close kip (#) Fr.: serré Having little or no space between elements or parts, as in → close binary, → close approach; tight and compact. M.E. clos, closed, from O.Fr., from L. clausus, p.p. of claudere "to close." Kip "close, tight" in spoken Pers. |
close approach nazdeš-e kip Fr.: approche serrée In astronomy a general term to describe the positions of two or more objects that come unusually near one to another. In particular, regarding an asteroid's position with respect to Earth, when it is within the Moon's orbit. |
close binary star setâre-ye dorin-e kip Fr.: étoile binaire serrée A binary system in which the separation of the component stars is comparable to their diameters, so that they influence each other's evolution most commonly by the tidal forces. |
close binary system râžmân-e dorin-e kip Fr.: système binaire serré A → binary system in which the distance separating the stars is comparable to their size. Most close binaries are spectroscopic binaries (→ spectroscopic binary) and/or eclipsing binaries (→ eclipsing binary). In most of them → mass transfer occurs at some stage, an event which profoundly affects the → stellar evolution of the components. The evolution of close binaries depends on the → initial masses of the two stars and their → separation. When the more massive star evolves into a → red giant first, material will spill through the inner point onto its companion, thereby affecting its companion's evolution. Mass transfer can also alter the separation and → orbital period of the binary star. |
close encounter ruyâruyi-ye kip Fr.: rencontre proche 1) In a → star cluster, coming across of two stars so
closely that their → orbits alter by
their mutual → gravitational attractions. |
closed basté (#) Fr.: fermé Having boundaries; limited. → closed curve; → closed Universe. Closed, p.p. of close, from M.E. clos, from O.Fr., from clore "to shut," from L. clausus, p.p. of claudere "to close." Basté p.p.of bastan, from Mid.Pers. bastan/vastan "to bind, shut," Av./O.Pers. band- "to bind, fetter," banda- "band, tie," Skt. bandh- "to bind, tie, fasten," PIE *bhendh- "to bind," cf. Ger. binden, E. bind, → band. |
closed curve xam-e basté (#) Fr.: courbe fermée A curve whose ends are joined. |
closed space fazâ-ye basté (#) Fr.: espace fermé A bounded space the surface of which has the property that if one travels in any direction upon it without changing direction, one will end up back to the departure point. An example is a sphere. Triangles which lie on the surface of a closed space will have a sum of angles which is greater than 180°. An closed space has a positive → curvature. See also → closed Universe, → open space. |
closed system râžmân-e basté Fr.: système fermé Thermodynamics: A system which can exchange energy with the surroundings but not matter. → open system; → isolated system. |
closed Universe giti-ye basté (#) Fr.: Univers fermé A → cosmological model, first formulated by Friedmann and Lemaître, in which the Universe has a → finite size and lifetime and → space has a → positive → curvature, e.g. a Universe with a density greater than the → critical density. See also → closed space. |
closed wff wff basté Fr.: FBF fermée In → predicate logic, a → wff with no → free occurrences of any → variable. Also called a → sentence. |
massive close binary dorin-e kip-e porjerm Fr.: binaire serrée massive A → close binary system composed of two → massive stars. → massive; → close binary star. |
quasi-closed subsystem zir-râžmân-e cunân-basté Fr.: sous-système quasi-fermé A subsystem if its intrinsic energy is large, on the average, with respect to the energy of its interaction with other portions of the → closed system. |