An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -ph pal par par par par Pas pat Pel per per per per Per per pha phi pho pho pho phy pip Pla pla pla pla ple poa pol pol pol pol pop pos pos pow pra pre pre pre pri pri pri pro pro pro pro pro pro pse pul pup > >>

Number of Results: 1037

Fr.: polarité   

1) Physics: The condition, in a system, of having opposite characteristics at different points, especially positive or negative with respect to electric charge or magnetic properties.
2) Chemistry: A property of a molecule caused by unsymmetrical charge distribution.

From → polar + → -ity.

polarity epoch
  زیمه‌ی ِ قطبیگی   
zime-ye qotbigi

Fr.: époque de polarité   

The time during which the Earth's magnetic field was of a single polarity; an interval of time between reversals of Earth's magnetic field.

polarity; → epoch.

polarity event
  رویداد ِ قطبیگی   
ruydâd-e qotbigi

Fr.: événement de polarité   

A specific event in the history of Earth's magnetic field. Usually used in reference to a specific → polarity reversal.

polarity; → event.

polarity reversal
  وارونش ِ قطبیگی، واگردانی ِ ~   
v âruneš-e qotbigi, vâgardâni-ye ~

Fr.: inversion de polarité   

1) A change in the → polarity of Earth's magnetic field in which the north magnetic pole becomes the south magnetic pole and vice versa. Also known as geomagnetic reversal or magnetic reversal. Earth's magnetic field has reversed many times in the past and the time intervals between these changes are known as → polarity epochs.
2) The change in the polarity of the → solar magnetic field with the ending of each → solar activity cycle so that the North magnetic pole becomes the South and vice versa.

polarity; → reversal.


Fr.: polarisable   

Able to be polarized.

polaize; → -able.

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) 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 star
  ستاره‌ی ِ قطبی   
setâre-ye qotbi (#)

Fr.: étoile polaire   

A star that lies in the direction pointed to by 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 associated with any bright 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").

<< < -ph pal par par par par Pas pat Pel per per per per Per per pha phi pho pho pho phy pip Pla pla pla pla ple poa pol pol pol pol pop pos pos pow pra pre pre pre pri pri pri pro pro pro pro pro pro pse pul pup > >>