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1962 Nick Holonyak Jr. develops the first practical visible-spectrum (red) light-emitting diode. 1963 Kurt Schmidt invents the first high pressure sodium-vapor lamp. [18] 1972 M. George Craford invents the first yellow light-emitting diode. 1972 Herbert Paul Maruska and Jacques Pankove create the first violet light-emitting diode.
1878 – Thomas Edison, following work on a "multiplex telegraph" system and the phonograph, invents an improved incandescent light bulb. This was not the first electric light bulb but the first commercially practical incandescent light. In 1879 he produces a high-resistance lamp in a very high vacuum; the lamp lasts hundreds of hours. While ...
The history of street lighting in the United States is closely linked to the urbanization of America. Artificial illumination has stimulated commercial activity at night, and has been tied to the country's economic development, including major innovations in transportation, particularly the growth in automobile use. [ 1 ]
Optics began with the development of lenses by the ancient Egyptians and Mesopotamians, followed by theories on light and vision developed by ancient Greek philosophers, and the development of geometrical optics in the Greco-Roman world. The word optics is derived from the Greek term τα ὀπτικά meaning 'appearance, look'. [1]
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The timeline of luminiferous aether (light-bearing aether) or ether as a medium for propagating electromagnetic radiation begins in the 18th century. The aether was assumed to exist for much of the 19th century—until the Michelson–Morley experiment returned its famous null result.
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Kerosine lamps were used in the home for lighting, since electric lighting was only beginning in the late 1800s. [22] Demand for kerosine lamps would continue for decades. By 1920 electricity reached only 35 percent of homes in the United States. [23] Lamps from the 1890s consisted of a stand, font, chimney, and often a shade. [24]