barn


barn
(b)
   a slightly humorous unit of area used in nuclear physics. When atoms are bombarded with smaller particles such as electrons, the electrons are scattered as if the nucleus of the atom was a tiny solid object. The barn is used to express the apparent cross-sectional area of this scattering object. One barn is equal to 10-28 square meters. Using this unit, physicists can say that such and such a nucleus is "as big as a barn," or 10 barns, or whatever. The proper SI unit to use for these measurements is the square femtometer (fm2); one barn equals 100 fm2.

Dictionary of units of measurement. 2015.

Look at other dictionaries:

  • barn — BARN, barni, s.m. Unitate de suprafaţă, de 10 24 cm2, în fizica nucleară. – Din fr. barn. Trimis de paula, 05.04.2002. Sursa: DOOM  barn s. m., pl. barni Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  BARN s.m. ( …   Dicționar Român

  • barn — barn·brack; barn; barn·ful; barn·man; barn·storm; mil·li·barn; barn·storm·er; …   English syllables

  • barn — [ barn ] n. m. • 1950; mot angl. ♦ Métrol. Unité de mesure de superficie (symb. b) utilisée en physique nucléaire (10 28 m2). ● barn nom masculin (de l anglais big as a barn, grand comme une grange) Unité d aire, valant 10−28 m2, utilisée pour… …   Encyclopédie Universelle

  • Barn — (b[aum]rn), n. [OE. bern, AS. berern, bern; bere barley + ern, [ae]rn, a close place. [root]92. See {Barley}.] A covered building used chiefly for storing grain, hay, and other productions of a farm. In the United States a part of the barn is… …   The Collaborative International Dictionary of English

  • Barn — Saltar a navegación, búsqueda El barn (símbolo b) es una unidad de superficie, equivalente a 10 28 m². Sus múltiplos son muy utilizados en física de partículas para medir las secciones eficaces en reacciones nucleares, y sus inversos para medir… …   Wikipedia Español

  • Barn — Barn, v. t. To lay up in a barn. [Obs.] Shak. [1913 Webster] Men . . . often barn up the chaff, and burn up the grain. Fuller. [1913 Webster] …   The Collaborative International Dictionary of English

  • barn — O.E. bereærn barn, lit. barley house, from bere barley (see BARLEY (Cf. barley)) + aern house, metathesized from *rann, *rasn (Cf. O.N. rann, Goth. razn house, O.E. rest resting place ) …   Etymology dictionary

  • barn — [bärn] n. [ME < OE bern, berern < bere,BARLEY + ærn, house: see REST1] 1. a farm building for sheltering harvested crops, livestock, machines, etc. ☆ 2. a large building for streetcars, trucks, etc. 3. [arbitrary use, from phr. as big as a… …   English World dictionary

  • Barn — barn. m. Fís. Unidad de medida de la superficie de choque en reacciones nucleares. Equivale a 10 28 m2. (Símb. b). * * * El barn (símbolo b) es una unidad de superficie, equivalente a 10 28 m². Sus múltiplos son muy utilizado …   Enciclopedia Universal

  • barn — [ barn ] noun count ** a large building on a farm where animals, crops, or machines are kept were you born/raised in a barn? SPOKEN a humorous way of telling someone to shut the door after they come into a room or building => DOOR …   Usage of the words and phrases in modern English

  • Barn — Sm Krippe, Heustock per. Wortschatz obd. md. (8. Jh.), mhd. barn (barm, baren), ahd. barn Stammwort. Ist vergleichbar mit ae. beren Scheuer , neben dem bere ærn u.a. steht. Im Englischen scheint das Wort für Gerste (ae. bere) zugrundezuliegen;… …   Etymologisches Wörterbuch der deutschen sprache

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