Empirically Confirmed Superluminal Velocities?
Perfectly Innocent
superluminal velocities and even negative transit times for pulses of
light propagating through atomic caesium vapor.
http://www.neci.nec.com/homepages/lwan/paper/paper39.pdf
http://www.neci.nec.com/homepages/lwan/paper/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/relativity/simultaneity.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
Richard
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
Sam Wormley
>
> 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.
>
And yet Nature's speed limit is not locally violated for mass in
motion, propagation of electromagnetic radiation or communication
of information.
Dirk Van de moortel
"Perfectly Innocent" <perfectl...@as-if.com> wrote in message news:c45b45b3.03101...@posting.google.com...
> 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/lwan/paper/paper39.pdf
> http://www.neci.nec.com/homepages/lwan/paper/paper49.pdf
See today's reply on a similar thread in sci.physics:
http://groups.google.com/groups?&threadm=5zjkb.821525$uu5.145166@sccrnsc04
Dirk Vdm
Mathew Orman
"Dirk Van de moortel" <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote
in message news:fPAkb.89991$gs2.4...@phobos.telenet-ops.be...
The Java applet is false
it shows several component waves traveling with different speed,
the top is the slowest and the bottom the fastest.
Also it is irrelevant to the subject of single pulse transient.
Bologna mathematicians are not able to show such applets for the single
gaussian pulse transient!
Mathematical bologna!
Sincerely,
Mathew Orman
www.ultra-faster-than-light.com
www.radio-faster-than-light.com
holog
holog
Perfectly Innocent wrote:
Why do people think if you go faster than light you can immediately go
back in time?
i.e. if you could travel at twice the speed of light it would still take
two years to get to alpha centuri, right?
holog
pstowe...@ix.netcom.com
Yup...
The problem is definitions of SR as to 'event sequencing'. LRT does
not have this problem since it does NOT have a defined
synchronization process that sets time as a pseudo-distance...
Paul Stowe
Richard
Exactly.
Richard Perry
EL
wrote in message news:<3F930377...@yahoo.com>...
> pstowe{Blues}@ix.netcom.com wrote:
> >
> > Yup...
> >
> > The problem is definitions of SR as to 'event sequencing'. LRT does
> > not have this problem since it does NOT have a defined
> > synchronization process that sets time as a pseudo-distance...
> >
> > Paul Stowe
>
> Exactly.
>
> Richard Perry
[EL]
Hi Richard and Paul.
Please help me on this because I really do not know what experiment
was being conducted when that discovery was made.
If it was not a discovery that was discovered during conducting
another experiment, then this is a fabricated setup with intentional
end results in mind and a complex rig to hide a glitch.
My very clear question is {What was the original research researching
when the alleged superluminal propagation was allegedly found out?}
Naturally, they never saw any results on any oscilloscope because a
scan line is constant time dependant and it is rather obscenely
ridiculous to assume an output showing before an input.
Therefore we expect them to tell us more numerical details on the
measurements without any hoopla of equations because until I see the
detailed circuit being used I doubt that they have measured and wave
propagation at all.
Those who know about electronics, know very well that a continuous
wave may be displayed by synchronising the sweep rate at an integer
multiple or part of the wave frequency otherwise the wave shape shall
slip on the screen.
However, they talk on something much more demanding because they talk
about a single pulse that demands a trigger to catch it.
Now if the input was not the trigger then they never caught anything
but if the input was the trigger then it is impossible to catch
anything before such an event.
This excludes all the negative time bull shit of course.
So we are left a sixty millimetre tube full of caesium gas and a LASER
pumped pulse as an input and a trigger that is supposed to traverse
the tube in 0.2 nanoseconds IN VACUUM.
If the signal was delayed by 62 ns in caesium then how can that be
faster than light?
To capture detailed data of a full pulse wave-shape within 0.2
nanoseconds is a formidable task and I demand the release of the
electronic parts that accomplished that feat if they dare, but I am
certain that it is all a fabrication.
They were not working on something else and made a discovery, but the
whole scam was planned ahead before any rig was constructed, right?
;)
Regards.
EL
Bilge
>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.
Neither.
>If I understand Richard P. Feynman correctly, photons are always
>particles; the wave nature of light only reveals itself in terms of
>probabilities.
Right.
> 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.
Yeah. That it doesn't make sense to think of quantum mechanics in the
same way one thinks of classical mechanics.
> Are individual photons in these experiments moving
>at velocities faster than light?
That doesn't really make much sense quantum mechanically.
>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.
Whatever.
>The alleged generation of superluminal velocities without violating
>causality is intentionally misleading physicists' hoopla and all the
>media hype is pure distortion.
Don't read the media hype.
>The fact that the dramatic 60 ns advance is only one fiftieth of
>the width of the pulse is a clear indication of this.
The fact that you're looking at a pulse means you aren't looking
at photons. However, I don't really feel like explaining it in
detail, as I'm sure it won't matter.
>If you were hoping to conceptualize how Einstein's special theory of
>relativity might be false, then don't let these facts disappoint you.
The "facts" you've mentioned don't really say much about it
one way or the other.
>It is possible to modify Einstein's special theory to allow for motion
>faster than light.
Sure, if you give light a mass. Then, a photon is just like any other
massive particle.
Richard
Who knows? What I do know is that upon reflection, SR is incompatible
with any superluminal speed, even of a non-thing. Let's apply again the
formula
(v+w)/(1 + vw/c^2)
Now let's take the FOR of some blue phase wave. From this FOR the red
phase wave is propagating at less than c, regardless of dispersion.
Now along the path there are nodes formed by the addition of these phase
waves, and these nodes can supposedly have a velocity greater than c wrt
lab frame. If however the node is propagating slower than one phase wave
wrt the other, then it is traveling at less than c wrt the phase waves
themselves, and thus by the above equation must also be traveling at
less than c wrt lab frame. Thus even a group velocity cannot exceed c
wrt lab frame.
Now as I see it, a group velocity was measured at greater than c, and
thus, in contrast to the Fizeau near fit, the relativistic velocity
addition equation fails in this current experiment. Not only that, but
the whole of special relativity has been proved false.
Moreover I have considered again the problem of a flashlight beam from a
rotating flashlight, regardless of the observed speed of the 'spot' on
surrounding reflectors, it too is constrained to less than c within SR.
If for instance the spot is moving at less than c wrt some point in
motion wrt the background, then it must, by the equation above, also be
moving at less than c wrt the background. Thus the disproof of SR is as
old as the rotating flashlight gedanken.
Richard Perry
http://www.cswnet.com/~rper
Electromagnetism: First Principles
(which is indirectly, another disproof of SR)
Paul Cardinale
Paul Cardinale
[snip]
>
> Who knows? What I do know is that upon reflection, SR is incompatible
> with any superluminal speed, even of a non-thing.
Wrong. As always. The speed limit of c in SR applies to matter,
energy, and information. The limit does not apply to interference
patterns, shadows, projections, and cuts.
Paul Cardinale
EL
[EL]
Hahaha
Dear Richard, I was not concerned about SR at this moment as I am
aware of Prf. Lorentz efforts to create a concept of a varying time
dimension, which I strongly rebuke.
I was very specific in my inquiry concerning the activity of that
research team before announcing superluminal measurements. You just
confirmed to me that there was no other research going on while an
anomaly popped up.
The whole hardware setup was constructed to make believe that there is
a superluminal propagation of electromagnetic waves at any cost.
I am aware of equipment from Fairchild and others, which electronic IC
manufacturers use to determine the slew rate and signal delay between
input pins and output pins.
In fact Integrated Circuits are much slower than high power discrete
transistors, and the fastest of all are switches and choppers. To give
you an example on NPN type switching transistors,
a 10 mA to 1 A range current (collector) has
20 ns <= t_on <= 70 ns,
which is the turn-on time, and
32 ns <= t_off <= 285 ns,
This means an obvious meaning, which is the fact that a trigger signal
MUST TAKE TIME to reach the circuit that captures the output of the
pulse for comparison.
Therefore, a 0.2 ns time window is too narrow for any real time
measurement, so what they must have done is to tune the circuit to
resonance such that they catch an Nth pulse in a train of pulses and
not THE pulse that caused the trigger.
This means that fractional delays may accumulate slipping the output
backwards until it seems as if it was ahead of the input. :)
A serious and professional wave plumber knows that for this type of
measurement a trigger technique is inapplicable.
What is applicable is a matched pair of lines that have perfectly
matched components on each side and that carry the signals to a
comparator of internally matched components as well. That comparator
can measure the difference in the gained potential difference as a
function of phase shifting. This technique admits a delay but which is
matched as a pair and cancels out. However, the phase shift in that
case could be due to any number of cycles in between and does not
measure the number of cycles in between to account for the total delay
between the incident wave at the starting of the caesium tube and the
ending of the caesium tube.
This restricts experiments to law frequency waves to guarantee that a
phase shift is that of a single wave, which is based on our empirical
knowledge that the wave must travel at less than [c] in caesium or any
medium other than vacuum.
So I was not surprised to read that they obtained a delay of 62 ns
inside the tube.
I tried to follow the equations but I stopped at being disgusted from
the relentless attempts to fit the results to a hypothesis.
Any way, thank you for your response Richard.
<sigh>
EL
Mark Palenik
"Paul Cardinale" <pcard...@volcanomail.com> wrote in message
news:64050551.03102...@posting.google.com...
Very true. That would be like denying the existence of space-like
geodesics, which obviously do exist. We just can't have real "things"
moving along them.
SR has no problem with, for example, someone spinning a flashlight around in
the center of a cyllindrical room with a radius of 1 light year at one
revolution per second.
holog
Paul Cardinale wrote:
I think the trick here is the barrier they use it to alter the wave form
so the peak of the wave is advanced. Then the detector detects it sooner
than if it was not manipulated. i.e. chart an x any y graph and run a
sine wave through so a new wave starts at zero, continue the wave in the
negative direction also. Now make a sine wave with a longer wavelength,
but only on the right side. A detector would detect the longer wave first.
holog
Starblade Darksquall
The stars really really far from me all go faster than the speed of
light when I spin around in circles because my spinning reference
frame is just as good as anybody else's.
(...Starblade Riven Darksquall...)
Richard
EL wrote:
> This restricts experiments to law frequency waves to guarantee that a
> phase shift is that of a single wave, which is based on our empirical
> knowledge that the wave must travel at less than [c] in caesium or any
> medium other than vacuum.
>
> So I was not surprised to read that they obtained a delay of 62 ns
> inside the tube.
>
> I tried to follow the equations but I stopped at being disgusted from
> the relentless attempts to fit the results to a hypothesis.
>
> Any way, thank you for your response Richard.
>
> <sigh>
>
> EL
You are probably correct EL, but I don't believe that it's that
complicated. All you need to measure is the dispersion, from there you
can calculate the group velocity, as demonstrated nicely by this applet
http://gregegan.customer.netspace.net.au/APPLETS/20/20.html
According to the link on that page, the group velocity is given by
v_g = c / (n(v) + vdn(v)/dv)
and can be greater than c.
OTOH, I have a problem with their explanation of why this doesn't
contradict SR. Let's suppose that wrt some given wave the speed of the
group wave is less than c. Thus wrt that wave a massive particle may be
moving in tandem with that group wave. According to SR velocity
addition, that particle is thus traveling at less than c wrt lab frame
as well, and thus the group wave is also moving at less than c wrt lab
frame because it is perpetually adjacent to the particle, which is
simply an invariant condition. Thus, according to SR and simple logic, a
group wave cannot move at greater than c wrt lab frame, 'unless' it is
also moving at greater than c wrt any single phase wave involved in the
group wave propagation. Thus the equation above cannot be
relativistically correct. OTOH, there is no doubt that the group wave
can indeed empirically surpass c, so that if SR is valid, then there is
a speed of the group wave that cannot be accompanied by the moving
particle. Once again this can only result in the group wave propagating
at greater than c wrt 'all' frames at the very instant that it exceeds c
wrt any one frame.
OTOH, even if the measurement in this case was improperly obtained,
there is no ambiguity in the similarity of group wave propagation and
the rotating flashlight beam-spot velocity, which latter has been
directly measured at greater than c. IOW, the same argument applies to
both experiments.
Let's look at it like this:
If the spot is moving at c + 1 m/s wrt lab frame, then what speed will
the spot appear to be moving wrt an observer that is moving at 1m/s wrt
lab frame in the same direction as the spot. Now in order to allow both
observers to actually measure the speed of the spot, we need only allow
for an omnidirectional reflection of the photons from the target. The
moving observer will measure a definite speed of the spot wrt himself,
do you doubt that? According to SR, what will that speed be? Who
knows, huh? SR can't even deal with the problem, and thus has zero
chance of providing a true description of relative motions, eh?
BTW, this is a very doable experiment. In fact I'm surprised, even
shocked, that it hasn't been done.
It is easy to say, "Well, the SR speed limit applies only to massive
particles and information", it is quite another to prove that statement,
and to be quite honest, in retrospect, I've not only never seen such a
proof, I've never even seen a citation of such a proof. This seems to be
one of those, "well it sounds reasonable so it must be correct" laws.
Never once questioned as it is being questioned now. And it would seem
that it was very easy to discredit it all this time. Hmmm...Sometimes I
wonder if man will ever actually be even half of what believes himself
to be:)
Deal with that EL, and leave your condescending tone out of it, I didn't
buy. Superiority isn't a matter of one's technobabble cache'.
'sigh'
Richard Perry
Starblade Darksquall
BTW, SR alone doesn't limit things to light speed. However, if we add
the restriction that there are no causal loops, IE, instances in which
a proceeds b, b proceeds c, and c proceeds a, then it does. However,
if Lorentz Symmetry was broken, like a spontaneously broken symmetry,
then this wouldn't necessarily be true.
(...Starblade Riven Darksquall...)
holog
Starblade Darksquall wrote:
correct, what there doing is manipulating data transfer speeds.
see next post-it has become a concern to control light data to improve
efficiency.
holog
Robert J. Kolker
Starblade Darksquall wrote:
> I know what goes faster than the speed of light.
>
> The stars really really far from me all go faster than the speed of
> light when I spin around in circles because my spinning reference
> frame is just as good as anybody else's.
You are not talking about the motion of the stars. You are talking about
changing coordinate systems.
Bob Kolker
holog
Robert J. Kolker wrote:
I thought he was just dizzy.
holog
Sam Wormley
>
> I thought he was just dizzy.
>
EL
[EL]
Excuse me Paul Cardinale sir, but I am not used to read blabbering in
your posts, so are you fine!
If you are talking about another [c] else than the one that Maxwell
calculated from vacuum's permeability and permittivity then you should
let us know first but if it is the same thing as that then it is a
constant speed of electromagnetic waves' propagation in vacuum and it
is a scalar and it is a constant by definition that describes the
SPEED OF EM WAVES in vacuum.
It is not up to SR or you to decide what a constant by definition is
and we are not waiting for your consent either.
So it is not SR that limits "things" to [c] and it is definitely not
up to SR to assume authority to twist arbitrated standards.
Air-force jets do occasionally break the sound speed barrier because
sound has such a barrier speed limit and that is why it is breakable.
Similarly, electromagnetic waves do have a scalar speed in vacuum and
it is [c].
This means that it is forbidden for any electromagnetic field of any
topological form to propagate changes of state in vacuum at faster
than [c], so let us not play with words concerning delta-opposite
velocities, shadows, projections and patterns because that is
irrelevant and nonsensical as an argument for FASTER THAN LIGHT or you
would be comparing between oranges blue cheese cylindrical sectors.
As for your claim on matter, energy and information to be limited to
[c] I can hardly see how is that physics!
We have confidence that [c] is the maximal OBSERVABLE scalar speed of
electromagnetic wave's propagation in vacuum because we have
confidence that vacuum is the most primordial continuum of space.
Exceeding that speed by particles is to tear the fabric of that
continuum rendering it discontinuous, which is neither tenable nor
logically acceptable. Information in its purest form is a set of coded
time-dependant or space-dependant variations of state and information
itself does not propagate but the carrier of that information is what
propagates so there is no sense in claiming that SR limits what is
irrelevant to begin with.
