(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…
(Encyclopedia) sale, in law, transfer of ownership in return for money. An exchange of goods for goods is termed barter, but the distinction between sale and barter is mainly technical; laws that…
(Encyclopedia) Ronaldo (Ronaldo Luiz Nazario de Lima), 1976–, Brazilian soccer player. A son of Rio de Janeiro's back streets, he signed with his first professional club at 14. Nicknamed “The…
(Encyclopedia) number, entity describing the magnitude or position of a mathematical object or extensions of these concepts.
A real or complex number z is called algebraic if it is the root of a…
(Encyclopedia) retrograde motion, in astronomy, real or apparent movement of a planet, dwarf planet, moon, asteroid, or comet from east to west relative to the fixed stars. The most common direction…
(Encyclopedia) Bolzano, BernardBolzano, Bernardbōltsäˈnō [key], 1781–1848, Czech philosopher, mathematician, and theologian. Though as a Catholic priest he himself was primarily concerned with…
(Encyclopedia) di Stéfano, Alfredo, 1926–2014, Argentinian-born soccer star, one of the game's greats. Nominally a center-forward, he became famous for his versatility on the field as well as for his…
Numbers Please: Economic DataThe Economist's ToolboxIntroductionNumbers Please: Economic DataWatch Out! In the business press, you will read economic data. Often these data are called economic…
(Encyclopedia) Agricola, Rudolphus, 1443–85, Dutch humanist, whose real name was Roelof Huysmann. He opposed scholasticism and spread the culture of the Renaissance throughout Germany greatly…
