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image

(Encyclopedia)image, in optics, likeness or counterpart of an object produced when rays of light coming from that object are reflected from a mirror or are refracted by a lens. An image of an object is also formed ...

tachyon

(Encyclopedia)tachyon tăkˈēŏnˌ [key], hypothetical elementary particle that travels only at speeds exceeding that of light. According to the theory of relativity, the speed of light is the limiting velocity fo...

Hovhaness, Alan

(Encyclopedia)Hovhaness, Alan hōvhäˈnəs [key], 1911–2000, American composer, b. Somerville, Mass., as Alan Vaness Chakmakjian. Hovhaness was of Armenian and Scottish descent, and many of his works are based o...

refraction

(Encyclopedia)refraction, in physics, deflection of a wave on passing obliquely from one transparent medium into a second medium in which its speed is different, as the passage of a light ray from air into glass. O...

Nakamura, Shuji

(Encyclopedia)Nakamura, Shuji, 1954–, Japanese physicist and electronics engineer, grad. Univ. of Tokushima (D.Eng., 1994). Nakamura joined the Nichia Corporation in 1977, and it was there that he began his life-...

Friedrich, Caspar David

(Encyclopedia)Friedrich, Caspar David käsˈpär däˈfēt frēˈdrĭkh [key], 1774–1840, German romantic landscape painter. After studying painting in Copenhagen he visited various scenic spots in Germany and ch...

Amano, Hiroshi

(Encyclopedia)Amano, Hiroshi, 1960–, Japanese physicist, Ph.D. Nagoya Univ., Japan, 1989. He is a professor at Nagoya Univ. in Japan. Amano is the joint recipient with Shuji Nakamura and Isamu Akasaki of the 2014...

firefly

(Encyclopedia)firefly or lightning bug, small, luminescent, carnivorous beetle of the family Lampyridae. Fireflies are well represented in temperate regions, although the majority of species are tropical and subtro...

photometry

(Encyclopedia)photometry fōtŏmˈətrē [key], branch of physics dealing with the measurement of the intensity of a source of light, such as an electric lamp, and with the intensity of light such a source may cast...

Bragg, Sir William Henry

(Encyclopedia)Bragg, Sir William Henry, 1862–1942, English physicist, educated at King William's College, Isle of Man, and Trinity College, Cambridge. He served on the faculties of the Univ. of Adelaide in Austra...