Can grandpa understand the Bell's Theorem?

[sfs01]

So what is your prediction for the experiment I described in the previous post and repeated below:

Let’s test this assumption using Aspect’s experimental setup.
1). First let's fully align polarizers A and B and observe a maximum (say 100%) correlation.
2). Set polarizer A and B at 90 deg and observe zero correlation.
3). Let’s add one more polarizers (C) between polarizer B and the source of photon and set this polarizers at intermediate angle of 45 deg and monitor correlated photons.

According to EPR model we should observe about 25% of correlated photons, because EPR photons on B side will be rotated by polarizers (B and C) and the intensity/probability of these photons could be calculated according to Malus’ law.

What is your prediction for Bell’s entangled photons for the step 3). ?

The question you asked does not have anything to do with Aspect's experimental setup. In his set-up, there is a switch before the polariser, so the photons would go either through B or C, not through both. You are just unnecessarily complicating the set-up for no purpose. All the extra polariser does really is absorb some photons that you could be measuring instead, making it harder to do the experiment because there is less signal.

In any case, don't have the time to go through the full calculation, but for this specific set of angles I think the predictions for correlation are the same. There is a reason why Bell test experiments don't generally use 45 and 90 degrees, namely that the effect appears at intermediate angles.

Really don't get what your problem with Bell's theorem is. You need to get away from the idea that it references any specific experimental set-up, assumptions about polarisation or physical model whatsoever.

It is simply a mathematical theorem that anyone with undergrad level statistics knowledge can follow and that is undoubtedly correct in itself. The only thing you can doubt is, if the assumptions made for the proof hold in the case of a specific physical experiment in question. But the assumptions Bell uses are actually very general, they are pretty much:
- you have 2 measurement devices A and B that measure the state of something (represented by a hidden variable or set of hidden variable that is the initial state)
- the result of the measurement by device A depends on the setting of device A and the hidden variable only (but not on the setting of device B)
- the result of the measurement by device B depends on the setting of device B and the hidden variable only (but not on the setting of device A)

Given that these assumptions hold, the correlation between the results of the measurements at A and B will follow Bell's inequalities per the mathematical proof.

Consequently, should we observe that anything in nature does not observe Bell's inequalities - such as Aspect's experiment - we have to conclude that either the experiment had systematic errors affecting the correlations or at least one of the assumptions made for this proof do not hold in nature (for example there are non-local interactions such that the result of device A depends on the result of device B as it does for entangled photons).

 

[JesseM]

Apparently Einstein didn’t know that. From EPR paper (1935)

“ … let us suppose that we have two systems I and II, which we permit to interact from the time t=0 to t=T, after which time we suppose that there is no longer any interaction between the two parts…
…We see therefore that, as a consequence of two different measurements performed upon the first system, the second system may be left in states with two different wave functions.

Apparently you once again are jumping to conclusions based on isolated quotes you seize on even though you don't really understand them, instead of asking questions like a person with basic intellectual humility would do. Einstein says nothing here about the systems having separate wave functions before measurement, but according to the QM rules, after one entangled particle is measured you can have two independent wave functions for the two particles, see this textbook for example:

The particle undergoes a dramatic change of physical state in the process of measurement. It converts from the entanglement with its distant partner into the disentangled state of its own. In the former state the particle, even though separated from its partner by the vastness of space, did not have its full identity totally independent of the partner's. Their identities remained intimately shared. In the final state, each particle has its own full identity and can be described by a wave function of its own, independent of the rest of the world.

Thus, the measurement made on Earth changes instantaneously the situation not only on Earth, but also on Rulia (and vice versa). In the language of the wave functions, we can say that the wave function of the whole entangled system instantly collapses into one of the two possible independent wave functions:

$$\Psi = a \mid \uparrow \rangle_1 \mid \downarrow \rangle_2 + b \mid \downarrow \rangle_1 \mid \uparrow \rangle_2 \Rightarrow \,either\, \mid \uparrow \rangle \mid \downarrow \rangle \,or\, \mid \downarrow \rangle \mid \uparrow \rangle$$

What does "EPR model" even mean? EPR don't suggest a specific model, they simply suggest that when you have a perfect correlation when you make the same measurement on both particles, then both particles must have local properties that predetermine what result they will give to that measurement…

So Bell was interested to see if there is any difference between original system and its reduced version ”stripped” from its key properties?As I understand there are four key properties of EPR model relevant to the Bell’s theorem:

1. After separation the particles have determined and perfectly correlated properties (spin, polarization, etc.).

Yes, but only for the first measurement of each particle, in QM the second measurement of each won't necessarily be correlated if the second measurement operator doesn't "commute" with the first.

2. The complementary particles don’t interact after separation.

Yes, EPR do assume that.

3. Particle’s behavior is independent from each other

Is this just a restatement of #2? They are not "independent" in the sense of statistical independence (if they were they couldn't give perfectly correlated measurement results), but they are supposed to be causally independent, i.e. they "don't interact after separation".

and is described by the corresponding independent wave functions.

No, there are no "independent wave functions" prior to measurement in QM, and in any case EPR are thinking about the possibility of a local hidden-variables theory which would reproduce the statistics of QM, but it presumably wouldn't use a QM "wave function" to do it because the QM wave function is not clearly a local entity.

I don’t worry about the particle #1 while applying the Malus’ law to the particle #2. Whlie passing two consecutive polarizers C (at 45 deg) and B (at 90 deg) the probability (intencity) to pass polarizer by the particle #2 is:

I(final) = I(max) * cos^2(45) * cos^2(90-45) = I(max)*0.25

That cos^2(45) term doesn't really make sense, the particles aren't initially created at a polarization of zero! Instead, in QM the probability of passing through the first polarizer C, whatever its angle, would just be 1/2 (which happens to be equal to cos^2(45), but my point is that this figure of 1/2 has nothing to do with taking the cosine squared of the angle of C). If it does pass through C at 45 degrees, the probability it will then also pass through B at 90 is cos^2(90-45), so the total reduction in intensity is I(max)*(1/2)*cos^2(90-45). In general if C is at c degrees and B is at b degrees, the reduction in intensity is I(max)*(1/2)*cos^2(b-c)

To comply with Malus’ law particle #2, as I understand, must change its polarization, so the correlated photons #1 and #2 will have different polarizations. This isn’t a problem for EPR model but is prohibited for Bom’s entangled photons that must have identical polarization.

Bohm's model doesn't say the particles must continue to have identical polarizations after multiple measurements of each! Its statistical predictions are the same as ordinary QM, only the first measurement of each will be correlated.

