One day in 1888 a German physics professor named Heinrich Hertz was teaching his students the experimental confirmation of the theories of a Scottish colleague, James Clerk Maxwell, on electromagnetism . Maxwell, after a superb effort at synthesis, had created a theory that described all electrical and magnetic phenomena in a single formulation. As a consequence of Maxwell’s theory, he had predicted the existence of waves that propagate at the speed of light. Furthermore, light itself was an electromagnetic wave.
That morning Hertz brought to his class a pair of instruments designed and built by himself: a transmitter and a receiver of electromagnetic waves . He put each one in a corner of the class and, as the genius from Scotland had predicted, Hertz made a spark fly in the receiver by turning on the emitter. After the demonstration, one of his students asked him if that would ever have a practical use. To which Hertz replied: “No way. This is just an interesting lab experiment that proves Maxwell right. I don’t see any application for this mysterious and invisible electromagnetic energy.”
Heinrich Hertz was a great physicist but a lousy prophet. Had he not died in 1894, when he was only 36 years old, he would have realized his mistake. Because just the following year another 20-year-old Italian, Guglielmo Marchese Marconi, using the instrument designed by Hertz, transmitted and received a message at his father’s house in Bologna. The era of wireless telegraphy began.
At the same time as Marconi, Alexander Stepanovich Popov was doing the same in his laboratory in Saint Petersburg . One day in May 1895 Popov sent and received a signal almost 600 meters away, and in March 1897 he equipped the Russian cruiser Africa with a radio receiver while installing another similar one on the coast, in Kronstadt. In 1900 the need for such facilities was proven: the warship Admiral General Apraksin was trapped in the ice in the Gulf of Finland. Thanks to Popov ‘s radio system , the ship was able to contact stations on Hogland and Kutsalo islands 45 km away , which sent a message to the icebreaker Ermak .
But there was a problem to solve. If there was only one transmitter, there would be no problems , but when there are many, the receiver captures the signals from all of them , which makes communication impossible. Marconi worked on this problem and in April 1900 he obtained the historic English patent 7777 for his frequency selector. In this way, different transmitters would emit at different wavelengths and the receiver would adjust the selector circuit to choose one or the other. That is, Marconi invented the dial on our radio sets.
On December 12, 1901, Guglielmo Marconi received a simple message off the coast of Newfoundland: the letter S in Morse code . The important thing was not the message itself, but that it had been broadcast from the other side of the Atlantic, from Cornwall, in England . Four days later, on December 16, the world press published Marconi’s feat . Until then, scientists believed that such a fact was impossible: a message could not be sent beyond the horizon because the signals propagate in a straight line and would be lost in space due to the curvature of the Earth. That they can actually do so is due to the layer of the atmosphere known as the ionosphere , at about 150 km altitude. This layer was predicted by Oliver Heaviside in 1902 but its existence was not confirmed until 1923.
And the transmission of the human voice? Marconi started working on it in 1913 , but an engineer and soldier from Castellón had achieved it 11 years ago, Julio Cervera. In 1898 and for three months he had been working in Marconi’s laboratory. On his return to Spain he got down to work and on August 31, 1899 he applied for his first patent in wireless radiotelegraphy. Cervera launched the second permanent network in the world between Tarifa and Ceuta (the first had been installed by Marconi between the Isle of Wight and Bournemouth), and made the first voice transmission in 1902: for 40 days, it communicated Jávea with Ibiza.
Meanwhile, on the other side of the Atlantic, the inventor and self-proclaimed ‘father of radio’ Lee De Forest developed in 1906 the first industrially useful vacuum tube in history, inaugurating the age of electronics : he called it a triode because it had three connections, Three legs. It was a major invention that made radio, long-distance telephony, and television possible .
On Christmas Eve of that year, a Canadian named Reginald Aubrey Fessenden broadcast from Brant Rock (Massachusetts, USA) the first radio program in the world : a couple of songs, the reading of a poem and a Christmas greeting written by Fessenden himself. The broadcast was heard by radio operators on a ship sailing several hundred kilometers away. Four years later, in 1910, the first daily radio program was broadcast from the Charles Herrold School of Radio Broadcasting in San Jose, California.
But history has given Marconi excessive credit that the US Supreme Court decided to amend with its ruling of June 21, 1943. In an unprecedented ruling, it ruled that it was not true that Marconi had been ahead of everyone with his fundamental patents of wireless telegraphy. The case was very clear: Marconi’s patent for the frequency selector was filed in April 1900. But someone had beaten him to it, one of the most peculiar and mythologized inventors in history, an extravagant man almost 2 meters tall, high-pitched voice and stork bearing: Nikola Tesla. His patent 645,576 on a similar device was filed on September 2, 1897 and was accepted on March 20, 1900. Justice, finally, justice.
The saddest part of this story is that in his lifetime Tesla embarked on a series of legal disputes against Marconi, which he ended up losing. And the Swedish Academy of Sciences, ignoring the non-agreed law that the discoverer is the one who publishes first, awarded the Nobel Prize in Physics to Marconi in 1909 .
