>>>>>>(snip)
>>>>>>>> (more snipping)
>>>>I think there may be a misconception coming from confusion between determining something versus causing it. Yes, the act of measurement determines the value of a property, and this may by implication - in some sense instantaneously - determine a property of some distant "entangled" object. An observation determines a value, i.e. it causes the value to be known, but it doesn't cause a particular result. Without the latter form of causation, there can be no real communication.
>>>>
>>>>That is my simple-minded way of skipping over the math, which appears to be an absurdly convoluted way of arriving at an obvious conclusion. I could be missing something, but my take on it is that this issue has been clouded by semantic arguments that have no physical significance. The deliberate act of flipping a spin at one location does not instantaneously propagate to another location, even though one could say that the mere act of observing one particle's spin may "instantaneously determine" the value of a distant particle's spin. So what? That is not a useful form of communication.
>>>
>>>You seem to be saying that it's all just math theory; there was no actual experiment performed to prove the theory. As far as I know, there was, but maybe I'm misunderstanding what was done. IIRC, the experiment was that they changed the spin on particles at one location using magnetics or other radiation, and the observation at the other location determinded that the percentages matched.
>>>
>>>In other words, there should be 50% up and 50% down spins at each location. However they changed the spins at one of the observation points so that what is observed is 75/25 instead of 50/50. Now the observation at the other location also shows 75/25 (at least roughly).
>>>
>>>Maybe I'm losing my mind, but I'm absolutely sure this was proved by actual experiments.
>>>
>>>If so, then it seems that information could be coded in a format as simple as morse code. If they could actually control the changed percentages, then it seems a lot of information could be transmitted.
>>
>>Alan,
>>
>>I'm not saying it's "just math" - just trying to cut to the heart of the matter, and suggesting we skip over the math. If the experiments were as you described, yes, they would appear to demonstrate the possibility of faster-than-light communication. However, I think you are mistaken about what the Bell experiments have shown, and frankly, I don't quite understand it myself. But what seems to be clear and consistently noted is that Bell's Theorem and the related experiments do not imply superluminal communication. The bottom line is in this quote from wikipedia about the Principle of locality:
>>
>>Because the differences between the different interpretations are mostly philosophical ones (except for the Bohm interpretation), the physicists usually use the language in which the important statements are independent of the interpretation we choose. In this framework, only the measurable action at a distance - a superluminal propagation of real, physical information - would be usually considered to be a violation of locality by the physicists. Such phenomena have never been seen, and they are not predicted by the current theories (with the possible exception of the Bohm theory).
>>
>>There is another wikipedia page about Bell test experiments, and none of these appear to be such as you describe. So what is it that these experiments are demonstrating? I can't exactly say, but it has to do with Bell's constraints on the correlations of measurements, which we are told imply this:
>>
>>No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics.
>>
>>OK, I can live with that, whatever the hell that really means. It's too bad that Richard Feynman isn't around to explain it all with his characteristic clarity. I tried searching Google for what Feynman had to say about Bell's theorem, and that yielded some interesting results, although not exactly what I was after. I didn't find any direct quotes from Feynman on it, but here's an entertaining page:
>>
>>Quotations for the Backyard Quantum Mechanic, Selected by Ben Best
>>
>>I also found this article pretty interesting and readable:
>>
>>Kantian Quantum Mechanics, by Kelley L. Ross
>>
>>and some more choice quotes are to be found on this page:
>>
>>Impossible facts, by Boris Tsirelson
>>
>>I am particularly amused by this quote from that page, attributed to none other than Bell himself:
>>
>>... what is proved by impossibility proofs is lack of imagination.
>>
>>Now that is funny!
>>
>>Mike
>
>Check out this page. Scroll down to The Bell Inequality. There is a nice little explanation of the 1982 experiment by Alain Aspect, Jean Dalibard, and Gérard Roger.
>
>To tell the truth, I'm not sure what it all means, and I know that a lot of physicists would like the results of the experiment to simply go away. But the results are real and they are accepted as such.
>
>One unfortunate aspect (no pun intended) to this experiment is the way it's been co-opted by the lunatic fringe to explain their astrological charts and out of body experiences to the terminally foolish.

Thanks for the reference - it seems to say something vaguely comprehensible about the experiment, but I'd like to find a much clearer, more authoritative explanation (some day). I definitely don't get it, and I don't see how this constitutes any useful form of communication. I would expect the measurements to correlate, as the total spin of the two particles was known in the first place, so measuring one implies the state of the other. There is no need to assume any underlying mechanism of signal propagation to grasp this, since no information is actually exchanged. Whatever physicists find disturbing about the Bell experiments, I don't think these results are generally regarded as proof of superluminal communication (except among the "lunatic fringe").

Manifestations of quantum mechanics always tend to be mysterious. If Bell's theorem or these experiments shed some new light on quantum effects, that would be unsettling, even without any violation of relativity. On the other hand, if Bell's theorem is meaningless, or the experiments are wrong, well that would be unsettling too. So it should come as no surprise that many people are disturbed by the Bell experiments, regardless of their significance!