So what is your prediction for the experiment I described in the previous post and repeated below:

Let’s test this assumption using Aspect’s experimental setup.
1). First let's fully align polarizers A and B and observe a maximum (say 100%) correlation.
2). Set polarizer A and B at 90 deg and observe zero correlation.
3). Let’s add one more polarizers (C) between polarizer B and the source of photon and set this polarizers at intermediate angle of 45 deg and monitor correlated photons.

Are you just asking what the QM prediction would be here, as opposed to your nonsensical statements about "the EPR model" vs. "the Bell concept"? The QM prediction would be that the probability particle #1 makes it through A at 90 degrees and particle #2 makes it through C at 45 is given by (1/2)*cos^2(90-45), then the probability that particle #2 makes it through B at 90 if it already made it through C at 45 is cos^2(90-45), so the total probability that both particles are detected passing through the polarizers is (1/2)*cos^2(90-45)*cos^2(90-45) = (1/2)*(1/2)*(1/2) = 1/8. And the more general QM answer would be (1/2)*cos^2(a-c)*cos^2(b-c).

 

[miosim]

... Einstein says nothing here about the systems having separate wave functions before measurement, but according to the QM rules, after one entangled particle is measured you can have two independent wave functions for the two particles, see this textbook for example:

“…The particle undergoes a dramatic change of physical state in the process of measurement. It converts from the entanglement with its distant partner into the disentangled state of its own. In the former state the particle, even though separated from its partner by the vastness of space, did not have its full identity totally independent of the partner's. Their identities remained intimately shared. In the final state, each particle has its own full identity and can be described by a wave function of its own, independent of the rest of the world….”

It seems to me that this textbook reflects the views that Einstein opposed and called “spooky actions at a distance.” As I understand, Einstein in the EPR paper expressed disagreement with the “the entanglement with its distant partner” by stating that
” … two systems I and II, which we permit to interact from the time t=0 to t=T, after which time we suppose that there is no longer any interaction between the two parts…”
Therefore after separation, according to EPR paper (the way I understand it), the correlated QM systems can’t share the same wave function/packet and the only choice is to admit that both independent systems have two independents wave functions/packets instead. As I understand, the EPR interpretation has one more important distinction from the orthodox QM interpretation. According to EPR each individual QM system has all their parameters already determined prior to act of measurement. The measurement, at later time, just allows us to learn about these parameters.

Are you just asking what the QM prediction would be here, as opposed to your nonsensical statements about "the EPR model" vs. "the Bell concept"? The QM prediction would be that the probability particle #1 makes it through A at 90 degrees and particle #2 makes it through C at 45 is given by (1/2)*cos^2(90-45), then the probability that particle #2 makes it through B at 90 if it already made it through C at 45 is cos^2(90-45), so the total probability that both particles are detected passing through the polarizers is (1/2)*cos^2(90-45)*cos^2(90-45) = (1/2)*(1/2)*(1/2) = 1/8. And the more general answer would be (1/2)*cos^2(a-c)*cos^2(b-c).

Question:

Would the entangled photons #1 and #2 after passing their respective pololarizers (A, B and C) have identical or different polarization?

 

[edguy99]

They didn't supply this value as I read it either. Since they define entangled as timetags within 6 ns, everything else is ignored. As the time window is increased, you get a lower value of S because a few unentangled* photon pairs are being considered.

*This may seem surprising, but pairs can be partially entangled. Anywhere between 0 and 100% fidelity, actually.

Are there other experiments with the N(a) and N(b) a little lower so you would "notice" (or not) the extra unentangled photons? Not providing those figures seems odd.

 

[edguy99]

Are you back to invisible photons? Those won't enter into any experimental statistics anywhere. Or?

Table I from the experiment you quoted http://arxiv.org/PS_cache/quant-ph/pdf/0205/0205171v1.pdf" provides a sample run (sorry, the copy and paste only works so well). Fundimentally you can see the runs are averaging 85000 hits on each detector with quite a range. Remember they are claiming the the photons that are falling off the "coincidence" column (second last, all under 1000) are not adding to the third column. In fact, the runs themselves are varying by much larger then 1000 hits when they are searching for something in the 100's? Dont they have some explaining to do?

 NA NB N NAc.
-45◦ -22.5◦ 84525 80356 842 10.0
-45◦ 22.5◦ 84607 82853 212 10.3
-45◦ 67.5◦ 83874 82179 302 10.1
-45◦ 112.5◦ 83769 77720 836 9.5
0◦ -22.5◦ 87015 80948 891 10.3
0◦ 22.5◦ 86674 83187 869 10.6
0◦ 67.5◦ 87086 81846 173 10.5
0◦ 112.5◦ 86745 77700 261 9.9
45◦ -22.5◦ 87782 80385 255 10.3
45◦ 22.5◦ 87932 83265 830 10.7
45◦ 67.5◦ 87794 81824 814 10.5
45◦ 112.5◦ 88023 77862 221 10.1
90◦ -22.5◦ 88416 80941 170 10.5
90◦ 22.5◦ 88285 82924 259 10.7
90◦ 67.5◦ 88383 81435 969 10.6
90◦ 112.5◦ 88226 77805 846 10.1
TABLE I: Singles (NA,NB) and coincidence (N) detections
as a function of polarizer angles , . The acquisition window
was T = 15 seconds, irises were fully open. Also shown are
“accidental” coincidences (NAc. = NANB/T) assuming a
coincidence window of  = 25 ns.

 

[JesseM]

It seems to me that this textbook reflects the views that Einstein opposed and called “spooky actions at a distance.”

The textbook is simply discussing the quantum formalism involving wave functions, and Einstein's understanding of how that formalism is applied was no different from any other physicist's. What Einstein was hoping for was a new model with a new formalism, that would be clearly local and would not involve the notion of quantum "wave functions" at all, but which would make the same predictions about observable measurement outcomes as the quantum formalism.

As I understand, Einstein in the EPR paper expressed disagreement with the “the entanglement with its distant partner” by stating that
” … two systems I and II, which we permit to interact from the time t=0 to t=T, after which time we suppose that there is no longer any interaction between the two parts…”
Therefore after separation, according to EPR paper (the way I understand it), the correlated QM systems can’t share the same wave function/packet

No, the EPR paper is talking about what they think would really be true in a complete physical description, not what is true in the "wave function" description of QM which the paper argues is incomplete. The whole point of the discussion of "elements of physical reality" was to try to argue that the QM wave function cannot be a complete description since it does not describe an element of physical reality they feel must be present at the location of the second particle.

As I understand, the EPR interpretation has one more important distinction from the orthodox QM interpretation. According to EPR each individual QM system has all their parameters already determined prior to act of measurement. The measurement, at later time, just allows us to learn about these parameters.