I am sorry to have found your attack on Richard as mere emotional
blabbering.
EL
Bill Hobba
> Perfectly Innocent:
>
> >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.
What do you mean by 'faster than light'? SR does not forbid considering
things happening faster than light (eg the sweep of a torch over clouds) but
the sending of information faster then light is not what is allowed. The
effects your alluded to can not be used to send information faster than
light.
Thanks
Bill
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Starblade Darksquall
Motion is relative. They are not moving in their own reference frame,
but they are in mine.
(...Starblade Riven Darksquall...)
Starblade Darksquall
> holog wrote:
> >
> > I thought he was just dizzy.
> >
> She
Thanks.
I really shouldn't spin around so much all the time.
(...Starblade Riven Darksquall...)
EL
> You are probably correct EL, but I don't believe that it's that
> complicated. All you need to measure is the dispersion, from there you
> can calculate the group velocity, as demonstrated nicely by this applet
>
> http://gregegan.customer.netspace.net.au/APPLETS/20/20.html
[EL]
Ah! The applet. :)
It is quite an amusing view, BUT.
Let us analyze that applet to find out how tricky wave mechanics can
be. :)
Firstly, that applet is simply a dynamic graph.
So let us assign some physical meanings to it before we proceed.
The horizontal axis should be definitely TIME.
The vertical axis could be the amplitude of differently offseted
waves.
This is rather very easy to demonstrate on a multi-channel
oscilloscope.
Since our screen image is a raster then the horizontal scan
time-window must be a single finite value.
Now let us assume that that oscilloscope's screen is subdivided
horizontally to 20 equal divisions.
We now lock our time-window onto twenty cycles of the highest
frequency displayed.
If it was for example 100MHz then each cycle takes 10 ns and we need a
horizontal sweep time of 200 ns.
That highest frequency must appear stationary on the scope's screen.
The applet shows a group of waves slipping backwards, which means that
they are slower than the reference frequency and the wavelengths are
not integer multiples of that wave length.
So we have a group of waves propagating at the same speed in the same
homogenous and isotropic medium but they have different frequencies
and they superimpose.
The group phase amplitude then is the sum of all superimposed phases
at any time. Therefore at any point in time we have a summed wave
propagating at [c] and the modulation is static over space while
changing over time.
Out of synch waves may slip backwards or forward depending on the sign
of the frequency delta with respect to the time-window of the
oscilloscope.
We chose for our example a 5 MHz reference frequency for the
oscilloscope and we choose our group to be based on a reference wave
frequency of 100 MHz and a band width less than 5MHz such that all
other group waves take frequencies less than 100 MHz but not less than
[95 MHz + epsilon].
This guaranties that the slipping effect is distributed over a single
division and is moving backwards (left side of screen).
The resulting interference-modulated wave, however, may be a new
frequency and we find Modulo 5 of that frequency to know the direction
of the slip of the resulting wave. If it was between .1 to 2.4 it
slips forward and if it was between 2.6 and to 4.9 it slips backwards.
The slipping speed is directly proportional to the delta of the modulo
and the horizontal scan frequency and it has absolutely nothing to do
with wave propagation time.
So this should take care of the fancy applet that means shit nothing
relevant to the being claimed hoopla.
>
> According to the link on that page, the group velocity is given by
>
> v_g = c / (n(v) + vdn(v)/dv)
>
> and can be greater than c.
[EL]
What velocity is that v?
If it was the modulation frequency I fail to relate propagating it at
any other velocity than [c] in vacuum or less in caesium.
How in hell do they ambitiously wish to make us believe that a
modulation result at time [T] can appear forward at time [T- t]? All
interfering waves at any moment has a finite superposition and at the
next time event has another superposition that follows the first at
the same space coordinates while the previous one propagates at [c]
forward in space.
We either monitor space from an inertial frame and observe changes to
that locked space of time or we monitor time from a moving frame such
that we lock time [freeze time] and inspect a paper tape graph record
of changing space.
Doing both concurrently is reckless and irresponsible child's play.
>
> OTOH, I have a problem with their explanation of why this doesn't
> contradict SR. Let's suppose that wrt some given wave the speed of the
> group wave is less than c. Thus wrt that wave a massive particle may be
> moving in tandem with that group wave. According to SR velocity
> addition, that particle is thus traveling at less than c wrt lab frame
> as well, and thus the group wave is also moving at less than c wrt lab
> frame because it is perpetually adjacent to the particle, which is
> simply an invariant condition. Thus, according to SR and simple logic, a
> group wave cannot move at greater than c wrt lab frame, 'unless' it is
> also moving at greater than c wrt any single phase wave involved in the
> group wave propagation. Thus the equation above cannot be
> relativistically correct.
[EL]
The equation above is meaningless because I have no freaking idea how
they fill in the values of the variables.
That hoopla does not shake a hair.
Group velocity is an Oxymoron from scratch because there are no
different wave velocities in one and the same homogenous and isotropic
medium.
Any phase velocity expressed in distance over time is zero because a
phase change takes place at a fixed coordinate while the invariant
phase-state is what propagates space over time.
Therefore wave velocity in [L/T] dimensions is the same as the phase
velocity in [L/T] dimensions.
It is the phase rate of change in [L=0 /T] (we call it the Slew Rate)
that is erroneously labelled as a velocity.
It is in units of wave Amplitude/Time, like volts per second.
>OTOH, there is no doubt that the group wave
> can indeed empirically surpass c,
[EL]
Objection, because I have amply demonstrated that that is impossible
too.
>so that if SR is valid, then there is
> a speed of the group wave that cannot be accompanied by the moving
> particle. Once again this can only result in the group wave propagating
> at greater than c wrt 'all' frames at the very instant that it exceeds c
> wrt any one frame.
[EL]
I am not a fan of SR either but c is a scalar constant of vacuum, and
we should never argue a constant by definition.
What is the meaning of group velocity!
Tow inertially locked light sources radiating expanding spherical
wavefronts must have the spherical shells approaching each other at 2c
by simple arithmetic. However, each sphere's radius must be increasing
length over time at [c].
I also give no flying monkey's fart to Einstein's observers and twins.
<snip>
>
> It is easy to say, "Well, the SR speed limit applies only to massive
> particles and information", it is quite another to prove that statement,
> and to be quite honest, in retrospect, I've not only never seen such a
> proof, I've never even seen a citation of such a proof. This seems to be
> one of those, "well it sounds reasonable so it must be correct" laws.
> Never once questioned as it is being questioned now. And it would seem
> that it was very easy to discredit it all this time. Hmmm...Sometimes I
> wonder if man will ever actually be even half of what believes himself
> to be:)
>
> Deal with that EL, and leave your condescending tone out of it, I didn't
> buy. Superiority isn't a matter of one's technobabble cache'.
>
> 'sigh'
>
> Richard Perry
[EL]
SR has nothing to do with asserting the fact that electromagnetic
waves propagate at c in vacuum.
You are giving Albert the credits of Maxwell by doing so.
There is nothing faster than light to accelerate anything faster than
light or are we going to violate the fact that energy may not be
created or destroyed now?
If you are driving a truck with speed limit 200 Km/h you may catch up
with a Fiat and give it a push and accelerate it to death, but when
you are in a Fiat how you, can catch up with a corvette zapping by at
180 km/h?
To apply a force to a particle you need to catch up with the particle
first and then push.
Nothing can be accelerated to more than [c] because [c] itself cannot
catch up with [c].
EL
Paul Cardinale
> Richard <no_mail...@yahoo.com> wrote in message news:<3F948703...@yahoo.com>...
>
> > You are probably correct EL, but I don't believe that it's that
> > complicated. All you need to measure is the dispersion, from there you
> > can calculate the group velocity, as demonstrated nicely by this applet
> >
> > http://gregegan.customer.netspace.net.au/APPLETS/20/20.html
>
> [EL]
> Ah! The applet. :)
> It is quite an amusing view, BUT.
> Let us analyze that applet to find out how tricky wave mechanics can
> be. :)
> Firstly, that applet is simply a dynamic graph.
> So let us assign some physical meanings to it before we proceed.
> The horizontal axis should be definitely TIME.
BZZZZZT!
Paul Cardinale
Sure. From a non-inertial frame of reference, you can observe massive
objects traveling faster than c. So?
Paul Cardinale
> EL wrote:
>
> > This restricts experiments to law frequency waves to guarantee that a
> > phase shift is that of a single wave, which is based on our empirical
> > knowledge that the wave must travel at less than [c] in caesium or any
> > medium other than vacuum.
> >
> > So I was not surprised to read that they obtained a delay of 62 ns
> > inside the tube.
> >
> > I tried to follow the equations but I stopped at being disgusted from
> > the relentless attempts to fit the results to a hypothesis.
> >
> > Any way, thank you for your response Richard.
> >
> > <sigh>
> >
> > EL
>
> You are probably correct EL, but I don't believe that it's that
> complicated. All you need to measure is the dispersion, from there you
> can calculate the group velocity, as demonstrated nicely by this applet
>
> http://gregegan.customer.netspace.net.au/APPLETS/20/20.html
>
> According to the link on that page, the group velocity is given by
>
> v_g = c / (n(v) + vdn(v)/dv)
>
> and can be greater than c.
>
> OTOH, I have a problem with their explanation of why this doesn't
> contradict SR. Let's suppose that wrt some given wave the speed of the
> group wave is less than c.
That supposition contradicts SR. Thus the richard perry has assumed his conclusion.
EL
Farted after a heavy meal and produced a congested sound
in message news:<64050551.03102...@posting.google.com>...
> BZZZZZT!
[EL]
Ah!
I see that your knowledge is shrinking and your power of argumentation
have been reduced to what a fly can produce passing by an ear.
Good.
Then we have one less asshole cancelled from the list of the credible
scientists.
Bye. :)
EL
EL
Ah! The applet. :)
It is quite an amusing view, BUT.
Let us analyze that applet to find out how tricky wave mechanics can
be. :)
Firstly, that applet is simply a dynamic graph.
So let us assign some physical meanings to it before we proceed.
The horizontal axis should be definitely TIME.
>
> According to the link on that page, the group velocity is given by
>
> v_g = c / (n(v) + vdn(v)/dv)
>
> and can be greater than c.
[EL]
What velocity is that v?
If it was the modulation frequency I fail to relate propagating it at
any other velocity than [c] in vacuum or less in caesium.
How in hell do they ambitiously wish to make us believe that a
modulation result at time [T] can appear forward at time [T- t]? All
interfering waves at any moment has a finite superposition and at the
next time event has another superposition that follows the first at
the same space coordinates while the previous one propagates at [c]
forward in space.
We either monitor space from an inertial frame and observe changes to
that locked space of time or we monitor time from a moving frame such
that we lock time [freeze time] and inspect a paper tape graph record
of changing space.
Doing both concurrently is reckless and irresponsible child's play.
>
> OTOH, I have a problem with their explanation of why this doesn't
> contradict SR. Let's suppose that wrt some given wave the speed of the
> group wave is less than c. Thus wrt that wave a massive particle may be
> moving in tandem with that group wave. According to SR velocity
> addition, that particle is thus traveling at less than c wrt lab frame
> as well, and thus the group wave is also moving at less than c wrt lab
> frame because it is perpetually adjacent to the particle, which is
> simply an invariant condition. Thus, according to SR and simple logic, a
> group wave cannot move at greater than c wrt lab frame, 'unless' it is
> also moving at greater than c wrt any single phase wave involved in the
> group wave propagation. Thus the equation above cannot be
> relativistically correct.
[EL]
The equation above is meaningless because I have no freaking idea how
they fill in the values of the variables.
That hoopla does not shake a hair.
Group velocity is an Oxymoron from scratch because there are no
different wave velocities in one and the same homogenous and isotropic
medium.
Any phase velocity expressed in distance over time is zero because a
phase change takes place at a fixed coordinate while the invariant
phase-state is what propagates space over time.
Therefore wave velocity in [L/T] dimensions is the same as the phase
velocity in [L/T] dimensions.
It is the phase rate of change in [L=0 /T] (we call it the Slew Rate)
that is erroneously labelled as a velocity.
It is in units of wave Amplitude/Time, like volts per second.
>OTOH, there is no doubt that the group wave
> can indeed empirically surpass c,
[EL]
Objection, because I have amply demonstrated that that is impossible
too.
>so that if SR is valid, then there is
> a speed of the group wave that cannot be accompanied by the moving
> particle. Once again this can only result in the group wave propagating
> at greater than c wrt 'all' frames at the very instant that it exceeds c
> wrt any one frame.
[EL]
I am not a fan of SR either but c is a scalar constant of vacuum, and
we should never argue a constant by definition.
What is the meaning of group velocity!
Tow inertially locked light sources radiating expanding spherical
wavefronts must have the spherical shells approaching each other at 2c
by simple arithmetic. However, each sphere's radius must be increasing
length over time at [c].
I also give no flying monkey's fart to Einstein's observers and twins.
<snip>
>
> It is easy to say, "Well, the SR speed limit applies only to massive
> particles and information", it is quite another to prove that statement,
> and to be quite honest, in retrospect, I've not only never seen such a
> proof, I've never even seen a citation of such a proof. This seems to be
> one of those, "well it sounds reasonable so it must be correct" laws.
> Never once questioned as it is being questioned now. And it would seem
> that it was very easy to discredit it all this time. Hmmm...Sometimes I
> wonder if man will ever actually be even half of what believes himself
> to be:)
>
> Deal with that EL, and leave your condescending tone out of it, I didn't
> buy. Superiority isn't a matter of one's technobabble cache'.
>
> 'sigh'
>
> Richard Perry
[EL]
Richard
My apologies EL, apparently I misread your reply. I mistook you for
the.... LOL, now I'm at a loss for a word to apply to them, I don't
regard them as enemies, even if that is functionally what they are,
enemies of truth, I guess. OTOH, as I said, the argument can be
transferred to the superluminal light beam spot, whether or not the
waves spoken of above are superluminal.
Here's something interesting to play with:
Suppose an observer is moving at 0.5c wrt lab frame. A superluminal beam
spot is moving wrt him at 2c.
Plugging these into the SR velocity equation:
W = (v+w)/(1 + vw/c^2)
gives
W ~ 2.5c
IOW we get a result that approximates normal velocity addition. I think
this is enough to show that the ticking rate dilations and length
contractions are now contradictory, since it is the same length of road,
fence, ground, etc. being contracted wrt the moving observer, by a
factor 1/gamma in the subluminal case, and virtually 1 in the
superluminal case. Different contractions, even though the observer
never changes speed wrt the background (lab frame).
Now plug in c and 'any' value, for v and w, in either order, you get
W=c
Thus even though a spot may be moving at any arbitrary speed wrt the
moving observer, including superluminally, then that same spot will be
moving at exactly c wrt lab frame. Thus it follows that all motions
occurring objectively wrt the moving observer are fictitious changes wrt
lab frame, since the lab frame observer sees all of these other points
(i.e. those that the moving observer sees as moving wrt him) as moving
at the same speed as the moving observer.
Need I continue?
Once again EL, pardon my grouping you in, I plead 'temporarily at my
wits end dealing with crackpots', hope you accept my sincerest apology:)
I've always found you to be one of the most level-headed amongst us, I
should've known better.
Richard Perry
J?rgen Clade
> Why do people think if you go faster than light you can immediately go
> back in time?
> i.e. if you could travel at twice the speed of light it would still take
> two years to get to alpha centuri, right?
That´s from the earth´s point of view. If you could travel to alpha
centauri at twice the speed of ligtht, the events "departure from
earth" and "arrival at alpha centauri" would be spacelike seperated
events. This means that their temporal sequence depends on the frame
of reference you choose. The violation of causality becomes obvious if
you immediately travel back from alpha centauri to earth, again at
twice the speed of light: Then your arrival on earth would be *before*
your departure from earth. SR avoids such violations of causality by
limiting the maximum speed at which you possibly can travel to the
speed of light.
regards,
Jürgen
J?rgen Clade
sorry, I made a mistake: Don´t travel to alpha centauri but rather to
a star which itself recedes from earth at *almost* the speed of light.
