First the disclosure. My academic training is in engineering and telecommunications. I've worked in one field or the other for thirty some years. I am a dilettante at physics. That said, I think that the experimental tests of Bell's Inequality disposed of the EPR paradox and there are no hidden variables. I also think the Michaelson Morely, Kennedy Thorndike, Brillet Hall and some other experiments I cannot recall at the moment reliably establish that the speed of light in vacuum is isotropic and invariant in all inertial frames of reference. Lately I tend toward the transactional interpretation of QM but not strongly because it -- well -- feels a little contrived. The advanced and retarded waves seem too convenient but that may be because I just haven't thought about it enough. There are people who disagree with my interpretations and you might want to track a few down on Google to get a different take on the subject.
Assuming similar relative velocity, and a position equidistant from both ends of communication, one would be able to establish what simultaneity is by having a station or something equidistant to two points transmitting lightspeed to the two points.
I'm not sure what you mean here. Is seems to me you are limiting FTL communication to frames where the difference between the classical and relativistic solutions are undetectable.
By the relativity, afaik. I really don't understand why there's an insistence that FTL would allow time travel or temporal communication. It'd just render two distant locations as in the same frame, or if one is moving at relatavistic velocity relatively the same frame. And if the math says instantaneous communication would allow you to communicate "back in time", I'm relatively certain that's an artifact of the math. Just because point B in frame B, assuming sufficient magnification, is observing a location with a time delay doesn't mean FTL communication to that location will occur to the point in time being visually observed.
This comes up periodically in the Physic forums.
The communication backwards in time is a consequence of time dilation which is pretty well tested for both special and general relativity. The GPS calculations take both into account (
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html) and GPS is used millions of times per day.
To construct a simple scenario for illustration: Observer A is on Ceres. Observer B is a relay satellite that simply resends any message it receives to A. To keep is really simple, the Cereans also have a laser launcher that can push the package from 0 to .866C in a very short time. The on board drive can produce enough thrust to to maintain the relative velocity against the resistance from interstellar hydrogen and the whole thing is hardened against radiation. So far it's all engineering
Next add superluminal communication using quantum entanglement meaning the range is, in theory, infinite.
Now they have a time dilation factor of 2 and the clocks have been running that way since shortly after the launch a year ago.
A sends a message at +31,536,000s in his frame of reference. It arrives "instantly" in the B frame where only 15,768,000s have elapsed. B resends the messages back to A where it arrives instantly at +7,884,000 in the A frame. The difference is 31,536,000s - 7,884,000s = 23,652,000.
The message returns about 273 days before it was first sent.
This is not just an artifact arising from a photon arriving at one end of train before the other in a particular frame. It is an inevitable consequence of superluminal communication and relativity.
Wayne Throop has some explanations on time dilation that may be helpful.
http://www.sheol.org/throopw/sr-ticks-n-bricks.htmlhttp://www.sheol.org/throopw/sr-twin-01.htmlSpecial Relativity may be incomplete (it is) but it has been tested to several decimal places. In fact, it is probably one of the best tested theories in modern physics. General Relativity may be incomplete (probaby is) but it has also stood up to intensive testing.
Not sure how that works. Wouldn't it be possible to "filter" the quantum states for non-random patterns? If the waveform consistently collapses into set oggledy for duration X, where "noise" would have it only collapse into oggledy only at chance, one could consider that, say, a zero bit. Then a consistent collapse for duration X of doodly could be a one bit. Even FTL dialup would be an improvement on lightspeed.
The states are entangled and undetermined but existent. So, when you measure a quantity in an entangled system you cause the state to collapse but do not determine what that state will be. It is randomly "selected" from the possibilities. If QM is linear, this means the state changes at the "receiving" end will appear to be random too.
Randomness alone doesn't means there is no information. For example, a perfect one time pad encryption system will generate results indistinguishable from randomness. There may be information in the gobbledygook but you cannot extract it without the key. In the entanglement scenario, the "key" is effectively being generated as the encryption is being done.
BTW, that last characteristic can be exploited for cryptography.
I am one of those who think QM is incomplete and not just because a workable theory of quantum gravity is missing. There may be be a loophole that will allow for FTL communication. I read somewhere that John Cramer is working on an experiment to test if "complementarity" can be exploited to send information. However, so far, the evidence is that nature does play dice with the universe and reserves any FTL telegraph for her own use.
