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: 72 Search : light
earthlight
  زمین‌تاب   
zamin-tâb (#)

Fr.: lumière cendrée   

The illumination of the dark part of the Moon's disk by the light reflected from the Earth's surface and atmosphere. Also called → earthshine.

earth; → light.

electromagnetic theory of light
  نگره‌ی ِ برقامغناتی ِ نور   
negare-ye barqâmeqnâti-ye nur

Fr.: théorie électromagnétique de la lumière   

The theory describing light as a wave phenomenon resulting from the combination of two electric and magnetic fields vibrating transversely and mutually at right angles. → electromagnetic radiation; → electromagnetic wave; → Maxwell's equations.

electromagnetic; → theory; → light.

elliptically polarized light
  نور ِ قطبیده‌ی ِ بیضی‌گون   
nur-e qotbide-ye beyzigun

Fr.: lumière polarisée elliptiquement   

Light exhibiting → elliptical polarization.

elliptic; → polarized; → light.

Enlightenment
  عصر ِ روشنگری   
asr-e rowšangari (#)

Fr.: Siècle des Lumières   

An intellectual movement in Europe during the 17th and 18th centuries celebrating human reason and scientific thought as the instruments of progress and subjecting conventional ways of thinking to rigorous critique. The Enlightenment culminated with the writings of Jean-Jacques Rousseau (1712-1778) and the Encyclopédistes, the philosophy of Immanuel Kant (1724-1804), and the political ideals of the French and American Revolutions, while the precursor in science and philosophy included Francis Bacon (1561-1626), René Descartes (1596-1650), Isaac Newton (1643-1727), John Locke (1632-1704), and Thomas Hobbes (1588-1679).

From enlighten, from en- + → light + -en + → -ment.

Asr, → age; rowšangari, noun from rowšangar "enlightener," from rowšan "light, bright, luminous, splendid," cognate with L. lux, → bright, + -gar a suffix of agent nouns, → -or.

extragalactic background light (EBL)
  نور ِ پس-زمینه‌ی ِ استر-کهکشانی   
nur-e paszimine-ye ostarkahkeši

Fr.: lumière du fond extragalactique   

The integrated intensity of all of the light emitted throughout the history of the Universe across the whole of the → electromagnetic spectrum, including those which are not individually detected. The EBL spectrum includes cosmological backgrounds associated with either primordial phenomena, such as the → cosmic microwave background radiation (CMBR), or photons emitted by stars, galaxies and → active galactic nuclei (AGN) due to → nucleosynthesis or other → radiative processes, including → dust scattering, → absorption and reradiation. The EBL may also contain signals that are diffuse and extended, including high-energy photons associated with dark matter particle decays or annihilation.

extragalactic; → background; → light.

first light
  نخستین فروغ، ~ نور   
naxostin foruq, ~ nur

Fr.: première lumière   

The first astronomical observation done with a major newly built telescope.

first; → light.

flight
  پرواز   
parvâz (#)

Fr.: vol   

The act, manner, or power of flying.

O.E. flyht "a flying, flight," from P.Gmc. *flukhtiz (cf. Ger. Flucht).

Parvâz, from Mid.Pers. parwâz; Av. pāirivāza- "overrunning," from pāiri- "over (of space), from" + vāza- from vaz- "to fly, float; to drive;" cf. Skt. vah-, vahati. Also Mid.Pers. vâz "jump, flight," Mod.Pers. Lori, Gilaki, Tabari vâz "jump, leap."

future light cone
  مخروط ِ نوری ِ آینده   
maxrut-e nuri-ye âyandé (#)

Fr.: cône de lumière futur   

The set of all points in a → space-time diagram that are reached by signals travelling from a specified point at the speed of light.

future; → light; → cone.

light
  ۱) نور، لوژ؛ ۲) سبک   
1) (n.) nur (#), luž (#); 2) (adj.) sabok (#)

Fr.: 1) lumière; 2) léger   

1) That portion of → electromagnetic radiation visible to the human → eye. However, other bands of the → electromagnetic spectrum are also often referred to as different forms of light.
2) Of little weight; not heavy.

