# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 422
 geodetic pole   قطب ِ زمین‌سنجیک   qotb-e zamin-sanjikFr.: pôle géodésique   Any of the interaction points of the axis of revolution of the → reference ellipsoid with its surface.→ geodetic; → pole. geodetic precession   پیشایان ِ کهین‌رهی   pišâyân-e kehinrahiFr.: précession géodésique   A → relativistic effect on the precession motion of a gravitational system due to the → curvature of the → space-time. When a body revolves around a primary, the → rotation axis of the orbiting body follows the curvature of spece-time. Over time the space-time warping causes the spin axis to precess. In the case of the Earth-Moon system, this means a small → direct motion of the → equinox along the → ecliptic, amounting to 1''.915 per century. The geodetic precession is given by: ψg = (3/2) k2 (1 - e⊕) n⊕, where k is the → constant of aberration (in radians), e⊕ the → eccentricity of the Earth and n⊕ the mean angular orbital motion of the Earth (in arcsec/cy). Also called → Einstein-de Sitter effect and → geodesic precession. geodetic refraction   شکست ِ زمین‌سنجیک   šekast-e zamin-sanjikFr.: réfraction géodésique   The limiting case of → astronomical refraction when the light path is entirely within the Earth's atmosphere.→ geodetic; → refraction. geodetic vertical   هجین ِ زمین‌سنجیک   hajin-e zamin-sanjikFr.: vertical géodésique   The direction defined by the → normal to the → reference ellipsoid at the point in question.→ geodetic; → vertical. geodetic zenith   سرسوی ِ زمین‌سنجیک   sarsu-ye zamin-sanjikFr.: zénith géodésique   The intersection of the prolongation of the outward → normal to the → reference ellipsoid at the point in question with the → celestial sphere.→ geodetic; → zenith. geographic   زمین‌نگاریک   zaminnegârikFr.: géographique   Of or pertaining to → geography.→ geography; → -ic. geographic coordinate system   راژمان ِ هماراهای ِ زمین‌نگاریک   râžmân-e hamârâhâ-ye zaminnegârikFr.: système de coordonnées géographiques   A → ccordinate system on the surface of the Earth that defines every location by a set of numbers and letters, indicating the → latitude and → longitude.→ geographic; → coordinate; → system. geographic latitude   ورونای ِ زمین‌نگاریک   varunâ-ye zaminnegârikFr.: latitude géographique   A synonym for → geodetic latitude or → astronomical latitude.→ geographic; → latitude. geographic north pole   قطب ِ هودر ِ زمین‌نگاریک   qotb-e hudar-e zaminnegârikFr.: pôle nord géographique   → geographic; → north; → pole. geographic south pole   قطب ِ دشتر ِ زمین‌نگاریک   qotb-e daštar-e zaminnegârikFr.: pôle sud géographique   → geographic; → south; → pole. geography   زمین‌نگاری   zaminnegâri (#)Fr.: géographie   The science dealing with the areal differentiation of the Earth's surface, as shown in the character, arrangement, and interrelations over the world of such elements as climate, elevation, soil, vegetation, population, land use, industries, or states, and of the unit areas formed by the complex of these individual elements (Dictionary.com).→ geo-; → -graphy. geoid   زمین‌وار   zaminvâr (#)Fr.: géoïde   The form of the → Earth obtained by taking average sea level surface and extending it across the continents. In other words, the → equipotential surface ("mean sea level") of the Earth's → gravitational field. The geoid is considered to represent the true physical figure of the Earth, in contrast to the → reference ellipsoid, which is idealized geometrical figure of the Earth.→ geo-; → -oid. geologic   زمین‌شناختی   zaminšenâxti (#)Fr.: géologique   Of, pertaining to, or based on → geology. Also geological.From geolog(y), → geology, + → -ic. geologic time   زمان ِ زمین‌شناختی   zamân-e zaminšenâxti (#)Fr.: temps géologique   The long span of time from the end of the formation of Earth during which our planet underwent its major transformations.→ geologic; → time. geology   زمین‌شناسی   zaminšenâsi (#)Fr.: géologie   The scientific study of the composition, structure, and physical history of the Earth.→ geo- + → -logy. geomagnetic   زمین‌مغناتیسی، زمین‌مغناتی   zamin-meqnâtisi, zamin-meqnâtiFr.: géomagnétique   Of or pertaining to → geomagnetism.→ geo-; → magnetic. geomagnetic activity   ژیرندگی ِ زمین‌مغناتیسی، ~ زمین‌مغناتی   žirandegi-ye zamin-meqnâtisi, ~ zamin-meqnâtiFr.: activité géomagnétique   The natural variations in the → geomagnetic field due to interactions of the Earth's field and → magnetosphere with energetic particles from the Sun.→ geomagnetic; → activity. geomagnetic excursion   زچار ِ زمین‌مغناتی   zocâr-e zamin-meqnâtiFr.: excursion géomagnétique   A geophysical event, distinguished from the → magnetic reversal, in which the Earth's magnetic field departs for a relatively short time from its usual near axial configuration, without establishing a reversed direction. During the excursion the intensity and direction of the Earth's magnetic field undergo drastic changes. Palaeomagnetic measurements have revealed that since the last full reversal the Earth's magnetic field has, for brief intervals, deviated from the behavior expected during "normal" secular variation.→ geomagnetic; → excursion. geomagnetic field   میدان ِ زمین‌مغناتیسی، ~ زمین‌مغناتی   meydân-e zamin-meqnâtisi, ~ zamin-meqnâtiFr.: champ géomagnétique   The magnetic field that is generated within the Earth and extends out around the Earth. The intensity of the magnetic field at the Earth's surface is about 0.32 → gauss at the equator and 0.62 gauss at the north pole.→ geomagnetic; → field. geomagnetic storm   توفان ِ زمین‌مغناتیسی، ~ زمین‌مغناتی   tufân-e zamin-meqnâtisi, ~ zamin-meqnâtiFr.: orage géomagnétique   A violent disturbance of the Earth's magnetic field, distinct from regular diurnal variations, following a → solar flare or → coronal mass ejection.→ geomagnetic; → storm.