An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Number of Results: 8 Search : contract
contract
  ترنگیدن   
terengidan

Fr.: se contracter, contracter   

1) To become smaller, shorter, tighter, as a metal when cooled.
2) To reduce to smaller size by or as if by squeezing or forcing together, e.g. contract a muscle.
contraction, → gravitational contraction, → Kelvin-Helmholtz contraction, → length contraction, → Lorentz contraction, → vena contracta.

From M.E., from O.F., from L. contractus, p.p. of contrahere "to draw together," from → com- "together" + trahere "to draw."

Terengidan, variant taranjidan [Dehxodâ] "to contract, become rough and hard, to be squeezed, compressed," Borujerdi terengessa "cramped, tightly dressed," Malâyeri terengidan "to be tightly dressed, cramped in a garment," related to tarang "horse girth, a strap for fastening a load," Proto-Iranian *trng- "to pull tight, squeeze, compress;" PIE base *strenk- "to pull tight, twist; tight, narrow" (cf. L. stringere "to bind or draw tight;" Gk. strangein "to twist;" Lith. stregti "to congeal;" O.E. streccian "to stretch," streng "string;" Ger. stramm, Du. stram "stiff").

contraction
  ترنگش   
terengeš

Fr.: contraction   

An act or instance of contracting; the quality or state of being contracted.
gravitational contraction, → Kelvin-Helmholtz contraction, → length contraction, → Lorentz contraction.

Verbal noun of → contract.

gravitational contraction
  ترنگش ِ گرانشی   
terengeš-e gerâneši

Fr.: contraction gravitationnelle   

Decrease in the volume of an astronomical object under the action of a dominant, central gravitational force.

gravitational; → contraction.

Kelvin-Helmholtz contraction
  ترنگش ِ کلوین-هلمهولتس   
terengeš-e Kelvin-Helmholtz

Fr.: contraction de Kelvin-Helmholtz   

The contraction of a volume of gas under its → gravity, accompanied by the → radiation of the lost → potential energy as → heat.

After the Scottish physicist William Thomson, also known as Lord Kelvin (1824-1907) and the German physicist and physician Hermann Ludwig Ferdinand von Helmholtz (1821-1894), who made important contributions to the thermodynamics of gaseous systems; → contraction.

length contraction
  ترنگش ِ درازا   
terengeš-e derâzâ

Fr.: contraction de longueur   

Same as → Lorentz contraction.

length; → contraction.

Lorentz contraction
  ترنگش ِ لورنتز   
terengeš-e Lorentz

Fr.: contraction de Lorentz   

The decrease in the length of a body moving in the direction of its length as measured by an observer situated in that direction. The shortening factor is [1 - (v/c)2]1/2, where v is the relative velocity and c light speed.

Lorentz; → contraction.

tensor contraction
  ترنگش ِ تانسور   
terengeš-e tânsor

Fr.: contraction de tenseur   

An operation of tensor algebra that is obtained by setting unlike indices equal and summing according to a summation convention.

contraction; → tensor.

vena contracta
  شاره‌گذر ِ ترنگیده   
šâre-gozar-e terengidé

Fr.: veine contractée   

The location in a → fluid stream where the → cross section of the → stream is at a minimum, and fluid velocity is the highest, such as in the case of a → jet issuing out of a → nozzle.

L. vena "channel;" contracta, "contracted," → contract.

Šâre-gozar "fluid passage," → fluid; → passage, terengidé, → contracted.