360Marconi receives the first radio signal across the Atlantic
On 12 December 1901, at Signal Hill in Newfoundland, Guglielmo Marconi heard three faint clicks through his earphone: the Morse code letter S, sent by radio from Poldhu in Cornwall, England, about 3,500 km away. It showed that radio waves could cross an ocean, and it began the age of long-distance wireless communication.
Many scientists in 1901 believed radio waves travelled in straight lines and could not follow the curve of the Earth. Guglielmo Marconi, a young Italian inventor working in Britain, set out to prove otherwise.
He built a powerful transmitter at Poldhu in Cornwall. Then he crossed the Atlantic to Signal Hill in St John's, Newfoundland, where he flew an aerial wire from a kite, about 150 m above the ground.
On 12 December 1901, at around midday, Marconi and his assistant heard three short clicks, the Morse code letter S, which Poldhu had been sending at agreed times. The signal had crossed about 3,500 km of ocean.
Some doubted the result, but Marconi soon confirmed long-distance reception on a ship at sea. By 1907 a regular commercial wireless service was running across the Atlantic.
Radio transformed safety at sea, news and, later, broadcasting. Marconi shared the Nobel Prize in Physics in 1909. Scientists later learned that a layer of the upper atmosphere, the ionosphere, bends radio waves back to Earth.
- 1896
- Marconi patents his wireless system in Britain
- 12 December 1901
- The first transatlantic signal is received
- 1907
- Regular transatlantic wireless service begins
- 1909
- Marconi shares the Nobel Prize in Physics
Sources: Marconi Society · Parks Canada (Signal Hill) · Britannica.