Hey Horace.
Damned if I can find my copy of QED, but it seems the
link to the original story is working again. Two
thoughts.
First, looking at the graph, we see the reference pulse/count profile
for light speed is spread over a huge range, something like
40 feet of free space. There is no need for any of the
experimenters clever messing with polarizing filters
or birefringent materials, if you are correct fully
half of the photons IN THE REFERENCE CONDITION are
traveling faster than C, not a tiny percentage of
them and at speeds 3*c and much more. Heck, if
my reference pulse was doing that, I'd drop
the actual experiment immediately and call the nobel
prize people. And as you say, it would be trivial
to construct the devices you suggest to achieve
superluminal velocity. Something is wrong here.
What the experimenters are doing to change the group
velocity is to make the dissipation different for
the leading and trailing edges. The result is an
overall reduction in counts, but less on the
leading edge than the trailing edge. Again I've
done the exact same thing with nonlinear transmission
lines, with roughly the same results. You can
indeed get the calculated group velocity to
exceed C.
Here's the rub. The gold standard I used to make
measurements in the radio circuits I worked with was the following.
The distance d is measured as direct line of site from the
sender to the receiver. If, for example, we make a triangle
of bare wire and launch a pulse on it, the first detectable signal
will arrive as if it traveled directly along the base of the
triangle, not up and down the arms. You might say this is
a ground wave, but really it looks more like all paths are
being traversed, not just the wire path, but at a much
lower signal strength. Sounds sort of familiar, huh??? (grin).
wire
*******************
* *
* d *
Sender * ------------------> *Receiver
The time is measured as the 50% point on the leading edge
of the shock wavefront. We used mercury relays and spark
gaps to generate the pulses, risetimes were in the
100's of picosecond range so from the point of view
of the total circuit the shock front was basically
a straight wall.
K.
-----Original Message-----
From: Horace Heffner [mailto:[EMAIL PROTECTED]
Sent: Wednesday, December 08, 2004 11:49 PM
To: [EMAIL PROTECTED]
Subject: RE: Superluminal cavity resonances was RE: Fast-food for
thought
At 1:53 PM 12/8/4, Keith Nagel wrote:
>Hi Horace.
>
>I wanted to address you points with the article text, but
>the link has gone sour...
>
>Anyway, I think your differentiation is moot. I can build
>a radio circuit that displays behavior EXACTLY as shown
>in the graph.
Yes, but that is not *my* point. My point is that the graph is really a
histogram comprised of individual photon measurements. Some are faster
than light. The subject measurements (in the graph) show that, but
conventional QM, especially QED shows that to be true theoretically also.
Some photons can be *statistically* depended upon to be faster than light.
The method I suggest takes advantage of that fact to transmit data faster
than light on average.
I don't know of any method for detecting single photon radio waves, but
such a method might exist.
>The link I posted to Nimtz illustrates
>how this can be done ( my own work is unpublished or
>I'd link you to it instead). The key issue remains, how do we
>define velocity?
It could be defined, for a two way data transmission system, as repeated
meaningful transmission of data x over distance d, and return in average
time t of transmission t of a meaningful response message f(x), as v =
t/(2d).
Achieving FTL is then the condition v > c, or t < 2d/c. I think the method
I proposed achieves this.
>As the authors point out, the older notions
>of group and phase velocity need be extended to include
>a third velocity, what they call the "signal velocity"
>or what I call the transistion or shock velocity.
>
>Horace writes:
>>I think it is fairly well known in QM that all photons
>>do not travel at c, but rather have a distribution of travel times.
>
>Really? Are you saying that photons in a vacuum can travel
>faster or slower than c according to QM? That doesn't
>seem right to me. Or are you trying to describe the fact
>that photons tend to take all possible paths from the
>source to the receiver and therefore arrival times can
>vary. I seem to remember this from Feynmans QED, and I've seen
>the exact same thing with free space antennae.
Both. In his book *QED - The Strange Theory of Light and Matter*,
Princeton University Press, 1985, Feynman states on page 89: "The major
contribution of P(A to B) occurs at the conventional speed of light - when
(X_2 - X_1) is equal to (T_2 - T_1). - where one would expect it all to
occur, but there is also an amplitude for light to go faster (or slower)
that the conventional speed of light. You found out in the last lecture
that light doesn't only go in straight lines; now you you find out it
doesn't only go at the speed of light!"
He does go on to say [importantly]: "It may surprise you that there is an
amplitude for a photon to go faster or slower than the conventional speed
c. The amplitudes for these possibilities are very small compared to the
contribution from speed c; in fact they canel out when light travels over
long distances."
It appears (from the data) the subject experimenters found a means of
extending the range of the alternative amplitudes through use of polarized
photons and a birefringent fiber. In any event, I think the data published
in the graph support the FTL communications means I proposed.
Regards,
Horace Heffner
