An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 41 Search : lens
achromatic lens
  عدسی ِ افام، ~ بیفام   
adasi-ye afâm, ~ bifâm

Fr.: lentille achromatique   

Lens (or combination of lenses) that brings different wavelengths within a ray of light to a single focus, thus overcoming chromatic aberration.

achromatic; → lens.

anastigmatic lens
  عدسی ِ گراور   
adasi-ye gerâ-var

Fr.: anastigmate   

A lens designed to correct → astigmatism.

astigmatism; → lens.

aplanatic lens
  عدسی ِ نابیراه   
adasi-ye nâbirah

Fr.: lentille aplanétique   

A lens designed so as to minimize both its → spherical aberration and → coma.

aplanatism; → lens.

apochromatic lens
  عدسی ِ اپافام   
adasi-ye apâfâm

Fr.: lentille apochromatique   

A lens that is → apochromatic.

apochromatic; → lens.

Barlow lens
  عدسیِ بارلو   
adasi-ye Barlow (#)

Fr.: lentille de Barlow   

A → negative lens placed in a telescope between the → objective and the → ocular. Its diverging action reduces the convergence of the light cone, forming a larger image at a slightly greater distance.

Peter Barlow (1776-1862), English physicist; → lens.

biconcave lens
  عدسی ِ دوکاو   
adasi-ye dokâv

Fr.: lentille biconcave   

Describing a lens with two concave faces.

Biconcave, from → bi- + → concave; → lens.

Adasi, → lens; dokâv "biconcave," from do-, → bi- + kâv, → concave.

biconvex lens
  عدسی ِ دوکوژ   
adasi-ye dokuž

Fr.: lentille biconvexe   

A spherical lens with two convex faces. The radii of curvature for the two surfaces may or may not be the same.

Biconvex, from → bi- + → convex; → lens.

Adasi, → lens; dokuž "biconvex" from do-, → bi- + kuž, → convex.

CMB lensing
  لنزش ِ CMB   
lenzeš-e CMB

Fr.: effet de lentille du rayonnement du fond cosmique, ~ ~ du CMB   

The gravitational effect of the intervening large-scale potentials on the → cosmic microwave background radiation (CMBR). This effect smoothes out the temperature peaks and alters the statistics of the CMB.

CMB; → lensing.

compound lens
  عدسی ِ چندساخت   
adasi-ye candsâxt

Fr.: lentille composée   

A lens system consisting of two or more lenses with the same radius used together in order to remove aberrations found in a single lens.

compound; → lens.

concave lens
  عدسی ِ کاو   
adasi-ye kâv (#)

Fr.: lentille concave   

A lens which is thinner at the center than at the edges and diverges the light rays.

concave; → lens.

concavo-convex lens
  عدسی ِ کاو-کوژ   
adasi-ye kâv-kuž (#)

Fr.: lentille concavo-convexe   

A type of → convergent lens that is concave on one surface and convex on the opposite surface. Also called → meniscus lens. Meniscus lenses are used most often in conjunction with another lens to produce an optical system of a longer or shorter → focal length than the original lens.

concave; → convex; → lens.

concentric lens
  عدسی ِ هم‌مرکز   
adasi-ye hammarkaz (#)

Fr.: lentille concentrique   

A lens having surfaces whose centers of curvature coincide.

concentric; → lens.

convex lens
  عدسی ِ کوژ   
adasi-ye kuž (#)

Fr.: lentille convexe   

A lens that converges an incident beam of light to a focus.

convex; → lens.

crystalline lens
  عدسی ِ چشم   
adasi-ye cašm (#)

Fr.: cristallin   

A → doubly convex, → transparent body in the → eye, situated behind the → iris, that focuses incident light on the → retina (

crystalline; → lens; → eye.

cylindrical lens
  عدسی ِ استوانه‌ای   
adasi-ye ostovâneyi (#)

Fr.: lentille cylindrique   

A lens in which at least one surface is formed like a portion of a cylinder. Also called astigmatic lens.

cylinder; → lens.


Fr.: déclinaison   

The → inflection of nouns, pronouns, or adjectives for case, number, and gender.

M.E. declenson, declynson (with suffix later assimilated to -sion), from O.Fr. declinaison, from L. declinatio, → declination


divergent lens
  عدسی ِ واگرا   
adasi-ye vâgerâ (#)

Fr.: lentille divergente   

A lens which causes a parallel beam of light passing through it to diverge or spread out; concave lens. Same as diverging lens and → negative lens.

divergent; → lens.

field lens
  عدسی ِ میدان   
adasi-ye meydân

Fr.: lentille de champ   

A lens placed at or near the focal plane of a telescope to create an image of the primary mirror inside the instrument.

field; → lens.

Fresnel lens
  عدسی ِ فرنل   
adasi-ye ferenel (#)

Fr.: lentille de Fresnel   

An optical lens composed of a series of rings of glass so curved that they all have the same focus. It is flat on one side and ridged on the other making it possible that nearly every ray of light from the source be re-directed out on a horizontal path. This design enables the construction of lenses of large aperture and short focal length avoiding thus the large weights and volumes of material which would be required in conventional lenses. The first Fresnel lens, designed for use in a lighthouse on the river Gironde, was installed in France in 1823, and by the 1850s many examples were in use everywhere. Fresnel lenses are most often used in light gathering applications, such as condenser systems or emitter/detector setups. They can also be used as magnifiers and projection lenses. Nowadays, Fresnel lenses made of optical plastics are widely used for various applications.

Fresnel diffraction; → lens.

gravitational lens
  عدسی ِ گرانشی   
adasi-ye gerâneši (#)

Fr.: lentille gravitationnelle   

A concentration of matter, such as a galaxy or a cluster of galaxies, that bends light rays from a background object, resulting in production of multiple images. If the two objects and the Earth are perfectly aligned, the light from the distant object appears as a ring from Earth. This is called an Einstein Ring, since its existence was predicted by Einstein in his theory of general relativity.

gravitational; → lens.

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