Let your speed be twice the speed of light *with respect to the earth*
for your way to the star and twice the speed of light *with respect to
this star* when you travel back to earth. Then you will come back
before you started.
regards,
Jürgen
J?rgen Clade
[...]
> Now as I see it, a group velocity was measured at greater than c, and
> thus, in contrast to the Fizeau near fit, the relativistic velocity
> addition equation fails in this current experiment. Not only that, but
> the whole of special relativity has been proved false.
No, it hasn´t. SR forbids *transport of energy-momentum at
superluminal speeds*, and in the case of anomalous dispersion, as in
this experiment, energy-momentum is not transported with the group
velocity of the wave package. So superluminal group velocities don´t
violate SR.
regards,
Jürgen
Richard
Where in the lorentz transform is it implicit that v corresponds only to
tangible particles? You are only repeating what you've heard over and
over. This was an outright lie imposed in order to save SR from very
observable superluminal speeds. It was a rationalization, it was a
fabrication, it was pulled out of their asses. Tell me, If a spot
(generated by a rotating laser) is moving at 2c along a fence wrt me,
then what speed will that spot be moving wrt an observer moving at x m/s
wrt the fence, as measured by that observer?
Richard Perry
>
> regards,
> Jürgen
EL
[EL]
Hi Jürgen,
I hope that you do not seriously believe in this chicken poop.
The distance between Earth and Alpha Centauri is a quantified
dimension of length that exists at once.
It is rather ridiculous to talk about a distance that shrinks in its
physical nature if an observer perceives it as shrunk.
Your perception may shrink indeed but the distance may not shrink and
if you do believe that poop then you do certainly need a shrink.
If the minimum distance is taken as a physical invariant then with a
constant velocity quantified in distance over time must take time by
simple division.
That time is a positive quantity that does not give a fuck to who is
assigning a sign to it and who is observing it.
SR takes no credit for the constancy of electromagnetic waves in
vacuum but Maxwell does.
SR takes credit to the waste of time and bandwidth and the chicken
poop you posted.
EL
Dirk Van de moortel
"Richard" <no_mail...@yahoo.com> wrote in message news:3F96CD3F...@yahoo.com...
>
[snip]
>
> Where in the lorentz transform is it implicit that v corresponds only to
> tangible particles? You are only repeating what you've heard over and
> over. This was an outright lie imposed in order to save SR from very
> observable superluminal speeds. It was a rationalization, it was a
> fabrication, it was pulled out of their asses. Tell me, If a spot
> (generated by a rotating laser) is moving at 2c along a fence wrt me,
> then what speed will that spot be moving wrt an observer moving at x m/s
> wrt the fence, as measured by that observer?
Primed frame 2 moving with velocity v<c wrt unprimed frame.
Spot_event 1: (x',t') = ( 0, 0 )
Spot_event 2: (x',t') = ( wt', t' )
velocity of spot = wt' / t' = w
for instance 2c
Spot_event 1: (x,t) = ( 0, 0 )
Spot_event 2: (x',t') = ( g(wt'+vt'), g(t'+vwt'/c^2 )
velocity of spot = (w+v)/(1+vw/c^2)
w < c <==> (w+v)/(1+vw/c^2) < c
w = c <==> (w+v)/(1+vw/c^2) = c
w > c <==> (w+v)/(1+vw/c^2) > c
Subluminal in one frame <==> subluminal in all frames
Luminal in one frame <==> Luminal in all frames
Superluminal in one frame <==> superluminal in all frames
Dirk Vdm
Dirk Van de moortel
[snip]
>
> Where in the lorentz transform is it implicit that v corresponds only to
> tangible particles? You are only repeating what you've heard over and
> over. This was an outright lie imposed in order to save SR from very
> observable superluminal speeds. It was a rationalization, it was a
> fabrication, it was pulled out of their asses. Tell me, If a spot
> (generated by a rotating laser) is moving at 2c along a fence wrt me,
> then what speed will that spot be moving wrt an observer moving at x m/s
> wrt the fence, as measured by that observer?
Primed frame moving with velocity v<c w.r.t. unprimed frame.
Spot_event 1: (x',t') = ( 0, 0 )
Spot_event 2: (x',t') = ( wt', t' )
velocity of spot = wt' / t' = w
for instance 2c
Spot_event 1: (x,t) = ( 0, 0 )
Spot_event 2: (x,t) = ( g(wt'+vt'), g(t'+vwt'/c^2 )
Dirk Van de moortel
"EL" <hem...@hotmail.com> wrote in message news:7563cb80.03102...@posting.google.com...
[snip]
> SR takes no credit for the constancy of electromagnetic waves in
> vacuum but Maxwell does.
SR takes credit for modifying Newton and Galileo in a way
that satisfies Maxwell and all people who think that physics
is about experiments.
Dirk Vdm
Randy Poe
<no_mail...@yahoo.com> wrote:
>
>
>J?rgen Clade wrote:
>>
>> Hello Richard,
>>
>> [...]
>> > Now as I see it, a group velocity was measured at greater than c, and
>> > thus, in contrast to the Fizeau near fit, the relativistic velocity
>> > addition equation fails in this current experiment. Not only that, but
>> > the whole of special relativity has been proved false.
>>
>> No, it hasn´t. SR forbids *transport of energy-momentum at
>> superluminal speeds*, and in the case of anomalous dispersion, as in
>> this experiment, energy-momentum is not transported with the group
>> velocity of the wave package. So superluminal group velocities don´t
>> violate SR.
>
>Where in the lorentz transform is it implicit that v corresponds only to
>tangible particles?
In working out the consequences. You can easily add up a bunch of
waves with subluminal speeds and get a superluminal group velocity.
It's simple addition. Therefore it follows that subluminal phase
velocity does not prohibit superluminal group velocity.
> You are only repeating what you've heard over and
>over.
No, you are attempting to do mathematical derivation without
mathematics. It's a simple consequence of the mathematics: If under
the postulates we find that something like superluminal group velocity
is allowed, we say "under the postulates, superluminal group velocity
is allowed". Because we show that under the postulates you can get
superluminal group velocity.
- Randy
mme...@cars3.uchicago.edu
>On Wed, 22 Oct 2003 13:32:31 -0500, Richard
><no_mail...@yahoo.com> wrote:
>
>>
>>
>>>
>>> Hello Richard,
>>>
>>> [...]
>>> > Now as I see it, a group velocity was measured at greater than c, and
>>> > thus, in contrast to the Fizeau near fit, the relativistic velocity
>>> > addition equation fails in this current experiment. Not only that, but
>>> > the whole of special relativity has been proved false.
>>>
>>> No, it hasn´t. SR forbids *transport of energy-momentum at
>>> superluminal speeds*, and in the case of anomalous dispersion, as in
>>> this experiment, energy-momentum is not transported with the group
>>> velocity of the wave package. So superluminal group velocities don´t
>>> violate SR.
>>
>>Where in the lorentz transform is it implicit that v corresponds only to
>>tangible particles?
>
>waves with subluminal speeds and get a superluminal group velocity.
>It's simple addition. Therefore it follows that subluminal phase
>velocity does not prohibit superluminal group velocity.
>
>>over.
>
>mathematics. It's a simple consequence of the mathematics: If under
>the postulates we find that something like superluminal group velocity
>is allowed, we say "under the postulates, superluminal group velocity
>is allowed". Because we show that under the postulates you can get
>superluminal group velocity.
>
generally misunderstood, perhaps due to the fact that lower level
textbooks don't explain it well. Group velocity *is not* signal
velocity. Under some circumstances, when the dependence of phase
velocity on frequency over the bandwidth of the signal is weak, group
velocity is a good approximation to signal velocity over distances
short enough so that the pulse shape does not change appreciably in
propagation. That's all. The conditions listed above are reasonably
well satisfied in most practical situations, but they totally fail
under anomalous dispersion situation.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
EL
> W = (v+w)/(1 + vw/c^2)
>
> Need I continue?
>
> Richard Perry
[EL]
From the paper, the group velocity is
{
vg = c/ng
}
From the same paper also, the group refractive index was measured to
be
{
Using a least square fitting procedure, we obtain a pulse
advancement shift of 63
(±1) nsec. Compared with the 0.2 nsec propagation time for light to
traverse the 6-cm
length of the atomic cell in vacuum, the 63nsec advancement gives an
effective group
index of ng = 315(±5).
}
They simply divided 63 ns by 0.2 ns and a dimensionless ratio is 315.
Therefore the group velocity is
vg = (3 x 10^8) / (315) = 952,381 meters/second
Can any one see any superluminal shit in this velocity?
Nevertheless, the suckers comment saying
{
We note here that the measured superluminal pulse propagation inside
the transparent
anomalous dispersion medium is a linear effect.
}
Naturally if they have divided 0.2 by 63 and stated that the new group
refractive index was 0.0031746[031746]° rather than
1.0031746[031746]°, then any decent scientist could have sued them for
fraud but what they did is pretend to misinterpret the result which is
a very normal delay in an extremely dispersive medium.
What that paper was doing is taking the reader in a wild tour
demonstrating a rigorous experimental setup to convince the reader
that it is serious science if that reader was competent and to get the
reader lost and baffled if the reader was incompetent. Then suddenly
they fabricate the outcome and while admitting that the so elaborately
prepared signal was delayed by 63 or 62 nano-seconds in the dispersive
caesium medium while in vacuum it is delayed by 0.2 ns only, you find
them claiming that it was 315 times faster rather than slower!
If they dare to say that that 62 ns is the time interval between
reading an output first and then pumping an input then how many asylum
residents would believe that claim?
Any forward shift must be an artefact of the 50 KHz continuous pulsing
where the output of a previous dispersive pulse is grouped with a
current vacuum reference pulse.
The scam is clearly based on the rabid desire from the physics
community to confirm time variance as proposed by Einstein
relativities.
This is really sick and I CAN debunk every single fraudulent claim
made by assholes who seek fame riding on an ancient error for
rewarding the biggest asshole a Nobel Prize.
EL
EL
[EL]
Pray tell Mr. de moortel.
Did the SR modification make Newton's apple fall upwards? :)
Then screwing the decent work of Galileo is called a virtue!
Satisfying Maxwell by plagiarising his results and screwing his ether!
Perhaps it is satisfying all people who think that physics is about
sex experiments such as screwing every decent theorem that existed
before and making crackpot lists for intimidating honourable and
credible professors by adding their names side by side with lunatics
and assholes of your type.
What a Dirk!
Be gone asshole.
EL
[EL]
The first postulate of SR is plagiarized from the Galilean
transformation postulate.
The second Postulate is plagiarized from Maxwell's constancy of light
speed in vacuum.
Observers are irrelevant to both postulates.
Lorentz transformation and the gamma factor are idiotic manipulations
of invariant dimensions.
Ah! And you are an asshole and it is not a pleasure to communicate
with you after demonstrating your bias and disrespect.
Be gone.
EL
Richard
Which I have already stated Dirk. OTOH this requires that the time of
occurrence, i.e. the exact moment of transition between subluminal and
superluminal, be the same instant in every frame. Thus if wrt some
observer two spatially separated 'spots' make the transition from
subluminal to superluminal simultaneously, then they must do so
simultaneously wrt all frames, thus negating SR's relativity of
simultaneity.
Now I know that you will respond, "not so", but consider that if this is
not in fact the case, then at some given instant we will have one of the
spots moving superluminally wrt K, but not wrt K'. This directly
contradicts either SR, or your assessment above, take your pick. As far
as I'm concerned, when one goes the other goes with it, and thus the
book is closed.
Now I know this may be difficult to understand, but you cannot argue the
points made in the Gravitomagnetism thread, and the result of those
premises is that the actually correct theory requires the incorrectness
of SR. I have no choice but to stick to the theory that explains nature
coherently, and it just doesn't happen to be SR. OTOH if not for the
overwhelming counter evidence that I've provided, I might also find SR
agreeable from an aesthetic point of view. It has nothing to do with
sentiment, not in my case. It's a matter of pure empiricism and logical
principles. My disgust with the illogic of the theory wasn't spawned by
the theory, but by the mentality of the majority of its die-hard
adherents.
Richard Perry
Richard
I bow before your greatness EL:) You really are bark 'and' bite. Now if
I could only get you to work on my direct particle interaction (DPI)
theory, maybe work out the propagational details, or just the
statistical aspects;)
Richard Perry
EL
> [Mati Meron]
> I'll add here as a comment that the issue of group velocity is
> generally misunderstood, perhaps due to the fact that lower level
> textbooks don't explain it well. Group velocity *is not* signal
> velocity. Under some circumstances, when the dependence of phase
> velocity on frequency over the bandwidth of the signal is weak, group
> velocity is a good approximation to signal velocity over distances
> short enough so that the pulse shape does not change appreciably in
> propagation. That's all. The conditions listed above are reasonably
> well satisfied in most practical situations, but they totally fail
> under anomalous dispersion situation.
>
[EL]
You sound like you do know what is a group velocity so why do you also
sound as if you are endorsing the superluminal lie?
I am not going to write the equations or derivations but to give you a
hinting example:
v_g = v_p - [Lambda (div-v_p/div-Lambda)]
also
v_g = dw/dk
Without going into meticulous details, a pure sign wave is not a
natural phenomenon but we usually have interference or a packet of
interacting waves and this is not a light in vacuum or gases exclusive
thing.
For example in deep water v_p = c.k^(-1/2), where c is a constant.
Thus w= c.k^(1/2) and v_g =dw/dk = 0.5 v_p.
These waves are strongly dispersive, and the individual wave crests
slide through the group at twice the group speed.
Those of you who still do not get it and find it hard to imagine why
it is a very funny lie or simply ignorance from those who claim
superluminal velocities, please recall Lord Kelvin's smoke rings.
Air is a dispersive medium and smoke is a visual indicator of the flow
of a wave.
The air compression along the axis of symmetry of the wave is at a
maximum and the velocity too is at its maximum along that axis.
However, the ring demonstrates velocities reduction as we step away
from that axis until they turn negative, which means that smoke
particles move backwards relative to the (Ring) group even though the
whole group is advancing forward, and this particular phenomenon is
observed on the outer shell topology of that smoke ring group.
The contrary may be observed on the smoke particles at the core of the
ring, where those particles would be moving at twice the group
velocity being accelerated on there way in and decelerated on there
way out at the group-wave-front.
Can any of you claim that a smoke ring may move in air faster than
sound can move in the same medium?
No, certainly not, because you are all wise and sane. :)
LASSER light pumping is neither better nor worse.
Caesium atoms undergo similar dispersion anomalies and a magnetic
field of 1Gauss is maintained parallel to the direction of light
packet propagation to define an axis.
Obviously, caesium atoms are huge particles that attain velocities far
slower than c.
While light propagates at c exactly along the empty axis that caesium
atoms do not enter due to preparing them by preparatory light pulses,
the group velocity is expected to be at half c but very roughly.
If the atoms absorb all the energy or the medium become saturated we
have no anomalies.
The anomaly is a replication of Lord Kelvin's smoke ring in a wave of
air gist but this time using a caesium ring-group hoping to accelerate
LASSER light packets at the core axis of the wave group.
So yes, indeed the light speed at the core axis is at a maximum and it
is at c but the group velocity is much lower.
The terrible mistake is to assume that the light packet is a group
that is propagating at c and then one discovers that relative to that
velocity a much faster speed is detected.
The equations are supposed to find the group velocity not to assume
it.
The group velocity by definition must be a fraction of the maximum
velocity that the medium allows.
Vacuum allows a maximum of c.
Caesium gas at 30 degrees Celsius should slow down light to a maximum
less than c.
The new refractive index may not be a fraction less than unity or it
would be a calculation mistake.
So what they really have is a set of data that they fail to interpret
properly and an oscilloscope that they have no freaking idea about
interpreting its screen or recorded tapes.
Those clowns need to go back to school and they disgrace their
credentials and smear our credentials too by being so irresponsible
and reckless.
EL
mme...@cars3.uchicago.edu
>mme...@cars3.uchicago.edu wrote in message news:<t7Clb.15$_4.3...@news.uchicago.edu>...
