Source: The National Aeronautics and Space Administration (NASA) The diameter of our closest star, the Sun, is 1,392,000 kilometers. The Sun is thought to be 4.6 billion years old. The Sun is a…
PUZZLE FOR THE EYEREFRACTION IN HEAT HAZEMIRAGEFIND OUT MORELight rays usually travel in straight lines, but when they pass from one material to another they can be forced to bend (change…
(Encyclopedia) Fridley, city (2020 pop. 29,590), Anoka co., SE Minn., a suburb north of Minneapolis, on the Mississippi River; settled 1847, inc. as a…
(Encyclopedia) Orbiting Astronomical Observatory (OAO), series of four orbiting observatories (see observatory, orbiting) launched between 1966 and 1972 by the National Aeronautics and Space…
(Encyclopedia) bichirbichirbĭchˈər [key], common name for African freshwater fishes as of the family Polypteridae, and particularly for those of the genus Polypterus. Bichirs are among the most…
CONTACT LENSCONCAVE AND CONVEX LENSESFRESNEL LENSSLIDE PROJECTORMAGNIFYING GLASSFIND OUT MOREA lens is a piece of transparent plastic or glass that can make things seem to change size. It works…
EUROPEAN SOUTHERN OBSERVATORYMAUNA KEA OBSERVATORYVERY LARGE ARRAYFIND OUT MOREOptical observatories study the visible radiation (light) from objects in space, and most are located high up on…
The Experiment That FailedTheories of the UniverseThe Dual Nature of LightYou Can't See It, but It Has to Be ThereThe Experiment That FailedA Little Bit of Quanta Goes a Long Way Now that the…
(Encyclopedia) Coolidge, William David, 1873–1975, American physical chemist, b. Hudson, Mass., grad. Massachusetts Institute of Technology, 1896. He joined the General Electric Company in 1905 and…
