| IMPORTANT DATES IN RADIO Source: WORLD BOOK ONLINE 1864: James Clark Maxwell predicted the existence of electromagnetic waves that travel at the speed of light 1880s: Heinrich Hertz proved Maxwell's theory 1895: Guglielmo Marconi became the first person to send radio communication signals through the air 1906: Reginald Fessenden broadcast voice by radio 1909: Passengers of the S.S. Republic were saved in the first sea rescue using radio 1918: Edwin H. Armstrong developed the superheterodyne circuit 1919: Woodrow Wilson became the first U.S. president to make a radio broadcast by speaking to a ship to World War I troops aboard other vessels 1920: Stations KDKA of Pittsburgh and WWJ Detroit made the first regular commercial broadcasts c. 1925-1950 Radio was a major source of family home entertainment, during the "Golden Age of Broadcasting" 1947: Scientists at the Bell Telephone Laboratories developed the transistor 1960: John F. Kennedy and Richard Nixon held the first radio and television debates between two presidential candidates 1961: Soviet space officials held the first radio talks with a man in space (cosmonaut Yuri Gagarin) 1960s: Stereophonic radio broadcasts began 1969: Radio signals carried to earth the first words spoken by astronauts on the moon 1982: AM radio stations in the United States began broadcasting in stereo 1998: The world's first commercial digital audio broadcasting (DAB) service began in the United Kingdom |