absorbing wedge gove-ye daršamandé Fr.: coin absorbant Optics: A strip or annulus of material, such as glass or film, whose density increases progressively from one end to the other. The function of the wedge is to weaken the light beam in an optical system. |
affine combination miyâzeš-e karvan Fr.: combinaison affine A linear combination of vectors in which all the vector coefficients add up to one. → affine; → combination. |
astrometric binary dorin-e axtarsanjik Fr.: binaire astrométrique A binary star in which the presence of an unresolved companion is revealed by small oscillations in the movement of the visible component caused by the gravitational influence of the unseen component. → astrometry; → binary. |
Babinet compensator pâhangandeh-ye Babinet Fr.: compensateur de Babinet A crystal device made of two → quartz → prisms with equal acute angles assembled in a rhombus that is used in analyzing → polarized light. The wedge-shaped prisms are placed against each other and can be displaced along their plane of contact by a → micrometer. Thus they form a parallel plate of variable thickness allowing the optical retardation to be adjusted. Jacques Babinet (1794-1872), French physicist; → compensator. |
Babinet point noqte-ye Babinet Fr.: point de Babinet One of several points on the sky where the degree of → linear polarization is zero in skylight. See also → neutral point; → Arago point, → Brewster point. → Babinet compensator; → point. |
Babinet's principle parvaz-e Babinet Fr.: principe de Babinet The → diffraction pattern for an → aperture is the same as the diffraction pattern for its → complementary aperture. → Babinet compensator; → principle. |
bin 1) bâvin; 2) bâvinidan Fr.: 1) bin; 2) binner 1a) General:A box or enclosed space for storing grain, coal, or
the like. M.E. binne, O.E. binn(e) "manger, crib," perhaps from O.Celt. *benna, akin to Welsh benn "a cart, especially one with a woven wicker body." The same Celtic word seems to be preserved in It. benna "dung cart," Fr. benne "a sort of box for transporting materials, especially in mines," Du. benne "large basket," from L.L. benna. Bâvin "a basket, more precisely a small basket which contains the cotton to be spun;" bâvinidan infinitive from bâvin. |
binarity dorini Fr.: binarité The quality or condition of being binary. |
binary dorin, dodoyi (#) Fr.: binaire General: Characterized by or consisting of two parts or
components. Binary, from L.L. binarius, from bini "two-by-two," from bis "twice, two times;" cf. Av. biš- "twice," bi- "two," Mod.Pers. do "two," PIE *dwo- "two." Dorin, from Mid.Pers. dorin "double, pair,"
from do (Av. dva-, Skt. dvi-, Gk. duo,
L. duo, E. two, Der. zwei, Fr. deux)
"two" + rin "time, turn." |
binary arithmetic hesâb-e dorin, ~ dodoi (#) Fr.: arithmétique binaire A system of calculation in which the only numerals used are 0 and 1. All the real numbers are represented in terms of powers of 2. → binary; → arithmetic. |
binary asteroid sayyârak-e dorin Fr.: astéroïde binaire A member of a population of double objects in the main → Asteroid Belt or the → Kuiper Belt which are gravitationally bound together. So far about 200 such binary systems have been identified, while their number is increasing. 243 Ida was the first binary asteroid to be discovered during the Galileo spacecraft flyby in 1993. Other examples are → Antiope and Kalliope in the main belt and QG_{298} in the Kuiper Belt. The importance of these objects resides in the fact that systems with well measured orbital parameters allow the total mass to be estimated. If the sizes of the components are known then their densities can be accurately calculated. Density is an important parameter since it yields information about composition and internal structure. |
binary black hole siyah câl-e dorin Fr.: trou noir binaire A → binary system consisting of two → black holes in close orbit around each other. Same as → black hole binary. |
binary digit (bit) raqam-e dorin, ~ dodoi, bit Fr.: chiffre binaire Either of the digits 0 or 1, used in the → binary number system. |
binary frequency basâmad-e dorinhâ Fr.: fréquence des binaires The fraction of stars that have at least one → companion. It is at least 50%. The binary fraction appears to increase with increasing → primary star mass, at least among the more massive stars: the → O stars and → B stars have a companion frequency of at least 70%, while for the → G stars the binary frequency is around 50% and the → M stars may have an even lower binary frequency of around 30-40%. Brown dwarfs are rare as companions to lower-main-sequence stars, although brown-dwarf binaries appear not to be rare. An increase in binary frequency with mass would be expected if most stars form in → multiple systems that disintegrate, since the more massive stars would then preferentially remain in binaries while the less massive ones would preferentially be ejected as single stars (see Richard B. Larson, 2001, in IAU Symposium 200, p. 93 and references therein). |
binary galaxy kahkašân-e dorin Fr.: galaxie binaire A pair of galaxies in orbit around each other. → binary; → galaxy. |
binary number system râžmân-e adadhâ-ye dirini Fr.: système des nombres binaires A → numeral system that has 2 as its base and uses only two digits, 0 and 1. The positional value of each digit in a binary number is twice the place value of the digit of its right side. Each binary digit is known as a bit. The decimal numbers from 0 to 10 are thus in binary 0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, and 1010. And, for example, the binary number 11101_{2} represents the decimal number (1 × 2^{4}) + (1 × 2^{3}) + (1 × 2^{2}) + (0 × 2^{1}) + (1 × 2^{0}), or 29. In electronics, binary numbers are the flow of information in the form of zeros and ones used by computers. Computers use it to manipulate and store all of their data including numbers, words, videos, graphics, and music. |
binary operation âpâreš-e dorin Fr.: opération binaire A mathematical operation that combines two numbers, quantities, sets, etc.,
to give a third. For example, multiplication of two numbers is a binary operation. |
binary pulsar pulsâr-e dorin, tapâr-e ~ Fr.: pulsar binaire A pulsar in a → binary system, the companion of which often being a → neutron star or a → white dwarf. The only known binary system with two pulsars components is the → double pulsar. As of 2010 about 70 binary pulsars have been identified. They are ideal laboratories for testing and studying the effects predicted by → general relativity, such as → spin precession, → Shapiro time delay, and → gravitational waves. The prototype, called PSR 1913+16, was discovered in 1974 by Russell A. Hulse and Joseph H. Taylor, Jr., who received the Nobel Prize for Physics in 1993. → Hulse-Taylor pulsar. |
binary star setâre-ye dorin Fr.: étoile binaire Two stars gravitationally bound to each other, so that they revolve around their common center of gravity. → double star; → spectroscopic binary. → binary; → star. |
binary supermassive black hole siyah-câl-e abar-porjerm-e dorin Fr.: trou noir supermassif double A → dual supermassive black hole whose components are separated by a few parsecs. → binary; → supermassive; → black; → hole. |