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: 972
average acceleration
  شتاب ِ میانگین   
šetâb-e miyângin

Fr.: accélération moyenne   

Of a body traveling from A to B, the change of → velocity divided by the time interval: ā = (v2 - v1) / (t2 - t1).

average; → acceleration.

average velocity
  تندای ِ میانگین   
tondâ-ye miyângin

Fr.: vitesse moyenne   

The ratio of the displacement (Δx) of a particle, as it moves from point A to point B, to the corresponding time interval: v = Δx/Δt.

average; → velocity.

averted vision
  نگاه ِ کژ   
negâh-e kaž (#)

Fr.: regard oblique   

The technique of looking slightly to the side of a faint object being studied while continuing to concentrate on the object. The technique helps bring out details which otherwise would be missed by looking directly at an object. The reason is that the portion of the eye's retina that best detects dim light (fovea) is located all around the edges rather than the center.

Averted p.p. from avert, from O.Fr. avertir, from L. avertere "to turn away," from → ab- "from, away" + vertere "to turn" (cognate with Pers. gardidan "to turn"); → vision.

Negâh, → vision; kaž "averted."

Avogadro constant
  پایای ِ آووگادرو   
pâyâ-ye Avogâdro (#)

Fr.: constante d'Avogadro   

The number of units in one → mole of any → substance (defined as its → molecular weight in grams), equal to 6.022 140 857 × 1023. The units may be electrons, atoms, ions, or molecules, depending on the nature of the substance.

Named after Amedeo Avogadro (1776-1856), whose law allowed other physicists to calculate Avogadro's number; → number.

Avogadro's law
  قانون ِ آووگادرو   
qânun-e Avogâdro (#)

Fr.: loi d'Avogadro   

A statement according to which equal volumes of different gases contain an equal number of molecules under the same conditions of temperature and pressure.

After Amedeo Avogadro (1776-1856), Italian chemist and physicist, who advanced the hypothesis in 1811.

Avogadro's number
  عدد ِ آووگادرو   
adad-e Avogâdro (#)

Fr.: nombre d'Avogadro   

Avogadro constant.

Named after Amedeo Avogadro (1776-1856), whose law allowed other physicists to calculate Avogadro's number; → constant.

avoid
  تسنیدن   
tosnidan

Fr.: éviter   

1) To keep away from; keep clear of; shun.
2) To prevent from happening (Dictionary.com). → abstain.

M.E. avoiden, from Anglo-French avoider "to clear out, withdraw (oneself)," from O.Fr. esvuidier "to empty out," from es- "out," → ex-, + vuidier "to be empty," from voide "empty, vast, waste," from L. vocivos "unoccupied, vacant," vacare "be empty," from PIE base *eue- "to leave, abandon, give out."

Tosnidan, from Baluci tôsênag "avoid," tusag "be quenched," tôsaq "quench;" related to Pers. tohi "empty, void;" Mid.Pers. tuhig "empty;" Parthian tôšênitan "to empty;" cf. Pashto taš; Ormuri tusk; Waxi töš, təš; Sariqoli tīs; Skt. tucchá-, tucchyá- "empty;" L. tesqua "deserts;" O.Slav tušti "empty;" Russ. tošcij "meager."

avoidable
  تسنیدنی   
tosnidani

Fr.: évitable   

Able to be avoided or prevented.

avoid; → -ance.

avoidance
  تسنش   
tosneš

Fr.: évitement   

The act of avoiding or keeping away from.

avoid; → -ance.

aware
  آگاه   
âgâh (#)

Fr.: conscient   

Having knowledge; conscious; informed; alert. → awareness.

M.E., variant of iwar, O.E. gewær; cf. O.S. giwar, M.Du. gheware, O.H.G. giwar, Ger. gewahr.

