# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 12 Search : dimension
 dimension   وامون   vâmunFr.: dimension   1) Math.: Independent extension in a given direction; a property of space. 2) Physics: → physical dimension.From L. dimensionem (nom. dimensio), from stem of dimetri "to measure out," from → dis- + metri "to measure."Vâmun, from vâ-, → dis-, + mun, variant mân "measure" (as in Pers. terms pirâmun "perimeter," âzmun "test, trial," peymân "measuring, agreement," peymâné "a measure; a cup, bowl"), from O.Pers./Av. mā(y)- "to measure;" PIE base *me- "to measure;" cf. Skt. mati "measures," matra- "measure;" Gk. metron "measure;" L. metrum. dimensional   وامونی   vâmuniFr.: dimensionnel   Of or pertaining to → dimension.→ dimension; → -al. dimensional analysis   آنالس ِ وامونی، آناکاوی ِ ~   ânâlas-e vâmuni, ânâkâvi-ye ~Fr.: analyse dimensionnelle   A technique used in physics based on the fact that the various terms in a physical equation must have identical → dimensional formulae if the equation is to be true for all consistent systems of unit. Its main uses are: a) To test the probable correctness of an equation between physical quantities. b) To provide a safe method of changing the units in a physical quantity. c) To solve partially a physical probable whose direct solution cannot be achieved by normal methods.→ dimensional; → analysis. dimensional formula   دیسول ِ وامونی   disul-e vâmuniFr.: formule dimensionnelle   Symbolic representation of the definition of a physical quantity obtained from its units of measurement. For example, with M = mass, L = length, T = time, area = L2, velocity = LT-1, energy = ML2T-2. → dimensional analysis.→ dimensional; → formula. dimensionless   بی‌وامون   bivâmunFr.: sans dimension   A physical quantity or number lacking units.→ dimension; → -less. dimensionless quantity   چندای ِ بی‌وامون   candâ-ye bivâmunFr.: quantité sans dimension   A quantity without an associated → physical dimension. Dimensionless quantities are defined as the ratio of two quantities with the same dimension. The magnitude of such quantities is independent of the system of units used. A dimensionless quantity is not always a ratio; for instance, the number of people in a room is a dimensionless quantity. Examples include the → Alfven Mach number, → Ekman number, → Froude number, → Mach number, → Prandtl number, → Rayleigh number, → Reynolds number, → Richardson number, → Rossby number, → Toomre parameter. See also → large number.→ dimension; → quantity. four-dimensional operator   آپارگر ِ چهار-وامونی   âpârgar-e cahâr-vâmuniFr.: opérateur à quatre dimensions   An operator defined as: ▫ = (∂/∂x, ∂/∂y, ∂/∂z, 1/(jc∂/∂t).→ four; → dimensional; → operator. nondimensional equation   هموگش ِ ناوامونی   hamugeš-e nâvâmuniFr.: équation non-dimensionnelle   An equation that is independent of the units of measurement as it only involves nondimensional numbers, parameters, and variables.→ non-; → dimensional; → equation. one-dimensional flow   تچان ِ یک-وامونی   tacân-e yek-vâmuniFr.: écoulement uni-dimensionnel   A hypothetical flow in which all the flow parameters may be expressed as functions of time and one space coordinate only. This single space coordinate is usually the distance measured along the center-line of some conduit in which the fluid is flowing (B. Massey, Mechanics of Fluids, Taylor & Francis, 2006).→ one; → dimensional; → flow. physical dimension   وامون ِ فیزیکی   vâmun-e fizikiFr.: dimension physique   Any of basic physical quantities, such as mass, length, time, electric charge, and temperature in terms of which all other kinds of quantity can be expressed.→ physical; → dimension. three-dimensional flow   تچان ِ سه-وامونی   tacân-e sé-vâmuniFr.: écoulement tri-dimensionnel   A flow whose parameters (velocity, pressure, and so on) vary in all three coordinate directions. Considerable simplification in analysis may often be achieved, however, by selecting the coordinate directions so that appreciable variation of the parameters occurs in only two directions, or even only one (B. Massey, Mechanics of Fluids, Taylor & Francis, 2006).→ three; → dimensional; → flow. two-dimensional flow   تچان ِ دو-وامونی   tacân-e do-vâmuniFr.: écoulement bi-dimensionnel   A flow whose parameters are functions of time and two space coordinates (x and y) only. There is no variation in the z direction and therefore the same → streamline pattern could at any instant be found in all planes in the fluid perpendicular to the z direction (B. Massey, Mechanics of Fluids, Taylor & Francis, 2006).→ two; → dimensional; → flow.