Hi Inertron and Farsight,
A lot of "flack" has gone up lately regarding the supposed FTL neutrinos at CERN... IMHO this is far more important and is slipping "under the carpet" as far as general public awareness is concerned. This story is in no way related to the CERN problem.
As promised I am going to discuss "nearly" recent theoretical developments regarding an apparent "loophole" in quantum theory. Pardon the "interlude" into the realms of Science Fiction but that is just the way it is. It is an issue with which I have a personal interest (ie. SETI). I think that this is our best chance for communication with alien species in our generation. It has to be stated at the outset this feat cannot occur without some cooperative intelligent technological beings already at the remote end of this experiment. Unlike other experiments this requires an active participation at both ends before any communication becomes possible. With an understanding of the intrinsic design of the experiment means it is not possible to simply "snoop" on these communications as we currently do with our larger telescopes.
Regarding actual experiments... a great deal of early experimental work on this problem was done by researchers named D Salart and N Gisin in Geneva Switzerland using a pair of glass fibers to conduct each member of the entangled BBO downconverted photon couplets created in Geneva to the separate targets in Satigny and Jeussy (click on image below). It is a long story and these two workers did arrive at their own conclusions regarding the series of experiments which more or less concluded in 2008. See this article...Physicists spooked by faster-than-light information transfer
Technical paper...Space-like Separation in a Bell Test assuming Gravitationally Induced Collapses D. Salart, A. Baas, J.A.W. van Houwelingen, N. Gisin, and H. Zbinden
Location of experiment is shown here...
By manipulating the end of one of the beams it was thought that signals may be sent instantly to the remote end of the other beam. The beams could have been sent through "free space" or they could be sent through glass fibers (as they were in this case)... it does not matter. It is important to realize that the beams themselves carry no serial information... the signal is "sent" via quantum entanglement between paired photons continuously arriving at the two remote ends of the beam.... that is the only place a signal actually exists. As background N Gisin has already used glass fibers to connect sections of the banking system in Switzerland with the first truly quantum secured information network in the world. This experiment mentioned links instantly to different locations which are in theory separated by many light years. What is clear is the "channel(s)" must already exist before any communication starts and this would generally mean that a communications port must exist at both ends and that the light signals have reached both ends of the path under a mutual understanding existing between these two communicating planets... this is the main problem since it would take a great deal of time for the initial channel to be set up as equipment and one of a pair of entangled beams are sent to the remote ends of the network. It is clear that this technology could be used to allow an ongoing telepresence on the system sent to the remote end and so the vehicles sent to remote solar systems can be surrogately "permanent manned" through this property of instantaneous communication.
The best chance of this communication channel being used today is in discovering an existing open channel that we can use... left "here" by some well meaning and friendly aliens. By friendly I mean they have been here before (at least in telepresence) and noted our emerging technology and have taken a decision to communicate with us rather than annihilate us. If they wanted to annihilate us as a species they would have easily done that a long time ago using a targeted "Andromeda Strain" like "solution". What I mean by "here" is an active communications port left somewhere inside of our solar system. What I mean by this is something like the large black monolith TMA-1 in 2001 A Space Odyssey... this object would point to the portal or indeed be the communications port itself.
Naturally no exotic wormhole journey is envisioned here but the experiment may have far reaching consequences for our culture if such an artifact were to be found. This real experiment has been verified but the conclusions regarding the transfer of information end to end has been disputed owing to some fundamental theoretical arguments. The complexity of this argument is formidable and Gisin has said as much himself and can lead to technical confusion... it is overly complicated by Mathematical Theory to the extent that it muddies the overriding experimental facts. Initially the arguments for instantaneous communication could be easily dismissed in a time when our technology was unable to create single entangled photons to order or unable to clone the original photons into more copies. The efficiency was one photon pair per 1012
photons and no copies could be made. Currently "swarms" of 8 entangled cloned photons are possible and entanglement can be made to order from newly invented technical devices spawning a pair of entangled downconverted photons from a single higher energy photon --- all of them either a perfect copy or a connected orthogonal copy of the original. Nowadays the objections to this experiment has become more technical regarding the possibility of "hidden variables" (the intervention of the mind or some other "prediction" events causing the coordination) and potential reordering of the two state data in the streams in a non-covariant way (scrambling of the superluminal information). Truly random streams of qubits have been sent with information and this random stream received and verified at the remote end. A speed of over 100,000 times the speed of light was verified (if the separation distance was used as the measure)... still objections of unconscious interference and inconsistency with the Theory of Relativity have been made.
