W
Wolfgang G. Gasser
At least from a superficial point of view, there is a fundamental
difference between Coulomb interaction (Maxwell's first law) and
and electromagnetic radiation.
- In the case of e.m. transversal radiation (photons), conservation
of momentum and energy occurs on the one hand between emitter and
radiation, and on the other hand between radiation and receiver,
but not between emitter and receiver, i.e. there is no retroaction
of the receiver on the emitter.
- Yet the measurement of a Coulomb force is not possible without
a direct retroaction on the source of the Coulomb force.
- The action via radiation from an emitter to a receiver can be
switched on and off. The action can be stopped by deviating or
absorbing the radiation. All this is impossible in the case of
pure electric and magnetic interaction. (The only way to prevent
the action of electric or magnetic fields consists in creating
inverse fields, e.g. using a Faraday cage.)
Considering these fundamental differences, the fact that e.m.
radiation propagates at c cannot be taken for experimental
evidence that changes of the Coulomb field also propagate at c.
Because there doesn't seem to exist (convincing) experiments on
the propagation speed of Coulomb field changes in the literature,
I started almost two years ago my own experiments with a not too
expensive oscilloscope (Tektronix TDS2022, 200 MHz, 2 GHz).
The main problem of measuring the propagation speed of electric
field changes results from the fact, that a substantial amount of
charge must be displaced in the emitter in a very short time (in
order to entail a measurable field change at a given distance). Yet
charges move only at around 2/3 c (20 cm/ns). The more distant
from the emitter a measurement takes place, the longer the charges
must move so that the field changes become measurable. (The field
of an electrostatic dipole decreases with 1/d^3.)
Therefore, even under the hypothesis that electric fields are
instantaneous actions at a distance, it would be quite easy to
design experiments resulting in time delays (of a distant antenna
wrt a near antenna) in the order of t = d/(2/3 c) = 1.5 d/c.
Nevertheless, high-voltage discharges between two conducting
spheres (each 30 cm diameter in my case) leading to substantial
charge transfers seem to be a practicable way in order to get
convincing experiments.
_ _
_ _ / \
/ \ / \ >- \ _ _ _ _ _ _ _ /
\ _ / \ _ / _|_|_ \
|_____|
spheres with
spark gap antenna oscilloscope antenna
A simple influence machine is enough to generate high voltage
sparks leading to substantial charge displacements in short
periods of time. The spheres, the probes with the Coulomb antennas
and the oscilloscope are all placed in one line (where transversal
radiation from the spark, emitted rather perpendicularly to this
line, is negligible).
When charging the spheres, the Coulomb antennas connected to the
probes take the opposite charge of the nearby of the two spheres.
Because the charging of the spheres and antennas occurs slowly, the
currents and voltages are too weak to show up on the oscilloscope.
The discharge however is in the nano-second range. Thus enough
charge per time goes from the antennas to the oscilloscope so
that measurable single-shot signals can be triggered. The time
difference of the two signals can be compared on the screen of
the oscilloscope.
Precautions:
- The signals of each channel must not be influenced by the
presence of the antenna of the other channel.
- The signals must disappear or at least become weaker and delayed
(because of input capacitance loss) in the absence of the Coulomb
antenna (the probe itself is a weak Coulomb antenna).
- The two signals should be of similar order of magnitude.
I've tried several different setups. I also used a few times a
LeCroy, WaveRunner 6100A, DC-1GHz, which showed me that the results
are essentially the same as with my own oscilloscope.
According to my experiments, time differences between the signals
of the nearby and the distant antenna of t = d/2c can easily be
achieved, e.g. 4 ns in the case of a distance 2.4 m, thus clearly
suggesting faster-than-light propagation of the field changes from
the nearby to the distant antenna (light needs 8 ns for 2.4 m).
Because these are single-shot experiments, the results also suggest
FTL information transfer.
Cheers,
Wolfgang Gasser (2007-07-07)
__________________________________________________________________
ADDENDUM (2007-07-11):
More than three days have passed since I posted the above message
to sci.physics.research, but the moderators probably don't want
to direct their reader's attention to "the shame that such a basic
property of electromagnetism as the speed of propagation of the
Coulomb and magnetic potentials still has not been measured".
