Heinrich Hertz - the man who proved that electricity can be turned into electromagnetic waves and led to the development of the telegraph and the radio

Hertz clarified and expanded the electromagnetic theory of light that was first proposed by the British physicist James Clark Maxwell in 1884. Hertz proved that electricity can be transformed into electromagnetic waves that travel at the speed of light and which exhibit many properties similar to those of light

The German physicist Heinrich Rudolf Hertz was born on February 22, 1857 in Hamburg, Germany and died on January 1, 1894 in Bonn, Germany and is 37.

Hertz's name is well known to everyone who listened to the radio, for example the Kol HaShalom announced in a whistle every hour on the half hour, that you are listening to the Kol HaShalom, medium waves 1540 kilohertz (ie 1540 thousand hertz). At FM we talk about runners, meaning the millions of runners.

Hertz was the son of a Jewish father, a lawyer who converted to Christianity like many Jews in Germany during the Enlightenment. He was educated at the University of Berlin. Between 1885 and 1889 he was professor of physics at the Karlsruhe Technical School and then moved to the University of Bonn.

Hertz clarified and expanded the electromagnetic theory of light first proposed by the British physicist James Clark Maxwell in 1884. Hertz proved that electricity can be transformed into electromagnetic waves that travel at the speed of light and which exhibit many properties similar to those of light. The experiments he conducted with the electromagnetic waves led to the development of the wireless telegraph and finally the radio.

His name also became a well-known term in the field of radio and electric frequencies. Hertz (kilohertz, megahertz). This term has been part of the international metric system since 1933.

Before Hertz worked as a professor in Karlsruhe and Bonn, he researched under the guidance of another well-known scientist - Hermann von Helmholtz in Bonn. It was Helmholtz who encouraged Hertz to try to win a scientific prize that led to some of Hertz's most important discoveries.
From 1885 to 1889, Hertz became the first person to transmit and receive radio waves, establishing the fact that light is a form of electromagnetic radiation. Italian inventor Giuliello Marconi did not begin his wireless experiments until 1894, and they were based on early work by Hertz that proved the hypotheses of British psychologist Robert Maxwell.

The connection was quite direct. In 1879, the year of Maxwell's death, the Academy of Sciences in Berlin announced a prize for whoever would discover electromagnetic waves and measure their speed of propagation, with the intention of proving that there is no independent field in which waves propagate at a finite speed.
Hertz entered the competition and built a system that included a transmitter and a receiver. The transmitter consisted of a voltage source, a coil and two metal spheres close to each other. The receiver was similar to the transmitter, but without a power source.

Hertz discovered that every time the voltage in the transmitter increased and a spark formed between the two marbles, a parallel, weaker spark appeared between the two marbles in the receiver. The conclusion was that the fluctuations of the electrical charges between the spheres in the first circuit created electromagnetic waves that spread in space and reached the second circuit. Later, Hertz performed a series of experiments in which he proved that these waves have all the properties of waves. He even measured their speed and showed that it is equal to the speed of light.

Heinrich Hertz's experiments in 1886-88 gave birth to the era of wireless communication. As early as 1896, the Italian Giuliello Marconi and the Russian Alexander Popov built radios that could transmit messages over short distances. In 1901 Marconi made the first transatlantic radio transmission.

One of the consequences of Hertz's discovery that light is an electromagnetic phenomenon. In 1905, Einstein published four works, each of which was exceptional in its field. One of the works for which Einstein received the Nobel Prize, rather than relativity, was the phenomenon of the photoelectric effect. This effect was first discovered by Hertz in 1887. Hertz discovered that light striking a metallic body causes the emission of electrons. This phenomenon contradicted the wave theory of light, since it was impossible to reconcile the interaction that resulted in the emission of individual electrons with the continuous nature of light. The assumption that light is not continuous but "made up" of discrete packets, which will later be called photons, solved the problem.
Although Einstein did not prove the existence of photons, he provided accurate predictions for confirmation in the context of the photoelectric effect. Later this discovery was the basis of quantum mechanics.

It is possible that if Hertz had lived longer, he would have contributed much more to science and perhaps he would have reached some of these conclusions himself.

More on the subject on the science website

• The effect of lightning on radio reception and its safety - an article from 1936
• The Great Quantum Leap
• Radar - an invention without an inventor
• James Clark Maxwell - father of the technology revolution
• The Great Quantum Leap