Edouard Branly
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Édouard Eugène Désiré Branly (October 23, 1844 - March 24, 1940) was a French inventor and physicist. He was the physics professor at the Catholic University of Paris. He is primarily known for his early involvement in wireless telegraphy and his invention of the Branly coherer around 1890.
The coherer was the first widely used detector for radio communication. Branly built upon the discoveries of Temistocle Calzecchi-Onesti, who demonstrated in experiments in 1884 through 1886 that iron filings contained in an insulating tube will conduct an electrical current under the action of an electromagnetic wave. The operation of the coherer is based upon the large resistance offered to the passage of electric current by loose metal filings, which decreases under the influence of radio frequency alternating current. The coherer became the basis for radio reception, and remained in widespread use for about ten years. It was used by, amongst others, Guglielmo Marconi, in his early experiments. Oliver Joseph Lodge improved Edouard Branly's coherer as a detector of radio waves by adding a "trembler" which periodically dislodged clumped filings, thus restoring the device's sensitivity. The next innovation in radio wave detection, between Nikola Tesla's and Guglielmo Marconi's progress in radio in the 1890s and the 1948 invention of the transistor, was John Ambrose Fleming's Fleming valve which replaced Branly's device for many uses.
In 1911 Branly was elected to the French Academy of Sciences
Edouard Branly died in 1940 and was interred in the Père Lachaise cemetery in Paris.
The quai Branly - a road that runs alongside the River Seine in Paris - is named after Branly. It is the name of this road, not of Branly himself, that led to the naming of the Musée du quai Branly.
[edit] See also
- Radio: History of radio, Invention of radio
- People: Alexander Stepanovich Popov, Karl Ferdinand Braun
- Other: List of people on stamps of France
[edit] External links and resources
- Eugenii Katz, "Edouard Eugène Désiré Branly". The history of electrochemistry, electricity and electronics; Biosensors & Bioelectronics.
- "Edouard Branly". Robert Appleton Company, The Catholic Encyclopedia, Volume II, 1907.
- "Edouard Eugène Désiré Branly"". Adventures in Cybersound.