Other experiments appear to show similar results without the end to end connectivity but supporting the validity of truly visible and measurable quantum information...Physicists produce quantum-entangled imagesResearchers Demonstrate 'Quantum Data Buffering' SchemeFirst observation of 8 entangled photons smash entangled record.Two crystals linked by quantum physics with N Gisin
... this last reference is in relation to large scale whole crystal entanglement for the purpose of building a "quantum repeater".
I stress the practical experiment has been done and the data transfer confirmed by way of some little understood channel not part of our current spacetime... this being the channel used for quantum entanglement and is separate from the other channels we currently use for communication which transfer energy and sometimes matter (such as light or snail mail respectively). This channel can only transfer entanglement so it affects the mutual configurations of the entangled entities at both ends. It was thought that the fact that the channel may only be used to communicate using streams of uncoordinated data and would be entirely stochastic. The process has been given a name ... Quantum Pseudo-telepathy
. Some objections needed to be addressed and Nicolas Gisin has addressed them in a rapid communication linked below.
So... Is faster than Light Communication Possible?…. The answer is apparently yes!
The first three papers below deal with three papers that N Gisin has published recently. The last paper is one onThe Strong Free Will Theorem
. The second and third paper involve the theory of quantum non-locality and measurements transmitting information faster than the speed of light (hundreds of thousands of times the speed of light). The second paper… Quantum Nonlocality: How Does Nature Do It? - N Gisin
- Science 4 December 2009:Vol. 326 no. 5958 pp. 1357-1358 DOI: 10.1126/science.1182103 (I can supply a copy if needed) ... agrees that it should not be possible to send information FTL but operationally this does indeed happen. The conventional answer to this is the ordering of the information may remove any causality violation issues. An argument has been developed by others that involved The Strong Free Will Theorem - JH Conway S Kochen
. This showed that FTL signals should not possible.
The argument itself involved the idea of covariance of information under special relativity of the signal. It is clear that if covariance is to hold then the information will be not possible to transmit in the intended sequence globally and this overcomes the difficult issues involved (that is causality violation) --- that is the signal traveled FTL and deposited information before it has had time according to the propagation time of light and also of intelligent signals on it. It is a trivial problem for light carrying a signal since the light must arrive after it was sent encoded the right way. In the case of end to end entanglement where two dynamically encoded and entangled photons occur… end to end of the entangled photon stream (as in Gisin's setup at Geneva, Satigny, Jussey) the signal must arrive in a relativistic covariant way even though the atoms which measure the property on the photons respond instantly to the stream of information encoded at one end. That is if there is no shortcut around spacetime.
The way the experiment shows FTL in the sequences is through the choices the experimenter makes by way of free will to measure the signals. The possibility for the intervention of the experimenters mind (a kind of "hidden variable"). The particles, themselves, that convey the information end to end are suspected of not having free will of themselves and are therefore the result of the consequences of events arriving at those particles in that part of the universe along with the data stream that was instantly sent. There is no doubt that signals can arrive "early"... just that the information gleaned "should" be appropriately degraded. So instead of a "mindless" response to the data a hypothetical choice is actually exercised by particles receiving and collecting the information that appear to travel FTL and mixing in local parameters impinging on the instrument. The proposal is local variables must exist at that remote end as well (such as the conditions around the receiving apparatus) which involve local causality depending on phenomena there that will influence the measurement outcomes of the experiment. These free will "choices" made by the apparatus obscure the total outcome in such a way to change the order or reduce the fidelity of the information in the data sent through a local act of "free will" by the experimenter to the receiving apparatus (it is a heap of "you know what" but this question must be answered not only experimentally but mathematically).
So it may be a "plausible argument".
