Perfectly Innocent wrote:

There are plenty of scientific papers and news reports touting
superluminal velocities and even negative transit times for pulses of
light propagating through atomic caesium vapor.

http://www.neci.nec.com/homepages/lw...er/paper39.pdf
http://www.neci.nec.com/homepages/lw...er/paper49.pdf

I wonder if this is all nonsensical hoopla based on the antiquated
wave theory of light or if there is a real, measurable
faster-than-light particle view of quantum mechanical tunneling going
on. If I understand Richard P. Feynman correctly, photons are always
particles; the wave nature of light only reveals itself in terms of
probabilities. All quantum mechanists know the rules of adding
amplitudes but I would like to know if something new about quantum
mechanical tunneling has been revealed. Are individual photons in
these experiments moving at velocities faster than light?

Answer:

The sheer mention of this result together with Einstein's theory of
special relativity and the principle of causality is a scam. Not a
single photon is moving faster than light.

The alleged generation of superluminal velocities without violating
causality is intentionally misleading physicists' hoopla and all the
media hype is pure distortion. The fact that the dramatic 60 ns
advance is only one fiftieth of the width of the pulse is a clear
indication of this.

If you were hoping to conceptualize how Einstein's special theory of
relativity might be false, then don't let these facts disappoint you.
It is possible to modify Einstein's special theory to allow for motion
faster than light.

http://www.everythingimportant.org/viewtopic.php?t=605
http://www.everythingimportant.org/r...multaneity.htm

Is there a real empirically confirmed theory of superluminal
velocities? No, not yet. But there is no evil in being able to
conceptualize such things.

Eugene Shubert

Suppose a particle is moving along in tandem with the group wave. SR
velocity addition applies to the particle, and the speed of the particle
wrt lab frame is

(v+w)/(1+vw/c^2)

and since for any velocity of the particle wrt the frame of any given
phase wave, the speed of the particle must always be less than c, then
according to the equation it will always be less than c wrt lab frame
also.

What we have in the cesium experiment though, is an apparent inability
to correlate the group wave to that of a particle moving in parallel to
it at the same velocity. If the group velocity exceeds c, then no
particle can move along in tandem with it. The interesting thing is,
that at c, the particle will traverse infinite lab frame distance in
zero time wrt its own frame, thus the group speed which is greater, per
above, requires that this group wave move backward in time wrt lab
frame.

However the group wave will not actually appear at the outlet before the
beam strikes the surface of the cesium cell, for obvious reasons, one of
which is that a shutter can be located at the entry point of the cell
that can shut off access of the photons to the cell after the group node
has already exited. Thus the beam will have never entered the cell to
create the group node that exited nonetheless. This is pure idiocy.

SR doesn't allow for group velocities greater than c, though it does
allow for transverse phase wave velocities greater than c. In the cesium
experiment you should note however that the group velocity is not
transverse, it is longitudinal.

SR has been proved by the experiment to be untenable.

Richard Perry