Yes, this part is correct, and if you assume this is true for the parameter of whether it will pass through or be reflected by polarizers at three possible angles, it's easy to derive a Bell inequality from this. Let A be the property of passing through a polarizer at angle a (while not-A would be the property of not passing through), B the property of passing through a polarizer at angle b (or not-B for not passing through), and C be the property of passing through a polarizer at angle c (not-C for not passing through). Then before being measured, each particle must either have or not have each of these properties, so if we could somehow know the values of these properties for a large series of particles, some particles might have (A, not-B, C) while others might have (not-A, B, not-C) and so forth. Then just look at the simple inequality discussed on this page:

The result of the proof will be that for any collection of objects with three different parameters, A, B and C:

The number of objects which have parameter A but not parameter B plus the number of objects which have parameter B but not parameter C is greater than or equal to the number of objects which have parameter A but not parameter C.

We can write this more compactly as:

Number(A, not B) + Number(B, not C) greater than or equal to Number(A, not C)

The relationship is called Bell's inequality.

In class I often make the students the collection of objects and choose the parameters to be:

A: male B: height over 5' 8" (173 cm) C: blue eyes

Then the inequality becomes that the number of men students who do not have a height over 5' 8" plus the number of students, male and female, with a height over 5' 8" but who do not have blue eyes is greater than or equal to the number of men students who do not have blue eyes. I absolutely guarantee that for any collection of people this will turn out to be true.

It is important to stress that we are not making any statistical assumption: the class can be big, small or even zero size. Also, we are not assuming that the parameters are independent: note that there tends to be a correlation between gender and height.

Sometimes people have trouble with the theorem because we will be doing a variation of a technique called proof by negation. For example, here is a syllogism:

All spiders have six legs. All six legged creatures have wings. Therefore all spiders have wings

If we ever observe a spider that does not have wings, then we know that at least one and possibly both of the assumptions of the syllogism are incorrect. Similarly, we will derive the inequality and then show an experimental circumstance where it is not true. Thus we will know that at least one of the assumptions we used in the derivation is wrong.

Also, we will see that the proof and its experimental tests have absolutely nothing to do with Quantum Mechanics.

Now we are ready for the proof itself. First, I assert that:

Number(A, not B, C) + Number(not A, B, not C) must be either 0 or a positive integer

or equivalently:

Number(A, not B, C) + Number(not A, B, not C) greater than or equal to 0

This should be pretty obvious, since either no members of the group have these combinations of properties or some members do.

Now we add Number(A, not B, not C) + Number(A, B, not C) to the above expression. The left hand side is:

Number(A, not B, C) + Number(A, not B, not C) + Number(not A, B, not C) + Number(A, B, not C)

and the right hand side is:

0 + Number(A, not B, not C) + Number(A, B, not C)

But this right hand side is just:

Number(A, not C)

since for all members either B or not B must be true. In the classroom example above, when we counted the number of men without blue eyes we include both those whose height was over 5' 8" and those whose height was not over 5' 8".

Above we wrote "since for all members either B or not B must be true." This will turn out to be important.

We can similarly collect terms and write the left hand side as:

Number(A, not B) + Number(B, not C)

Since we started the proof by asserting that the left hand side is greater than or equal to the right hand side, we have proved the inequality, which I re-state:

Number(A, not B) + Number(B, not C) greater than or equal to Number(A, not C)

Please look over this and tell me whether you agree or disagree with the inequality Number(A, not B) + Number(B, not C) greater than or equal to Number(A, not C). If you're not sure because you don't understand some line of the proof, point out which is the first line you have trouble with.

Question:

Would the entangled photons #1 and #2 after passing their respective pololarizers (A, B and C) have identical or different polarization?

Your question is ambiguous because in quantum mechanics particles cannot have definite polarizations at all possible angles. In your experiment, the photons are no longer entangled after they have passed through the polarizers, so they are no longer guaranteed to give identical results at all angles. But the last polarizer each one passed through was at 90 degrees, so they would both be guaranteed to pass through another polarizer at 90 degrees, and likewise both be guaranteed not to pass through another polarizer at 0 or 180 degrees. On the other hand, if the next polarizer each encountered was at some different angle like 80 degrees or 45 degrees, it might be that one would pass through but the other would be reflected.

 

[DrChinese]

Are there other experiments with the N(a) and N(b) a little lower so you would "notice" (or not) the extra unentangled photons?

Sure, there are a bunch. Keep in mind that the tester wants a source of ENTANGLED pairs so that those can be analyzed. Here is one which was done on ions instead of photons, and all events are considered. This means a lower S value, but it is still greater than 2 - which is the Local Realistic max.

http://www.nature.com/nature/journal/v409/n6822/full/409791a0.html

"If we take into account the imperfections of our experiment (imperfect state fidelity, manipulations, and detection), this value agrees with the prediction of quantum mechanics.

The result above was obtained using the outcomes of every experiment, so that no fair-sampling hypothesis is required. In this case, the issue of detection efficiency is replaced by detection accuracy. The dominant cause of inaccuracy in our state detection comes from the bright state becoming dark because of optical pumping effects. For example, imperfect circular polarization of the detection light allows an ion in the |↓right fence state to be pumped to |↑right fence, resulting in fewer collected photons from a bright ion. Because of such errors, a bright ion is misidentified 2% of the time as being dark. This imperfect detection accuracy decreases the magnitude of the measured correlations. We estimate that our Bell's signal would be 2.37 with perfect detection accuracy.

We have thus presented experimental results of a Bell's inequality measurement where a measurement outcome was recorded for every experiment. Our detection efficiency was high enough for a Bell's inequality to be violated without requiring the assumption of fair sampling, thereby closing the detection loophole in this experiment."

 

[edguy99]

Einstein didn’t know that his concept could be transformed into a circus.

According to EPR argument the two correlated particles are represented by the two different and independent wave functions. When the first wave function collapses it reviled one complemented parameter (+spin) that gaves us a knowledge about another complemented parameter (-spin) of the second wave function. Because this wave functions has no description of this parameter the wave function and QM accordingly is incomplete.

Now let see the Bell’s ‘reasonable’ reproduction of this EPR model:

“…Let us illustrate the possibility of what Einstein had in mind in the context of the particular quantum mechanical predictions already cited for the EPRB gedanken experiment. These predictions make it hard to believe in the completeness of quantum formalism…”
Then Bell ‘mumbles’ the following:
“…But of course outside that formalism they make no difficulty whatever for the notion of local causality. To show this explicitly we exhibit a trivial ad hoc space-time picture of what might go on. It is a modification of the naive classical picture already described. Certainly something must be modified in that, to reproduce the quantum phenomena. Previously, we implicitly assumed for the net force in the direction of the field gradient (which we always take to be in the same direction as the field) a form: F cos Q ….”