>
>> [Mati Meron]
>> generally misunderstood, perhaps due to the fact that lower level
>> textbooks don't explain it well. Group velocity *is not* signal
>> velocity. Under some circumstances, when the dependence of phase
>> velocity on frequency over the bandwidth of the signal is weak, group
>> velocity is a good approximation to signal velocity over distances
>> short enough so that the pulse shape does not change appreciably in
>> propagation. That's all. The conditions listed above are reasonably
>> well satisfied in most practical situations, but they totally fail
>> under anomalous dispersion situation.
>>
>
>You sound like you do know what is a group velocity so why do you also
>sound as if you are endorsing the superluminal lie?
>
nice guy, I won't even check. If you've any issues with group
velocity, feel free to consult Jackson's "Electrodynamics", chapt. 7.
Dirk Van de moortel
"Richard" <no_mail...@yahoo.com> wrote in message news:3F972E6B...@yahoo.com...
No. You did not state. You just *asked*:
| "Tell me, If a spot (generated by a rotating laser) is moving
| at 2c along a fence wrt me, then what speed will that spot
| be moving wrt an observer moving at x m/s wrt the fence,
| as measured by that observer?"
You asked so you got an answer.
Dirk Vdm
EL
Frankly, you still sound like you do know what is a group velocity so
why do you also sound as if you are endorsing the superluminal lie?
Let us discuss Jackson's "Electrodynamics", chapt. 7 another time.
First we need to know how a compound wave is compounded from a group
of waves.
The topology is critical to the interpretation.
Here is a reminder of what was snipped.
Octafish
> > Starblade Darksquall wrote:
> > > I know what goes faster than the speed of light.
> > >
> > > The stars really really far from me all go faster than the speed of
> > > light when I spin around in circles because my spinning reference
> > > frame is just as good as anybody else's.
> >
> > changing coordinate systems.
> >
> > Bob Kolker
>
> Motion is relative. They are not moving in their own reference frame,
> but they are in mine.
>
Wrong. However, possibly the majority of everthing in the universe
*is* moving away from us at superluminal velocities.
Robert J. Kolker
Octafish wrote:
>
> Wrong. However, possibly the majority of everthing in the universe
> *is* moving away from us at superluminal velocities.
Wrong. You are making the Galilean error of assuming that velocities add.
Bob Kolker
J?rgen Clade
[...]
> > No, it hasn´t. SR forbids *transport of energy-momentum at
> > superluminal speeds*, and in the case of anomalous dispersion, as in
> > this experiment, energy-momentum is not transported with the group
> > velocity of the wave package. So superluminal group velocities don´t
> > violate SR.
>
> Where in the lorentz transform is it implicit that v corresponds only to
> tangible particles?
Where did I say this?
> You are only repeating what you've heard over and
> over. This was an outright lie imposed in order to save SR from very
> observable superluminal speeds.
You will have to prove this.
> It was a rationalization, it was a
> fabrication, it was pulled out of their asses.
You should avoid such vocabulary if you want further discussion.
> Tell me, If a spot
> (generated by a rotating laser) is moving at 2c along a fence wrt me,
> then what speed will that spot be moving wrt an observer moving at x m/s
> wrt the fence, as measured by that observer?
Tell me why do you think that your light spot is transporting
energy-momentum along the fence at superluminal speed. Energy-momentum
in this example is only transported from the light source to the fence
with speed c.
regards,
Jürgen
J?rgen Clade
> ...chicken poop.
> ...fuck...chicken
> poop
Is this your usual way of discussing? You should not only learn some
physics, but also some manners.
regards,
Jürgen
George Jones
You are making the special relativistic error (i.e., the universe is not
modeled by special relativity) that there is a unique definition of
velocity. Some (reasonable) definitions of cosmological velocity give
superluminal speeds. This doesn't violate the spirit of relativity since
these superluminal speeds cannot be used for information transfer.
Another possible stance is that there is no reasonable general
definition of distance and speed in general relativity, and therefore
this whole discussion is meaningless.
Regards,
George
Dirk Van de moortel
"J?rgen Clade" <cl...@isc.fhg.de> wrote in message news:54bc2946.03102...@posting.google.com...
[possibly posted twice - sorry, news server problem]
Impossible.
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/AndersenLogic.html
Look at the "interesting follow-ups" at the bottom ;-)
Enjoy...
Dirk Vdm
EL
[EL]
Are you accusing me of not recognising chicken shit when I see it?
Then who do you suggest can teach me physics if you all seem to be
chicken that has no freaking idea about any physics else than
excreting shit.?
If you had had the knowledge required to teach a professor then
certainly I do have the manner with which I should address such a
master.
I am really sorry to have offended you, and I never meant to offend
you in retaliation to being offended by your post.
Most probably you did not intentionally mean to offend me except that
there is nothing you can do about yourself being offensive.
Try posting science and I shall show you elite manners.
Post the same chicken shit you posted and I shall identify it on the
spot.
EL
Robert Clark
> I'll add here as a comment that the issue of group velocity is
> generally misunderstood, perhaps due to the fact that lower level
> textbooks don't explain it well. Group velocity *is not* signal
> velocity. Under some circumstances, when the dependence of phase
> velocity on frequency over the bandwidth of the signal is weak, group
> velocity is a good approximation to signal velocity over distances
> short enough so that the pulse shape does not change appreciably in
> propagation. That's all. The conditions listed above are reasonably
> well satisfied in most practical situations, but they totally fail
> under anomalous dispersion situation.
>
> Mati Meron | "When you argue with a fool,
> me...@cars.uchicago.edu | chances are he is doing just the same"
You're aware of the discussions on sci.physics.relativity that to
determine if a signal travelled superluminally what would be required
is a round-trip measurement. This is because of the uncertainty of
synchronizing clocks in two different locations. The standard SR
method of using light-signals requires the assumption of the constancy
of the one-way speed of light. [1]
I was interested to see that in some descriptions of the experiment
of Wang et.al. using lasers in cesium gas, that the light pulse was
said to exit the chamber before it entered:
"Can c, the speed limit of the universe, the speed of light in vacuum,
be exceeded? In July, 2000, the science-oriented news media were full
of reports that pulses of laser light had broken the speed-of-light
barrier. Physicists L. J. Wang, A. Kuzmich, and A. Dogarliu of the
NEC Research Institute in Princeton, NJ, had a paper about to be
published in the prestigious journal Nature describing an experiment
in which not only had laser pulses traveled faster than light, but had
actually emerged from the apparatus before they had entered it." [2]
It occurs to me that this is what would appear to happen if the
entrance and exit were synchronized using light signals but the actual
signal to be measured was traveling superluminally or if light signals
provided an inaccurate means of synchronizing clocks. What would be
needed to see if the signal pulse was being propagated superluminally
would be to have the pulse reflected back to the source and seeing if
the total travel time was less than the time for light to make the
round trip.
Another experiment might have made such round trip measurements.
These were experiments by Ranfagni et.al. of microwaves propagating in
a wave guide:
"In the new experiments, led by Anedio Ranfagni of the Italian
National Research Council in Firenze, the setup looks innocent enough:
The team sent microwaves (3.5 cm wavelength) through a narrow,
ring-shaped opening onto a large and nearby focusing mirror, which
collimated the waves into a beam propagating back from the mirror,
beyond and behind the source. They "modulated" the microwaves with
rectangular pulses (sharp "amplify" and "attenuate" commands, in rapid
succession) and detected the pulses at positions between 30 and 140 cm
from the source, along the beam axis. The slope of their plot of
arrival times vs. distance led to an apparent propagation speed of 5
to 7% above c, although beyond about 1 m, the speed approached c, all
of which agreed with previous predictions." [3]
The experimenters claim some speeds exceeding c in the reflected
waves but it is difficult to tell here if any of these speeds are for
a round trip signal back to the source.
Bob Clark
1.)Conventionality of Simultaneity
http://plato.stanford.edu/entries/spacetime-convensimul/
2.)Faster-than-Light Laser Pulses?
by John G. Cramer
http://www.npl.washington.edu/AV/altvw105.html
3.)Faster than a Speeding Light
http://focus.aps.org/story/v5/st23
mme...@cars3.uchicago.edu
>mme...@cars3.uchicago.edu wrote in message news: <t7Clb.$_4.3...@news.uchicago.edu>...
>> generally misunderstood, perhaps due to the fact that lower level
>> textbooks don't explain it well. Group velocity *is not* signal
>> velocity. Under some circumstances, when the dependence of phase
>> velocity on frequency over the bandwidth of the signal is weak, group
>> velocity is a good approximation to signal velocity over distances
>> short enough so that the pulse shape does not change appreciably in
>> propagation. That's all. The conditions listed above are reasonably
>> well satisfied in most practical situations, but they totally fail
>> under anomalous dispersion situation.
>>
>> Mati Meron | "When you argue with a fool,
>> me...@cars.uchicago.edu | chances are he is doing just the same"
>
I'm certainly not aware of any discussions on sci.physics.relativity,
nor do I have any interest in these.
Actually all the above experiments yield results fully consistent with
the existing theoretical predictions, based on classical
electrodynamics (even QM is not really required) and fully consisten
with relativity. You should read the scientific publications, not
writeups in popular media. There are all sorts of funny htings you
can do with pulses which change shape across small distnaces.
Bilge
>> I'll add here as a comment that the issue of group velocity is
>> generally misunderstood, perhaps due to the fact that lower level
>> textbooks don't explain it well. Group velocity *is not* signal
>> velocity. Under some circumstances, when the dependence of phase
>> velocity on frequency over the bandwidth of the signal is weak, group
>> velocity is a good approximation to signal velocity over distances
>> short enough so that the pulse shape does not change appreciably in
>> propagation. That's all. The conditions listed above are reasonably
>> well satisfied in most practical situations, but they totally fail
>> under anomalous dispersion situation.
>>
>> Mati Meron | "When you argue with a fool,
>> me...@cars.uchicago.edu | chances are he is doing just the same"
>
> You're aware of the discussions on sci.physics.relativity that to
>determine if a signal travelled superluminally what would be required
>is a round-trip measurement.
That is not the case.
>This is because of the uncertainty of synchronizing clocks in
>two different locations.
It's completely unnecessary to synchronize anything.
Dirk Van de moortel
Impossible.
Robert Clark
It is well known among researchers in the foundations of relativity
the need to synchronize clocks at two locations for comparing times at
those locations.
See this post by Stephen Speicher:
From: Stephen Speicher (s...@speicher.com)
Subject: Re: Speed of light
Newsgroups: sci.physics.research, sci.physics.relativity
Date: 2003-06-24 20:06:03 PST
http://groups.google.com/groups?selm=Pine.LNX.4.33.0306232227290.2147-100000%40localhost.localdomain
Bob Clark
EL
> It's completely unnecessary to synchronize anything.
[EL]
Hi Bilge. :)
Why is it so difficult for people to imagine group velocities as wave
envelopes!
All decent empirical wave-group-velocity measurements show that they
are much lower than phase velocity in the same dispersive medium.
I wish to make an analogy to establish a law.
When many people walk in a corridor while their legs are not equal in
length and their steps are not synchronized the group velocity of the
crowd is obviously slower than the fastest person in that crowd.
When six sportsmen are rowing a boat the speed of that boat is the
same as the collective speed of that synchronized group.
The envelope of the rowing mechanics may not exceed the speed of the
boat and the boat tip-front must lead at all times and never be
exceeded.
EL
ueb
>> ...chicken poop.
>> ...fuck...chicken
>> poop
Don't let irritate, if this man leaves some farts. He is only a chemist,
but he sees more than lots of paid physicists. See also
http://home.t-online.de/home/Ulrich.Bruchholz/article2.txt
(Reading that, you may better understand the subject of this thread.)
Regards
Ulrich Bruchholz
Randy Poe
>dub...@radioactivex.lebesque-al.net (Bilge) wrote in message news:<slrnbphhor....@radioactivex.lebesque-al.net>...
>
>> It's completely unnecessary to synchronize anything.
>
>[EL]
>Hi Bilge. :)
>
>Why is it so difficult for people to imagine group velocities as wave
>envelopes!
>
>All decent empirical wave-group-velocity measurements show that they
>are much lower than phase velocity in the same dispersive medium.
Except in negatively-dispersive media, where both theory and
experiment show the opposite.
- Randy
EL
Thank you dear Ulrich, I know myself that I am an old ranting fart,
but I still appreciate your testimony. :)
ueb <Ulrich.B...@t-online.de> wrote in message news:<q3udnb...@Muse2.private.de>...
EL
> >[EL]
> >Hi Bilge. :)
> >
> >Why is it so difficult for people to imagine group velocities as wave
> >envelopes!
> >
> >All decent empirical wave-group-velocity measurements show that they
> >are much lower than phase velocity in the same dispersive medium.
>
> Except in negatively-dispersive media, where both theory and
> experiment show the opposite.
>
> - Randy
[EL]
Bring back the grudge and let us grind.
What is the merit in being a beautifully coloured parrot?
The merit is to admire the colourful feathers (mostly in a mirror).
However, a parrot is a sound mimicking bird with a bird's brain.
Dispersion is another word for scattering.
Scattering if you did not know is like what happened to the Jews all
over history.
Scattering is like holding a handful of seeds and then tossing them
for random distribution during planting processes.
A dispersive medium is a medium as media are defined in being either
homogenous or not and isotropic or not.
The quality of a medium indicates if it was able to induce scattering
or not.
Now try to imagine pinball the game and look for Pachinko.
The many steal marbles are supposed to be scattered randomly by design
to induce a factor of luck.
The dispersion of light and this means its scattering among air
molecules or any transparent or semitransparent medium should make you
understand that the waves are being physically scattered by deflection
and reflection on the particles of that medium.
Of course by now you should have realised that negative-dispersion is
an expression coined by an idiot.
The phenomenon being the heart of this debate is definition dependant.
In optics dispersion is also defined as the Rate of Change of the
Refractive Index over wavelength scale at a specific wavelength.
Therefore, that definition implies that a wavelength scale must be
constructed by arbitrating a periodical interval indicating wavelength
increments against which we plot the refractive index to extract a
rate of change of that RI with respect to the change in wavelength
about the wavelength in question to illustrate a dispersion figure.
If my sentence was too complex for you to understand, here it is again
in different words.
We have a specific frequency of a wave of light.
We put a point on a graph's x-axis to represent that frequency and we
extend our scale to the left and to the right.
The graph's y-axis then represents the refractive index.
This means that in that specific material the refractive index is
frequency dependant.
By plotting all the different refractive index values we illustrate
the scattering of the refractive index about (before and after) the
frequency at question.
What does the idiotic negative-dispersion supposed to mean!
Pick up any respectable reference that tabulates the refractive index
of materials and try to find any negative value.
The overwhelming majority of indexes have a value between 1 and 2 and
they are POSITIVE VALUES.
Now the rate of change of positive values over positive intervals is
quite unlikely to make sense being negative.
A faster rate and a slower rate are simply seen in the aggregation/
dispersion of the plotted points of the refractive index against the
wavelengths.
So please educate yourself before defending idiots because it only
makes an idiot out of you too.
EL
Randy Poe
>Randy Poe <rpo...@removethis.yahoo.com> wrote in message news:<mqvkpvg9knhufdg7g...@4ax.com>...
>> >[EL]
>> >Hi Bilge. :)
>> >
>> >Why is it so difficult for people to imagine group velocities as wave
>> >envelopes!
>> >
>> >All decent empirical wave-group-velocity measurements show that they
>> >are much lower than phase velocity in the same dispersive medium.
>>
>> Except in negatively-dispersive media, where both theory and
>> experiment show the opposite.
>>
>[EL]
>Bring back the grudge and let us grind.
>What is the merit in being a beautifully coloured parrot?
>The merit is to admire the colourful feathers (mostly in a mirror).
>However, a parrot is a sound mimicking bird with a bird's brain.
Nice poetry, if unfathomable. Shall we discuss physics?
>
>Dispersion is another word for scattering.
Incorrect.
Dispersion in wave physics means wavelength-dependence of the speed of
propagation. A medium can be dispersive but, in theory, lossless.
Scattering is inherently lossy. It refers to energy being sent in many
other directions away from the line of propagation.
Normal (positive) dispersion does have the tendency to spread signals
out in time, but this is a different phenomenon than dispersion.
