Columbia Encyclopedia

Search results

326 results found

Boleslav I

(Encyclopedia)Boleslav I bōˈləsläfˌ [key], d. 967, duke of Bohemia (929–67). He became duke by assassinating his elder brother, Duke Wenceslaus (see Wenceslaus, Saint). Although Boleslav was involved in cons...

celestial sphere

(Encyclopedia)celestial sphere, imaginary sphere of infinite radius with the earth at its center. It is used for describing the positions and motions of stars and other objects. For these purposes, any astronomical...

activation energy

(Encyclopedia)CE5 Energy profile of an exothermic reaction: Although the total energy of the products is less than that of the reactants, the activation energy must be added to weaken or break existing bonds bef...

Selinus

(Encyclopedia)Selinus sĭlīˈnəs [key], ancient city of Sicily. It was founded (628? b.c.) by Dorian Greeks. The constant rival of neighboring Segesta, Selinus got Syracuse to interfere in a quarrel, which led to...

identity

(Encyclopedia)identity, in philosophy, problem of distinguishing sameness from change, or unity from diversity; primarily examined in connection with personal identity, universals, and the law of identity in logic....

negotiable instrument

(Encyclopedia)negotiable instrument, bill of exchange, check, promissory note, or other written contract for payment that may serve as a substitute for money. It is simple in form and easy to transfer. Transfer of ...

talus

(Encyclopedia)talus tāˈləs [key], deposit of rock fragments detached from cliffs or mountain slopes by weathering and piled up at their bases. A talus is a common geologic feature in regions of high cliffs. The ...

phylacteries

(Encyclopedia)phylacteries fĭlăkˈtərēz [key] [Gr.,=safeguard], two small leather boxes worn during morning prayers by Orthodox and Conservative Jews after the age of 13 years and one day. Each box contains str...

Nestroy, Johann Nepomuk

(Encyclopedia)Nestroy, Johann Nepomuk yōˈhän nāˈpōmo͝ok nĕsˈtroi [key], 1802–62, Austrian dramatist and actor. A successful performer in comedies and operettas, he later proved himself a brilliant writer...

volt

(Encyclopedia)volt [for Alessandro Volta], abbr. V, unit of electric potential and electromotive force. It is defined as the difference of electric potential existing across the ends of a conductor carrying a const...