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Who Invented the Radio
The heliograph successfully transmitted messages via a beam of light rays,
which could be modulated by means of a shutter to carry signals in the form
of the dots and dashes of the Morse code. However, History of radio really
began in 1873, with the publication by the British physicist James Clerk
Maxwell of his theory of electromagnetic waves.
The Italian electrical engineer and inventor Guglielmo Marconi is generally
credited with being the inventor of radio. Starting in 1895 he developed an
improved coherer and connected it to a rudimentary form of antenna, with its
lower end grounded. He also developed improved spark oscillators, connected
to crude antennas. The transmitter was modulated with an ordinary telegraph key.
The coherer at the receiver actuated a telegraphic instrument through a
relay, which functioned as a crude amplifier.
In 1896, using the radio he transmitted signals for a distance exceeding
1.6 km (more than 1 mi), and applied for his first British patent. In 1897 he
transmitted signals from shore to a ship at sea 29 km (18 mi) away. In 1899
he established commercial communication between England and France that
operated in all types of weather; early in 1901 he sent signals 322 km (200 mi),
and later in the same year succeeded in sending a single letter across the
Atlantic Ocean. In 1902 messages were regularly sent across the Atlantic,
and by 1905 many ships were using radio for communications with shore stations.
For his pioneer work in the field of radio, Marconi shared the 1909 Nobel Prize
in physics with the German physicist Karl Ferdinand Braun.
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