>Scattering if you did not know is like what happened to the Jews all
>over history.
>Scattering is like holding a handful of seeds and then tossing them
>for random distribution during planting processes.
Again, nice poetry, but not very closely related to either dispersion
or scattering as the terms are used in physics.
>A dispersive medium is a medium as media are defined in being either
>homogenous or not and isotropic or not.
A dispersive medium is one in which speed depends on frequency. As we
all know from prisms, glass is a dispersive medium. Most real media
area, though the slope depends on the details of the interaction
between the energy and the molecules of the medium. Most of the time,
the slope of a speed vs. wavelength curve is positive, i.e., the speed
increases with wavelength, or decreases with frequency. Low frequency
waves propagate faster. You can see this in water with storm systems,
with low frequency components traveling reaching shore far ahead of
the rest of the system.
But there are materials which exhibit an opposite slope over some
wavelength regimes, with higher frequencies having higher speeds. This
is not magic, but it leads to a different effect on the shape of a
multiple-frequency pulse as it propagates.
>What does the idiotic negative-dispersion supposed to mean!
Indicated above.
>
>Pick up any respectable reference that tabulates the refractive index
>of materials and try to find any negative value.
>The overwhelming majority of indexes have a value between 1 and 2 and
>they are POSITIVE VALUES.
Dispersion refers to slope. How low frequencies move compared to high
frequencies is what leads to the effect.
>
>Now the rate of change of positive values over positive intervals is
>quite unlikely to make sense being negative.
Huh? You're saying it doesn't make sense for a positive value to
decrease? Why the hell not?
http://en.wikipedia.org/wiki/Dispersion_(optics)
http://www.corning.com/opticalfiber/discovery_center/future_page2.asp
http://adsabs.harvard.edu/cgi-bin/nph-bib_query?2000OptCo.179..107W
- Randy
EL
> Huh? You're saying it doesn't make sense for a positive value to
> decrease? Why the hell not?
[EL]
Because less positive and more positive is still positive and I am
talking about refractive indexes.
The refractive index may increase or decrease away from the tested
frequency (wavelength) about which dispersion is being measured but in
all those cases dispersion is positive, absolute or simply unsigned.
What you are talking about is not negative dispersion at all but we
may describe it better as the rate of dispersion.
Since dispersion itself is the rate of change in the refractive index
then what you are talking about is the rate of the rate of change,
which is irrelevant to group velocity.
>
> http://en.wikipedia.org/wiki/Dispersion_(optics)
[EL
Just as an example to demonstrate how silly you can be Randy I copied
the contents of that link and here it is.
{{{
Dispersion (optics
From Wikipedia, the free encyclopedia.
Find out how you can help support Wikipedia's phenomenal growth.
(There is currently no text in this page)
}}}
So you are referring me to a page that has no text in it which means
that you did not even read the content of the links you supplied.
Stop fabricating responses and get serious please.
I do not even know why you are being so enthusiastic defending those
idiots while you are much better a parrot than that. :):)
Please invest your precious time in mathematics where you know better.
Regards. :)
EL
Mark Palenik
"Bilge" <dub...@radioactivex.lebesque-al.net> wrote in message
news:slrnbphhor....@radioactivex.lebesque-al.net...
Besides, as long as two clocks are synchronized from the frame in which the
experiment is being carried out, the measurement they give for the speed of
light should be C.
Randy Poe
>Randy Poe <rpo...@removethis.yahoo.com> wrote in message news:<psslpvgbvrmbcc29f...@4ax.com>...
>
>> Huh? You're saying it doesn't make sense for a positive value to
>> decrease? Why the hell not?
>
>[EL]
>Because less positive and more positive is still positive and I am
>talking about refractive indexes.
Yes. But why does that mean a positive function can't decrease?
Consider exponential decay: a function which is positive everywhere,
but always decreasing.
>The refractive index may increase or decrease away from the tested
>frequency (wavelength) about which dispersion is being measured but in
>all those cases dispersion is positive, absolute or simply unsigned.
What? Dispersion is the slope of the curve. If the slope is negative,
it's not "positive, absolute, or unsigned", it's negative.
>What you are talking about is not negative dispersion at all but we
>may describe it better as the rate of dispersion.
Instead of making up definitions, why don't you do a search for
"negative dispersion" and read a definition? Speed is positive. Index
of refraction is generally greater than 1. We can all agree on that.
Now imagine a curve which is always above 1. Can you picture such a
curve sometimes increasing and sometimes decreasing? Where it
decreases, the grownups say "this has a negative slope".
As the name for this slope is "dispersion", then where the slope is
negative we call that "negative dispersion". It has nothing to do with
negative speeds, with speeds greater than c, or with any other
crackpot strawman you seem to have latched onto.
>Since dispersion itself is the rate of change in the refractive index
Very good. The slope of the curve vs. frequency.
>then what you are talking about is the rate of the rate of change,
>which is irrelevant to group velocity.
No, what I'm talking about is the rate of change. In a negatively
dispersive regime, shorter waves move faster than longer waves. They
have a higher speed. A lower index of refraction.
Draw a line representing index of refraction vs. frequency. Draw the
line so it slopes downward. Can we agree we're talking about the slope
of the index of refraction curve? I hope so. Can we agree that a
downward slope on this plot means higher frequencies have a lower
index, i.e. a higher speed? I hope so.
Negative dispersion: higher frequencies have higher speed. Is that
really so difficult?
And you're incorrect, the dn/d(lambda) value has everything to do with
group velocity.
- Randy
Eric Taylor
>I am really sorry to have offended you, and I never meant to offend
>you in retaliation to being offended by your post.
>Most probably you did not intentionally mean to offend me except that
>there is nothing you can do about yourself being offensive.
>
>Try posting science and I shall show you elite manners.
>
>Post the same chicken shit you posted and I shall identify it on the
>spot.
>
>EL
bwaahaha. this is excellent. I can't tell from the post if EL is the
kook or if EL is responding to the kook, but either way, excellent
rant.
--- edt
Paul Cardinale
[snip]
>
> Here's something interesting to play with:
>
> Suppose an observer is moving at 0.5c wrt lab frame. A superluminal beam
> spot is moving wrt him at 2c.
>
> Plugging these into the SR velocity equation:
>
> W = (v+w)/(1 + vw/c^2)
>
> gives
>
> W ~ 2.5c
>
Go back to 4th grade and study arithmetic.
Paul Cardinale
EL
[EL]
I think that you are only trying to make me angry by telling lies and
putting words in my mouth.
I know very well that dn/d(lambda) is the rate of change in the
refractive index with respect to the change in frequency.
I did say up here and there that that is what dispersion is.
This is analogous to speed being a rate of change in distance with
respect to change in time (mathematically speaking) and we know that
such a scalar may be represented as a slope and that speed may
increase or decrease while stile being a positive mathematical entity.
To decrease speed you need NEGATIVE acceleration (deceleration), which
is the rate of change in the rate of change in distance with respect
to time.
The same applies here and that is precisely what I said.
We do not care about the rate of dispersion here because dispersion
itself is the rate we need for group velocity not group acceleration.
A negative velocity is an absolute-quantity-velocity in the opposite
direction of a positive velocity reference direction.
However, the speed scalar is an absolute quantity that cannot be less
than zero.
That is why I insist that the terminology of {negative-dispersion} is
Oxymoronic because an increasing index with an increasing frequency or
a decreasing index with an increasing frequency does not imply that
rate of change itself is negative but the relation between the
direction of frequency magnitudes and the index magnitudes are zusamen
or entgegen.
You certainly do not call counter clockwise to be a negative circle.
However, I noticed now that delta-refractive-index could be
mathematically negative when we subtract a higher index from a lower
index. So your terminology is purely mathematical and not physical.
So I do agree of course that all positive values of refractive indexes
measured to coincide with specific frequencies may be increasing or
decreasing proportionally to the frequencies. While you keep the sign
as if it was a vector I remove the sign because dispersion is absolute
because it is a scalar.
The error being avoided by taking the absolute value is to assume a
negative refractive index which is nonexistent physically.
A negative refractive index violates the conservation of energy law of
physics, and an inert "negatively dispersive" medium implies that the
medium can accelerate a wave beyond its propagation constant.
In fact I am grateful to you for helping me to pinpoint the source of
the error that the idiots made.
This reminds me of similar silliness regarding the sign of time and
assuming a negative causality chain to be tenable.
Mathematics is a tool for physics and physics is a field of
applications for mathematics but you may not create physics by
applying wanton mathematics that does not reflect physical concepts.
EL
Randy Poe
> Randy Poe <rpo...@removethis.yahoo.com> wrote in message news:<psslpvgbvrmbcc29f...@4ax.com>...
> >
>
> [EL
> Just as an example to demonstrate how silly you can be Randy I copied
> the contents of that link and here it is.
> {{{
> Dispersion (optics
> From Wikipedia, the free encyclopedia.
> Find out how you can help support Wikipedia's phenomenal growth.
>
> (There is currently no text in this page)
I noticed that when I posted the part after the underscore
was not underlined (optics) but that is indeed part of
the URL.
> So you are referring me to a page that has no text in it which means
> that you did not even read the content of the links you supplied.
It's a longish article that begins like this:
"In optics, dispersion is a phenomenon that causes the
separation of a wave into components with different
frequency. It is most often observed in light waves,
though it may happen to any kind of wave that interacts
with a medium, such as sound waves."
Had you searched Wikipedia you would have found it. Had
you followed my suggestion to search google for "negative
dispersion" you would have found it. Had you done any rudimentary
amount of searching you would have found it. Try again.
> Stop fabricating responses and get serious please.
> I do not even know why you are being so enthusiastic defending those
> idiots while you are much better a parrot than that. :):)
I'm attacking your silly version of "negative dispersion".
There are people who see relativity under every bed and are
ready to jump on it with their favorite rant. Negative dispersion
is an effect in classical optics.
Other links I posted were from fiber-optic cable manufacturers
who are using negatively-dispersive materials to achieve
better propagation properties (no, not faster than light
communication, but better cohesiveness on pulses).
Here is the next section of the article you think doesn't
exist.
"Another consequence of dispersion manifests itself as
a temporal effect. The formula above, v = c / n
calculates the phase velocity of a wave; this is
the velocity at which the phase of any one frequency
component of the wave will propagate. This is not the
same as the group velocity of the wave, which is the
rate that changes in amplitude (known as the envelope
of the wave) will progagate. The group velocity vg
is given by:
vg = c*[n - dn/d(lambda)]^(-1)
The group velocity vg is often thought of as the velocity
at which energy or information is conveyed along the wave.
In most cases this is true, and the group velocity can be
thought of as the signal velocity of the waveform. In some
unusual circumstances, where the wavelength of the light
is close to an absorption resonance of the medium, it is
possible for the group velocity to exceed the speed of
light (vg > c), leading to the conclusion that superluminal
faster than light) communication is possible. In practice,
in such situations the distortion and absorption of the wave
is such that the value of the group velocity essentially
becomes meaningless, and does not represent the true signal
velocity of the wave, which stays less than c."
Immediately below this point you will see a discussion of
negative dispersion, also called anomalous dispersion.
- Randy
Randy Poe
> > On 25 Oct 2003 23:07:46 -0700, hem...@hotmail.com (EL) wrote:
> > And you're incorrect, the dn/d(lambda) value has everything to do with
> > group velocity.
> >
> [EL]
> I think that you are only trying to make me angry by telling lies and
> putting words in my mouth.
With unaltered quotes from your own post?
> I know very well that dn/d(lambda) is the rate of change in the
> refractive index with respect to the change in frequency.
That's the part where I said "correct". Earlier you said this:
> > >The refractive index may increase or decrease away from the tested
> > >frequency (wavelength) about which dispersion is being measured but in
> > >all those cases dispersion is positive, absolute or simply unsigned.
Which is incorrect. The slope can be positive or it can be
negative. As it happens, interaction theory predicts that
the anomalous case of negative dispersion happens only
under very specific circumstances. Hence it is called
"anomalous".
If you understand that dispersion refers to the sign of
dn/d(lambda) how can you simultaneously say that no matter
what the sign of dn/d(lambda), dispersion is never
negative?
> I did say up here and there that that is what dispersion is.
Then since the slope can be negative, and you claim to agree
dispersion is the slope, why claim dispersion can't be
negative? You don't see a contradiction there?
> This is analogous to speed being a rate of change in distance with
> respect to change in time (mathematically speaking) and we know that
> such a scalar may be represented as a slope and that speed may
> increase or decrease while stile being a positive mathematical entity.
>
> To decrease speed you need NEGATIVE acceleration (deceleration), which
> is the rate of change in the rate of change in distance with respect
> to time.
dn/d(lambda) is not an acceleration. Time is not involved.
> The same applies here and that is precisely what I said.
> We do not care about the rate of dispersion here
Are you now saying dn/d(lambda) is the "rate of dispersion"
and "not dispersion itself"?
Do you realize that a few sentences above you said that
dispersion and dn/d(lambda) are the same, and now you appear
to be saying something different?
> because dispersion
> itself is the rate we need for group velocity not group acceleration.
What we need is dn/d(lambda). I'm calling that "dispersion".
Can we agree that what we need is dn/d(lambda) so we don't
have a moving target here? Can we agree that this can be
either positive or negative?
> A negative velocity is an absolute-quantity-velocity in the opposite
> direction of a positive velocity reference direction.
There are no negative velocities here.
> However, the speed scalar is an absolute quantity that cannot be less
> than zero.
What does dn/d(lambda) have to do with this? n is a positive
number greater than or equal to 1. What does dn/d(lambda)
have to do with velocities being negative or speed being
negative? Didn't you just agree dn/d(lambda) can be
negative?
[I keep confusing myself on the sign. I think of this in terms
of dv/df, the rate of change of speed with frequency. In
anomalous dispersion, v increases with frequency. That means
n decreases with frequency, or increases with wavelength.
So "negative dispersion" => dn/d(lambda) is POSITIVE, while
the more common case is that dn/d(lambda) is NEGATIVE]
> That is why I insist that the terminology of {negative-dispersion} is
> Oxymoronic because an increasing index with an increasing frequency or
> a decreasing index with an increasing frequency does not imply that
> rate of change itself is negative
What? The rate of change with frequency IS the slope. You're
now saying that a negative derivative does not imply a
negative slope?
"Negative derivative" and "downward" are the same thing.
A decreasing index with wavelength does indeed imply that
dn/d(lambda) is negative. Let me repeat your words again:
An increasing index with an increasing frequency
[dn/df being positive...]
or a decreasing index with an increasing frequency
[dn/df being negative...]
does not imply that the rate of change itself is
negative
[does not imply that dn/df is negative...]
I'm sorry, I really can't make sense of that remark. But I
don't really care if you can't get your mind around the
concept of first derivatives and their signs. Let's work
through a really simple example. I'm going to try to derive
the group velocity for this example.
Suppose we have a really simple wave composed of two
frequencies, f1 and f2. Let us suppose that f2 = 2f1.
Let us also suppose that the speed of propagation for
wave 1 is v, and for wave 2 is 1.5v. So the higher
frequency wave (wave 2) has 50% higher velocity.
The wave is described by
S(x,t) = cos(2*pi*f1*(x/v1 - t)) + cos(2*pi*f2*(x/v2 - t))
You should first make sure you believe that. Each term
describes a wave which is:
- constant for x - v*t = constant
- for fixed t, has spatial period (wavelength)
v/f = lambda
- for fixed x, has temporal period 1/f1
- has phase 0 at x = 0, t = 0.
The first wave has a wavelength of v1/f1 = lambda1, the
second has a wavelength of v2/f2 = (1.5*v1)/(2*f2)
= (3/4)*lambda1
So every 4 wavelengths of wave 2 corresponds to
3 wavelengths of wave 1, and the packet is in phase
every 4*lambda2 = 3*lambda1. If you fix time t, you
will see the waves add up constructively at x=0
and every 4*lambda1 afterward. These peaks will move
as the wave moves. The rate of advance of the peaks
will be the group velocity, as it is the motion of our
coherent pulse.
So let's analyze what happens as time evolves. Suppose
it is no longer time 0, but a little later, time T.
