Nikola Tesla - The Founder of High-Frequency and Radio Engineering Page 6

1) that electric oscillations can appear in a circuit with capacitance and self-induction if the ohmic resistance is less than \(2\sqrt{\frac{L}{C}}\), where \(L\) denotes self-induction and \(C\) capacitance;

2) that, under this assumption, every circuit has its own period of oscillation, which, with a small ohmic resistance that can be neglected, depends only on capacitance and self-induction and amounts to \(\frac{1}{2\sqrt{CL}}\);

3) that oscillations are damped, i.e., suppressed and lost, more quickly the greater the ohmic resistance and the smaller the self-induction of the oscillatory circuit.

Another famous English physicist, Maxwell, in 1865 proposed his mathematical theory of the electromagnetic propagation of light, by which he established that light, heat, and electricity are phenomena of the same nature and that their action at a distance is carried out by means of electromagnetic waves. The accuracy of Maxwell’s theory was experimentally proven by the famous German physicist Hertz in 1887 using an electric spark oscillator and resonator, establishing the existence of electromagnetic waves at short distances of 10 to 20 meters. Hertz used for his experiments an electric spark, which Henry in 1842, Helmholtz in 1847, and Thomson in 1853 theoretically, and Feddersen in 1859 experimentally, had already determined to be a source of oscillations that very quickly, after a few oscillations, die out due to air resistance and other losses.

This was the state of affairs before Tesla’s historical discoveries of 1891–1893. And in these works of famous physicists we actually find the very first beginnings of the manifestation of high-frequency currents and wireless transmission of electrical energy. But neither Thomson’s theory nor Hertz’s experiments at that time offered prospects for considering that one day it would be possible to create electric currents of high frequencies of several hundred kilowatts and several million periods per second, and that by means of them wireless transmissions for radiotelegraphic and radiotelephonic purposes could be carried out over practically unlimited distances.

Just as Galvani-Volta’s discovery of galvanic current and Faraday’s discovery of the law of induction did not mean a solution to the problems of electric lighting, long-distance transmission of electrical energy, electric telegraph, and telephone, so too the discoveries of Thomson, Maxwell, and Hertz did not constitute the foundations of high-frequency technology, nor radio engineering. Rather, new discoveries and a whole series of new scientific findings were needed to achieve the immense works of human civilization, which are today encompassed by these names.