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: 912
axion
  اکسیون   
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.

axis
  آسه   
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.

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

Fr.: axisymétrique   

Having → axisymmetry.

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

Fr.: axisymétrie   

Same as → axial symmetry.

azimuth
  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.

azimuthal
  سوگانی   
sugâni

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.

azimuthal projection
  فراشانش ِ سوگانی   
farâšâneš-e sugâni

Fr.: projection azimutale   

A map projection on which the → azimuths of all points are shown correctly with respect to the center. A plane tangent to one of the Earth's poles is the basis for polar azimuthal projection.

azimuthal; → projection.

azimuthal quantum number
  عدد ِ کو‌آنتومی ِ سوگانی   
adad-e kuântomi-ye sugâni

Fr.: nombre quantique azimutal   

In quantum mechanics, a quantum number that distinguishes the different shapes of the orbitals.

Azimuthal, adj. from → azimuth; → quantum number.

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