1) O.E. leoht, leht, from W.Gmc. *leukhtam (cf. O.Fris. liacht, M.Du. lucht, Ger. Licht), from PIE *leuk- "light, brightness," cognate with Pers. rowšan "bright, clear," ruz "day," rowzan "window, aperture;" foruq "light," and afruxtan "to light, kindle;" Mid.Pers. rôšn "light; bright, luminous," rôc "day;" O.Pers. raucah-rocânak "window;" O.Pers. raocah- "light, luminous; daylight;" Av. raocana- "bright, shining, radiant;" akin to Skt. rocaná- "bright, shining," roka- "brightness, light;" Gk. leukos "white, clear;" L. lux "light" (also lumen, luna); Fr. lumière.
2) From O.E. leoht, from P.Gmc. *lingkhtaz (cf. O.N. lettr, Swed. lätt, O.Fris., M.Du. licht, Ger. leicht, Goth. leihts), from PIE base *le(n)gwh- "easy, agile, nimble."

1) Nur, from Ar.
Luž "light," in Sangesari (luženg variant of rowzan "vent, window"), variant of Pers. ruz "→ day," cognate with light, as above.
2) Sabok, from Mid.Pers. sapuk "light, brisk;" from O.Pers. *θapu-ka-, from Proto-Iranian *θrapu-ka-, from PIE *trep- "to shake, tremble;" cf. Gk. trepein "to turn;" L. trepidus "agitated, anxious;" Skt. trepa- "hasty."

light adaptation
  نیاوش به روشنایی   
niyâveš bé rowšanâyi

Fr.: adaptation à la lumière   

The reflex adaptation of the eye to bright light, consisting of an increase in the number of functioning cones, accompanied by a decrease in the number of functioning rods; opposed to dark adaptation.

light; → adaptation.

light clutter
  آلوزه‌ی ِ نوری   
âluze-ye nuri

Fr.:   

A bright, confusing, and excessive grouping of light sources. Light clutter is a type of → light pollution. It is a general term relating to lights put up everywhere, without regard to what their purpose really is.

light; → clutter.

light cone
  مخروط ِ نور   
maxrut-e nur (#)

Fr.: cône de lumière   

The set of all directions in which a light signal can travel toward an event (past light cone) or from an event (future light cone).

light; → cone.

light curve
  نور-خم، خم ِ نور   
nur-xam, xam-e nur

Fr.: courbe de lumière   

1) A curve showing the behavior of the light from a → variable star over a period of time.
2) → supernova light curve.

light; → curve.

light cylinder
  استوانه‌ی ِ نور   
ostovâne-ye nur

Fr.: cylindre de lumière   

A cylinder of radius cP/(2π) around a → pulsar's spin axis, where P is the pulsar period and c the → speed of light. At this surface, the velocity of a hypothetical object that corotates with the → neutron star would reach the speed of light.

light; → cylinder.

light deflection
  واچفت ِ نور   
vâcaft-e nur

Fr.: déflexion de la lumière   

The deviation of a light ray by the gravitational field of a massive body. For example, stellar light passing near the Sun will be deviated by 1''.75 at the Sun's limb.

light; → deflection.

light echo
  پژواک ِ نوری   
pažvâk-e nuri (#)

Fr.: écho de lumière   

Reflection of light from a stellar outburst by successively more distant clouds of dust surrounding the star. For example, the light echoes from two shells of dust near supernova 1987A, or those of star V838 Mon.

light; → echo.

light element
  بن‌پار ِ سبک   
bonpâr-e sabok (#)

Fr.: élément léger   

In astrophysics, a chemical element that has an atomic number of one, two, or three, such as hydrogen, helium, and lithium; sometimes also beryllium and boron.

light; → element.

light pillar
  ستون ِ نور   
sotun-e nur

Fr.: colonne lumineuse   

An atmospheric optical phenomenon appearing as a vertical shaft of light extending from the Sun or other bright light source during very cold weather. Light pillars or → sun pillars occur when artificial light or sunlight near the horizon is reflected from falling ice crystals associated with thin, high-level clouds. The ice crystals have a hexagonal plate shape and fall with a horizontal orientation, gently rocking from side to side as they fall.

light; → pillar.

light pollution
  آلودگی ِ نوری   
âludegi-ye nuri (#)

Fr.: pollution lumineuse   

The inappropriate or excessive use of artificial light. It brightens the sky and has a particularly damaging effect on astronomical observations. More generally, light pollution can have serious environmental consequences for humans, wildlife, and our climate. Types of light pollution include: → glare, → skyglow, → light trespass, and → light clutter.

light; → pollution.

light ray
  پرتو ِ نور   
partow-e nur

Fr.: rayon de lumière   

An imaginary line directed along the path that the light follows. In other words, light pictured simply in terms of straight lines.

light; → ray.

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