Third Loophole Against Entanglement Eliminated

[billschnieder]

The claim that real numbers commute?

No, the claim that you can add results from non-commuting operations as if they were commuting operations and expect to have an expression that is meaningful in any way. BTW you had exactly nothing to say about Bell's argument which I quoted to you.

 

[stevendaryl]

No, the claim that you can add results from non-commuting operations as if they were commuting operations and expect to have an expression that is meaningful in any way.

If the results are real numbers, then you can add them.

BTW you had exactly nothing to say about Bell's argument which I quoted to you.

That's right, I had exactly nothing to say about it.

 

[DevilsAvocado]

1) Do you agree that there are two scenarios involved in this discussion:

Scenario X, involving the three correlations:

C(a,b) = correlation for what we would get if we measure (a,b)
C(b,c) = correlation for what we would get if we measure (b,c)
C(a,c) = correlation for what we would get if we measure (a,c)​

Scenario Y, involving the three correlations:

C(a,b) = correlation for what we would get if we measure (a,b)
C(a,c) = correlation for what we would have gotten had we measured (a,c) instead of (a,b)
C(b,c) = correlation for what we would have gotten had we measured (b,c) instead of (a,b)​

For the first time it looks like there’s something coherent...

Scenario X => QM theory => EPR-Bell experiments => what actually works
Scenario Y => assumptions of Local Realism => definite values all the time => CFD => not working

For clarity we exchange Scenario X = QM theory and Scenario Y = Local Realism, and then it’s easy to see where it goes wrong.

2) Do you agree that Scenario X is different from Scenario Y?

Yes of course, it’s big difference between QM theory and Local Realism.

3) Do you agree that the correlations in Bell's inequalities correspond to Scenario Y NOT Scenario X?

Yes of course, Bell's inequalities sets the upper limit for what any model of Local Realism can achieve.

4) Do you agree that correlations calculated from QM correspond to Scenario X not Scenario Y?

Yes of course, calculated correlations of QM theory naturally will correspond to QM theory.

5) Do you agree that correlations measured in experiments correspond to Scenario X not Scenario Y?

Yes of course, when we perform QM experiments in form of EPR-Bell test experiments, it will naturally correspond to QM theory.

Do you now see the issue?

No I don’t see the issue, but I can guess what windmills you are tilting.

Let me try to “read your mind”:

To make Bell's inequalities a valid test of Local Realism, we need to be able to perform experiments that delivers *real data* for the inequalities of Local Realism, i.e. we do not necessarily need to violate Bell's inequalities, but just get the data in our hands. If we can’t do this, then it’s impossible to say that we have violated Bell's inequalities for Local Realism, because there is absolutely nothing there to violate, just a vacuum of buffoonery and mysticism!​

A lot of people have spent a lot of time trying to show you exactly how erroneous this “counterfactual logic” of yours really is. This is what you fail to see:

1. All modern science builds on the framework; Idea -> Mathematical model -> Empirical test -> Yes/No. Do you get this??
   
   
2. We can build a mathematical model of the properties that Local Realism must possesses to be a model of local realism, and one of these properties is that every value (LHV) in the model naturally has to be definite from the beginning. Do you get this??
   
   
3. This definite property of LHV unconditionally leads to Counterfactual definiteness (CFD). Do you get this??
   
   
4. In QM, non-commuting operators cannot simultaneously be known precisely, which mean that definiteness of non-commuting values [before measurement] is impossible. Do you get this??
   
   
5. According to the proponents of local realism the problem with non-commuting operators and the [current] inability to simultaneously/precisely measure counterfactual values could be due to the incompleteness of QM and/or [current] shortcomings in measurement techniques. Do you get this??
   
   
6. Bell's inequalities is a mathematical model for setting the upper boundaries what Local Realism and LHV/CFD could ever produce when it comes to particle correlations between space-like separated measurements. Do you get this??
   
   
7. There is nothing in Bell’s theorem, or any other place, that states that we must be able to simultaneously measure all the values that counterfactual definiteness represents in Local Realism. In fact, this would require the potential to measure non-commuting operators precisely, which would mean that the measurement would refute QM, which would mean that if someone could actually perform this measurement he/she would get an instant Nobel Prize in Physics. Do you get this??

Sum up:

• You are tilting windmills while painting yourself into a corner.
• If you rebut counterfactual definiteness, you also rebut local realism.
• If you admit counterfactual definiteness, your “counterfactual logic” leads to the bizarre situation where local realism could never be scientifically tested, which automatically puts local realism in the metaphysical/philosophical/religious domain.
• Your corner is getting narrower and narrower and narrower...

DO YOU GET THIS??

 

[billschnieder]

DA, This discussion has to continue in a different thread if you are interested.

 

[lugita15]

Your no-conspiracy condition is essentially that Scenario X and Scenario Y (from above) are exactly the same,

Yes, the no-conspiracy condition says that if a statement is meaningful in both scenarios, then the probability is equal for both scenarios.

in other words, your no-conspiracy condition is equivalent to saying, the QM result from a single wavefunction must be the same as the QM result from three different wavefunctions.

Where in the world did you get that from? We're talking about different possible measurements we could perform on a system with the same wavefunction. We're not talking about different wavefunctions.

And I showed you that step (3) was incomplete, Step (3) What does no-conspiracy say about P(AB|w). According to your logic, no-conspiracy also implies that P(AB|w)=P(AB|x,y).

No-conspiracy states that if a statement S is meaningful in both x and w, then P(S|w)=P(S|x) (and similarly for y and z). But A & B is not meaningful in x, so no-conspiracy doesn't tell you anything in this case.

Also, what do you mean by P(A & B|x,y)? Do you mean a combined space which is the union of x and y? Well, my reasoning doesn't talk about combined spaces like that. It only discusses x, y, z, and w.

But x and y are two different sets of photons, which means P(AB|x,y) is undefined/meaningless

Again, I didn't say anything about P(A & B|x,y).

. All you have proven is the triviality that the joint probablity distribution P(ABC|x,y,z) for outcomes from three different sets of photons (x,y,z) is undefined, although the joint probability distribution P(ABC|w) from the single set of photons (w) is well defined.

I didn't say anything about P(A & B & C|x,y,z). And again, since A & B & C is meaningless in x, y, or z, the no-conspiracy condition says nothing in this case either.

 

[harrylin]

Upon my comments concerning Bell's sweeping claims:

What is the more general conception of locality you have in mind? Regardless, it's possible to give a proof of Bell's theorem with this meager definition of locality: events can only influence events within their future light cone.

Yes, I just replied to DevilAvocado. To sum up, in principle the term "counterfactual definiteness" COULD refer to something more general, but for the purposes of Bell's theorem all we need is the meaningfullness of asking what a measurement that you didn't make would yield if you had made it. [..]

I had in mind to reply in a more general thread, but I see that today Dadface has started a new topic on just this same issue:
https://www.physicsforums.com/showthread.php?t=697939

I hope to comment there soon, after contemplating on a few more papers.