An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 1068
qotbeš (#)

Fr.: polarisation   

1) Optics: A process or state in which the directions of the electric or magnetic fields of an → electromagnetic radiation change in a regular pattern. Light can be polarized by a variety of ways, involving the following processes: reflection, transmission, double refraction, and scattering. See also → unpolarized light; → linear polarization; → circular polarization; → elliptical polarization. The study of the polarization of light from astronomical sources can yield unique information in particular related to the properties of magnetic fields.
2) Electricity: A process or state in which the → dipole moments of → polar molecules in a → dielectric material get aligned under the action of an external electric field. Actually thin layers of bound charges with opposite signs appear on the surfaces of the dielectric.
3) Electricity: The accumulation of ions, produced during electrolysis, on the electrodes of a cell, increasing the resistance of the cell.

Verbal noun of → polarize.

polarization angle
  زاویه‌ی ِ قطبش   
zâviye-ye qotbeš (#)

Fr.: angle de polarisation   

Same as → polarizing angle and → Brewster angle.

polarization; → angle.

polarization charge
  بارِ قطبش   
bâr-e qotbeš


Same as → bound charge.

polarization; → charge.

polarization degree
  درجه‌ی ِ قطبش   
daraje-ye qotbeš (#)

Fr.: degré de polarisation   

degree of polarization.

polarization; → degree.

polarization fraction
  برخه‌ی ِ قطبش   
barxe-ye qotbeš

Fr.: fraction de polarisation   

The ratio expressed by P = (Ipar - Iper) / (Ipar + Iper), where Ipar and Iper are the light intensities with the electric field vector respectively parallel and perpendicular to the incident beam.

polarization; → fraction.

qotbidan (#)

Fr.: polariser   

To cause → polarization. To undergo polarization.

Infinitive of → polarization.

qotbidé (#)

Fr.: polarisé   

Of or pertaining to a medium or physical phenomenon that exhibits → polarization.

P.p. of → polarize.

polarized light
  نور ِ قطبیده   
nur-e qotbidé (#)

Fr.: lumière polarisée   

Electromagnetic radiation in the optical region which has undergone → polarization.

Past participle of → polarize; → light.

qotbandé (#)

Fr.: polariseur   

An optical device capable of transforming natural light into polarized light, usually by selective transmission of polarized rays.

Agent noun of → polarize.

polarizing angle
  زاویه‌ی ِ قطبش   
zâviye-ye qotbeš (#)

Fr.: angle de polarisation   

The angle of → incidence for which the reflected light is completely polarized. Also called the → Brewster angle and → polarization angle. See also → Brewster's law.

Polarizing, adj. of → polarize; → angle.

polarizing filter
  پالایه‌ی ِ قطبنده   
pâlâye-ye qotbandé (#)

Fr.: filtre polarisant   

A filter that polarizes light passing through it.

Polarizing, adj. of → polarize; → filter.

polarizing prism
  منشور ِ قطبنده   
manšur-e qotbandé

Fr.: prisme polarisant   

A prism that is used to produce or analyze plane-polarized light.

Polarizing, adj. of → polarize; → prism.

qotb (#)

Fr.: pôle   

1) Either extremity of the axis of the Earth or of any spherical body.
2) Either of the two regions or parts of an electric battery, magnet, or the like, at which the magnetic flux density is concentrated.
3) → pole of a mirror.
4) The fixed point in a system of polar coordinates that serves as the origin.

M.E., from L. polus "end of an axis, the sky," from Gk. polos "pivot, pole," polein "move around;" from PIE base *kwel- "to turn, move around, sojourn, dwell;" cognate with Pers. carx "every thing performing a circulatory motion; a wheel; a cart;" Av. caxra- "wheel," caraiti "he moves, approaches;" cf. Skt. cakra- "wheel, circle; cycle," carati "he moves, wanders;" Gk. kyklos "circle, wheel" (loaned L.L. cyclus); L. colere "to dwell in, to cultivate, move around," colonus "farmer, settler;" O.E. hweol "wheel;" Rus. koleso "wheel."

Qotb, from Ar. quTb.

pole of a mirror
  قطب ِ آینه   
qotab-e âyene

Fr.: pôle de mirroir   

The point where the → principal axis passes through the mirror.

pole; → mirror.

pole star
  ستاره‌ی ِ قطبی   
setâre-ye qotbi (#)

Fr.: étoile polaire   

A star that lies along the Earth's → rotation axis. The term usually refers to the star → Polaris, which is the current → North Celestial Pole star. The → South Celestial Pole is not currently associated with any bright star. See also: → North Pole Star, → South Pole Star.

pole; → star.


Fr.: polhodie   

Mechanics: For a rotating rigid body not subject to external torque, the closed curve described on the → inertia ellipsoid by the intersection with this ellipsoid of an axis parallel to the angular velocity vector and through the center.
Astro.: The path described by the North pole of the Earth in a reference frame attached to the Earth. The rotation axis of our planet is not fixed with respect to the Earth's crust. It describes a motion within a square with an amplitude reaching 20 m.

Polhode, from Fr. polhodie, coined by Louis Poinsot (1777-1859), a French mathematician and physicist, the inventor of geometrical mechanics, from → pole + Gk. hodos "way."

Qotbrâh, from gotb, → pole, + râh "way, path" (from Mid.Pers. râh, râs "way, street," also rah, ras "chariot;" from Proto-Iranian *rāθa-; cf. Av. raθa- "chariot;" Skt. rátha- "car, chariot," rathyā- "road;" L. rota "wheel," rotare "to revolve, roll;" Lith. ratas "wheel;" O.H.G. rad; Ger. Rad; Du. rad; O.Ir. roth; PIE *roto- "to run, to turn, to roll").

  کاراه، کارراه   
kârâh, kârrâh

Fr.: 1) ligne d'action; 2) politique   

1) A definite course of action adopted for the sake of expediency, facility, etc.
2) A course of action adopted and pursued by a government, ruler, political party, etc. (

M.E. policie "government, civil administration," from O.Fr. policie "political organization, civil administration," from L.L. politia "the state, civil administration," from Gk. politeia "state, administration, government, citizenship," from polites "citizen," from polis "city, state."

Kârâh, contraction of kâr râh, or râh-e kâr literally "way of doing, ~ ~ action," from râh, → way, + kâr "doing, action, → work."

policy maker
kârâh pardâz

Fr.: responsable politique, décideur   

A person responsible for making policy, especially in government (

policy; → make; → -er.

nasu kardan

Fr.: polir   

To make smooth and glossy by rubbing with something.

M.E. polishen, from O.Fr. poliss-, pr.p. stem of polir "to polish," from L. polire "to polish, make smooth," of unknown origin.

Nasu kardan (Dehxodâ) "to polish, smooth, brighten," from nasu "smooth, bright" (mirror, sword), Mid.Pers. Manichean Parthian nswg "tender," from Proto-Iranian *ni-sau-, from prefix ni- "down," → ni- (PIE), + *sau- "to rub;" cf. Mod.Pers. sâbidan, variants sâyidan, pasâvidan "to touch, to rub;" Khotanese sauy- "to rub;" Sogdian ps'w- "to touch."


Fr.: polissage   

A stage in the process of mirror making after grinding that puts a highly finished, smooth and apparently amorphous surface on a mirror. → figuring; → grinding.

Verbal noun of → polish.

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