This is it. These are all efforts to recreate the EPR model in spirit of Einstein. Based on these ‘exhaustive’ efforts, Bell proclaimed that it isn’t possible to build such a model.
Is this hilarious? Is this a circus?

Bell (and his supporters) just forgot that the EPR particles are represented by the two independent wave functions and therefore their cos^2 behavior are identical to Bell’s QM model.

Secondly, if Bell decided to model EPR particles as classical ones, he must at least include interactions of these particles with polarizers (QM formalism has this interactions builtin) as follows: the polarizers, like optical ‘funnel’, modifies polarization of both photons in the direction of higher correlation and this way eliminating inequality with the QM prediction.

It seems to me that the Bell’s theorem is dead.

I agree with this post and would like to add another quote that was just brought to my attention. From the experiment quoted http://arxiv.org/PS_cache/quant-ph/pdf/9810/9810080v1.pdf"

Yet we agree with John Bell that ”. . . it is hard for me to believe that quantum mechanics works so nicely for inefficient practical set-ups and is yet going to fail badly when sufficient refinements are made. Of more importance, in my opinion, is the complete absence of the vital time factor in existing experiments. The analyzers are not rotated during the flight of the particles.”

He is talking about Bob rotating his measuring device and Alice "instantly" seeing a change.

In my opinion, a far better explanation has been quoted earlier "... the two events are separated by a "space-like" interval; not a "time-like" interval, so effectively, in half of the reference frames a is before b, and in another half of the reference frames b is before a, and, of course, in some specifically defined reference frames, the two events are simultaneous. "

 

[DrChinese]

In my opinion, a far better explanation has been quoted earlier "... the two events are separated by a "space-like" interval; not a "time-like" interval, so effectively, in half of the reference frames a is before b, and in another half of the reference frames b is before a, and, of course, in some specifically defined reference frames, the two events are simultaneous. "

For the cited experiments, there are no reference frames in which Alice's selection of settings and Bob's selection of settings are within the same light cone regardless of direction of causality. So what you are implying is incorrect. Not that it would matter for a local realist, as realism is ejected immediately if you assert that locality holds.

 

[edguy99]

Sure, there are a bunch. Keep in mind that the tester wants a source of ENTANGLED pairs so that those can be analyzed. Here is one which was done on ions instead of photons, and all events are considered. This means a lower S value, but it is still greater than 2 - which is the Local Realistic max..."

Are there any using photons? If you were modeling an ion compared to a photon, you would certainly want to consider spin, but the model of the ions vs photons would have many other differences and switching to ions raises more issues then it solves in my opinion.

 

[JesseM]

I agree with this post

Did you read my response? Most of miosim's comments there are completely confused.

and would like to add another quote that was just brought to my attention. From the experiment quoted http://arxiv.org/PS_cache/quant-ph/pdf/9810/9810080v1.pdf"

Yet we agree with John Bell that ”. . . it is hard for me to believe that quantum mechanics works so nicely for inefficient practical set-ups and is yet going to fail badly when sufficient refinements are made. Of more importance, in my opinion, is the complete absence of the vital time factor in existing experiments. The analyzers are not rotated during the flight of the particles.”

He is talking about Bob rotating his measuring device and Alice "instantly" seeing a change.

No he isn't, that would imply Bob could send a message to Alice faster than light, which isn't possible in QM. Bell's comment about rotating devices is to suggest that the settings need to be chosen after the source has already emitted the particles and they are in "flight", since if the settings were chosen beforehand, some kind of hidden signal could travel from the devices to the source so that it could use that information to decide the hidden variables of the particles and violate Bell's inequality without violating locality. Only if the device settings are chosen after the particles have been emitted can you rule out a local explanation for violations of Bell inequalities. I think this issue has been resolved with later experiments, for example the Bell test loophole wiki article section on the locality loophole says "Weihs et al. improved on this with a distance on the order of a few hundred meters in their experiment in addition to using random settings retrieved from a quantum system. Scheidl et.al. (2010) improved on this further by conducting an experiment between locations separated by a distance of 144 km."

In my opinion, a far better explanation has been quoted earlier "... the two events are separated by a "space-like" interval; not a "time-like" interval, so effectively, in half of the reference frames a is before b, and in another half of the reference frames b is before a, and, of course, in some specifically defined reference frames, the two events are simultaneous. "

This is part of how Bell experiments are supposed to be performed, but why do you call this a "far better explanation"? Explanation for what? The very fact that the measurements are conducted at a spacelike interval is essential to why it is impossible for any local realistic theory to reproduce the violations of Bell inequalities predicted by QM.

 

[DrChinese]

Are there any using photons? If you were modeling an ion compared to a photon, you would certainly want to consider spin, but the model of the ions vs photons would have many other differences and switching to ions raises more issues then it solves in my opinion.

Try:
http://arxiv.org/abs/quant-ph/0303018

I think what you are saying is really: I want an experiment done in Ireland on a rainy Tuesday. I mean, a simple read will tell you why a Bell test is a Bell test is a Bell test. They ALL SAY THE SAME THING. S>2 to X standard deviations, or similar. The one cited above has much greater source fidelity, so local realism is ruled out by over 213 standard deviations.

So, perhaps you should consider searching for yourself. Here is a good starting point:

http://arxiv.org/find/all/1/abs:+AND+experimental+AND+bell+photon/0/1/0/all/0/1

Or, on a more humorous note: Try this

 

[edguy99]

Try:
http://arxiv.org/abs/quant-ph/0303018

I think what you are saying is really: I want an experiment done in Ireland on a rainy Tuesday. I mean, a simple read will tell you why a Bell test is a Bell test is a Bell test. They ALL SAY THE SAME THING. S>2 to X standard deviations, or similar. The one cited above has much greater source fidelity, so local realism is ruled out by over 213 standard deviations. ...

I think the accuracy they are quoting is the ability to detect pairs within a lot of hits, as they must measure say 100 to 800 pairs in a total of 85000 hits on each side in the prior experiment. If you note, being able to detect 100 to 800 pairs in a total of 170000 hits would be consider "more" accurate in their sense of the word.

In the context of what we are talking about, the more hits on the detectors, especially relative to pairs, the more inaccurate the measurement.

 

[miosim]

Please look over this and tell me whether you agree or disagree with the inequality Number(A, not B) + Number(B, not C) greater than or equal to Number(A, not C). If you're not sure because you don't understand some line of the proof, point out which is the first line you have trouble with.

