>>>(snip)
>>>>>>I remember reading an article about Einsteinian Locality and the Bell experiments quite a while ago and thinking that it might be a great way to send messages faster than the speed of light.
>>>>>>
>>>>>>In general, the problem of locality is that no information can travel faster than the speed of light, but in the Bell experiments it was found that information did seem to break that law. If I recall, certain particles are created in pairs with opposite spin, colour, etc. Because energy cannot be created or destroyed, the characteristics of the pairs must cancel each other out exactly. So, what happens if the spin on one of the particles is changed? The other shouldn't hear about the change any sooner than it would take light to travel from one to the other. However, what they found was that changing the spin on one changed the spin on the other at the same time. It was measurable and repeatable.
>>>>>>
>>>>>>That being the case, if you coded a message by changing the spins on a lot of particles at one place, then their twins, which sped off in another direction, would show the same coding. I don't have any idea how this would be set up and made to work, but the idea is almost scary.
>>>>>
>>>>>Well, if they had really proven it, it would be easy enough to confirm with a simple telegraph and some synchronized atomic clocks. Somehow, I doubt that this has been done, as I believe that the impossibility of communicating at greater than light speed is a very deep principle. I don't think quantum computation is nearly so far-fetched, although I don't claim to have a deep understanding of it. The way I think of it, QC enables direct computation of certain kinds of useful functions - those that are basic to the mathematics of QM - in a manner that overcomes the inherent limitations of performing those calculations by conventional means. The most direct application of QC might be something like understanding the shapes of large molecules, or taking it further, modeling the folding of complex proteins, a very important topic in biochemistry.
>>>>
>>>>Well, Bell's Theorem is well known in Physics since it stood the scientific world on it's ear back in the mid 1970's. It's been proven more than once, and is pretty much part of the accepted quantum system now. In fact as I understand it, not only did it prove that locality was not a requiremnt, it proved that non-locality is.
>>>
>>>A Google search on "Bell's Theorem" turns up plenty of interesting references, e.g.:
>>>
>>>NCSU - Spooky Action at a Distance - An Explanation of Bell's Theorem, by Gary Felder, 1999
>>>http://www.ncsu.edu/felder-public/kenny/papers/bell.html
>>>
>>>Stanford - Encyclopedia of Philosophy - Bell's Theorem
>>>http://plato.stanford.edu/entries/bell-theorem/
>>>
>>>Wikipedia - Bell's theorem
>>>http://en.wikipedia.org/wiki/Bell's_theorem
>>>
>>>and especially note this one:
>>>
>>>Wikipedia - No-communication theorem
>>>http://en.wikipedia.org/wiki/No-communication_theorem
>>>
>>>I think the gist of it is that while Bell's Theorem shakes up the concept of "locality", as the term is used in this context, it does not violate the relativistic principle that communication can not exceed the speed of light. To put it another way, while there may be some valid notion of "instantaneous" entanglement at a distance, the hypothetical experiment does not constitute any form of useful communication. The relationship between these distant events is not really causal: what one observer sees is indicative of what the other will see, but that's not the same as saying one observer can deliberately cause an instantaneous effect seen by the other observer. I will not lose any sleep over this "paradox" until someone performs a simple telegraph experiment that proves otherwise.
>>
>>But isn't that what they did? By deliberately changing the spin at one observation point, they [presumably] affected the spin at another observation point. No?
>
>So, you are not satisfied with my proof of the no-communication theorem, eh? Well, I don't pretend to understand the math, but there seems to be a general concensus that such arguments resolve the paradox, and the relativistic limit on communication still holds. I'm not aware of any experimental evidence contradicting this fundamental limit.
>
>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.