About violation of Bell's inequalities

[NateTG]

Besides: any theory which agrees with the predictions of QM is not local realistic, per Bell. So if you want to impress with your hypothesis, put forward an ACTUAL theory which contains LHV and matches the predictions of QM. Saying that it is "possible" is like saying string theory can "possibly" unify physics... maybe, maybe not.

Not that it's my favorite, but in the 'deterministic universe' interpretation, the entire universe is Bell-local, and, thus, under this sort of interpretation there are no experiments to which Bell's theorem applies.

I expect that conclusively demonstrating Bell non-locality by experiment would turn modern physics on its head in a big way.

 

[DrChinese]

Not that it's my favorite, but in the 'deterministic universe' interpretation, the entire universe is Bell-local, and, thus, under this sort of interpretation there are no experiments to which Bell's theorem applies.

My point is that there is no such theory which can give results which match QM once you attempt a Bell test. It is easy to say that there is such an interpretation, much more difficult to actually concoct one. Please keep in mind that every particle must carry around a lot of information if it is to respond correctly to all tests that it may be subjected to... since there is no entangled state any longer!

 

[NateTG]

My point is that there is no such theory which can give results which match QM once you attempt a Bell test. It is easy to say that there is such an interpretation, much more difficult to actually concoct one.

It's trivial to produce an non-predictive interpretation that matches QM exactly that is deterministic by simply postulating that, for any measurement, the result was determined at the time of the big bang. (Technically, it's a bit ambiguous whether this interpretation is actually realistic, but that's a semantic discussion.)

I suppose MWI is a more popular example of this sort of theory. Instead of using a classical determinism, it takes the 'branch both ways' approach, and you already know that MWI is consistent with QM.

 

[DrChinese]

It's trivial to produce an non-predictive interpretation that matches QM exactly that is deterministic by simply postulating that, for any measurement, the result was determined at the time of the big bang.

I used to think as you, until I thought about it a while. IF you try to take that a step further, you realize that a Bell test actually requires that there be all kinds of new forces and particle attributes so that the result works out right. If you stipulate that it is to be a local theory, that is... because the measurements are taken at space like separated points and the measuring apparatus setting can be set to trigger off of independent triggers (like radioactive isotopes, or similar) which are random. Trying to explain these as being predetermined requires you to postulate that they are working in concert to achieve the ultimate results, a very complex theory indeed.

 

[NateTG]

I used to think as you, until I thought about it a while. IF you try to take that a step further, you realize that a Bell test actually requires that there be all kinds of new forces and particle attributes so that the result works out right. If you stipulate that it is to be a local theory, that is... because the measurements are taken at space like separated points and the measuring apparatus setting can be set to trigger off of independent triggers (like radioactive isotopes, or similar) which are random. Trying to explain these as being predetermined requires you to postulate that they are working in concert to achieve the ultimate results, a very complex theory indeed.

These 'random' independant triggers are measurements. Ergo, they are predetermined in this trivially deterministic interpertation. In a strongly deterministic interpretation, there is no randomness.

You're welcome to keep bashing your head into the wall about this, but in a strongly deterministic universe with a big bang, Bell's theorem does not apply, because all space-times are Bell-local with each other.

 

[Careful]

These 'random' independant triggers are measurements. Ergo, they are predetermined in this trivially deterministic interpertation. In a strongly deterministic interpretation, there is no randomness.

You're welcome to keep bashing your head into the wall about this, but in a strongly deterministic universe with a big bang, Bell's theorem does not apply, because all space-times are Bell-local with each other.

Look, I am local realist but I do support Dr Chinese in his remarks to come up with a plausible theory. Don't get me wrong, I think it is a huge mistake to support non local or consciousness theories or rubbish alike. Perhaps you should look for something else...

Careful

 

[DrChinese]

These 'random' independant triggers are measurements. Ergo, they are predetermined in this trivially deterministic interpertation. In a strongly deterministic interpretation, there is no randomness.

I understand the concept. But it hardly explains why there are correlations between distant measurements. It only explains the idea that all apparent randomness has a common prior cause. With this hypothesis, you are hard pressed to explain why all measurements of spin (for example) don't yield the same value (as would be expected if they share a common origin). In other words, your hypothetical theory basically says that the entire universe is entangled.

 

[Nacho]

There is another way to look at this, that is actually quite amusing, to me at least.

We don't know how, but we mostly accept it as "the way it is" and don't look any deeper into it when QM (nature) throws us randomness. Yet we almost become indignant and unaccepting (or, at least questioning) when it does almost the opposite to us .. shows us correlations of random events!

Are correlations of random events more of a mystery than **true** randomness?

If and when we get to the bottom of the randomness, might not we get to the bottom of the correlations? Or conversely, is it futile to try to explain why we get correlations of randomness when we can't even explain why we get randomness?

 

[NateTG]

I understand the concept. But it hardly explains why there are correlations between distant measurements.

It's not a theory, it's an interpretation, and it's not a particularly attractive one. From a scientific perspective, it's no different than explaining QM as the action of billions of invisible devils using invisible strings to pull particles along.

Ultimately, the point is that Bell's theorem itself requires multiple unfalsifiable assumptions such as Bell Locality and Bell Realism. Which are probably strictly stronger than the usual notions of locality and realism respectively. Moreover, and this is perhaps surprising, to date, locality and realism are *interpretation* issues. That is to say, they are unfalisfiable.

Providing even a single interepretation of QM that is, in fact local and realistic, no matter how ugly, is sufficient to refute the assertion that QM is intrinsically not local realistic.