An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 153 Search : ten
Laser Interferometer Space Antenna (LISA)
  آنتن ِ فضایی ِ اندرزنش‌سنج ِ لیزری   
ânten-e fezâyi-e andarzanešsanj-e leyzeri

Fr.: Observatoire d'ondes gravitationnelles par interférométrie laser   

A collaborative project between → NASA and → ESA to develop and operate a space-based gravitational wave detector sensitive at frequencies between 0.03 mHz and 0.1 Hz. LISA detects gravitational-wave induced strains in → space-time by measuring changes of the separation between fiducial masses in three spacecraft 5 million km apart. Ultimately, NASA and ESA decided in 2011 not to proceed with the mission. LISA was not the highest ranked mission in the 2010 Decadal Survey and funding constraints prevented NASA from proceeding with multiple large missions ( → LISA pathfinder.

laser; → interferometer; → space; → antenna.

nahân (#)

Fr.: latent   

Present but not visible, apparent, or actualized; existing as potential ( → latent heat.

From L. latentem (nominative latens), pr.p. of latere "to lie hidden."

Nahân "concealed, hid; clandestine;" Mid.Pers. nihân "secrecy, a secret place, a hiding place," nihânik "concealed;" Av. niδāti- "deposing, deposit."

latent heat
  گرمای ِ نهان   
garmâ-ye nahân (#)

Fr.: chaleur latente   

The amount of → thermal energy that is absorbed or released by a unit amount of a substance in the process of a phase change under conditions of constant pressure and temperature.

latent; → heat.

lensing potential
  توند ِ لنزش   
tavand-e lenzeš

Fr.: potentiel de l'effet de lentille gravitationnelle   

An important quantity in the characterization of → gravitational lensing. The lensing potential is obtained by projecting the three-dimensional Newtonian potential on the lens plane and by properly re-scaling it. It is a two-dimensional analog to the → gravitational potential.

lensing; → potential.

limb brightening
  روشنش ِ لبه   
rowšaneš-e labé

Fr.: embrillancement centre-bord   

An observed increase in the intensity of radio, extreme ultraviolet, or X-radiation from the Sun from its center to its limb.

limb; → brightening.

line intensity
  درتنویی ِ خط   
dartanuyi-ye xatt

Fr.: intensité de raie   

A measure of the total effect of an absorption or emission line. The line intensity is equal to the integration of the absorption coefficient over the entire shape of the absorption line.

line; → intensity.

luminous intensity
  درتنویی ِ تابشی   
dartanuyi-ye tâbeši

Fr.: intensité lumineuse   

A measure of the amount of light that a point source radiates in a given direction. It is expressed by the luminous flux per unit leaving the source in the direction per unit of solid angle.

luminous; → intensity.

magnetic intensity
  درتنویی ِ مغناتیسی   
dartanuyi-e meqnâtisi

Fr.: intensité magnétique   

Strength of a magnetic field at a point, denoted H. The force which could be exerted on unit north magnetic pole situated at that point. Measured in oersteds. Same as → magnetic field strength.

magnetic; → intensity.

magnetic tension
  تنش ِ مغناتیسی   
taneš-e meqnâtisi

Fr.: tension magnétique   

In → magnetohydrodynamic (MHD) treatment of → plasmas, that component of the → Lorentz force which is directed toward the centre of curvature of the → magnetic field lines and thus acts to straighten out the field lines. The Lorentz force can be decomposed into two components orthogonal to the magnetic field: j× B = (B . ∇) B / μ0 - ∇ (B2 / 2μ0), where j is the → current density, μ0 is the → magnetic permeability of free space, and B is the → magnetic flux density. The left side term is the Lorentz force, the first term on the right side is the magnetic tension and the second term the → magnetic pressure.

magnetic; → tension.

magnetic vector potential
  توند ِ برداری ِ مغناتیسی   
tavand-e bordâri-ye meqnâtisi

Fr.: vecteur potentiel magnétique   

A vector field A defined so that the → magnetic field  B is given by its → curl: B = ∇ x A.

magnetic; → vector; → potential.

metric tensor
  تانسور ِ متریک   
tânsor-e metrik

Fr.: tenseur métrique   

The abstract tensor operation which is computed in a particular → reference frame using the → metric components. The metric tensor defines magnitude and direction of vectors about a point.

metric; → tensor.


Fr.: moufle   

A hand covering enclosing the four fingers together and the thumb separately ( → glove, → mitt.

M.E. miteyn, from M.Fr., O.Fr. mitaine, from from O.Fr. mite "mitten," and from M.L. mitta.

Dasmtuž, literally "hand-shoe" (Ger. Handschuh, "glove," literally "hand-shoe"), from dast, → hand, + Muž, variant of Pers. muzé "shoe," Mid.Pers. môg "shoe, boot;" cf. Pers. paymôz- / paymôxtan "to dress;" Av. (+ pati-paitišmaoc- "to shoe;" Proto-Ir. *(h)mauc-? "to dress, clothe" (Cheung 2007).

Newtonian potential
  توند ِ نیوتنی   
tavand-e Newtoni

Fr.: potentiel newtonien   

A potential in a field of force obeying the inverse-square law such as → gravitational potential.

Newtonian; → potential.

  ناهستومندی، ناهستی   
nâhastumandi, nâhasti

Fr.: non existence   

Math.: The fact that no → solution exists for a given → problem. In mathematics, nonexistence usually is a matter of impossibility.

non-; → existence.

paxi (#)

Fr.: aplatissement   

The property possessed by a round body that is flattened at the poles.

Noun from → oblate.


Fr.: souvent   

Many times; frequently; in many cases.

M.E. oftin, from O.E. oft "often, frequently," akin to cognates: O.Frisian ofta, Danish ofte, O.H.G. ofto, Ger. oft, of unknown origin.

Basvân, from bas "many, much," → frequency, + -vân on the model of farâvân, → abundance.

visp-tavân (#)

Fr.: omnipotent   

Having very great or unlimited power or authority.

omni-; → power.

optical oblateness
  پخی ِ نوری   
paxi-ye nuri

Fr.: aplatissement optique   

(polar flattening) The ratio of the difference between equatorial and polar diameters to the equatorial diameter. A sphere has an oblateness of 0; an infinitely thin disk has an oblateness of 1 (Ellis et al., 2007, Planetary Ring Systems, Springer).

optical; → oblateness.

order of a tensor
  رایه‌ی ِ تانسور   
râye-ye tânsor

Fr.: ordre de tenseur   

The maximum number of the indices (→ index) of a tensor.

order; → tensor.

parabolic antenna
  آنتن ِ سهمی   
ânten-e sahmi (#)

Fr.: antenne parabolique   

An antenna comprising a parabolic reflector with a receiving and/or transmitting element positioned at or near its focal point.

parabolic; → antenna.

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