The phase of wave 1 is f1*(x/v1-T) and of wave 2 is
f2*(x/v2-T) = 2*f1*(x/(1.5*v1)-T)
These phases are equal where
f1*x/v1 - f1*T = 1.33*f1*x/v1 - 2*f1*T
or f1*T = 0.33*f1*x/v1
or x = 3*v1*T
The place where the waves are in phase has moved by a
distance 3*v1*T in time T. Thus, the peak appears to
be moving forward at 3*v1, despite the fact that
one wave is moving at v1 and the other at 1.5*v1.
As the whole thing has a spatial periodicity of 3*lambda1,
you will find that all of the peaks, spaced 3*lambda1
apart, are similarly marching forward at 3*v1.
The fact that their point of coincidence can move
forward faster than either wave alone is a consequence
of the shorter wave moving faster than the longer one.
In other words, of the longer wave having higher index
of refraction, or of dn/df being negative.
If the longer wave moved faster (had lower index of
refraction), you would not get this "superluminal"
effect.
You can do everything I just did in the more general
case of a complex, multi-frequency wave packet and
an arbitrary slope. You can further work out that
there is no information being propagated at speed >v1.
This has nothing to do with relativity. It's pure
classical wave physics, analyzing sines and cosines.
- Randy
EL
>
> > [EL]
> > I think that you are only trying to make me angry by telling lies and
> > putting words in my mouth.
>
> With unaltered quotes from your own post?
No, it is about the dumb interpretation of what is being written.
>
> > I know very well that dn/d(lambda) is the rate of change in the
> > refractive index with respect to the change in frequency.
>
> That's the part where I said "correct". Earlier you said this:
[EL]
Amen.
>
> > > >The refractive index may increase or decrease away from the tested
> > > >frequency (wavelength) about which dispersion is being measured but in
> > > >all those cases dispersion is positive, absolute or simply unsigned.
>
> Which is incorrect. The slope can be positive or it can be
> negative. As it happens, interaction theory predicts that
> the anomalous case of negative dispersion happens only
> under very specific circumstances. Hence it is called
> "anomalous".
[EL]
I shall try to make it very simple and in plain English.
Let us put some marks at regular intervals on the Asphalt with chalk.
We mark one of those marks as a reference and we place one single
stone at the mark on the left of that mark.
We then skip the right mark and place a stone on the next and skip
even two and place one stone and we say that our stone distribution is
dispersed.
If we put ten stones on the first mark and 15 on the next and 3 on the
next and 100 on the next and 1 on the next the stones are still
dispersed but they are less dispersed.
If you cannot understand English forget about the mathematics and all
semantics.
If you dumbly see my analogy as irrelevant then you are dumber than I
thought.
Now let us get back to frequency dependant refractive indexes.
Let us use now more civil techniques like paper and pencils.
Take a mean wavelength of 100 nano-meters and label your intervals
regularly with 10 nm increments and decrements to the right and left
respectively.
Now you have an x-axis with a frequency scale all of which are
positive frequencies to the right side of the origin labelled zero.
Your vertical axis the y-axis shall be used for refractive indexes as
a dependant variable.
The origin is also zero and your maximum may be assumed at 2 and your
effective plotting zone is trapped between y = 1 and y = 2 while the
points are scattered to the left and right of the 100 nm line extended
vertically at x =100 nm.
This means that any discreet frequency must have a positive refractive
index that is more than one and less than 2 for air as an example.
Now let us take a real and practical and emptirical example and work
it out to cut all the crap.
Phosphate crown glass has a refractive index set that correspond a set
of frequencies as follows.
1060.0 nm -> 1.51519
546.1 nm -> 1.52736
365.0 nm -> 1.54503
312.6 nm -> 1.5574
As you can see, as the wavelength decreases (the frequency increases)
the RI increases.
Now the rate of increase can be calculated from the ABSOLUTE deltas
and we may build a new set of |dn|.
{0.01217, 0.01767, 0.01237}
These values are not even a refractive index value category because
they are deltas.
As you can OBVIOUSLY SEE (at least I hope) from this empirical example
that there is no fucking slope.
The first delta is smaller than the second and the second is greater
than the third.
The variance of those deltas is an expression of how much the
refractive-indexes are dispersed or scattered apart.
If the frequency dependant refractive indexes were linearly
proportional over regular wavelength intervals, The variance would be
Zero.
The only slope there is that of the refractive indexes themselves and
the meaningful slope is that of represented as a mean refractive index
for a mean wavelength but delta refractive indexes is not a refractive
index and it is totally irrelevant here.
Delta refractive index is a good measure for scattering or dispersion
and you may wish to convert it into a standard deviation concept
during analysis such that if the group refractive index was 1.5 (ą
0.09) the consequential group velocity should is more or less vg = c /
1.5 (ą 0.09).
There is no such anomaly in which the refractive index dives below [1]
and fabricating equations that effects otherwise is pure bullshit.
Stop fighting it.
Given that the wave number k = 2pi/lambda and omega = 2pi.f
The group velocity
vg = dw/dk
Now you are a mathematician so work it out for yourself as you did
here before to save bandwidth.
This means that the group velocity itself could be negative and could
be positive envelope-wise but deltas do not reflect absolute speeds.
In other words, even if the envelope's relative location seems to be
advancing over identical parts of the carrier wave as a superposition
the past waves that had advanced in propagation are totally unaffected
and the propagation speed is medium dependent constant when that
medium is homogenous and isotropic.
EL
Bilge
>news:<slrnbphhor....@radioactivex.lebesque-al.net>...
>> Robert Clark:
>> >determine if a signal travelled superluminally what would be required
>> >is a round-trip measurement.
>>
>> That is not the case.
>>
>> >This is because of the uncertainty of synchronizing clocks in
>> >two different locations.
>>
>> It's completely unnecessary to synchronize anything.
>
> It is well known among researchers in the foundations of relativity
>the need to synchronize clocks at two locations for comparing times at
>those locations.
Why is it necessary to compare times at two locations? That would
seem to be the hard way to determine whether or not a signal is
superluminal and it would be less accurate in making the determination.
It would seem to me that the simplest way to make this determination
is for the source to arrange that the pulse be split, with one part
of te pulse propagating in vacuum and the other through the apparatus.
You then compare the two pulses and see which leads which.
Bilge
Huh?
Randy Poe
If I throw flour up in the air in a high wind, I say that
the flour is dispersed as well. But that is not what is
meant by "dispersion" in wave propagation. And you know
it, since you admitted (but then backed away from agreeing
with) that dispersion is another name for dn/df.
> If we put ten stones on the first mark and 15 on the next and 3 on the
> next and 100 on the next and 1 on the next the stones are still
> dispersed but they are less dispersed.
> If you cannot understand English forget about the mathematics and all
> semantics.
The thing about the English language is that words have
multiple meanings. I can not guess why you choose this one
in a discussion of wave physics.
I agree the semantics is getting us into ridiculous arguments
about everything but the physics. Let me skip all the
semantic part and see how you reacted to the physics
part: The demonstration that if dn/df is negative (that
if higher frequencies propagate with higher speeds) you
can get wave packets moving faster than the propagation
velocity.
[snip]
> Now let us take a real and practical and emptirical example and work
> it out to cut all the crap.
>
> Phosphate crown glass has a refractive index set that correspond a set
> of frequencies as follows.
>
> 1060.0 nm -> 1.51519
> 546.1 nm -> 1.52736
> 365.0 nm -> 1.54503
> 312.6 nm -> 1.5574
>
> As you can see, as the wavelength decreases (the frequency increases)
> the RI increases.
Right. Therefore this would be a case of positive dispersion,
the usual case, not the anomalous case that gives rise to
superluminal group velocities.
>
> Now the rate of increase can be calculated from the ABSOLUTE deltas
> and we may build a new set of |dn|.
>
> {0.01217, 0.01767, 0.01237}
>
> These values are not even a refractive index value category because
> they are deltas.
> As you can OBVIOUSLY SEE (at least I hope) from this empirical example
> that there is no fucking slope.
There is no slope? What?
> The first delta is smaller than the second and the second is greater
> than the third.
Oh, you mean the trend is not linear over a factor of
3 in wavelength. Do you know what a derivative is?
Apparently not.
Are you aware that the curve y = x^2 has a slope
everywhere, a nonzero derivative everywhere but at
x = 0?
> The variance of those deltas is an expression of how much the
> refractive-indexes are dispersed or scattered apart.
Apparently not only do you not know what a derivative is,
you don't know what a slope is. That explains the
misunderstanding. Remember "rise over run"?
You didn't calculate the slope between points,
but just the delta between y values. The slope dn/d(lambda)
is APPROXIMATED by delta-n divided by delta-lambda.
(rise over run).
In your table I get the values:
-0.0000237 -0.0000976 -0.0002361
The slope dn/d(lambda) is clearly getting more negative
as wavelength decreases.
However, this is only an approximation of slope. A better
one is found by interpolating a smooth curve that passes
through these points, and taking its derivative at
each point. Using that procedure I find these estimates
(second column below):
lambda dn/d(lambda) linear estimate
1060.0 nm -0.0
546.1 nm -0.0000422 -0.0000237
365.0 nm -0.0001495 -0.0000976
312.6 nm -0.0002671 -0.0002361
The estimate of 0 at 1060 was an artifact of the
interpolation procedure I used. It estimated that the
curve was bottoming out at that point, but obviously
if you included more data beyond 1060 nm it would do
a better job.
The last column shows the estimate from "rise over
run". You can see it's the right order of magnitude
but not really a good estimate.
Again, let me skip this obvious misconception and see what
you did with my example of an actual propagating wave
packet.
[snip]
Nothing. You ignored it entirely to focus on the semantic
argument again.
I'm getting off this part of the train. I'm sorry that you
don't understand what a derivative or the slope of a curve
means, or what the sign of a derivative means. That's
irrelevant. I'm going to ask you again, politely, to please
look at my derivation, in which I took:
- one wave moving at speed v1
- another wave of higher frequency moving at speed 1.5*v1
- summed together they give a wave packet with peaks
wherever they are in phase (wavelength 3*lambda1 where
lambda1 = wavelength of first wave)
and showed
- the peaks of that wave packet propagate at 3*v1
This demonstrates that by taking a sum of waves with the
property that higher frequency wave move faster, I get
a wave packet that moves much faster than any individual
wave.
- Randy
EL
Randy wrote
{{{
[Randy]
I'm going to ask you again, politely, to please
look at my derivation, in which I took:
- one wave moving at speed v1
- another wave of higher frequency moving at speed 1.5*v1
- summed together they give a wave packet with peaks
wherever they are in phase (wavelength 3*lambda1 where
lambda1 = wavelength of first wave)
and showed
- the peaks of that wave packet propagate at 3*v1
This demonstrates that by taking a sum of waves with the
property that higher frequency wave move faster, I get
a wave packet that moves much faster than any individual
wave.
- Randy
}}}
And per his request I decided to include his example here to test its
physical validity while having confidence in Randy's mathematical
knowledge.
His example is included complete with his comments and my comments
would be interleaved.
{{{
[Randy]
Suppose we have a really simple wave composed of two
frequencies, f1 and f2. Let us suppose that f2 = 2f1.
Let us also suppose that the speed of propagation for
wave 1 is v, and for wave 2 is 1.5v. So the higher
frequency wave (wave 2) has 50% higher velocity.
The wave is described by
S(x,t) = cos(2*pi*f1*(x/v1 - t)) + cos(2*pi*f2*(x/v2 - t))
You should first make sure you believe that. Each term
describes a wave which is:
- constant for x - v*t = constant
- for fixed t, has spatial period (wavelength)
v/f = lambda
- for fixed x, has temporal period 1/f1
- has phase 0 at x = 0, t = 0.
The first wave has a wavelength of v1/f1 = lambda1, the
second has a wavelength of v2/f2 = (1.5*v1)/(2*f2)
= (3/4)*lambda1
}}}
[EL]
This is a very small glitch and here is the correction.
v2/f2 = (1.5*v1)/(2*f1)
{{{
[Randy]
So every 4 wavelengths of wave 2 corresponds to
3 wavelengths of wave 1, and the packet is in phase
every 4*lambda2 = 3*lambda1. If you fix time t, you
will see the waves add up constructively at x=0
and every 4*lambda1 afterward. These peaks will move
as the wave moves. The rate of advance of the peaks
will be the group velocity, as it is the motion of our
coherent pulse.
So let's analyze what happens as time evolves. Suppose
it is no longer time 0, but a little later, time T.
}}}
[EL]
Here I would like to emphasize on the word "later".
In fact, relativity did not screw anything else than the conception of
time and certainly every thing else consequently.
The classical calculation of wave modulation represented by Randy is
quite legitimate but the problem is in the interpretation of time
"what happens where".
Bare with me because this example should be a perfect example to see
what relativity destroyed, it destroyed the ability of quality minds
to distinguish between reckless sequencing and the impeccable
precision of logical event sequencing.
{{{
[Randy]
The phase of wave 1 is f1*(x/v1-T) and of wave 2 is
f2*(x/v2-T) = 2*f1*(x/(1.5*v1)-T)
These phases are equal where
f1*x/v1 - f1*T = 1.33*f1*x/v1 - 2*f1*T
or f1*T = 0.33*f1*x/v1
or x = 3*v1*T
}}}
[EL]
As you have noticed that I emphasized on the word "later", I would
like to drive the attention of the reader to some facts. When we draw
a graph representing a wave with time on the x-axis and amplitude on
the y-axis, we should pay attention to the meaning of zero time and
positive time more than zero where zero time comes first and more than
zero time comes "later".
This means that looking at the wave graph we should imagine the wave
evolving towards the left side and not to the right side as in
oscilloscopes where raster scanning begins at the left side of the
screen.
The implication of this fact is so great but quite overlooked by many
physicists and almost all mathematicians who take the hype O thesis
from physicists for granted.
Randy demonstrated that x = 3.v1.T, where the product of velocity and
time is a distance of course and that distance is where identifiable
group-wave-peaks may appear in LATER.
I shall not discuss the out-of-synchronisation artefacts of
oscilloscopes here again as you can read it up in this thread.
Now I shall focus on the paper graph and what the physical meaning of
wave modulation means.
It is quite easy to confuse the Time versus Amplitude chart with
velocity chart where Time is versus distance.
If you can avoid that confusion then that is precisely what we need
from the reader here.
{{{
[Randy]
The place where the waves are in phase has moved by a
distance 3*v1*T in time T.
}}}
As you can read in Randy's own statement, he used the expression "a
distance in time T".
We know that the velocity v1 is the distance per unit time traversed
by the wave W1.
We know that the velocity v2 is the distance per unit time traversed
by the wave W2.
To understand how the modulation proceeds we need a spatial reference
GATE through which the two waves propagate and modulate. That gate is
an infinite plane placed orthogonal to the waves' propagational
direction axis, assuming that they are coincident in direction.
T must be a multiple of time units in which a finite portion of each
wavelength is propagating through the medium and across our
referential gate.
Now that portion of the wave is what advances in one time unit.
So what does that distance [3.v1.T] mean?
Randy said that there is a periodically repeating event at which the
two waves become in phase once more and then go out of phase for some
time.
Here are Randy's own words again.
"So every 4 wavelengths of wave 2 corresponds to 3 wavelengths of wave
1"
Naturally W2 is given to be faster than W1 such that every 4 cycles of
W2 correspond to 3 cycles of W1.
The resulting modulation IS a consequence of those two physical
velocities of wave propagation in Length over time dimensions.
{{{
[Randy]
Thus, the peak appears to
be moving forward at 3*v1, despite the fact that
one wave is moving at v1 and the other at 1.5*v1.
As the whole thing has a spatial periodicity of 3*lambda1,
you will find that all of the peaks, spaced 3*lambda1
apart, are similarly marching forward at 3*v1.
}}}
[EL]
This is the crux of the confusion.
Here we ask; what is it that is moving forward and relative to what?
In this particular case, as time advances, the difference in the two
velocities causes the in-phase event to show up at our referential
gate at regular time intervals when 3 cycles of W1 have passed through
the gate or 4 cycles of W2 have passed through the gate.
This means that the frequency of the in-phase event is a Third of the
frequency of W1 or a Quarter of the frequency of W2 if we assumed
proper time to dominate such frequencies.
