support it. It doesn't mean the two particles exist in space and time inside the program... only when they are measurement subroutine running that the program outputs it. I think this is how physicists look at the orthodox view. Now hope you get the context of what I meant by correlations which don't have to be FTL yet both ends are affected instantaneously (by the equations in the program).

Not sure. In your OP you assert that the correlations need to have speed and a speed limit. So, if you could clarify exactly what you're referring to by "correlations" and that they "need to have speed" and "need to have speed limit", then that would help. Avoid analogies if possible and just state exactly what it is that you're talking about and what you're saying about it. Thanks.

 

[Rodsw]

Not sure. In your OP you assert that the correlations need to have speed and a speed limit. So, if you could clarify exactly what you're referring to by "correlations" and that they "need to have speed" and "need to have speed limit", then that would help. Avoid analogies if possible and just state exactly what it is that you're talking about and what you're saying about it. Thanks.

I have more clear understanding of it now. I didn't even know at the start it meant differently to different people. When I mentioned about Correlations could have speed. I meant the influence takes time to occur. I wasn't exactly thinking about wave function expanding but more like the equations taking time to hop from galaxy to galaxy before it reaches 92 billion light years. But this doesn't really make sense. So when you hear the word "correlation", you either meant the particles were communicating long distance or the correlations are just hidden variables without any influence. But consider the third possibility that there is no communication or hidden variables. The correlations are behind the scene (in the equations or whatever).. which is what orthodox physicists believe (which you have probably missed).

 

[ThomasT]

I have more clear understanding of it now. I didn't even know at the start it meant differently to different people.

Neither did I. But it does.

When I mentioned about Correlations could have speed. I meant the influence takes time to occur.

What influence? This seems to imply some sort of physical propagation between entangled particles.

... when you hear the word "correlation", you either meant the particles were communicating long distance or the correlations are just hidden variables without any influence.

Yes, those seem to be the alternatives. Either there's some sort of physical communication between separated entangled particles, or the correlations are due to a common cause that has created a relationship between the motional properties of the particles that can be predictably measured by a global instrumental variable.

But consider the third possibility that there is no communication or hidden variables. The correlations are behind the scene (in the equations or whatever).. which is what orthodox physicists believe (which you have probably missed).

I think that orthodox physicists believe that quantum entanglement correlations are due to either a relationship between entangled particles due to a common cause, or that quantum entanglement correlations are due to physical communication between entangled particles.

I have no idea which is the majority view. But it should be clear enough that nobody knows, or currently has any way of knowing, definitively, which view is correct.

So, again, you're free to assume what you want wrt the origin/explanation/understanding of quantum entanglement correlations.

 

[Rodsw]

Neither did I. But it does.

What influence? This seems to imply some sort of physical propagation between entangled particles.

Yes, those seem to be the alternatives. Either there's some sort of physical communication between separated entangled particles, or the correlations are due to a common cause that has created a relationship between the motional properties of the particles that can be predictably measured by a global instrumental variable.

I think that orthodox physicists believe that quantum entanglement correlations are due to either a relationship between entangled particles due to a common cause, or that quantum entanglement correlations are due to physical communication between entangled particles.

I have no idea which is the majority view. But it should be clear enough that nobody knows, or currently has any way of knowing, definitively, which view is correct.

So, again, you're free to assume what you want wrt the origin/explanation/understanding of quantum entanglement correlations.

The majority view is neither of what you described. Or as Jesse emphasized, hidden variables were already refuted by numerous experiments. So by this you would think the majority view would be that both particles are in communications? No. Don't forget the majority view is Copenhagen.. in that the wave function is not physical but in the equations only. They don't have physical picture or think it is necessary. So in quantum correlations. They don't need to visualize what's going on but just focus on the equations. Remember this always so you won't confuse other beginners inquiring about quantum entanglement.

 

[ThomasT]

The majority view is neither of what you described.

How do you know that?

Or as Jesse emphasized, hidden variables were already refuted by numerous experiments.

That's incorrect. Bell himself showed that a hidden variable formulation of individual detections is compatible with QM. What's been refuted is Bell-type LRHV formalizations of quantum entanglement. Whether or not this is general is an open question, afaik.

So by this you would think the majority view would be that both particles are in communications? No.

Well, no. At least not necessarily. But I don't know what the majority view is. And, anyway, the majority view doesn't matter in science, because the majority view might be a matter of taste due to social pressures or whatever. The point is that it's an open question, and that neither view has been definitively demonstrated.

One is free to assume that the correlations are due to nonlocal communications between entangled particles, or due to relationships produced via common causes, ie., local transmissions.

Don't forget the majority view is Copenhagen.. in that the wave function is not physical but in the equations only. They don't have physical picture or think it is necessary. So in quantum correlations. They don't need to visualize what's going on but just focus on the equations. Remember this always so you won't confuse other beginners inquiring about quantum entanglement.

Ok, I'll remember this always. Can we close this thread now?