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Heinrich Hertz. Heinrich Rudolf Hertz (/ hɜːrts / HURTS; German: [ˈhaɪnʁɪç ˈhɛʁts]; [1][2] 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell 's equations of electromagnetism. The unit of frequency, cycle per second, was ...
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]
Early experiment demonstrating refraction of microwaves by a paraffin lens by John Ambrose Fleming in 1897. After their discovery many scientists and inventors experimented with transmitting and detecting "Hertzian waves" (it would take almost 20 years for the term "radio" to be universally adopted for this type of electromagnetic radiation). [8]
Like all electromagnetic waves, radio waves in a vacuum travel at the speed of light, and in the Earth's atmosphere at a slightly lower speed. Radio waves are generated by charged particles undergoing acceleration, such as time-varying electric currents. [1] Naturally occurring radio waves are emitted by lightning and astronomical objects, and ...
British-American. Known for. Teleprinter, Microphone, Early radio wave detection. David Edward Hughes (16 May 1830 – 22 January 1900), was a British-American inventor, practical experimenter, and professor of music known for his work on the printing telegraph and the microphone. [3] He is generally considered to have been born in London but ...
Audio broadcasting (1915 to 1950s) 1919: First clear transmission of human speech, (on 9XM) after experiments with voice (1918) and music (1917). 1920: Regular wireless broadcasts for entertainment began in Argentina, pioneered by the group around Enrique Telémaco Susini. 1920: Spark-gap telegraphy stopped.
With Thomson's encouragement, Rutherford detected radio waves at 0.5 miles (800 m), and briefly held the world record for the distance over which electromagnetic waves could be detected, although when he presented his results at the British Association meeting in 1896, he discovered he had been outdone by Guglielmo Marconi, whose radio waves ...
“The object we’ve discovered is spinning way too slowly to produce radio waves — it’s below the death line,” Hurley-Walker said. “Assuming it’s a magnetar, it shouldn’t be possible ...