A strengthening of the experimental conditions seems to have removed the influence of a human mind acting in free will from this experiment by sending entirely random streams of data. This stream is collected at the other end and later compared with the stream that was sent. No human mind was involved so human free will was removed. Any "hidden variables" of this kind were removed yet the data sent and was received at many thousands of times the speed of light between the two end stations. A paper…Impossibility of covariant deterministic nonlocal hidden-variable extensions of quantum theory NGisin
(published 28/02/2011) PHYSICAL REVIEW A 83, 020102(R) (2011). The conclusion is this...
N Gisin wrote:We end this Rapid Communication with a few comments. First, our argument assumes a deterministic model, i.e., for any given λ, there is a unique pair of results, one on each side. For stochastic models, the situation is interesting [9,10] but goes far beyond the scope of this Rapid Communication. Next, our result emphasizes once again the extraordinary robustness of quantum theory against any conceivable change. This may explain why the founders of quantum theory could discover it based on the very sparse data available to them at the time: There was simply little alternative. Finally, one should mention that a way out of our entire argumentation is to assume the existence of one preferred universal reference frame which determines unequivocally one and only one time ordering for all events .
Note added. Recently, the results were discovered independently by Blood . (my emphasis)
This would be a "universal frame" of instantaneous availability of certain types of data everywhere there was a suitable entanglement, a special frame not according with covariant special relativity, in which there is a universal "now" despite the separation of observers and instruments, in which there is no causality violation. We see that the argument in [9
] above is countered by Gisin in [10
] in his paper… The Free Will Theorem, Stochastic Quantum Dynamics and True Becoming in Relativistic Quantum Physics - N Gisin
- 06/02/2010 and an emphasis of these conclusions is found in his latest paper Impossibility of covariant deterministic nonlocal hidden-variable extensions of quantum theory NGisin
28/02/2011 published PHYSICAL REVIEW A 83, 020102(R) (2011). So far Gisin's paper in PRA has survived all challenges to the contrary and may be considered the current interpretation, though it most probably sits very uneasily with Mathematicians and many Physicists alike (not me of course). I would point out this conclusion is the result of a practical experiment over 16 Kms rather than some esoteric maths argument.
Good Elf wrote:My personal favorite interpretation is the "signal" goes by way of one or more of the extra folded dimensions in our universe which never expanded at the expense of the current three spatial and one temporal dimension which may make our universe a very small size in those smaller dimensions... certain "features" of signaling may choose to take the shortest path between two points if those "vestigial" dimensions can be utilized. Immediately after the the big bang "went off" these vestigial dimensions never developed any further as the inflation (which still continues today) went into the three "lowest" dimensions plus time. This allows this entanglement by a universal shortcut (the entanglement of information ... not energy or particles). Another possibility (or same possibility said another way) is this is evidence for Cramer's Transactional Interpretation (upbeat version of Wheeler and Feynman's Absorber Theory... a precursor extension to Feynman's Quantum Electrodynamics -- a spinor version of the Path Integral Method) in which instantaneous entanglement in this special frame sends an offer wave and the entangled photon accepts this offer wave (a confirmation wave) along the shortened path instantly since no physical matter or even photons travel there only configuration information like a polarization may pass (it is known that entanglement is strongly linked to the idea of mutual orthogonal resonance like the separately oscillating arms of a tuning fork... one with the other and linked by some similarly short path in some sub or superspace)... energy and matter passes separately along "real spacetime" channels... in this special case only "information" is sent and may be noticed in our universe as particle "resonance" as a precursor to the absorption of an incoming photon. This suspected "resonance" may be linked to "zero point energy" which is the unresolved but permanent residual quantum energy of all particles in our universe... an energy that appears very difficult to tap but ultimately keeps our atoms from collapsing back into a black hole or reversing everything back to the "big bang"? If we choose to use particles (or photons) as "carriers" they must travel from point to point with their "packaged" information "bit" and constrained by the finite speed of light. No laws are broken other than assumptions about the basic nature of quantum information.
This avenue of investigation into the Absorber Theory is presently pursued by R.E. Kastner independently
of these investigations but seem highly suggestive of true instantaneous connections set up instantly that allow for the timely exchange of photons in our universe through these additional "vestigial dimensions".N Gisin Homepage