On December 11, 1901, Guglielmo Marconi amazed the world when he successfully transmitted a Morse code signal 2,137 miles (3,440 km) from England to Canada using radio waves. The feat was not only remarkable but, according to the experts, impossible.

Scientists had been dabbling with radio waves ever since 1885, when German physicist Heinrich Rudolf Hertz (1857-1894) used a spark-gap to create them. Nine years later English physicist Oliver Lodge invented the coherer, a device to detect Hertzian waves, and in 1895 Russian physicist Aleksandr Popov invented an antenna to send and receive signals.

It was known that radio waves were a part of the electromagnetic spectrum, located below the wavelengths of visible light. Although radio waves cannot be detected with the eye, they were expected to behave in the same manner as light waves; that is, they should move in straight lines and not bend around corners. It was believed that...