FTL communication: might QM entanglement trump relativity?

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Re: FTL communication: might QM entanglement "trump" relativity?

This has gone way off topic. The discussion on the light source for candles, incandescent light bulb, synchrotron light sources, etc. have already been discussed ad nauseum on here. I may even have to put up a FAQ on this sooner or later.

It is seriously wrong to assume that atomic transition (and matter-antimatter annihilation) are the only mechanism to generate EM radiation. It ignores THE most common terrestrial mechanism by human to generate EM radiation.
I made no such assumption, and indeed, discussing it would be off-topic. The crucial point regarding this topic is that in photon emission, (at least in some cases), before the emission, the energy, which will be transformed (for lack of a better word) into a photon, is not moving at the speed of light, but after the emission, it will move at the speed of light. Such a process may not contradict SR, since it is already known that certain statements resulting from SR do not apply to massless particles, but it is outside of what SR (or GR) can describe. This is relevant to this topic since arguments against the possibility of FTL are often based on relativity and/or causality.


OK, then let's move on by saying that it would take us several lifetimes if we continue to discussion various passages out of Wikipedia. The very same way that we simply do not have the time or the patience to answer every single crackpottery that exists out there, I would also insist that, unless one has a more reputable sources, quoting passages out of Wikipedia should not be done in here.

Is that clear enough?

Zz.
Sorry for the confusion, my intention was not to discuss the question of whether relativity requires causality based on any wikipedia passage, which is why I first didn't quote it. I was only interested in comments on this question (independently of wikipedia) from forum members. I think that the concept of causality is highly relevant to the question of whether FTL might be possible, and so it is also relevant whether causality is required by relativity, or independent of it, and in either case, which assumptions or research causality is based on. This is a question to which I have no answer, and I'm certainly not basing an opinion on the passage from wikipedia. However, it seems a crucial question regarding the discussion of FTL, and also I would like to understand more about it, this is why I brought it up.

I hope I could express myself more clearly this time.
 
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Re: FTL communication: might QM entanglement "trump" relativity?

From my message above:

The crucial point regarding this topic is that in photon emission, (at least in some cases), before the emission, the energy, which will be transformed (for lack of a better word) into a photon, is not moving at the speed of light, but after the emission, it will move at the speed of light.
Here is link describing photon emission from a change in electron energy level:

http://cass.ucsd.edu/public/tutorial/Planck.html (see at the bottom of the page).

Not that I would expect anyone here to actually require this reference, yet I hope University of California, San Diego (Prof. H. E. Gene Smith), counts as a reputable source.
 
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atyy

Science Advisor
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Re: FTL communication: might QM entanglement "trump" relativity?

BTW, I've recently read that 'causality' is not really a requirement of SR, even though it is often presented as if it were. Comments on this are welcome :).
Nature of time and causality in Physics
Francisco S. N. Lobo
http://arxiv.org/abs/0710.0428
 
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Re: FTL communication: might QM entanglement "trump" relativity?

Generalizing entanglement: If as it seems, the speed of the collapsing wave front of entangled particles occurs at a superluminal velocity, what is special about entangled particles? It follows that all quantum changes occur at ftl rates, e.g. the orbital shifts of an electron that absorbs or emits a photon in the process. If this orbital shift is not fast with respect to the speed of light, the peppy little photon will be stretched out across space and would then itself have to snap into a coherent, respectable photon at ftl speeds. Either way, something is happening at trans light speed. Similarly, regarding a photon that passes through a diffraction grating, it seems one explanation of the strange finding that even single photons create a diffraction pattern in the two slit diffraction experiment is that the un-collapsed photon is such a large wavicle--wave packet—that it interferes with itself. (In fact isn't the "wave-like nature of light" a property of photons? Is there any evidence that when the intensity of light increaes and massive numbers of photons are released they mysteriously become entangled and turn into some de novo "wave of light?" It's just photons all the way down!) When this relatively large photonic probability waveform strikes the sensor at the back and causes an electronic discharge, doesn't the collapse of its wave function and the subsequent transfer of energy also have to occur at a rate which is “fast” relative to light speed or part of the photon will have had time to bounce off the sensor and would be racing back towards the grating once again stretching it out so that it must be “sucked in” at ftl speeds or some part of it will never actually “get in.” None of this actually contradicts SR, but I doubt AE would be that comfortable with it.
 
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Re: FTL communication: might QM entanglement "trump" relativity?

We could also say that the spatial separation does not play a role in correlations - its not in the entanglement equation at all.
Then I suppose, we are all asking why not? Why is it not in that equation?
 
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