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The early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting.
The timeline of radio lists within the history of radio, the technology and events that produced instruments that use radio waves and activities that people undertook. Later, the history is dominated by programming and contents, which is closer to general history .
Before the discovery of electromagnetic waves and the development of radio communication, there were many wireless telegraph systems proposed and tested. [4] In April 1872 William Henry Ward received U.S. patent 126,356 for a wireless telegraphy system where he theorized that convection currents in the atmosphere could carry signals like a telegraph wire. [5]
The hot comb was an invention developed in France as a way for women with coarse curly hair to achieve a fine straight look traditionally modeled by historical Egyptian women. [44] However, it was Annie Malone who first patented this tool, while her protégé and former worker, Madam C. J. Walker, widened the teeth. [45]
Radio waves were first predicted by the theory of electromagnetism that was proposed in 1867 by Scottish mathematical physicist James Clerk Maxwell. [5] His mathematical theory, now called Maxwell's equations, predicted that a coupled electric and magnetic field could travel through space as an "electromagnetic wave".
Although they often faced obstacles and policy limitations, beginning in the early 1900s a few women were able to participate in the pioneering development of radio communication. Anna Nevins began working for United Wireless in 1906 , and is shown here at the station atop the Waldorf-Astoria Hotel in New York City in 1909.
The first practical radio transmitters and receivers invented in 1894–1895 by Guglielmo Marconi used radiotelegraphy. [5] It continued to be the only type of radio transmission during the first few decades of radio, called the "wireless telegraphy era" up until World War I , when the development of amplitude modulation (AM) radiotelephony ...
Ray, William B. FCC: The Ups and Downs of Radio-TV Regulation (Iowa State University Press, 1990) Rosen, Philip T. The Modern Stentors; Radio Broadcasting and the Federal Government 1920–1934 (Greenwood, 1980) Settel, Irving. A Pictorial History of Radio (1960) Sies, Luther F. Encyclopedia of American Radio: 1920–1960 (McFarland, 2nd ed. 2 ...