Let us call this in-phase frequency F, then;
F = f1/3 = f2/4
Hence f2 = 4/3 f1, which contradicts our premise where we assumed that
f2 = 2 f1.
Something hidden must be screwed up here; can you guess what is it?
TIME.
Good guess!
If wave number one was 1000 Hz and wave number two was 2000 Hz then
our referential gate must be THE OBSERVER through which relative
velocities cause a frequency shift, such that 1000 complete cycles are
introduced less frequently than 2000 complete cycles being introduced
more frequently.
Here we propose a standard time window of one proper second in which
1000 complete cycles of wave number one happens and 2000 complete
cycles of wave number two happens concurrently.
By taking the proper time window during which W1 passes through the
gate of observation at its own velocity as our standard time frame we
realise that W2 introduces 3000 complete cycles rather than 2000
because the velocity of observation is 1.5 times faster. This means
that from the Observational gate's point of view the number of
complete cycles of W2 within one time window is 3 times greater than
the complete cycles encountered from W1 and it is not the velocity of
anything at all. When those two waves interfere the less frequent wave
becomes an envelope for the more frequent wave Such that each
composite wave is W1 subdivided into 3 cycles of W2.
This modulated wave becomes a moving reference envelope inside which
the other wave is moving and we end up with (v2/v1).(f2/f1) being a
dimensionless product of ratios that would yield the number 3 that
means nothing in physical essence.
You can see clearly that we could have taken the faster wave as the
reference to which modulation is happening less frequent rather than
more frequent.
So we have the observational freedom to see the faster wave slipping
forward inside the slower wave or to see the slower wave as a
peristaltic motion moving backwards over the faster wave as a
modulation of some constant peak amplitude.
Here I would like to make a historical declaration.
The observational gate that I have proposed does not observe any
velocities once both wavefronts have arrived and being observed, and
all that that gate could observe is the frequency of events because
the gate is stationary in the space of both wave velocities.
You could repeat this exercise by assuming a gate on a railway and let
one train be 1.5 times faster than the other train but both arrive at
the gate simultaneously. Let the size of the cars be twice longer on
the slow train and record your observations regarding the coincidence
of car-joints on both trains.
The gate-observer may have a clock but all he may observe is a
frequency of coincidences and no velocities are perceived at all. The
true velocities are what the trains' wheels make on the iron railway.
This in-phase frequency (car-joints on both trains coinciding) may be
(as in our example) the frequency of 3 cars on the slow train or 4
cars on the fast train.
Now we have two lambdas and one frequency so how can you decide on a
single velocity?
3 cars take 3 times as much as one to pass on the slow train and 4
cars take 4 times as much as one to pass on the fast train. The static
length of 3 slow cars is equivalent to 6 fast cars not 4 and that is
what Lorentz Fitzgerald contraction is all about. Time dilation
follows if we compare times and fix the lengths.
So this idiotic game of juggling numbers makes no physics and makes no
science.
We can hybridize mathematics and physics and come up with negative
dispersion, time dilation, length contraction, black holes and big
bangs, but for what end is this clownish path taking us Randy?
What is so funny and pleasing in fucking with innocent minds?
There are so many people out there that believe that such fiction is
true and real.
I am seriously asking why.
Why the academic establishment allows this comedy?
Are all scientists becoming incompetent to realise and figure out how
this modern wave of fiction is screwing with their sanity and sound
logic?
I see Lemmings, plenty of them, all the time and everywhere.
Rarely do I see like those men that made the solid foundations on
which we stand today.
Lemmings and clones are what the academic institutions are producing
today.
Perhaps it is time for humans to go extinct and rid nature from the
asshole species.
EL
{{{
[Randy]
Robert Clark
Your suggestion may indeed work. What the experimenters appear to
have done in the Wang experiment was to note the time of departure at
the starting point and compare that to the time of the signals arrival
at the endpoint. To make that comparison you need some means of
synchronizing the starting and end points. The standard SR way is to
send a light signal (or some electromagnetic signal) from a point
midway between the two points both ways and the clocks will be started
when they each receive the light signal. This assumes that the light
signal will travel the same speed each way.
Suppose though that light speed is actually slower in the one
direction that the other. Then if there is a signal that travels at a
faster than light speed then it may *appear* to have reached the end
point before it left the start point.
The objection might be made that light speed has been measured and
has been found not to vary. But as discussed in the post by Speicher,
in reality what has been measured is the round trip light speed since
the starting and endpoints have to be synchronized and since this is
done by EM signals this results in a circularity when you deduce the
one way light speed by dividing the round trip travel time by 2.
Bob Clark
EL
> > [Bilge]
> > Why is it necessary to compare times at two locations? That would
> > seem to be the hard way to determine whether or not a signal is
> > superluminal and it would be less accurate in making the determination.
> > It would seem to me that the simplest way to make this determination
> > is for the source to arrange that the pulse be split, with one part
> > of te pulse propagating in vacuum and the other through the apparatus.
> > You then compare the two pulses and see which leads which.
>
> Your suggestion may indeed work. What the experimenters appear to
> have done in the Wang experiment was to note the time of departure at
> the starting point and compare that to the time of the signals arrival
> at the endpoint.
<snip>
> Bob Clark
[EL]
Not true, and I have the Adobe file of Wang Superluminal thing and
here is the label under the fugure.
{{{
Fig. 2. Pulse propagation through a medium of a length L at a group
velocity
vg = c/(n + ν dn/dν). and through vacuum for the same
length.
}}}
As you can see, they planned the equation to force a negative quantity
for (ν dn/dν) such that it exceeds the fraction above unity
in the refractive index of caesium.
If you care to inspect carefully the physical meaning of (ν
dn/dν) you shall realise that relativistic issues are hidden
within this innocent classic form of simple calculus.
The resulting relative velocity assumes [c] to be the moving
observer's speed and then multiply the modulation slipping velocity by
it. So no wonder they came up with a velocity that is 315 times faster
than light. :)
The experimental setup is almost perfect if not literally perfect and
it is exactly as Bilge said.
However, they do not have any physical electronic devices that can
respond to times as small as less than 0.2 ns delays.
That is why they have to record complete traces of waves with equally
compensated delays.
The consequence of the mathematical manipulations is that relative
frequency shifts is taken as a direct consequence of relative velocity
with respect to that of the LASER beam in vacuum.
Naturally, the wave is dispersed due to the different way the medium
responds to different frequencies such that it is quite possible that
the fastest component's propagation speed could be 315 times as fast
as the slowest while all speeds stay below c.
If the slowest wave was assumed to be propagating at c then they must
conclude accordingly that they have achieved superluminal speeds, but
did they?
EL
EL
news:<832ea96d.03102...@posting.google.com>...
> > [Bilge]
> > Why is it necessary to compare times at two locations? That would
> > seem to be the hard way to determine whether or not a signal is
> > superluminal and it would be less accurate in making the determination.
> > It would seem to me that the simplest way to make this determination
> > is for the source to arrange that the pulse be split, with one part
> > of te pulse propagating in vacuum and the other through the apparatus.
> > You then compare the two pulses and see which leads which.
> [Clark]
> Your suggestion may indeed work. What the experimenters appear to
> have done in the Wang experiment was to note the time of departure at
> the starting point and compare that to the time of the signals arrival
> at the endpoint.
<snip>
Robert Clark
The original paper in Nature is available here:
Gain-assisted superluminal light propagation.
L. J. Wang, A. Kuzmich & A. Dogariu
NEC Research Institute, 4 Independence Way, Princeton, New Jersey
08540, USA
NATURE, VOL 406, 20 JULY 2000, p. 277-279.
http://www.physik.uni-stuttgart.de/institute/pi/5/lehre/wp2001/nature2001-chien.pdf
A passage on page 278 suggests the departure points and arrival
points have to be time synchronized:
"A high-sensitivity avalanche photodiode,
reverse-biased below breakdown, serves as detector D2 to measure
the weak probe pulse that propagates through the atomic cell. The
photoelectric current produced by detector D2 is converted to a
voltage signal using a 500-Q load resistor and recorded by a
digitizing oscilloscope using a synchronized output signal from
the pulse generator as the trigger."
Gain-assisted superluminal light propagation, p. 278
The equations that you cited I think are actually in a more detailed
examination that is available on lead author Lijun Wang's web site:
Superluminal Light Pulse Propagation at a
Negative Group Velocity.
http://www.neci.nec.com/homepages/lwan/paper/paper46.pdf
The equations you cited used greek letters that didn't show up in the
usenet post. I'll use the letter w to represent the frequency that
appears in the first equation you cited. Then the equation says:
Vg = c/(n + wdn/dw) , where Vg is group velocity, c is light speed, n
is refractive index and w is frequency.
The researchers were able to achieve superluminal group velocity by
making the derivative dn/dw highly negative, that is, the refractive
index rapidly decreases as the frequency increases.
They explain their work simply here:
Detailed statement on faster-than- c light pulse propagation.
http://www.nec.co.jp/press/en/0007/images/1901.pdf
Here they explain that the laser pulse exited the 6 cm long cesium
chamber 62 nanoseconds sooner than if the laser traveled the 6 cm in
vacuum. Since it takes only 0.2 nanoseconds for light to traverse 6 cm
in vacuum, this means the pulse exited the chamber before it entered
it.
The suggested explanation for this effect is that some portion of the
entering pulse reaches the end detector before the full pulse enters
the chamber from which the full pulse was reconstructed. This
explanation however could be applied whenever you did get a result
that suggested the pulse traveled superluminally.
An improved test to see if the signal is traveling superluminally
might be to use a longer chamber 100 meters long for example. Light
takes 330 nanoseconds to traverse this length. In the first experiment
the authors say the exiting pulse traveled 20 meters before the
starting pulse entered the chamber. If the time shift is the same in
the 100 meter long chamber, the exiting pulse should leave after the
starting pulse enters this time. Then you could see if the travel time
is less than that for light in vacuum. You might still be able to
argue that what is happening is some portion of the starting pulse is
being transmitted early to the end detector, but it won't really
matter if it still provides a means of signaling in a shorter time
that light signals would take.
Bob Clark
EL
> Here they explain that the laser pulse exited the 6 cm long cesium
> chamber 62 nanoseconds sooner than if the laser traveled the 6 cm in
> vacuum. Since it takes only 0.2 nanoseconds for light to traverse 6 cm
> in vacuum, this means the pulse exited the chamber before it entered
> it.
[EL]
My problem with those supposedly scientists is that they do not feel
ashamed to say that nonsense and repeat it as if it was so normal
logic and they claim with boldness that it does not violate causality.
If that nonsense did not violate causality then what else does?
> The suggested explanation for this effect is that some portion of the
> entering pulse reaches the end detector before the full pulse enters
> the chamber from which the full pulse was reconstructed.
[EL]
How strange!
I was under the impression that a group velocity demands the full
arrival of the wave envelope to the detector or else there is no group
to have a velocity. If only a portion of the modulated wave have
arrived first then it must be the fastest component wave which we
already know its frequency and its refractive index and its velocity
to be subluminal as well. So what is this game, hide and seek?
>This
> explanation however could be applied whenever you did get a result
> that suggested the pulse traveled superluminally.
[EL]
What results, the mathematical calculations and the curve fitting?
My dear sir, the results were set before the experiment even started.
Once the scientist's conscious accepts a negative frequency, which is
the reciprocal of negative time then that scientist's conscious is
elastic enough to hold all the shit a bull could handle. :)
Wave modulation of different velocities demands that the full cycles'
phases sweep each other interactively which takes positive time.
Therefore the wave envelope needs positive time to be created and we
can see that wave packets have envelopes that are less frequent than
the waves that combine.
I suggested taking the absolute value of the deltas to avoid the
illogical negative time concept being introduced.
When all mathematical manipulation are repeated by taking the absolute
value of the differentiation all results shall fit perfectly without
any paradoxes or anomalies that demand twisted logic and inverse
causality, or selling bull shit wrapped in shinolla. :)
EL
EL
> Your suggestion may indeed work. What the experimenters appear to
> have done in the Wang experiment was to note the time of departure at
> the starting point and compare that to the time of the signals arrival
> at the endpoint. To make that comparison you need some means of
> synchronizing the starting and end points. The standard SR way is to
> send a light signal (or some electromagnetic signal) from a point
> midway between the two points both ways and the clocks will be started
> when they each receive the light signal. This assumes that the light
> signal will travel the same speed each way.
> Suppose though that light speed is actually slower in the one
> direction that the other. Then if there is a signal that travels at a
> faster than light speed then it may *appear* to have reached the end
> point before it left the start point.
> The objection might be made that light speed has been measured and
> has been found not to vary. But as discussed in the post by Speicher,
> in reality what has been measured is the round trip light speed since
> the starting and endpoints have to be synchronized and since this is
> done by EM signals this results in a circularity when you deduce the
> one way light speed by dividing the round trip travel time by 2.
>
>
> Bob Clark
[EL]
I was under the impression that in all dispersive media the phase
velocity was a function of the wavelength, which also means that the
refractive index is a function of frequency.
If my information was correct then that is why a dispersion prism can
separate a compound wave into its components by separating each
frequency along a different angle of refraction.
If that was true then dispersive prisms should have no wave packets or
a group velocity at all.
Why in theory, the mathematical formulism does not state that the
angle of incidence must be normal to the plane of the dispersive
medium surface to avoid separating the packet into its components?
Also if FTL experiments are not fallacious then why is there no mixing
of blue and violet to obtain ultraviolet ahead of the group, which
should be separable by a prism?
Indeed I know why, because those waves are ink on paper only and
fabricated hoopla that is founded on hypnotized audience clapping for
every clown under the light spot in the modern physics circus.
Kind regards.
EL
Bilge
>news:<832ea96d.03103...@posting.google.com>...
>
>> Here they explain that the laser pulse exited the 6 cm long cesium
>> chamber 62 nanoseconds sooner than if the laser traveled the 6 cm in
>> vacuum. Since it takes only 0.2 nanoseconds for light to traverse 6 cm
>> in vacuum, this means the pulse exited the chamber before it entered
>> it.
>
>[EL]
>My problem with those supposedly scientists is that they do not feel
>ashamed to say that nonsense and repeat it as if it was so normal
>logic and they claim with boldness that it does not violate causality.
>If that nonsense did not violate causality then what else does?
You actually have to read several of their papers to figure out what
they mean. The buzzword used is "rephasing". It's not clear to me that
"superluminal" applies to a signal that can carry information, or at least
carry information superluminally. The papers show some plots that give a
better idea of what's going on, but it's too hard to try and reproduce
them or describe them here. Search for "rephasing" and "superluminal"
EL
[EL]
Thank you Bilge for giving me such valuable advice to do my homework.
However, I did not need to wait for a good man to push me to educate
myself before ranting.
My dear friend, that Wang group admitted to have set the results
before the experiment and that they tuned the experiment to provide
the data which they plugged into the equations, hence there was no
superluminal measurements of any credible sense.
The whole scam is not their fault really because classical wave
mechanics already teaches that group velocities may exceed any and all
of the components velocities in special anomalous dispersive media,
which is utter nonsense.
Even if Jackson's was an almost perfect and impeccable reference, I
still demand to reserve my rights as a scientist to question
ambiguities and illogical assertions.
The official formalism of group velocity in dispersive media
overlooked the critical condition of the angle of incidence that would
prevent the wave separation into its components as we know with
prisms.
Let V stand for velocity, F for frequency, L for wavelength and N for
refractive index.
Reliable references state that
Vg = c / Ng
Some clever dude thought that if Ng fell below unity then a group's
velocity may exceed c.
To cut a long post short, the whole idea boils down to take Vg = delta
F Times delta L
So the trick is to find such a high frequency that is also related to
a long wavelength to exceed c.
All reliable sources prove that this case is impossible and beyond
impossible.
Fabrications go around finding a negative frequency such that its
reciprocal is negative time, which the mathematician may subtract from
the required period rather than adding it to the period of
propagation.
We all know that negative velocities are absolute speeds in the
relatively negative spatial direction, so why is time allowed to be
subtractive rather than qualitatively descriptive?
