TESLA'S BIG MISTAKE?
If we wrap a single-layer coil of wire upon a very long plastic tube, we
have a Tesla resonator as in Fig 1 above. In essence, this is an an
electrical transmission line. We can inject AC into one end using a
little primary coil wrapped around. Now examine Fig 2 below. We've
placed a second "primary coil" at the far end of the long coil.
This second coil acts as a "receive coil," and will collect the energy we
had injected into the "transmit coil" at the other end.
Since our long thin coil is actually a single piece of wire, we've managed
to send electrical energy along a single wire. There is no electric
circuit involved! This only can work because the long, thin coil will
support slowly-moving electromagnetic waves, and the electron-sea within
the metal of this coil behaves as if it's become compressible.
Now we put a metal sphere on either end to prevent corona from spewing out
of the dangling wire tips, and we've built a simple electrical power
system. Inject some high-freq AC power into the first "primary coil", and
the same AC power comes out of the second "primary coil" at the far end.
If we choose the correct value of load resistor for the "receive" coil,
then all of the electromagnetic energy flowing along the long thin
secondary will be absorbed by the receive coil without reflecting.
In conventional cables there are two conductors, and the voltage between
them forms the "E" part of the EM wave. In the above one-wire coil
device, the voltage between the travelling lumps of net-charge distributed
along the long thin coil forms the "E" part of the wave. The single wire
acts as its own "circuit." The motion of the net-charge is an electric
current, and this creates the "M" part of the EM wave.
Interesting? A single wire transmission line! It doesn't violate the
rule forbidding longitudinal EM waves. However, it violates the
fundamental rule regarding electric circuits in that there *is* no
circuit here. The two ends of the system are connected by a single wire.
The charges within the coil flow back and forth, while the electrical
energy flows along the coil from source to load.
HOWEVER, this is not unique. Once long ago I encountered an article about
a single-wire transmission line. This had nothing to do with Tesla; it
was about an old microwave transmission scheme called a Goubau
transmission line or "G-line." The article was in an old copy of QST
magazine (amateur radio mag) in the 1960s or '70s.
It turns out that you can send microwave or UHF signals along a *single*
wire as long as that wire is coated with a dielectric. To do this, you
start out with a normal coaxial cable. You strip the shield from a
central section, then solder on a pair of large, cone-shaped copper horns
which attach to the coax shield at either end of the coax cable. The
dielectric-coated single wire extends between the ends of the coax. Sort
of like this:
In the above diagram, the single-wire section between the two hollow cones
can be as long as desired, but it must be fairly straight. Those
cone-shaped parts must be about one wavelength across (or was it 1/2
wavelength? I don't remember exactly.) The metal cones act as "wave
launchers" or "wave catchers". As the EM waves come out of the coax
cable, the cones allow the waves to spread out and attach to the "G-line"
part. There must be a plastic coating on the "G-line" wire, otherwise the
waves will not lock onto it, and they will tend to wander away into space.
The plastic tends to slow the waves below "c," so they bend slightly
inwards towards the wire.
The article noted that you could put a bend in the G-line, as long
was a long, smooth bend of large radius. Because of the plastic coating,
the waves would follow the bend. If there was no plastic coating, the
waves would miss the bend and go straight out into space, missing the
"catcher cone" entirely.
Obviously this can only work with AC. There is no electric circuit,
instead we have waves of "electron compression" which propagate along a
single wire. Let's briefly look at a fluid analog. The fluid analogy of
a conventional electric circuit is a closed loop of
water-filled hose. To send energy to any part of the loop, we simply
force the water in one part of the loop to begin flowing, and all the
water in the entire loop must therefore flow as well. It acts like a
drive belt. Might it be possible to break the circuit and use a
straight-line hydraulic system? Can we send compression waves through the
electrical "water" in the "hose" made of wire? Sure! That's what the
G-line does. If we have a long hose with closed ends, we can send "sound
waves" through the "water" of the hose, although we cannot create constant
flowing DC as we can with the closed circuit hose-loop. These single-wire
systems are inherently AC systems. They are analogous to sending sound
energy along a fluid-filled tube.
