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Walter Hans Schottky (German: [ˈvaltɐ ˈʃɔtki]; 23 July 1886 – 4 March 1976) was a German physicist who played a major early role in developing the theory of electron and ion emission phenomena, [2] invented the screen-grid vacuum tube in 1915 while working at Siemens, [3] co-invented the ribbon microphone and ribbon loudspeaker along with Dr. Erwin Gerlach in 1924 [4] and later made ...
Heinrich Rudolf Hertz (/ h ɜːr t s / HURTS; German: [ˈhaɪnʁɪç hɛʁts]; [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, laying the foundation for the radio and modern telecommunications.
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 his family moved around that time so he may have been born in Corwen, Wales. [4]
While conventional cameras were becoming more refined and sophisticated, an entirely new type of camera appeared on the market in 1949. This was the Polaroid Model 95, the world's first viable instant-picture camera. Known as a Land Camera after its inventor, of 1965, was a huge success and remains one of the top-selling cameras of all time.
In the early 1890s Nikola Tesla began his research into high-frequency electricity. Tesla was aware of Hertz's experiments with electromagnetic waves from 1889 on [12] [13] but, (like many scientists of that time) thought, even if radio waves existed, they would probably only travel in straight lines making them useless for long range ...
Edwin Herbert Land, ForMemRS, [2] FRPS, Hon.MRI (May 7, 1909 – March 1, 1991) was an American scientist and inventor, [4] best known as the co-founder of the Polaroid Corporation. He invented inexpensive filters for polarizing light, a practical system of in-camera instant photography , and the retinex theory of color vision , among other things.
1814 – Joseph von Fraunhofer discovered and studied the dark absorption lines in the spectrum of the sun now known as Fraunhofer lines; 1816 – David Brewster discovers stress birefringence; 1818 – Siméon Poisson predicts the Poisson-Arago bright spot at the center of the shadow of a circular opaque obstacle
Alexander Graham Bell (/ ˈ ɡ r eɪ. ə m /; born Alexander Bell; March 3, 1847 – August 2, 1922) [4] was a Scottish-born [N 1] Canadian-American inventor, scientist, and engineer who is credited with patenting the first practical telephone.