When Vg = V – L (dV/dL) we tend to overlook the fact that a negative
(dV/dL) is in fact a negative dF.
Negative frequency means negative time as well and rather than being
added it is subtracted and the velocity is increased rather than
decreased. But we do know that wave modulation envelopes are less
frequent than all of the contributing components, so why do we allow
this illogical formula to smear our books?
EL
Bilge
>dub...@radioactivex.lebesque-al.net (Bilge)
>> EL:
>> >rgrego...@yahoo.com (Robert Clark) wrote in message
>> >news:<832ea96d.03103...@posting.google.com>...
>> >
>> >> Here they explain that the laser pulse exited the 6 cm long cesium
>> >> chamber 62 nanoseconds sooner than if the laser traveled the 6 cm in
>> >> vacuum. Since it takes only 0.2 nanoseconds for light to traverse 6 cm
>> >> in vacuum, this means the pulse exited the chamber before it entered
>> >> it.
>> >
>> >[EL]
>> >My problem with those supposedly scientists is that they do not feel
>> >ashamed to say that nonsense and repeat it as if it was so normal
>> >logic and they claim with boldness that it does not violate causality.
>> >If that nonsense did not violate causality then what else does?
>>
>> You actually have to read several of their papers to figure out what
>> they mean. The buzzword used is "rephasing". It's not clear to me that
>> "superluminal" applies to a signal that can carry information, or at least
>> carry information superluminally. The papers show some plots that give a
>> better idea of what's going on, but it's too hard to try and reproduce
>> them or describe them here. Search for "rephasing" and "superluminal"
>
>[EL]
>Thank you Bilge for giving me such valuable advice to do my homework.
>However, I did not need to wait for a good man to push me to educate
>myself before ranting.
some of the details in the papers I've seen referenced on this
forum may be found by searching for "rephasing" and "superluminal".
None of the papers mentioned so far actually describe what the
authors mean by "rephasing". The term is only referenced.
>My dear friend, that Wang group admitted to have set the results
>before the experiment and that they tuned the experiment to provide
>the data which they plugged into the equations, hence there was no
>superluminal measurements of any credible sense.
claiming without discussing rephasing and how that might relate
to what they mean by signal propagation.
>The whole scam is not their fault really because classical wave
>mechanics already teaches that group velocities may exceed any and all
>of the components velocities in special anomalous dispersive media,
>which is utter nonsense.
>
>Even if Jackson's was an almost perfect and impeccable reference, I
>still demand to reserve my rights as a scientist to question
>ambiguities and illogical assertions.
I offered a means to resolve the ambiguities over which the arguments
here have so far been based. The fact is, they _did_ measure something
and there is no reason to doubt that they measured what they claim
in the articles being discussed. It would be illogical to to deny that
they measured the pulse propagation through the dispersive media
to arrive earlier than the one in vacuum. However, their explanations
reference articles which aren't being discussed here.
>The official formalism of group velocity in dispersive media
>overlooked the critical condition of the angle of incidence that would
>prevent the wave separation into its components as we know with
>prisms.
It's actually irrelevant _how_ the pulse mangages to propagate through
the medium at an apparently superluminal velocity. All that matters is
whether it did without distorting the pulse shape and whether the pulse
shape can be used to propagate information at superluminal velocities.
They've obviously managed to acheive the former and the articles being
discussed here do not really address the latter. The articles referenced
in those papers address the latter in more detail.
[...]
>So the trick is to find such a high frequency that is also related to
>a long wavelength to exceed c.
>
>All reliable sources prove that this case is impossible and beyond
>impossible.
>
>Fabrications go around finding a negative frequency such that its
>reciprocal is negative time, which the mathematician may subtract from
>the required period rather than adding it to the period of
>propagation.
The fact is, the investigators demonstrate a gaussian pulse traversing
a medium and then emerging undistorted in a time less than that of
a pulse in vacuum. How they explain it in the article apperently being
discussed might or might not be very clear, but I suggesting searching
for the terms "rephasing" and "superluminal" for that very reason.
EL
> >[EL]
> >Thank you Bilge for giving me such valuable advice to do my homework.
> >However, I did not need to wait for a good man to push me to educate
> >myself before ranting.
>
> I'm not ranting.
[EL]
I never meant that you were but I thought that you might consider that
I am ranting and need education.
> I'm pointing out that articles which describe
> some of the details in the papers I've seen referenced on this
> forum may be found by searching for "rephasing" and "superluminal".
> None of the papers mentioned so far actually describe what the
> authors mean by "rephasing". The term is only referenced.
[EL]
Oh! But I did and all search take you into a full round fools picnic
and brings you back to where you started.
I strongly suggest that if you have some knowledge on the issue that
would add or change my stance you are strongly being encouraged to
bring it forth before I make my mind irreversibly on this matter.
The error is classic and all modern justifications brings in GR and
even unsettled issues concerning virtual particles and similar
fiction.
I apologise for snipping the rest of your responses together with mine
but I though that it would be a waste of time if you were just going
to refer me to a web search that yields nothing fruitful.
If I did not do my homework and know that vacuum is a homogenous and
isotropic medium that is affected by all forms of fields that can
populate it such as magnetic and or gravitational fields, when long
distances are the case along which propagation takes place, I would
have swallowed the re-phasing issue but the best that can affect EMR
as far as I know empirically is bending the path without affecting the
speed or the wave-shape.
So this excludes the hoopla of virtual particles effect and the
general-relativity negative time.
Now we were talking about a caesium gas in which light is claimed to
propagate with a superluminal group velocity and I have pointed out my
reasons for rejecting all their fundamental explanations and the
formula they are using, so what is the merit of searching for
irrelevant explanations like a fool unless I was a fool in your eyes.
Bring your argument and let us settle this Bilge because I am willing
to learn from you or teach you something new. I can admit a mistake if
I made one and I can teach you how to say {NO This Is Not Science}.
EL
ralph sansbury
year or so ago but maybe this will help.
Rationale of Lijun Wang's experiment on
superluminal light propagation July 20,, Nature,
1) An advance( or delay) of phase of a received oscillation
appears
as if the arrival of a hypothetical
wave at the receiver occurred after a delay that is less(or
greater) than the
speed of light delay.
This advance(delay) of phase is relative to that which would
occur if
the received oscillation was
transmitted through air instead of a medium with a value of the
refraction
index less than(greater than) one.
It is important to note that the wave description is a
metaphor and is not
something directly observed as a wave in water.
The effect of such a medium is to produce secondary
oscillations
in the atoms of the medium that produce oscillations at a
distance that
interfere with each other and the oscillations produced by the
source.
The observed effect of such a medium is to bend the normal
direction
of the hypothetical wave fronts which requires, for an equal
boundary,
a change in the velocity to c/n and wavelength to (lambda)/n
between wave
fronts of the hypothetical waves.
If Wang's 6cm long paraffin coated pyrex container (of
ceasium) had an index of
refraction of n, then n-1 times
6(10^-2)/8.52(10^-7) is the difference in the number of
wavelengths in the
medium versus that in a vacuum and the fractional value here
would
give the advance or delay of phase of the individual
oscillations.
852nm is the Cesium D2 oscillation.
The diffraction index value is due to the dispersion equation
and the
relative oscillator strength of an oscillator in the material
just a little
lower in frequency than the transmitted frequency and to the
damping
coefficient characteristic of the material of the medium.
2) If you are adding two waves of slightly different
wavelengths and the
longer wavelength wave is moving faster( slower), the sum of the
crests will
move back(forward) somewhat because of this but forward also
because both
waves are moving forward.
In the forward-forward case, if the individual waves are
faster than
light in the sense above, then the group velocity would also be
faster than
light in the sense above contrary to statements in some texts
that the phase
velocity may exceed the speed of light but the group velocity
doesn't.
But again the result of the effects of the source and
secondary
scatterers on the receiver is what is being observed. The
resulting 'faster
than light speed' delay between two wave peaks of the group wave
is not
the same as observing a faster than light speed delay between a
light
pulse leaving the source and a light pulse occuring at the
receiver.
I gather that Lijun Wang's experiment shows a specific example
of this
possibility involving the Raman effect in molecules of a cesium
gas medium
and subject to an applied magnetic field etc.
"EL" <hem...@hotmail.com> wrote in message
news:7563cb80.03110...@posting.google.com...
EL
Hello Ralph Sir. :)
"ralph sansbury" <sans...@bestweb.net> wrote in message news:<vqaj30d...@corp.supernews.com>...
> It is important to note that the wave description is a
> metaphor and is not something directly observed as a
> wave in water.
[EL]
A metaphor!
You mean it is not really a thing with a Wave-length and a
Wave-frequency and a Wave-velocity!
Oh! Then there is nothing to worry about since this should lead to a
Hype O' theatrical faster than light speed.
How comforting! :)
> The effect of such a medium is to produce secondary
> oscillations in the atoms of the medium that produce
> oscillations at a distance that interfere with each other and
> the oscillations produced by the source.
[EL]
Very interesting indeed (as if I did not know <smiling>).
This means that both the source signal and OTHER signals (echoes)
originating from the resonant gas cavity must coexist to interact and
that also means that the timing at which the source signal enters the
cavity is irrelevant to what we can see on the output as a result of
the resonant gas cavity originated waves.
So we may leave the cavity to oscillate for let us say 315 times
before we send another source signal to trigger the comparator for
time interval measurements and we pretend to be very surprised that
there was output before we even send an input.
How nice! :)
> But again the result of the effects of the source and secondary
> scatterers on the receiver is what is being observed.
> The resulting 'faster than light speed' delay between two wave
> peaks of the group wave is not the same as observing a faster
> than light speed delay between a light pulse leaving the source
> and a light pulse occuring at the receiver.
[EL]
This is fabulously priceless.
Thank you sir for being so informative.
My retarded mind deluded me into understanding wrongly that faster was
an adjective that concluded a race.
You know, like on your MARKS, get SET and GO!
In my rotten and old fashioned mind, faster meant covering the same
distance in less time or covering more distance within the same time
interval.
How silly of me! :)
>
> I gather that Lijun Wang's experiment shows a specific example
> of this
[EL]
You mean cheating in a wave race competition!
Yes they certainly succeeded in giving us an example but we need to
make an example of those scientists to deter others from repeating
such deceit.
I suggest putting them in a caesium chamber, where caesium is pure and
not mixed with oxygen. :)
Then shower them with LASER waves faster than light so that they die
before even entering the chamber. ;)
LOL.
It was nice having fun with you sir, and I do hope to read your posts
around a new scam and have a couple of laughs, if you do not mind of
course. :)
EL.
Bilge
>dub...@radioactivex.lebesque-al.net (Bilge)
>> I'm pointing out that articles which describe
>> some of the details in the papers I've seen referenced on this
>> forum may be found by searching for "rephasing" and "superluminal".
>> None of the papers mentioned so far actually describe what the
>> authors mean by "rephasing". The term is only referenced.
>
>[EL]
>Oh! But I did and all search take you into a full round fools picnic
>and brings you back to where you started.
So, what about rephasing did you find to be s problem?
>I strongly suggest that if you have some knowledge on the issue that
>would add or change my stance you are strongly being encouraged to
>bring it forth before I make my mind irreversibly on this matter.
What makes you think I have an opinion one way or the other
or really care whether you do? If you aren't interested in the
experiment at all why are you bothering to post? If you're interested
in the experiment, I've told how to find more information. If
not, don't look and save the effort. Besides, I'd have to post it
last week for it to have an effect on what you've decided.
EL
> EL:
> >dub...@radioactivex.lebesque-al.net (Bilge)
>
> >> I'm pointing out that articles which describe
> >> some of the details in the papers I've seen referenced on this
> >> forum may be found by searching for "rephasing" and "superluminal".
> >> None of the papers mentioned so far actually describe what the
> >> authors mean by "rephasing". The term is only referenced.
> >
> >[EL]
> >Oh! But I did and all search take you into a full round fools picnic
> >and brings you back to where you started.
>
> So, what about rephasing did you find to be s problem?
[EL]
How many new expressions do physicists have to invent to cover up
their asses?
If all that jumbled mumbles are about wave shapes then I still have
objections on claiming that a wave shape deformation can happen faster
than light because every local field vector that does not involve a
distance is not a speed, and any propagation is a function of the
parameters of the medium and have nothing to do with a wave shape.
This silly game is identical to here we go round the mulberry bush.
>
> >I strongly suggest that if you have some knowledge on the issue that
> >would add or change my stance you are strongly being encouraged to
> >bring it forth before I make my mind irreversibly on this matter.
>
> What makes you think I have an opinion one way or the other
> or really care whether you do?
[EL]
The thread is still on the record, and I did not invite you to give
the advice you gave willingly.
Giving such advice implies that you assume my ignorance of something
you know and that you so kindly felt that I should be educated.
So I am here on this thread as a pear and refuting the silly fallacy,
while I have no freaking idea what you want to say and if you have
nothing to say then what the flower are you posting here for? :)
> If you aren't interested in the experiment at all why are you bothering to post?
[EL]
Dear Bilge, are you suggesting that I must be interested or shut up?
How about being disgusted rather than interested!
Does pear review mean saying Amen!
Get a grip.
> If you're interested in the experiment,
> I've told how to find more information.
[EL]
And I told you that I complied and found links pointing me to links
pointing me to links pointing me to links pointing me to links
pointing me to links pointing me to links like a real fool, so tell me
if you have enjoyed that ride. :)
> If not, don't look and save the effort.
[EL]
I made the effort in good faith to give the Wang group the benefit of
the doubt.
The result was more confirmation of the fallacy being a hoopla and
hype of theses.
> Besides, I'd have to post it last week for it to have an effect on what you've decided.
>
[EL]
Funny, but I am seriously willing to change my mind if you could find
an error in my reasoning to condemn that superluminal claim.
I am very sorry to have found your suggestion to be an obvious way to
gain time or to avoid the embarrassment of an agreement with or
against the fallacy.
If you have no opinion at all then let me be.
EL
Bilge
>in message news:<slrnbqbm50....@radioactivex.lebesque-al.net>...
>> EL:
>> >dub...@radioactivex.lebesque-al.net (Bilge)
>>
>> >> I'm pointing out that articles which describe
>> >> some of the details in the papers I've seen referenced on this
>> >> forum may be found by searching for "rephasing" and "superluminal".
>> >> None of the papers mentioned so far actually describe what the
>> >> authors mean by "rephasing". The term is only referenced.
>> >
>> >[EL]
>> >Oh! But I did and all search take you into a full round fools picnic
>> >and brings you back to where you started.
>>
>> So, what about rephasing did you find to be s problem?
>
>[EL]
>How many new expressions do physicists have to invent to cover up
>their asses?
phrase suggests anything about "covering asses"? To the contrary, I
don't see that it's "covering" anything except in the case that
someone mistakes the group velocity for the signal velocity.
>If all that jumbled mumbles are about wave shapes then I still have
>objections on claiming that a wave shape deformation can happen faster
>than light because every local field vector that does not involve a
>distance is not a speed, and any propagation is a function of the
>parameters of the medium and have nothing to do with a wave shape.
>This silly game is identical to here we go round the mulberry bush.
demonstrates the non-deformation of a gaussian pulse propagating
through cesium and arriving ahead of the same pulse in vacuum.
>> >I strongly suggest that if you have some knowledge on the issue that
>> >would add or change my stance you are strongly being encouraged to
>> >bring it forth before I make my mind irreversibly on this matter.
>>
>> What makes you think I have an opinion one way or the other
>> or really care whether you do?
>
>[EL]
>The thread is still on the record, and I did not invite you to give
>the advice you gave willingly.
What does that have to do with what you assume my opinion about
the description of the phenomenon happens to be? You immediately
assumed something based only on me pointing out where additional
information might be found.
>Giving such advice implies that you assume my ignorance of something
>you know and that you so kindly felt that I should be educated.
Given your argument regarding group velocities, the assumption is
valid since you aren't talking about the same thing as the authors,
who differentiate between signal velocity and group velocity. If
you wish to take that as some slight to your manhood, ok. There's
nothing I can do about that. I usually read the material someone
suggests rather than looking for my dueling pistols under the
assumption the reference was a glove being slapped in my face.