In the beginning of this century a Croatian engineer, emigrant to America, Nikola Tesla, measured the electrical charge of the
planet Earth and found it of a very high potential. He made his observation during thunder storms.

     My instruments were affected stronger by discharges taking place at great distances than by those near by. This
     puzzled me very much. . . . No doubt whatever remained: I was observing stationary waves. As the source of the
     disturbances [thunderstorm] moved away, the receiving circuit came successively upon their nodes and loops.
     Impossible as it seemed, this planet, despite its vast extent, behaved like a conductor of limited dimensions. The
     tremendous significance of this fact in the transmission of energy by my system had already become quite clear to
     me. Not only was it practicable to send telegraphic messages to any distance without wires, as I recognized long
     ago, but also to impress upon the entire globe the faint modulations of the human voice, far more still, to transmit
     power, in unlimited amounts, to any terrestrial distance and almost without loss.(1)

Nikola Tesla was a pioneer in many fields of electrical theory and technology. He was the first to utilize alternating current,
conceiving an effective system for its generation, transmission, and utilization. Edison appealed to the public, warning that the
alterating current of Tesla would cause great harm to its users, being dangerous, and that only direct current can be harmlessly
used. Tesla referred to Edison as an inventor, to himself as a discoverer. Today everyone knows that alternating current, with
the help of the polyphase induction motor, can be converted into mechanical energy more effectively and economically than
direct current. He invented new forms of dynamos, transformers, condensers, and induction coils. He discovered the principle
of the rotary magnetic field, upon which the transmission of power from the Niagara Falls and other waterfalls and dams is
carried on. A regal recluse, he despised the short-seeing men of science. Many of his pioneer inventions he carried with him to
his grave. But he believed in the destiny of man who, in his words, “searches, discovers and invents, designs and constructs,
and covers with monuments of beauty, grandeur and awe, the star of his birth.”

This teaches us that not only have the contempories of a revolutionary idea in science repeatedly rejected the idea, but also that
a rejection of such an idea even by the best qualified men in the field in the generation of the revolutionary, and often still in the
following generations, has occurred not once or twice, but many times. Archimedes rejected the heliocentric system of
Aristarchus; Brahe rejected the system of Copernicus; and Galileo was deaf and blind to the discoveries of Kepler, just as
Edison warned against the alternating current developed by Tesla. And who was more competent to judge than Archimedes, in
his time, Brahe in his, Galileo in his, and Edison in his?

References

   1.Electrical World and Engineer May 5? l904; see also Century, June 1900. Quoted from J. J. O’Neill, The Prodigal
     Genius: Life of Nikola Tesla, 1944, p. 181.