Marconi National Historic Sites of Canada Marconi National Historic Sites of Canada The Marconi National Historic Site and the Marconi Wireless Station National Historic Site are two National Historic Sites of Canada located on Cape Breton Island, Nova Scotia, Canada. Both sites commemorate the efforts of Guglielmo Marconi to transmit transatlantic radio signals between North America and Europe in the first decade of the 20th century. The two sites are located within approximately of one another, and are connected by the Marconi Trail. Signal Hill in St. John's, Newfoundland and Labrador is another National Historic Site related to Marconi's work in Canada. Signal Hill was designated,
Invention of radio It is now well known that long-distance transmission at a wavelength of 366 meters is not possible during the daytime, because the skywave is heavily absorbed by the ionosphere. It is possible that what was heard was only random atmospheric noise, which was mistaken for a signal, or that Marconi may have heard a shortwave harmonic of the signal. The distance between the two points was about . The Poldhu to Newfoundland transmission claim has been criticized. There are various science historians, such as Belrose and Bradford, who have cast doubt that the Atlantic was bridged in 1901, but other