I don’t want to repeat my arguments against careless application of math or formal logic to the complex physical problems without carefully analyzing initial (physical) conditions. Instead, if you don’t mind, I would like to focus on an experiment that may falsify the concept on non-locality.

As I understand, a photon that passed the polarizer may change its polarization as result of photon/polarizer interaction. Let’s assume that we have a pair of entangled photons. Using rotating polarizer we are changing the polarization of photons on one side while monitoring the polarization of entangled photons on other side. If the second entangled photon follows the polarization of the first photon we may claim that the non-local interaction exists. Is it true?

 

[JesseM]

I don’t want to repeat my arguments against careless application of math or formal logic to the complex physical problems without carefully analyzing initial (physical) conditions.

But you agreed that according to EPR, the particles must have predetermined results for all possible measurements. It's a simple matter to show that from this assumption, the inequality I mentioned follows. Of course the inequality is only telling you that out of all the particle pairs it's true that Number(A, not B) + Number(B, not C) ≥ Number(A, not C), a small amount of additional reasoning is needed to show this implies the experimental inequality:

[of the subset of all particle pairs where #1 was measured at angle a and #2 was measured at angle b, the number in this subset where particle #1 had property A and particle #2 had property not-B]

+

[of the subset of all particle pairs where #1 was measured at angle b and #2 was measured at angle c, the number in this subset where particle #1 had property B and particle #2 had property not-C]

greater than or equal to

[of the subset of all particle pairs where #1 was measured at angle a and #2 was measured at angle c, the number in this subset where particle #1 had property A and particle #2 had property not-C]

Actually the reasoning from going from the first inequality to this one is fairly simple, it just involves the idea that the source doesn't have any "precognition" about what settings the experimenters will choose when it creates a pair of particles with a given set of properties. But I'm not even asking about this experimental inequality now. I just want to know whether you agree that, if EPR are correct that every particle pair must have an identical set of predetermined measurement results like [A, not-B, not-C] or [A, B, not-C], then if N particle pairs were created and some imaginary omniscient being knew the full set of hidden properties for each one, that imaginary omniscient being would necessarily see that this inequality is satisfied for the total collection of N particle pairs:

Number(A, not B) + Number(B, not C) ≥ Number(A, not C)

If you don't agree, do you think that given enough time you could find a list that violates it? For example, here is a list of 10 particle pairs, with the full set of properties seen by the omniscient being listed alongside each one:

pair #1: [A, B, C]
pair #2: [A, not-B, not-C]
pair #3: [not-A, B, not-C]
pair #4: [A, B, not-C]
pair #5: [A, not-B, C]
pair #6: [not-A, not-B, C]
pair #7: [A, B, not-C]
pair #8: [not-A, not-B, not-C]
pair #9: [A, B, C]
pair #10: [A, not-B, not-C]

Here we can see that Number(A, not B)=3, Number(B, not C)=3, and Number(A, not C)=4, so the inequality is satisfied. Again, if you disagree or doubt that claim that the inequality is always satisfied under the assumption each particle has definite predetermined measurement results for all three settings, then you should try to back that up with a counter-example.

Instead, if you don’t mind, I would like to focus on an experiment that may falsify the concept on non-locality.

Oh but I do mind, my question is a very simple one and if you are remotely sincere about trying to understand the Bell/EPR argument, as opposed to just making a lawyer-like rhetorical case against Bell, then you should have no problem answering this. If you refuse to answer this simple question I'll conclude you have no intellectual integrity and are just trying to "win" the argument at all costs, in which case there is no point to further discussion.

As I understand, a photon that passed the polarizer may change its polarization as result of photon/polarizer interaction.

As I said the phrase "its polarization" doesn't have a clear meaning in QM, since for most angles the quantum state just gives you probabilities that the particle will pass through the polarizer.

Let’s assume that we have a pair of entangled photons. Using rotating polarizer we are changing the polarization of photons on one side while monitoring the polarization of entangled photons on other side. If the second entangled photon follows the polarization of the first photon we may claim that the non-local interaction exists. Is it true?

No, I already told you several times that the first measurement of each particle breaks the entanglement, after that the two photons are no more correlated than two non-entangled photons which happened to give the same two results to those first measurements.

 

[miosim]

But you agreed that according to EPR, the particles must have predetermined results for all possible measurements. It's a simple matter to show that from this assumption, the inequality I mentioned follows.

No I don’t agree with this interpretation of the EPR concept. The EPR concept doesn’t claim that the ‘hidden parameters” are deterministic (and Bell understood that). They could be for example combination of a deterministic component and stochastic processes so the final result isn’t absolutely determined. Einstein didn’t collaborate about nature of these variables/processes but just provided an argument in favor of their existence. The criteria for searching these parameters is such that they should provide the realistic description in full agreement with the established formalism of QM. Therefore if Bell built his inequity based on the differences in behavior between EPR and traditional QM particle his inequities are invalid by definition. If Bell would at least provide an adequate justification for the violation (simplification) of EPR concept, I would accept his view at least as a reasonable hypothesis.

my question is a very simple one and if you are remotely sincere about trying to understand the Bell/EPR argument, as opposed to just making a lawyer-like rhetorical case against Bell, then you should have no problem answering this. If you refuse to answer this simple question I'll conclude you have no intellectual integrity and are just trying to "win" the argument at all costs, in which case there is no point to further discussion.

I understand Bell’s mathematical formalism that led him to his inequality (“Beltmann socks …” pages C2-48 through C2-52). However I have a hard time forcing my self to study in more details the additional reasoning of his ‘torturous’ (for me) logic that led him to conclusion I refuse to accept because of incorrect initial conditions. However because the Bell’s inequalities are the large part of today conversation within physics I will spend some time this week to study them in more details (including your post). I will be on the road most of this week so I will not be able to provide timely responce.

 

[JesseM]

No I don’t agree with this interpretation of the EPR concept. The EPR concept doesn’t claim that the ‘hidden parameters” are deterministic (and Bell understood that).

Uh didn't you say the exact opposite earlier when you said "According to EPR each individual QM system has all their parameters already determined prior to act of measurement"? Anyway I'm not sure what you mean by "parameters", if you're talking about the values of all hidden variables (which might be arbitrarily complex) or simply the predetermined facts about what result the particle will give if measured with any particular detector setting. I wasn't talking about the hidden variables, I was talking specifically about the predetermined results which are determined by those variables. For example it's possible that the variables fluctuate in a partially random way, but nevertheless at any time prior to measurement if you had complete knowledge of the hidden variables (along with any observable variables prior to measurement) you would be able to predict with certainty what result would be found if the particle was measured at setting A or B or C. If this wasn't true there would be no way (in a local realist universe respecting the no-conspiracy condition) to explain the fact that, whenever the particles are measured with the same detector setting, we are guaranteed to get identical (or opposite) results, even when there is a spacelike separation between the two measurements and choices of settings, so that according to local realism one experimenter's choice of setting cannot possibly have had a causal influence on the other experimenter or the other particle.