It would be great if someone could repeat the experiment. Even
better would be a replacement of the spark gap by a high voltage
thyristor or a set up with a powerful semiconductor nanosecond
pulser.
difference between Coulomb interaction (Maxwell's first law) and
and electromagnetic radiation.
- In the case of e.m. transversal radiation (photons), conservation
of momentum and energy occurs on the one hand between emitter and
radiation, and on the other hand between radiation and receiver,
but not between emitter and receiver, i.e. there is no retroaction
of the receiver on the emitter.
- Yet the measurement of a Coulomb force is not possible without
a direct retroaction on the source of the Coulomb force.
- The action via radiation from an emitter to a receiver can be
switched on and off. The action can be stopped by deviating or
absorbing the radiation. All this is impossible in the case of
pure electric and magnetic interaction. (The only way to prevent
the action of electric or magnetic fields consists in creating
inverse fields, e.g. using a Faraday cage.)
Considering these fundamental differences, the fact that e.m.
radiation propagates at c cannot be taken for experimental
evidence that changes of the Coulomb field also propagate at c.
Because there doesn't seem to exist (convincing) experiments on
the propagation speed of Coulomb field changes in the literature,
I started almost two years ago my own experiments with a not too
expensive oscilloscope (Tektronix TDS2022, 200 MHz, 2 GHz).
The main problem of measuring the propagation speed of electric
field changes results from the fact, that a substantial amount of
charge must be displaced in the emitter in a very short time (in
order to entail a measurable field change at a given distance). Yet
charges move only at around 2/3 c (20 cm/ns). The more distant
from the emitter a measurement takes place, the longer the charges
must move so that the field changes become measurable. (The field
of an electrostatic dipole decreases with 1/d^3.)
Therefore, even under the hypothesis that electric fields are
instantaneous actions at a distance, it would be quite easy to
design experiments resulting in time delays (of a distant antenna
wrt a near antenna) in the order of t = d/(2/3 c) = 1.5 d/c.
Nevertheless, high-voltage discharges between two conducting
spheres (each 30 cm diameter in my case) leading to substantial
charge transfers seem to be a practicable way in order to get
convincing experiments.
_ _
_ _ / \
/ \ / \ >- \ _ _ _ _ _ _ _ /
\ _ / \ _ / _|_|_ \
|_____|
spheres with
spark gap antenna oscilloscope antenna
A simple influence machine is enough to generate high voltage
sparks leading to substantial charge displacements in short
periods of time. The spheres, the probes with the Coulomb antennas
and the oscilloscope are all placed in one line (where transversal
radiation from the spark, emitted rather perpendicularly to this
line, is negligible).
When charging the spheres, the Coulomb antennas connected to the
probes take the opposite charge of the nearby of the two spheres.
Because the charging of the spheres and antennas occurs slowly, the
currents and voltages are too weak to show up on the oscilloscope.
The discharge however is in the nano-second range. Thus enough
charge per time goes from the antennas to the oscilloscope so
that measurable single-shot signals can be triggered. The time
difference of the two signals can be compared on the screen of
the oscilloscope.
Precautions:
- The signals of each channel must not be influenced by the
presence of the antenna of the other channel.
- The signals must disappear or at least become weaker and delayed
(because of input capacitance loss) in the absence of the Coulomb
antenna (the probe itself is a weak Coulomb antenna).
- The two signals should be of similar order of magnitude.
I've tried several different setups. I also used a few times a
LeCroy, WaveRunner 6100A, DC-1GHz, which showed me that the results
are essentially the same as with my own oscilloscope.
According to my experiments, time differences between the signals
of the nearby and the distant antenna of t = d/2c can easily be
achieved, e.g. 4 ns in the case of a distance 2.4 m, thus clearly
suggesting faster-than-light propagation of the field changes from
the nearby to the distant antenna (light needs 8 ns for 2.4 m).
Because these are single-shot experiments, the results also suggest
FTL information transfer.
Cheers,
Wolfgang Gasser (2007-07-07)
__________________________________________________________________
ADDENDUM (2007-07-11):
More than three days have passed since I posted the above message
to sci.physics.research, but the moderators probably don't want
to direct their reader's attention to "the shame that such a basic
property of electromagnetism as the speed of propagation of the
Coulomb and magnetic potentials still has not been measured".
It would be great if someone could repeat the experiment. Even
better would be a replacement of the spark gap by a high voltage
thyristor or a set up with a powerful semiconductor nanosecond
pulser.
