An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 10 Search : degree
degree
  درجه   
darajé (#)

Fr.: degré   

1) Subdivision of an interval in a scale of measurement.
2) Geometry: Measure of angle, the 360th part of a circle.
3) Math.: Rank of an equation or expression as determined by the sum of the exponents of the variables.

From O.Fr. degré, from V.L. *degradus "a step," from L.L. degredare, from L. → de- "down" + gradus "step."

Darajé, from Ar. darajat "step, ladder."

degree of coherence
  درجه‌ی ِ همدوسی   
dareje-ye hamdusi

Fr.: degré de cohérence   

The extent of → coherence of an → electromagnetic wave, as indicated by a → dimensionless number. Since interference takes place when waves are → coherent, using a → Young's experiment, the degree of coherence is measured from the → fringe  → visibility, V. It is defined as the ratio V = (Imax - Imin) / (Imax + Imin), where Imax is the intensity at a maximum of the → interference pattern, and Imin is the intensity at a minimum of the interference pattern. The electromagnetic wave is considered to be highly coherent when the degree of coherence is about 1, incoherent for nearly zero values, and partially coherent for values between 0 and 1.

degree; → coherence.

degree of freedom
  درجه‌ی ِ آزادی   
daraje-ye âzâdi (#)

Fr.: degré de liberté   

Of a → mechanical system, the number of → independent variables needed to describe its configuration.

degree; → freedom.

degree of ionization
  درجه‌ی ِ یونش   
daraje-ye yoneš (#)

Fr.: degré d'ionisation   

The number of electrons a neutral atom has lost in an ionizing physical process (radiation, shock, collision). In spectroscopy, the degree of ionization is indicated by a Roman numeral following the symbol for the element. A neutral atom is indicated by the Roman numeral I, a singly ionized atom, one which has lost one electron, is indicated by II, and so on. Thus O VI indicates an oxygen atom which has lost five electrons.

degree; → ionization.

degree of polarization
  درجه‌ی ِ قطبش   
daraje-ye qotbeš

Fr.: degré de polarisation   

The ratio of the intensity of polarized portion of light to the total intensity at a point in the beam.

degree; → polarization.

degree of stability
  درجه‌ی ِ پایداری   
daraje-ye pâydâri

Fr.: degré de stabilité   

Statics: The → energy that must be expended to permanently disturb a specific state of → equilibrium of a body.

degree; → stability.

degree of vertex
  درجه‌ی ِ تارک   
daraje-ye târak

Fr.: degré de vertex   

The → number of → edges incident on the → vertex.

degree; → vertex.

first degree equation
  هموگش ِ درجه‌ی ِ یکم   
hamugeš-e daraje-ye yekom

Fr.: équiation du premier degré   

A equation in which the highest → exponent of the → variable is 1. Same as → linear equation.

first; → degree; → equation.

polarization degree
  درجه‌ی ِ قطبش   
daraje-ye qotbeš (#)

Fr.: degré de polarisation   

degree of polarization.

polarization; → degree.

square degree
  درجه‌ی ِ چاروش   
daraje-ye câruš

Fr.: degré carré   

A solid angle whose cone is a tetrahedral pyramid with an angle between its edges equal to 1°. 1 square degree = 3.046 x 10-4 sr = 2.424 x 10-5 solid angle of a complete sphere.

square; → degree.