If still don't see why this fact of guaranteed identical results when the same setting is chosen implies predetermined answers to all possible settings (under the assumption of local realism), then we should really focus on this issue. I could try to explain it using analogies like the game show analogy [post=3290921]here[/post], though I know you have said in the past you don't like analogies. If you want a more rigorous derivation I would use an argument involving light cones as Bell did in the paper I linked to and discussed in [post=3248153]this post[/post]...so firstly, are you familiar with the concept of a "light cone" in special relativity, and why under local realism events can only be causally influenced by other events in their past light cone? If you're not familiar with this concept, this page might be a good place to start.

 

[miosim]

Uh didn't you say the exact opposite earlier when you said "According to EPR each individual QM system has all their parameters already determined prior to act of measurement"? Anyway I'm not sure what you mean by "parameters", if you're talking about the values of all hidden variables (which might be arbitrarily complex) or simply the predetermined facts about what result the particle will give if measured with any particular detector setting …

The way I interpret the EPR argument, we can predict in advance the photon’s polarization as a parameter, however (as I mentioned before) not necessarily as deterministic argument but in terms of probability instead. For example, the photon’s polarization may fluctuate around a specific value causing the result of measurement to be probabilistic.
It seems to me that during interaction with polarizer, a photon’s polarization is rotated to align with the polarizer if their angles are close enough. It is why regardless that correlated photons may have slightly different polarizations, after interacting with their respective polarizers having identical setting the polarization of these photons will be realigned and the result of the measurement will be close to 100% correlation. However if the polarizers aren’t aligned the result of the measurement is less deterministic and follows cos^2 correlation (instead of linear correlation that, as I understand is associated with the absolutely deterministic outcome).

…. I wasn't talking about the hidden variables I was talking specifically about the predetermined results which are determined by those variables. For example it's possible that the variables fluctuate in a partially random way, but nevertheless at any time prior to measurement if you had complete knowledge of the hidden variables (along with any observable variables prior to measurement) you would be able to predict with certainty what result would be found if the particle was measured at setting A or B or C. If this wasn't true there would be no way (in a local realist universe respecting the no-conspiracy condition) to explain the fact that, whenever the particles are measured with the same detector setting, we are guaranteed to get identical (or opposite) results, even when there is a spacelike separation between the two measurements and choices of settings…

We can't predict the result of measurement because we don't have a complete knowledge about photon that is randomly changing its parameters. We also don't have a complete knowledge about fluctuations of the polarizer setting. It is why the local realistic EPR model may not include the "complete" knowledge of reality. The QM is “wise” enough to deal with this situation in term of probability by “refusing” to predict individual events. It is why QM is EMPERICALL theory that preidict the statisticaly processed observations but can't to explaine them. EPR model may have the same deficiency in prediction, but at least offers realsitic explanation of events.

I could try to explain it using analogies like the game show analogy here, though I know you have said in the past you don't like analogies.

I have no problem with analogies if they are adequate to phenomena we try to explain. Good analogy helps, but wrong one leads us further from destination.

If you want a more rigorous derivation I would use an argument involving light cones as Bell did in the paper I linked to and discussed in this post...so firstly, are you familiar with the concept of a "light cone" in special relativity, and why under local realism events can only be causally influenced by other events in their past light cone? If you're not familiar with this concept, this page might be a good place to start.

I read the link you provided and I understand the concept of a "light cone" in special relativity. I tried to read “La nouvelle cuisine” using the link you provided, but found just a beginning of this paper (ended at page 217). Bell started with an example of instantaneous events:

“...there are things which do go faster than light. British sovereignty is the classical ex-
ample. When the Queen dies in London (long may it be delayed) the Prince of Wales,
lecturing on modern architecture in Australia, becomes instantaneously King... And there are things like that in physics. In Maxwell’s theory … Coulomb gauge the scalar potential propagates with infinite velocity… “

Indeed the fact that “Prince of Wales becomes instantaneously King” and “the Coulomb scalar potential propagates with infinite velocity” are very good analogies between FORMAL LOGIC and MATHEMATICAL ABSTRACTION. However, they have nothing to do with a reality and therefore it would be a bad analogy to reality. I wasn’t able to find the entire paper, but I get feeling that Bell’s views on reality are influenced by this analogy.

As I understand, a photon that passed the polarizer may change its polarization as result of photon/polarizer interaction.

As I said the phrase "its polarization" doesn't have a clear meaning in QM, since for most angles the quantum state just gives you probabilities that the particle will pass through the polarizer.

However, as I understand, QM describes a photon’s polarization at least in terms of probability. Therefore, could we suggest that a photon interaction with polarizer may shift/rotate the “parameter” that describes the “probability vector” of the photon’s polarization?

Let’s assume that we have a pair of entangled photons. Using rotating polarizer we are changing the polarization of photons on one side while monitoring the polarization of entangled photons on other side. If the second entangled photon follows the polarization of the first photon we may claim that the non-local interaction exists. Is it true?

No, I already told you several times that the first measurement of each particle breaks the entanglement, after that the two photons are no more correlated than two non-entangled photons which happened to give the same two results to those first measurements.

Does it mean that any interaction between photon and other particles breaks the entanglement? Does photon interaction with molecules of air breaks the entanglement? Did Aspect perform his experiment in a vacuum?

 

[harrylin]

[...] Does photon interaction with molecules of air breaks the entanglement? Did Aspect perform his experiment in a vacuum?

Good question! I searched and found the -rather recent- answer here:

http://www.esa.int/esaMI/GSP/SEMXM7Q08ZE_0.html

 

[Jonathan Scott]

Regardless of the mechanism, there is a "magic" result in QM that the observation of one of the two entangled particles effectively puts the other one into a pure state as given by that result. Although the initial state of the pair of particles can be described by probabilities, once an observation has been made, the state at the other end is known exactly, and the other particle behaves like one prepared with a precisely known state.

If the observations are separated by a spacelike interval (that is, they are sufficiently far apart in space and close enough in time that there could not be a light-speed signal between them) then the question of which observation is "first" seems to depend on the frame of reference, but the same result is obtained either way.