Because there is only one conductor in the G-line, the "E" part of the EM
wave must extend between successive lumps of net-charge which propagate
along the wire. The "voltage" on the transmission line extends outwards
as radial e-field flux, but rather than the flux connecting with a coaxial
as it does in a normal cable, it curves around and connects with the
opposite flux-lines which extend from another spot on the wire. The "M"
component of the wave acts like the magnetic field around any normal wire:
acting like circles which surround the wire. The
energy flows lengthwise along the wire as is commonly shown by Poynting's
vector (E x B).
__ | _____ | ___ \ | / \ | / \ | / \ | / | | | | | | | | | | | | | | | | | | wire ======= ------ =============== ++++++ ======== wire | | | | | | | | | | | | | | | | | | / | \ / | \ ___/ | \_____/ | \___ fig. 5 The e-field of the "G-Line", extending between propagating regions of opposite surface chargeSo, here we have a one-wire transmission line based on transverse EM wave in space, and electron density waves within the wire. Inside the metal surface of that single wire, the electrons wiggle back and forth while the EM wave propagates outside at about the speed of light. It's almost like sound waves moving on the string of a tin-can telephone, but electrons take the place of those cellulose fibers, and the sound waves are replaced by transverse EM waves. But in the case of the "G-line," the energy gets stored in the EM fields connected to the electrons, rather than being stored in the kinetic energy and potential energy of the string.
How does this relate to Tesla? Well, once we have the ability to send
energy along a single wire, we should also have the ability to send energy
along any conductor at all, as long as that conductor has a dielectric
coating. Like this:
Any large, metallic hunk could be stuck in series with the "G-line". Yes,
there might be wave-reflections where the thin wire connects to the big
metal hunk. But that's beside the point. With the above setup, we can
send waves along the surface of a conductive object, while within the
object itself the "electron sea" vibrates longitudinally. Hmmm. Where
have I heard that before?
I know. Nikola Tesla's "World System,"
which he intended to transmit usable electrical energy to any receiver
anywhere on the Earth.
"I have often been told that my most important results in invention was the demonstration of the practicability of transmitting energy over one wire; because, once we can transmit energy over one wire we can use also the earth, for the earth is equivalent to a large conductor" - N. Tesla 1916In the above diagram, suppose the "hunk of conductor" is the entire planet Earth! Suppose the "cone shaped" launchers are replaced with an elevated sphere which supplies a "virtual ground" reference capacitance? Suppose the frequency of the waves is below the UHF band in frequency? The entire Earth will then behave as a "G-line" single wire transmission system.
In his writings, Tesla was convinced that his devices did not use
physics as Hertzian waves. He was right... and wrong. When
radio- frequency energy propagates through empty space, the E and the M
components are transverse, and the waves propagate at 90 degrees to both
of them. However, when EM energy is sent along a cable, we also have
electrons involved: the electron-sea within the metal wires. The
electrons slosh back and forth in the cable while the EM waves flow along
outside of the metal surfaces. Why is this important? Because the
physics of a transmission line is the physics of the "near field" of a
coil or capacitor, not the physics of freely-propagating "Hertzian" waves.
When Tesla sent energy around the Earth, he was treating the Earth as an
electrical cable. His waves were coupled to the charges within the
of the Earth. He was not transmitting pure radio waves, even though
the frequency of the wave-energy might be the same as any normal radio
wave. Instead he was using a one-wire transmission system where the
conductive Earth served as the wire. Tesla's technology used "near field"
effects of coils, capacitors, and transmission lines, not the dipole
antennas that Hertzian waves use, and in that sense his waves were
But wait a minute. This stuff can only work if there is a dielectric
substance coating the Earth. Without that coating, the waves will not
slow and bend to follow the curve of the Earth, they will just fly out
into space. The
atmosphere supplies this coating, and the resistive earth also helps to
slow the waves so they bend to follow the surface. And even better, there
ionosphere which will act a lot like the "shield" of a coaxial cable and
force the waves to go around the Earth.
Tesla was using the ground as a transmission line. He was correct when he
insisted that he was producing longitudinal waves in the "natural medium."
He was correct in saying that the ground was not just a voltage reference.
In this case the "natural medium" is the population of mobile ions in the
dirt and oceans which cause the Earth act as a conductor. He was
converting the Earth's surface into a "G-line" conductor. Any
electrical device could intercept a portion of that energy, as long as
that device was connected to the ground and to an elevated metal object.
