energy Reference Libraries

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Exotic Shorthair
2007-12-13 14:28:03

The Exotic Shorthair, a cross between the American Shorthair and the Persian is a breed of cat first created in the 1960s. The breed is often referred to as the "Lazy man's Persian" because it has the same body type and personality as a Persian but lacks the long haired coat that requires so much grooming. The body of the Exotic Shorthair is round, compact, powerful, and low to the ground....

2005-05-26 11:24:59

Coal is a fossil fuel extracted from the ground either by underground mining, open-pit mining or strip mining. It is a readily combustible black or brownish-black sedimentary rock. It is composed primarily of carbon and hydrocarbons, along with assorted other elements, including sulfur. Often associated with the Industrial Revolution, coal remains an enormously important fuel and is the most...

2004-10-19 04:45:42

Supernova -- A supernova is a star that increases its brightness drastically within a matter of days, making it appear as if a "new" star was born (hence "nova"). The "super" prefix distinguishes it from a mere nova, which also involves a star increasing in brightness, though to a lesser extent and through a much different mechanism. Astronomers have classified supernovae in several...

Stellar Evolution
2004-10-19 04:45:42

Stellar Evolution -- Stellar evolution is the process of formation, life, and death of stars. It is one of the major topics of cosmogony. Star Birth and Life A star starts out as an enormous cloud of gas and dust many light-years across. Star formation begins when the cloud begins to condense under its own gravity. The processes that initiate this contraction are not fully understood....

2004-10-19 04:45:42

Quasar -- A quasar (from quasi-stellar radio source) is an astronomical object that looks like a star in optical telescopes (i.e. it is a point source), but has a very high redshift. The general consensus is that this high redshift is cosmological, the result of Hubble's law and that their redshift indicates that they are typically very distant from Earth; we observe them as they were...

2004-10-19 04:45:42

Orbit -- An orbit is the path that an object makes around another object under the influence of some force. The classical example is that of the solar system, where the Earth, other planets, asteroids, comets, and smaller pieces of rubble are in orbit around the Sun; and moons are in orbit around planets. These days, many artificial satellites are in orbit around the Earth....

2004-10-19 04:45:42

Nova -- A nova is an enormous nuclear explosion caused by the accretion of hydrogen onto the surface of a white dwarf star. When a white dwarf has a close companion star, the companion will often begin to have its outer atmosphere drawn away from it by the white dwarf's gravity as the companion star ages and expands into a red giant. The gases so captured consist primarily of hydrogen...

2004-10-19 04:45:41

Geodesic -- In mathematics and specifically in differential geometry, a geodesic is a path that furnishes shortest paths between any points on it that are close enough together. The most familiar examples are the straight lines in Euclidean geometry. In more general spaces the geodesics can be more complicated, but one often still thinks of them as "straight" in a sense. On a sphere,...

Gamma-Ray Burst
2004-10-19 04:45:41

Gamma-Ray Burst -- In astronomy, Gamma-ray bursters (GRBs) are flashes of gamma rays that last from seconds to hours, the longer ones being followed by several days of X-ray afterglow. They occur at random positions in the sky several times each day. They are now believed to result from tremendous explosions in far away galaxies, during the creation of a black hole from a dying star or two...

Escape Velocity
2004-10-19 04:45:41

Escape Velocity -- An escape velocity is the minimum speed at which an object without propulsion can move away from a source of a gravitational field indefinitely if there is no friction. This definition may need modification for the practical problem of two or more sources in some cases. In any case, the object is assumed to be a point with a mass that is negligible compared with that of...

Word of the Day
  • A somewhat riotous parade, accompanied with the blowing of tin horns, and other discordant noises; also, a burlesque serenade; a charivari.
'Callithump' is a back-formation of 'callithumpian,' a 'fanciful formation' according to the Oxford English Dictionary. However, the English Dialect Dictionary, says 'Gallithumpians' is a Dorset and Devon word from the 1790s that refers to 'a society of radical social reformers' or 'noisy disturbers of elections and meetings.'