Making waves in Clifden
Ninety years ago today, Clifden, Co Galway, acquired a little niche in the history of technology. On October 17th, 1907, Guglielmo Marconi began the first commercial transatlantic radio service from the little village, sending messages from there to Cape Breton, Nova Scotia. The age of wireless transatlantic communication had begun in earnest.
Marconi had been working on his new-fangled ideas for a long time. At home in Bologna he started by sending messages from his house to a receiver in the back garden, and by 1895 he had succeeded in transmitting his signals over a mile or more. But the Italians showed no great interest in his efforts.
He came to Britain in 1896, where the far-sighted postmaster-general of the time, William Preece, saw the potential of radio as a new means of communicating over long distances, and provided the young genius with support - moral and financial.
The seemingly impossible feat of transmitting a radio signal across the Atlantic was achieved in 1901 when the three dots of the letter S in Morse were sent repeatedly to Newfoundland from Cornwall. The faint but clear signals were detected almost immediately on the other side of the Atlantic - and the scientific world was astounded.
Radio waves were known to travel in a straight line, and for this reason, in normal atmospheric conditions, radio reception should not be possible much beyond the horizon. As it happens, the waves are slightly bent - or refracted - by the atmosphere, so that the so-called radio horizon is somewhat further away than its optical equivalent. But not by any stretch of the imagination should the signal have carried the 2,100 miles across the North Atlantic.
The answer was provided in due course by Oliver Heaviside. He deduced the existence of the ionosphere some 60 miles or more above the surface of the Earth - a region of the atmosphere where ultra-violet radiation from the sun reacts with the molecules of air to form tiny electrically charged particles called ions.
A layer of ions - one of the most important of which is now called the Heaviside layer - can act like a gigantic mirror to reflect radio waves back down to Earth, allowing them to be received a great distance from the original point of transmission. Marconi turned out to be a shrewd and successful man of business. He protected his invention under the celebrated patent No.777 7 of 1900, and went on to exploit the commercial potential of his many gadgets. Long before he died in 1937 he had become a very, very wealthy man.