ThomasT said:
1. Say Alice and Bob are counter-propagating sinusoidal (light) waves that share a cloned property, eg., they're identically polarized. Analyze this cloned property with crossed polarizers and you get entanglement correlation. Cos^2 |a-b| in the ideal. It's just optics. Not that optics isn't somewhat mysterious in it's own right. But we can at least understand that the entanglement stats so produced don't have to be due to Alice and Bob communicating with each other, or that nonseparability means that Alice and Bob are the same thing in the sense that they're actually physically connected when they reach the polarizers.
DrChinese said:
1. I have news for you: this is patently FALSE. If you take 2 identically polarized photons and run them through the polarizers as you describe here, you do NOT get Cos^2 |a-b| or anything close to it.
In the cases you're talking about, the explanation is that the photons (while sometimes very closely polarized) aren't identically polarized. They're not 'clones' of each other. How do we know that? Precisely because when you run them through the polarizers you don't get cos^2 |a-b| entanglement stats (but you do get a range of approximations of essentially the same sinusoidal angular dependency -- which suggests to me that 'entanglement' is simply a special case involving the same underlying physical principles, which include, but aren't limited to, (1) the principle of locality and (2) the cos^2 theta rule).
DrChinese said:
You ONLY get this for ENTANGLED photons.
I agree. They (or a common property that's being jointly measured) are clones of each other. Which means that they're, eg., identically polarized. Which is deduced via the production of entanglement stats.
DrChinese said:
In other words: in the case where your assumption is actually valid - and I do mean identical and identically polarized photons coming out of a PDC crystal - you do NOT get entangled state statistics.
Then, as I said above, these photons aren't cloned (ie., entangled) wrt polarization. In this case, we can assume that |L
1 - L
2| > 0 (ie., we can assume that they weren't identically polarized), where L
1 and L
2 denote the optical vectors of the photons.
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ThomasT said:
2. Bell didn't address this case, because it's precluded by the EPR requirement that lhv models of entanglement be expressed in terms of parameters that determine individual results.
DrChinese said:
2. Bell quite discussed the case where the correlations are due anti-symmetric considerations.
That's not what I'm talking about -- which is that if Bell had modeled the joint situation in the global (ie., nonseparable) terms that it actually required (involving some modification in the representation of the 'beables' involved), then he might have presented a local realistic model which would have reproduced the qm correlation. The point of departure for viable local realistic models is that an experimental situation measuring a joint microphysical parameter vis a joint measurement parameter requires a 'nonseparable' representation. Such models have been produced, they work, and they remain unrefuted.
(Wrt my statement 2. above, I've come to think that EPR's definition of reality doesn't require that LR models of entanglement be expressed in terms of parameters that determine individual results. That is, there can be a common, underlying parameter that determines joint results while not determining individual results, and this, realistic, conception isn't contradicted by the EPR's conception of reality and definition thereof vis elements of reality.)
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ThomasT said:
3. On the other hand, since a local realistic computer simulation of an entanglement preparation is not the same as a local realistic formal model (in the EPR sense), then it wouldn't be at all surprising if such a simulation could reproduce the observed experimental results, and violate a BI appropriate to the situation being simulated -- and this wouldn't contradict Bell's result, but, rather, affirm it in a way analogous to the way real experiments have affirmed Bell's result.
DrChinese said:
3. I would like to see one (and yes, it would surprise me). This is a somewhat complex subject and I am currently working with the De Raedt team (and another independent theoretical physicist) regarding some concerns I have expressed about their model. Their model does have some very interesting features. If it were possible to suitably express such a simulation, I think it might require some additional experimental analysis. It would not affect Bell's Theorem.
Not the math itself, no, but it would affect the physical interpretation of BI violations wrt locality and determinism -- rendering them irrelevant wrt those considerations.
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From the thread: "Why the De Raedt Local Realistic Computer Simulations are wrong", you stated:
DrChinese said:
In trying to show that there "could" be an exception to Bell, please consider the following to add to your list of tests for you candidate LHV theory:
... snip ...
DrChinese said:
b) The formula for the underlying relationship will be different than the QM predictions, and must respect the Bell Inequality curve. I.e. usually that means the boundary condition which is a straight line, although there are solutions which yield more radical results.
If you're requiring that an LR model of entanglement not agree with qm predictions or experimental results, then I now see the point of your 'LR dataset' requirement. Well, yes, I certainly agree that one way to rule out qm compatible and viable LR accounts of entanglement is to simply require them to be incompatible with qm and inaccurate. But that would be inane. So I must be misunderstanding what you mean.