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The media have not reported (as far as I know) a beautiful swiss experiment

about the superluminal quantum *influence*. This experiment has tested the

s.c. *conspiracy* or *peaceful coexistence* between quantum mechanics and

special relativity and has shown that such an *influence* (spooky action -

or *passion*, or *fashion* - at a distance) acts with a velocity which is

greater than 10^6 C (one million times C).

Whether or not such an *influence* is actually carrying some kind of

information, or *is* itself the information (is quantum mechanics an

information theory?), or is nothing but a distant quantum state preparation,

or is supported by possible *preformed and non local* structures of quantum

objects, are still open questions.

The experiment. Two entangled photons are emitted (in Geneve), one directed

to a Franson interferometer (in the village of Bellevue), one directed to a

Franson interferometer (in the village of Bernex). The geometry (Geneve,

Bellevue, Bernex) is triangular and each side is about 10 kilometers long.

When both photons reach these interferometers a (second order) interference

pattern appears, violating Bell's inequalities and thus showing that *local*

hidden variables do not exist. This interference pattern means that the

dynamics of an entangled photon into the interferometer in Bellevue and the

dynamics of the other entangled photon into the interferometer in Bernex are

*identical*. Actually entangled photons behave *coherently* at very long

distances. This is called the nonlocality (or nonseparability) problem.

Nonlocality comes directly from: the superposition principle (entangled

photons states are superposed in a singlet state); the s.c. *collapse* (when

some *selective* or recordable measurement is performed) of the wavefunction

describing the entangled photons superposition; the indistinguishability of

the entangled particles; the wave-like nature of particles.

Now if we move, very fast, one interferometer (Bellevue) and-or the other

(Bernex) we must take into account the special relativity. These relative

movements can indeed lead to a tension between quantum mechanics and special

relativity, so that the interference pattern could breakdown. That is

because, due to the (relative) movements of interferometers, *each* of the

two natural reference frames (Bellevue interferometer, Bernex

interferometer) can realize that the local measurement takes place *before*

the distant one and can also think that the state of the distant photon is

knowable performing some local measurement (on the local photon). Of course

if we perform measurements in regions which are space-like separated (no

causal correlation) we lose even the lorentzian invariant way of determining

which measurement was carried out first, but the experiment Iım speaking

about does not require this assumption. (Whether or not operators localized

in space-like separate regions commute is an interesting question!).

In this context the term measurement means *collapse* (or sudden

decoherence) of the wavefunction describing both entangled photons

(singlet), hence a unique irreversible nonlocal process. This process is not

dependent on any time ordering of measurements, because it is based on the

superposition principle and on the indistinguishability of the entangled

particles. We can also say that while this process is not dependent on any

time ordering of measurements it could be linked to an absolute universal

order of succession: the Bohmian *quantum aether* or some other preferred

reference frame. So this quantum nonlocality could take us to a quantum

causality principle, based on that preferred universal (cosmic) reference

frame (and on the absolute time ordering of measurement).

Thus from quantum mechanics we get the following points: the measurements

can create events which are simultaneously correlated (even in space-like

separate regions); the time ordering of measurements is irrelevant; the

relativistic causality is not necessarily a rule; the superposition seems to

be the main principle and is based on the indistinguishability of entangled

particles; the (second order) interference pattern is predicted.

But from special relativity we get: the postulate which says that the laws

of physics have the same form in all inertial frames; the prediction which

says that in space-like separate regions causality does not exist (no

possible causal correlations); the postulate which says that the velocity of

light *in vacuo* is independent of the velocity of the source; the necessity

of some time ordering of measurements; the essentiality of the relativistic

causality; the interference pattern breakdown prediction.

Experimental results show no evidence for a breakdown of the interference

pattern. Is this a sharp violation of the relativity postulate which says

that laws have the same form in all inertial frames ? The answer is this:

actually the Hardy-Percival theorem has already shown that a quantum

*nonlocal* process needs a preferred lorentzian reference frame.

Experiments also show that the quantum *influence* velocity exceeds 10^6 C.

Is this almost infinite speed in conflict with relativity which says that

the front velocity of a signal cannot be greater than C, and the group

velocity of a signal can be greater than C (but the peak cannot overtake the

front) ? Is this almost infinite velocity in conflict with the relativistic

causality which says that the source cannot cause effects outside its

forward light cone ? Answers to these questions depend on the meaning of the

terms *influence* and *collapse* and also on the possible *preformed and non

local* structures of those entangled particles.

Anyway it is largely accepted that if a *perfect quantum cloning machine*

could create *identical* particles this machine could easily violate

Heisenberg's (uncertainty) principle. The perfect knowledge of all

observables (measuring many particles which are identical) could then allow

an effective superluminal quantum signaling. But that machine unfortunately

can not exist (there is the *no quantum cloning* theorem). So the

*conspiracy* is back again ! A new old fashioned principle could be on the

way (the quantum mechanics and relativity complementarity).

Since things are, at present time, so subtle, what about the very beginning

of the story when - as Boltzmann once said, commenting on the entropy law -

the universe was in a very unlikely condition ?

scerir

swiss experiment

http://xxx.lanl.gov/abs/quant-ph/0002031

http://xxx.lanl.gov/abs/quant-ph/9704038

particle's infinite (or superluminal) tails

http://xxx.lanl.gov/abs/quant-ph/9809030

http://xxx.lanl.gov/abs/quant-ph/0003075

is quantum mechanics nothing but an information theory?

http://xxx.lanl.gov/abs/quant-ph/9806047

**Next message:**GBurch1@aol.com: "Re: Extropian principles - #5 - lets take a look"**Previous message:**Chuck Kuecker: "Re: Project Orion"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]

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