(Encyclopedia) PolarisPolarispōlârˈĭs [key] or North Star, star nearest the north celestial pole (see equatorial coordinate system). It is in the constellation Ursa Minor (see Ursa Major and Ursa…
(Encyclopedia) Roche limit, the closest distance that a celestial body held together only by its own gravity can come to a planet without being pulled apart by the planet's tidal (gravitational)…
(Encyclopedia) wave, in physics, the transfer of energy by the regular vibration, or oscillatory motion, either of some material medium or by the variation in magnitude of the field vectors of an…
(Encyclopedia) Hereward the WakeHereward the Wakehĕrˈĭwərd [key], fl. 1070, Anglo-Saxon rebel against William I. A thane, he apparently held land in Lincolnshire. In 1070 he sacked Peterborough with…
(Encyclopedia) era of good feelings, period in U.S. history (1817–23) when, the Federalist party having declined, there was little open party feeling. After the War of 1812 all sections were anxious…
(Encyclopedia) Boyle, Kay, 1903–93, American writer, b. St. Paul, Minn. A European expatriate in the interwar years, she returned to Europe as a correspondent for the New Yorker (1946–53) and…
(Encyclopedia) Benet, JuanBenet, Juanbənetˈ [key], 1927–93, Spanish novelist and essayist. He earned a degree in civil engineering and worked as a highway engineer before publishing (1961) his first…
(Encyclopedia) sleet, precipitation of small, partially melted grains of ice. As raindrops fall from clouds, they pass through layers of air at different temperatures. If they pass through a layer…
(Encyclopedia) chemical equilibrium, state of balance in which two opposing reversible chemical reactions proceed at constant equal rates with no net change in the system. For example, when hydrogen…
