How were electromagnetic waves first launched?

Nowadays, we are transmitting colossal streams of data, including cellular and Wi-Fi, using ultra-high frequency electromagnetic waves. This had began in 1820, with the discovery of Oersted and Ampere that the movement of a charge in a conductor creates a magnetic field. After 10 years, Faraday demonstrated that, and vice versa, a change in the magnetic field inside a coil of wire creates an impulse to move the charge in it. At the same time, an idea appeared about the similarity of this impulse with a wave on water. Thirty years later, Maxwell gave to Faraday’s ideas a rigorous mathematical form by writing equations whose solutions are a wave of electric and magnetic fields propagating at the speed of light. After another 30 years, Hertz demonstrated an electrical discharge, a spark in a break in an electrical wire located meters away from a wave source (induction coil) with a frequency of 100 MHz. He called his discovery “rays of electrical force”. By the beginning of the 20th century, Lebedev studied the propagation of radio waves with a frequency of tens of gigahertz and Popov increased the transmission range to 50 km. People have built radio-transmitters and the practical use of radio waves started for transmitting information.

Riding the radio waves šŸ™‚

Modulated waves of electric and magnetic fields have become a means of remote information exchange

Popov’s radiotelegraph came in handy when rescuing an battleship that sat on stones.


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