An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 902
âgâhi (#)

Fr.: conscience   

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

aware; → -ness.

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.

  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. 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.


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.

aksion (#)

Fr.: axion   

A hypothetical weakly-interacting → boson of small mass required by models of → particle physics in order to solve the strong CP problem and explain a number of observed astrophysical/cosmological phenomena, including → dark matter, and the dimming of → type Ia → supernovae (→ accelerating Universe). Photons traveling in the → intergalactic medium would in part turn into axions in the presence of magnetic fields. The transformed photons are not detected on Earth and therefore supernovae would appear fainter even if the Universe is not accelerating.

Axion, first coined by Frank Wilczek (2004 Nobel Prize in Physics) apparently after a brand of washing detergent! The reason seems to be the idea that the particle will iron out a wrinkle in the → standard model of fundamental particles and forces while solving the problem of the Universe's → missing mass.

âsé (#)

Fr.: axe   

1) One of the principal lines through the center of a figure or a solid, especially, the line which divides the figure or solid symmetrically.
2) A fixed line along which distances are measured or to which position are referred.

L. axis "axle, pivot," akin to O.E. eax "axis, axle," Gk. axon "axle," Skt. aksa- "axle, axis, beam of a balance;" PIE base *aks- "axis."

Âsé, from Pers. dialects: Qâyeni asak "the shaft connecting the plough to the yoke," Lori esi "a pillar (used to put up a tribal tent)," variants hosi, hosin, Tabari âssen "the foot of a door on which it turns," cf. Skt. ISA- "pole or shafts of a carriage or plough," Av. aêša "the two shafts," Mod.Pers. xiš "plough(share)," Gk. oiax "handle of rudder, tiller, helm," PIE base *ei-, *oi- "pole, thill."

axis of rotation
  آسه‌ی ِ چرخش   
âse-ye carxeš

Fr.: axe de rotation   

Same as → rotation axis and → rotational axis.

axis; → rotation.

  همامون ِ آسه‌ای، آسه-همامون   
hamâmun-e âse-yi, âse-hamâmun

Fr.: axisymétrique   

Having → axisymmetry.

  همامونی ِ آسه‌ای، آسه-همامونی   
hamâmuni-ye âse-yi, âse-hamâmuni

Fr.: axisymétrie   

Same as → axial symmetry.

  سوگان، سمت   
sugân, samt

Fr.: azimut   

Angular distance from the north point eastward to the intersection of the horizon with the vertical circle passing through the object. Azimuth is 0° for an object due north, 90° due east, 180° due south, and 270° due west. Altitude and azimuth constitute the the horizontal coordinate system.

From O.Fr. azimut, from Ar. as-sumut "the directions, ways," pl. of as-samt "the direction, way."

Sugân, from su "direction" + -gân direction suffix.

azimuth circle
  پرهون ِ سوگان، دایره‌ی ِ ~   
parhun-e sugân, dâyere-ye ~

Fr.: cercle d'azimut   

One of great circles of the → celestial sphere which passes through the → zenith, → nadir, and the star, cutting the horizon at right angles. Same as → vertical circle.

azimuth; → circle.


Fr.: azimutal   

Or, or pertaining to an → azimuth.

azimuth + → -al.

azimuthal angle
  زاویه‌ی ِ سوگانی   
zâviye-ye sugâni

Fr.: angle azimutal   

In → spherical coordinates, an angle measured from the x-axis in the xy-plane.

Azimuthal, adj. from azimuth; → angle.

azimuthal magnetic field
  میدان ِ مغناتیسی ِ سوگانی   
meydân-e meqnâtisi-ye sugâni

Fr.: champ magnétiquue azimutal   

In the → solar dynamo model, a magnetic field that points from east to west or vice-versa.

azimuthal; → magnetic; → field.

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