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Which Morse code letter did Guglielmo Marconi receive across the Atlantic Ocean?
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Guglielmo Marconi
Italian physicist Guglielmo Marconi, shown here about 1908, invented a successful wireless telegraph (that is, a radio) in 1896.
The Morse code letter that Guglielmo Marconi successfully received across the Atlantic Ocean on December 12, 1901, was the letter S.1
This historic transmission was sent from Poldhu in Cornwall, England, and received by Marconi at St. John’s, Newfoundland. The achievement demonstrated that radio waves could travel across the ocean despite the curvature of the Earth, marking a pivotal moment in the development of global radio communication.21