2010-04-13 09:44:13
In 1860, the physicist James Clerk Maxwell predicted the existence of waves associated with electrical and magnetic phenomena (electromagnetic radiation), of which light waves were only a small part. He did not get to witness to what extent his theory was going to change the world, in fact, the first experimental demonstrations of the existence of these enigmatic waves would not come until seven years after his death.
In 1887, the German physicist Heinrich Rudolf Hertz generated a high-voltage alternating current that caused electrical sparks to fly between two charged balls. Under these circumstances —and as predicted by Maxwell’s equations— electromagnetic radiation capable of being transmitted through space should be produced. Hertz used a receiving apparatus of his invention to detect the waves generated by sparks from the opposite end of the room. With this simple experiment he was able to show that electromagnetic energy is transmitted as Maxwell had predicted.
Hertz’s experiments allowed him to gradually discover information about the waves generated by his devices. He placed his detector in different places, checked the different shapes of the generated waves and calculated his frequency, much lower than that of light. Later they would be known as “hertzian waves” or “radio waves”.
Once the existence of hertzian waves was demonstrated, many researchers began to suspect that they could be used to send messages at a distance, without the need for any material support. The matter seemed like a matter of magic and there was the case of an English researcher, Oliver J. Lodge, who achieved some fame as a spiritualist after managing to send messages in Morse Code 800 meters away.
The great architect of radio wave communications was the Italian inventor Guglielmo Marconi, whose life we offer you today. Marconi perfected the transmitting equipment by grounding one side of the generator and receiver, and the other to a piece of wire that would later be called the “antenna.” In 1897 he installed the first wireless station on the Isle of Wight and thanks to it he was able to establish contact with a steamship 14 and a half kilometers away. Two years later, the signals traveled 50 kilometers and crossed the English Channel without difficulty. Those experiments were the prelude to what would be his great epic, the transmission of radio waves from Cornwall to Newfoundland, separated 3,378 km on either side of the Atlantic Ocean. It happened on December 12, 1901, a historic day in which the barriers that cut off humanity were broken.
On December 10, 1909, during the award ceremony of the Nobel Prize in Physics to Guglielmo Marconi, the Member of the Royal Swedish Academy of Sciences who presented it said:
“Regardless of the fixed routes of the conductor cables and regardless of space, thanks to Marconi’s achievements we can connect very distant places, over vast expanses of waters and deserts.”
Listen to his biography.
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