Tesla described his wireless
transmission method by three important characteristics:
- It did
not use electromagnetic radiation.
- It operated
through the earth or water.
- The mechanism
of transmission is an electric current - not radiation.
Modern analysts, both those
who believe Tesla had discovered something new and those who believe
he was mistaken in his observations,
see Tesla's transmission method the same as present day broadcast
radio technology. The broadcast model assumes that there is an
antenna propagating electromagnetic waves omnidirectionally
into the air. The Tesla supporters propose many ingenious,
but implausible, schemes that would account for Tesla's claims
for his wireless system. The Tesla opponents simply point out
that according to electromagnetic theory, Tesla's ideas are impossible.
Both groups are incorrect in thinking that his wireless method
is the same as the broadcast technology used today.
- applying the assumptions of today's electrical theories to Tesla's
original turn of the century researches - is only half the problem
of understanding the inventor's wireless method.
The situation is further complicated by the similar sounding
descriptions Tesla gave to his earlier and later transmission
In his early
work, Tesla attempted electronic transmission by electrifying
the atmosphere. This is
the case in his patent entitled Method
of Intensifying and Utilizing Effects Transmitted Through Natural
Media, #685,953, applied for in June 1899. In this patent,
he proposes a very powerful transmitter to ionize atmospheric
gases and, by that, create a conductive path between the transmitter
and receiver through which a current could be sent. Later, when Tesla disclosed his through-the-earth,
and through water1, transmission
with essentially the same type of apparatus and operating at ELF
frequencies, modern authorities have assumed that Tesla was mistaken about his method
of propagation and was really
cavity resonance at Schuman frequencies.2
More recent scholarship, however, has shown that that Tesla was
aware of the differences between conventional wireless transmission
methods and the technology he was developing.3
Tesla was more than an engineer of conventional
methods. He was an electrical
researcher who investigated fundamental issues of the science.
It will be shown that the three characteristics of Tesla's
wireless transmission system describe an electrostatic wireless
method that used the earth as a conductor and transmitted displacement
currents. At moderate energy
levels, the system could be used for communication. At greater levels, power could be sent by
During-1899 - 1900, Tesla set up a laboratory
in Colorado Springs to investigate wireless signal transmission.
It was during this period he discovered that a properly
configured receiver could detect waves, initiated by lightning
strikes, propagating through the earth. Many details about the
apparatus for generating and receiving electrical signals (such
as tuned resonant circuits that were recognized in 1943 by the
Supreme Court as the basis of commercial radio designs) are given
in his writings, but he never directly reveals the physics behind
the mode of propagation. Tesla does point toward his novel transmission
technique when he notes that his transmission method is "the
diametrical opposite of a transmitting circuit typical of telegraphy
by Hertzian or electromagnetic radiations."4
This claim alone indicates a technology different from the transmission
technology of today.
One of his early lectures on evacuated tube illumination
provides a good example of physical effects he was using. Tesla
describes a setup for illuminating bulbs.
It consists of two plates on either side of the bulbs. The plates are connected to a transformer
driven by an oscillator. The two plates are similar to a capacitor
and the electrical activity