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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 5 Search : سایان
tangent
  ۱) سایان؛ ۲) تانژانت   
1) sâyân (#); 2) tânžânt

Fr.: tangente   

1) A straight line or plane that touches a curve or curved surface at one and only one point. Conversely, a curve or curved surface that touches a straight line, curve, or curved surface at one and only one point.
2) In trigonometry, the function of an acute angle of a right triangle defined as the ratio of the length of the opposite side to that of the adjacent side.

From L. tangentem (nominative tangens), pr.p. of tangere "to touch," from PIE base *tag- "to touch, to handle" (cf. L. tactus "touch," Gk. tetagon "having seized," O.E. þaccian "stroke, strike gently"); tânžânt, loan from Fr.

1) Sâyân, pr.p. of sâyidan "to touch, to rub," variants sâbidan, pasâvidan; Khotanese sauy- "to rub;" Sogdian ps'w- "to touch;" ultimately Proto-Iranian *sau- "to rub."
2) Tânžânt, loan from Fr.

tangential
  سایانی   
sâyâni (#)

Fr.: tangentiel   

Pertaining to or of the nature of a tangent.

tangent + -ial variant of → -al.

tangential motion
  جنبش ِ سایانی   
jonbeš-e sâyâni

Fr.: mouvement tangentiel   

That component of a an object's motion which is perpendicular to the observer's → line of sight.

tangential; → motion.

tangential velocity
  تندای ِ سایانی   
tondâ-ye sâyâni

Fr.: vitesse tangentielle   

1) The instantaneous linear velocity of a body moving in a circular path. It is equal to the → angular velocity multiplied by the radius: vt = ωr.
3) The component of the velocity of an object, such as a star, that is at right-angles to the observer's → line of sight; also known as transverse velocity. See also → radial velocity.

tangential; → velocity.

tangentially polarized light
  نور ِ قطبیده‌ی ِ سایانی   
nur-e qotbide-ye sâyâni

Fr.: lumière polarisée tangentiellement   

The → linearly polarized light that vibrates perpendicularly to an imaginary line joining the source to the point of observation.

Tangentially, adverb of → tangential; → polarized; → light.