So, what was Tesla's big mistake? Initially he did not realize that the
Earth's atmosphere was critically important for his system to work. If
the Earth had acted like a perfectly-conducting metal ball hanging in a
vacuum, then Tesla's
would not have worked. The waves would have travelled along the ground
and then shot straight out into space. His
system would have been like a "G-line" with a sharp bend in the middle:
except for a bit of diffraction, the waves refuse to follow the bend and
instead go right
off the cable and are lost.
Because of the "dielectric" effect of the atmosphere, and also because a
conductive ionosphere was present, Tesla's system was feasible. Yet any
scientist of the time would "correctly" see that Tesla's system totally
violates well-known theory. If Tesla had started out from known theory,
he would never
have pursued the path he did. Tesla actually started out with empirical
observations that the Earth resonated electromagnetically like a struck
bell. The atmosphere and the ionosphere made this so, but Tesla only knew
that it worked, and he really did not know why, at least at first.
Tesla's other big mistake was in thinking that his wireless
transmission system had nothing to do with "Hertzian" waves. In fact, the
waves in a coaxial transmission line are not much different than the waves
which fly off any dipole antenna connected to the end of that transmission
line. Whether it is ruled by "near field" or "far field" equations,
electromagnetism is electromagnetism.
Tesla's mistake was not really so big. Especially not a big mistake when
compared to those contemporary scientists who were absolutely certain that
the Earth *didn't* have any resonant frequencies, who *knew* that radio
waves would not travel around the curve of the Earth, and who dismissed
Tesla's wireless transmission system as crackpottery; as an unworkable
violation of known physics. When "Schumann" VLF earth-resonance was
rediscovered in the 1950s, nobody in the conventional sciences dared court
the embarassment of admitting that Tesla had been right all along.
Tesla is mostly a hero among the non-scientist "underground," while in
conventional circles he is still ridiculed for trying to distribute
electric power without using wires, or rather, by sending it through the
ground. Everyone (still) knows that this is
impossible, even in theory.
Tesla FAQ (search on Zenneck Surface Wave)
Geog Goubau, "Surface waves and their Application to Transmission Lines,"
Journal of Applied Physics, Volume 21, Nov. (1950)
bert hickman: http://188.8.131.52/frames/Non-Herzian_Waves.html
Notes: See the *excellent* above link "Non-Hertzian Waves" by P. Nicholson. It exactly hits the nail on the head: Tesla, whether or not he was correct empirically, was completely wrong in his explanations and theory. If his reported results were real, then they had to be accidental, serendipidous rather than due to non-EM energy flowing inside conductors, or due to 'scalar' or other violations of Maxwell's equations. One possibility is that Tesla's devices worked because they rely on the Schumann resonances actually having enormous Q, and a major artifact plagues all published spectra at the low end. Long integration times and drifting resonance frequency would mask the true value of Q factor at frequencies well below 1KHz. Another possibility is that Tesla discovered some valid empirical method of "helping along" his faulty theory. He may have found how to persuade his devices to operate as desired, but not for the reasons he suspected. My growing suspicions lead to some pure speculation: Tesla genuinely accomplished the seeming miracles as reported, but then he kept the techniques secret, and only revealed information about the (faulty) theory and the unmodified hardware which supports that theory. That way both the idea-theives and his enemies in academia would be unable to replicate, and thus remain unable to uncover the actual theory behind the amazing phenomena. Yes, dishonest and repulsively unethical for a scientist, but Tesla was an inventor-engineer, where such things are common or even essential necessities. If Tesla wasn't simply lying or distorting his results, well, this wouldn't be the first time that the way through to valid new experiments in physics was opened by a faulty theory. Asimov notes that the most exciting phrase is not "Eureka," but "that's funny..." And in that case, we should avoid being led down the incorrect path; avoid experi- ments based on Tesla's wrong theories. Instead, take the empirical path: replicate Tesla's actual experiments very carefully, while paying close attention to any unexpected and anomalous results. Avoid promoting our pet theories and expectation bias, since the results may completely repudiate your personal pet theories and mine, yet still lead to breakthrough advancements. OK, so his worldwide Wireless Power Transmission doesn't work. How would Tesla have helped it along? What could have been added? Or, what known physics could have accidentally been included to drastically alter his system? Hmm. Ionizing radiation. Odd 'rifle shot' discharges...