 

[miosim]

Regardless of the mechanism, there is a "magic" result in QM that the observation of one of the two entangled particles effectively puts the other one into a pure state as given by that result. Although the initial state of the pair of particles can be described by probabilities, once an observation has been made, the state at the other end is known exactly, and the other particle behaves like one prepared with a precisely known state.

If the pure state (spin, polarization, etc.) of the other particle is known exactly and if this state isn’t included in the QM wave function the QM is incomplete. So we came back to EPR argument that, as I understand, wasn’t yet challenged directly. The best known indirect challenge is the Bell’s theorem that is based on the formal logic, algebra, and violates relativism.

 

[miosim]

I think that it is critical to understand how the photon passes the translucent media. If this is a series of collapses and reemergences (as JesseM suggested (if I understood him correctly)) the Aspect-like experiments cannot be interpreted as the influence over the distance between remotely placed targets, because entangled photons, as soon they are produced, are collapsing and loosing their entanglement by interacting with the optical media of the source.

To hold the existing interpretation of the Aspect-like experiment as influence over the distance we must to admit that the wave function of entangled photons doesn’t collapse whithin translucent media. Is it true?

 

[DrChinese]

I think that it is critical to understand how the photon passes the translucent media. If this is a series of collapses and reemergences (as JesseM suggested (if I understood him correctly)) the Aspect-like experiments cannot be interpreted as the influence over the distance between remotely placed targets, because entangled photons, as soon they are produced, are collapsing and loosing their entanglement by interacting with the optical media of the source.

To hold the existing interpretation of the Aspect-like experiment as influence over the distance we must to admit that the wave function of entangled photons doesn’t collapse whithin translucent media. Is it true?

No, no, no, it is not. You need to quit writing things which you simply make up as being factual, as I have told you previously.

Bell tests FIRST generate a proven entangled source by looking for perfect correlations at any angle. This is the definition of an entangled source. It does NOT matter about things like potential medium interactions the photons have as they travel, and in fact there are several specific ones that are actually planned in such experiments. But they do not affect the outcome as long as entanglement fidelity of the end stream is sufficient. That is how we know there is no collapse, it is experimentally demonstrated by examination of the resulting stream. It is called creating an EPR state. Period.

I realize you do not understand any of this, after all of the time we have tried to explain this. So I believe the answer to your original post is NO, grandpa cannot understand Bell.

(Hey, you win some, and you lose some. )

 

[harrylin]

Originally Posted by miosim:
"[..] To hold the existing interpretation of the Aspect-like experiment as influence over the distance we must to admit that the wave function of entangled photons doesn’t collapse whithin translucent media. Is it true?"

No, no, no, it is not. [..] That is how we know there is no collapse, it is experimentally demonstrated by examination of the resulting stream. It is called creating an EPR state. [..]

Are you sure that you actually read what he wrote?? Your answer after your "no" constitutes a "that's right, the wave function of entangled photons doesn’t collapse".

However, I had already given him a link to that fact... So it does appear that he "didn't get it".

 

[DrChinese]

Originally Posted by miosim:
"[..] To hold the existing interpretation of the Aspect-like experiment as influence over the distance we must to admit that the wave function of entangled photons doesn’t collapse whithin translucent media. Is it true?"Are you sure that you actually read what he wrote?? Your answer after your "no" constitutes a "that's right, the wave function of entangled photons doesn’t collapse".

... So it does appear that he "didn't get it".

He was essentially trying to say that it is an assumption, and that assumption could be challenged. But that is not the case. It is something which is demonstrated experimentally, and need not be assumed. And therefore cannot be challenged, since it is demonstrated.

miosim's (wrong) statement:

"the Aspect-like experiments cannot be interpreted as the influence over the distance between remotely placed targets, because entangled photons, as soon they are produced, are collapsing and loosing their entanglement by interacting with the optical media of the source."

He is trying to say that the experiment needs to be done in vacuum and with optical media that can be proven NOT to do anything to the photon. But that is flat wrong. In actuality, Bell tests use crystals, filters, wave plates, fiber optics and other things to move the photons to where they get into the polarizer/detector apparatus. That is perfectly legitimate and in no way alters the conclusion in and of themselves. Obviously, if the resulting entangled stream is of poor quality, that would be a different story. But then you couldn't get results rejecting local realism to such a high confidence level, currently much greater than 10 SD.

 

[miosim]

...However, I had already given him a link to that fact... So it does appear that he "didn't get it".

Don't worry I got it. According to your reference 'entanglement' is considered to be intact over a distance of 144 kilometers. And I have no problem with that.
So, if photons’ entanglement remains intact over long distance in the air this entanglement could be also preserved while photons are passing another translucent media – polarizer for example. However when I suggest an experiment that is based on this preservation of entanglement:

“…Using rotating polarizer we are changing the polarization of photons on one side while monitoring the polarization of entangled photons on other side…”

JesseM objected:

No, I already told you several times that the first measurement of each particle breaks the entanglement, after that the two photons are no more correlated than two non-entangled photons which happened to give the same two results to those first measurements…

So what does constitute the measurement and the wave function collapse? Is photon’s wave function collapses while it is passing a polarizer?

To demonstrate the inconsistency of JesseM response I pushed it to its limit and demonstrated that collapse of photon’s wave function, while it passes the translucent media, undermines all Aspect-like experiments and especially those that were conducted through the fibro optic media.

So my question is: does entangled photons that passed their respective polarizers remained entangled? Yes or No?
I would like to have a definite answear on this trivial question.

 

[SpectraCat]

Don't worry I got it. According to your reference 'entanglement' is considered to be intact over a distance of 144 kilometers. And I have no problem with that.
So, if photons’ entanglement remains intact over long distance in the air this entanglement could be also preserved while photons are passing another translucent media – polarizer for example. However when I suggest an experiment that is based on this preservation of entanglement:

“…Using rotating polarizer we are changing the polarization of photons on one side while monitoring the polarization of entangled photons on other side…”

JesseM objected:
So what does constitute the measurement and the wave function collapse? Is photon’s wave function collapses while it is passing a polarizer?

To demonstrate the inconsistency of JesseM response I pushed it to its limit and demonstrated that collapse of photon’s wave function, while it passes the translucent media, undermines all Aspect-like experiments and especially those that were conducted through the fibro optic media.

So my question is: does entangled photons that passed their respective polarizers remained entangled? Yes or No?
I would like to have a definite answear on this trivial question.

I believe that there is no simple answer to that question. The interaction with the polarizer breaks the polarization-entanglement, but does not completely collapse the state, as long as the photon has not been destructively detected. Rather, the individual photons become entangled (locally, I believe) with their respective measurement devices until one of the photons is detected. In fact, it has been shown experimentally that the entanglement can be transferred between pairs of photons using this method, by delaying detection and using the appropriate combinations of polarizers. I don't have the reference for the paper handy, but I think it is linked on Dr. Chinese's site .. it is one of the delayed choice quantum eraser (DCQE) papers.