Âgâh "aware, knowing," related to negâh "look, attention;" Mid.Pers. âkâh; Av. ākas- "to look;" Proto-Iranian *kas- "to look, appear;" cf. Skt. kāś- "to become visible, appear;" Gk. tekmar, tekmor "sign, mark;"

awareness
  آگاهی   
âgâhi (#)

Fr.: conscience   

The state or condition of being aware; having knowledge; consciousness (Dictionary.com).
See also: → Space Situational Awareness.

aware; → -ness.

axial
  آسه‌ای   
âse-yi (#)

Fr.: axial   

Of, pertaining to, characterized by, or forming an axis.

axis; → -al.

axial inclination
  درکیل ِ آسه   
darkil-e âsé

Fr.: inclinaison de l'axe   

The angle at which a planet's axis of rotation is tilted, with respect to that of the planet's orbit.

axial; → inclination.

axial precession
  پیشایان ِ آسه‌ای   
pišâyân-e âse-yi

Fr.: précession axiale   

1) A change in the orientation of the → rotation axis of a non-spherical, spinning body caused by → gravity. A rotating top will precess in a direction determined by the → torque exerted by its → weight. The precession → angular velocity is inversely proportional to the spin angular velocity, so that the precession is faster and more pronounced as the top slows down.
2) In particular, the gradual shift in the orientation of Earth's rotation axis which traces out a conical path once every ~ 26,000 years. The cause of the Earth's precession is the → equatorial bulge of the Earth, brought about by the → centrifugal force of the → rotation, which has changed the Earth from a perfect sphere to a slightly flattened one, thicker across the equator. The attraction of the Moon and Sun on the bulge is the reason which makes the Earth precess.

axial; → precession.

axial symmetry
  همامونی ِ آسه‌ای   
hamâmuni-ye âse-yi

Fr.: symmétrie axiale   

A symmetry with respect to a line. A geometric configuration is said to have axial symmetry if it remains unchanged when rotated about a given line.

axial; → symmetry.

axial tilt
  گرای ِ آسه   
gerâ-ye âsé

Fr.: inclinaison de l'axe   

The angle between an object's → rotation axis and its → orbital axis. In other words, the angle between its → equatorial plane and → orbital plane. Same as → axial inclination and → obliquity, but not to be confounded with → orbital inclination.

axial; → tilt.

axiom
  بنداشت، ارز‌آغازه   
bondâšt (#), arzâqâzé (#)

Fr.: axiome   

In any system of mathematics or logic, a statement or proposition from which secondary statements or propositions are derived. The truth of an axiom is either taken for granted or assumed. Axioms serve as the starting point of other mathematical statements called → theorems. In modern practice, axiom and → postulate have the same meaning.

M.Fr. axiome, from L. axioma, from Gk. axioma "authority," literally "something worthy," from axioun "to think worthy," from axios "worthy," from PIE adj. *ag-ty-o- "weighty," from base *ag- "to drive, draw, move."

Bondâšt, literally "taking as the base," from bon "root, origin, base" + dâšt "held," from dâštan "to have, to hold, to maintain, to consider."
Arzâqâzé, from arz "value" + âqâzé "beginning, principle," from âqâz "beginning."

axiom of constraints
  بنداشت ِ پاوندها   
bondâšt-e pâvandhâ

Fr.: axiome des contraintes   

An axiom in → statics, stating that any → constrained body can be treated as a → free body detached from its → constraints, provided the latter are represented by their → reactions.

axiom; → constraint.

axiomatic
  بنداشتی   
bondâšti

Fr.: axiomatique   

Of, relating to, or resembling an → axiom.

axiom; → -ic.

axiomatic system
  راژمان ِ بنداشتی   
râžmân-e bondâšti

Fr.: système axiomatique   

Any system of → logic which explicitly states → axioms from which → theorems can be → deduced.

axiomatic; → system.

<< < -ab ab- abo abs abs acc acc ack act acu add adi adv aff agg Ald Alf ali all alp alt Ama amp ana ang ang ann ano ant ant ape apo app app arc are Ari art asp ast ast ast Ata atm ato att aut ave axi > >>