So I think the answer to your question is, for the polarization-entangled photon pair (A,B), if A interacts with a polarizer, then it is no longer entangled with B (and vice-versa), but as long as neither have been destructively detected, then it may still be entangled with something else (e.g. a measurement device or another photon).

I should probably note that interaction with a traditional "one-way" polarizer, like a Polaroid filter, that will only pass one polarization, would count as destructive detection in the context of my comment. Interaction with a photon-counting device would obviously also count as destructive detection.

The polarizers I was thinking of are polarizing beam splitters (PBS's), which transmit both polarization states, but split them so they travel along different paths. That is why the entanglement can be transferred to such polarizers .. until you know which path the photon traveled along (i.e. by destructively detecting the photon), it's polarization state is entangled with the paths emerging from the beamsplitter, in analogous fashion to the double-slit experiment.

I haven't studied this stuff in detail for about a year, so I am a little rusty, but I think that my description above is essentially correct.

 

[DrChinese]

So my question is: does entangled photons that passed their respective polarizers remained entangled? Yes or No?
I would like to have a definite answear on this trivial question.

The general rule is no, they are no longer polarization entangled.

However, if you send them through wave plates (which rotate them), they remain polarization entangled. If you send them through polarizing beam splitters, and then recombine the stream so the which path information is erased, they will still be entangled (this is not easy to do however, more theoretical). If you use mirrors on them, they are still entangled.

I hope this helps.

 

[DrChinese]

To demonstrate the inconsistency of JesseM response I pushed it to its limit and demonstrated that collapse of photon’s wave function, while it passes the translucent media, undermines all Aspect-like experiments and especially those that were conducted through the fibro optic media.

I repeat, this is flat out wrong. There is nothing about the media per se - of which there are quite a number and I have enumerated many of these - that affects the results/conclusion of Bell tests. If the fidelity is too low, that could be a problem but that simply reduces the S value.

 

[miosim]

... So my question is: does entangled photons that passed their respective polarizers remained entangled? ...

The general rule is no, they are no longer polarization entangled.
However, if you send them through wave plates (which rotate them), they remain polarization entangled. If you send them through polarizing beam splitters, and then recombine the stream so the which path information is erased, they will still be entangled (this is not easy to do however, more theoretical). If you use mirrors on them, they are still entangled.

I hope this helps.

It helps a lot, because now I can propose the experiment that hopefully will directly prove the existence of an “influence over distance” in spirit of Bell’s theorem.

In this experiment we will rotate the polarization of one entangled photon in hope to observe the symmetrical rotation of another entangled photon.

We may start with the experimental setup very similar to Aspect’s, but with the polarized light source of entangled photons. We also will use two polarizers A and B set in parallel with each other and parallel with the light source polarization. However instead of correlation we will simply measure a light intensity on both sides.

Now, let’s place the wave plates (to rotate photon’s polarization) between light source and polarizer A. Because light beam that passes wave plates isn’t parallel any more to the polarizer A the intensity of the beam that passes this polarizer is changed according to Malus’ law.

If the light source is closer to the polarizer A (for the photon a to collapse first) we should observe the intensity of light at another side is changing in sync with side A that will be a direct proof of an “influence over distance”

What is your prediction of this experiment?

 

[Schrodinator]

20 pages?

Local realism is still not capable of predicting the results of quantum measurement right?

Inequalities still exist k and are violated. Just checking.

 

[Schrodinator]

It helps a lot, because now I can propose the experiment that hopefully will directly prove the existence of an “influence over distance” in spirit of Bell’s theorem.

In this experiment we will rotate the polarization of one entangled photon in hope to observe the symmetrical rotation of another entangled photon.

We may start with the experimental setup very similar to Aspect’s, but with the polarized light source of entangled photons. We also will use two polarizers A and B set in parallel with each other and parallel with the light source polarization. However instead of correlation we will simply measure a light intensity on both sides.

Now, let’s place the wave plates (to rotate photon’s polarization) between light source and polarizer A. Because light beam that passes wave plates isn’t parallel any more to the polarizer A the intensity of the beam that passes this polarizer is changed according to Malus’ law.

If the light source is closer to the polarizer A (for the photon a to collapse first) we should observe the intensity of light at another side is changing in sync with side A that will be a direct proof of an “influence over distance”

What is your prediction of this experiment?

Spooky action at a distance is what happens in experiment so it's kind of a pointless question. We've already showed that non local interactions in entangled systems occur, in fact its been shown so many times that the experiment itself now is kinda redundant, unless its for educational/instruction purposes there's probably not much point in flogging a dead horse.

We've also demonstrated that Bell's inequalities hold for almost all experiments and derivatives you can possibly imagine. Some would say this is not conclusive proof, but frankly the loop holes that people are coming up with now are getting pretty wild and speculative.

Holographic universes etc, it's really quite amusing really.

 

[harrylin]

20 pages?
Local realism is still not capable of predicting the results of quantum measurement right?

Don't worry, it took atomism hundreds (or thousands?) of years to predict the non-atomistic gas law

Inequalities still exist k and are violated. Just checking.

In case you overlooked it: it's still a matter of debate if that is even relevant.

 

[miosim]

Spooky action at a distance is what happens in experiment so it's kind of a pointless question…

You are right because QM is an empirical theory that isn’t in the business of explaining, but predicting only.

We've already showed that non local interactions in entangled systems occur, in fact its been shown so many times that the experiment itself now is kinda redundant, unless its for educational/instruction purposes there's probably not much point in flogging a dead horse …

According to Einstein only a theory “knows” what we observe during experiment. Regarding Aspect-like experiments they proved that correlation between entangled particle follow cos^2 (the same as Malus’ law). The interpretations of this result, as non local interactions, in my humble opinion, are based on

• Reading miscomprehension of the EPR (1935) paper
• Redefining the reality
• Formal logic and algebra

that eventually led to the violation of the respected relativistic theory.

I would be happy to collaborate my views on Bell’s theorem and related experiments in more details , but first …

… what did you say about prediction of the experiment in the post #310?

 

[DrChinese]

20 pages?

Local realism is still not capable of predicting the results of quantum measurement right?

Inequalities still exist k and are violated. Just checking.

I hear you. This discussion is sad, really. There are several folks here are sadly deluded into thinking there is an open debate on Bell in the scientific community (when there is none of substance). Actually, the biggest debate about Bell is whether he would have won the Nobel if he had not died somewhat prematurely.