An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < -le Lag lam Lan Lar las law lea Lem Leo Ley lig lim lin lin lin lit Loc Loc Lom Lor low lum lun lun Lym > >>

Number of Results: 508
Leyden jar
  بطری ِ لیده   
botri-ye Leydé

Fr.: bouteille de Leyde   

An early form of → capacitors which is a glass jar coated inside and outside about half way up the side with metal foil. A chain connects the inner coating to a rod which usually terminates in a small brass knob. The jar is charged by connecting the knob, that is the inner metal coating, to a charged body, meanwhile grounding the outer coating. Same as Leiden jar

Named after Leyden (Leiden) the city where it was invented by the Dutch scientist Pieter van Musschenbroek in 1745, independently from the German Ewald Georg von Kleist; jar a usually "cylindrical vessel," from M.Fr. jarre, from Provençal jarra, from Ar. jarrah.

Botri, → bottle.

Li I line
  خط ِ Li I   
xatt-e Li I

Fr.: raie Li I   

lithium I line.

lithium; I for → neutral atom; → line.

Li-rich giant
  غول ِ لیتیوم-پردار   
qul-e Li-pordâr

Fr.: géante rich en Li   

A → giant star whose observed → lithium abundance is much higher (A(Li) ~ 2.95) than that predicted by stellar → evolutionary models. Standard evolutionary models predict severe → depletion of surface Li → abundance, which is as low as 1.4 → dex in K giants, a factor of about 80 lower than the maximum value of about 3.3 dex observed in → main sequence stars. Observations confirm model predictions showing much less Li compared to model predictions in most → red giant branch (RGB) stars (Kumar et al., 2018, J. Astrophys. Astr. 39, 25 and references therein).

lithium; → rich; → giant.

Libra
  ترازو   
Tarâzu (#)

Fr.: Balance   

The Scales. An inconspicuous constellation in the southern hemisphere and a sign of the → Zodiac, at 15h 30m right ascension, 15° south declination. Abbreviation: Lib; genitive: Librae.

L. libra "balance," of obscure origin.

Tarâzu "balance, scales," Mid.Pers. tarâzên-, taraênidan "to weigh," Proto-Iranian *tarāz-, from *tarā- "balance, scale" (cf. Skt. tulā- "scales, balance, weight," from tul- "to weigh, make equal in weight, equal," tolayati "weighs, balances," L. tollere "to raise," Gk. talanton "balance, weight," Atlas "the Bearer" of Heaven," Lith. tiltas "bridge;" PIE base telə- "to lift, weigh") + Av. az- "to convey, conduct, drive," azaiti drives" (cf. Skt. aj- "to dive, sling," ájati "drives," ajirá- "agile, quick," Gk. agein "to lead, guide, drive, carry off," L. agere "to do, set in motion, drive," from PIE root *ag- "to drive, move," → act).

libration
  هلازان، رخگرد   
halâzân, roxgard (#)

Fr.: libration   

Small oscillations of a → celestial body about its mean position. The term is used mainly to mean the Moon's libration caused by the apparent wobble of the Moon as it orbits the Earth. The Moon always keeps the same side toward the Earth, but due to libration, 59% of the Moon's surface can be seen over a period of time. This results from three kinds of libration working in combination: → libration in longitude, → libration in latitude, and → diurnal libration. See also: → geometrical libration, → physical libration.

L. libration- "a balancing."

Halâzân "to and fro motion, oscillation," literally "a swing: a seat suspended by ropes on which a person may sit for swinging," from Gilaki halâcin "a swing," Ilâmi harazân "a swing," variants (Dehxodâ) holucin, holu "a swing," probably from Proto-Ir. *harz- "to send, to set."
Roxgard, literally "turning the face," from rox, variant ru(y) "face, surface; aspect; appearance" (Mid.Pers. rôy, rôdh "face;" Av. raoδa- "growth," in plural form "appearance," from raod- "to grow, sprout, shoot;" cf. Skt. róha- "rising, height") + gard "turning, changing," from gardidan "to turn, to change" (Mid.Pers. vartitan; Av. varət- "to turn, revolve;" Skt. vrt- "to turn, roll," vartate "it turns round, rolls;" L. vertere "to turn;" O.H.G. werden "to become;" PIE base *wer- "to turn, bend").

libration in latitude
  هلازان ِ ورونایی   
halâzân-e varunâ-yi

Fr.: libration en latitude   

A tiny oscillating motion of the Moon arising from the fact that the Moon's axis is slightly inclined relative to the Earth's. More specifically, the Moon's polar axis is tilted nearly 7° with respect to the plane of its orbit around Earth. Hence for half of each orbit we see slightly more of the north pole when its tipped toward us, and for the other half we see slightly more of its south pole. Libration in latitude displaces the mean center of the Moon north-south by between 6°.5 and 6°.9.

libration; → latitude.

libration in longitude
  هلازان ِ درژنایی   
halâzân-e derežnâyi

Fr.: libration en longitude   

A tiny oscillating motion of the → Moon arising from the fact that the Moon's orbit is not a precise circle but rather an → ellipse. Therefore, Moon is sometimes a little closer to the Earth than at other times, and as a result its → orbital velocity varies a bit. Since the Moon's rotation on its own axis is more regular, the difference appears as a slight east-west oscillation. Libration in longitude is the most significant kind of libration. It varies between about 4°.5 and 8°.1 because of gravitational perturbations in the Moon's orbit caused by the Sun.

libration; → longitude.

life
  زیست   
zist (#)

Fr.: vie   

The condition that distinguishes living organisms from inorganic objects, i.e. non-life, and dead organisms. It is manifested by growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally.

O.E. life, from P.Gmc. *liba- (cf. O.N. lif "life, body," Du. lijf "body," O.H.G. lib "life," Ger. Leib "body"), properly "continuance, perseverance," from PIE *lip- "to remain, persevere, continue, live;" cf. Gk. liparein "to persist, persevere."

Zist "life, existence," from zistan "to live;" Mid.Pers. zivastan "to live," zivižn "life," zivik, zivandag "alive, living;" O.Pers./Av. gay- "to live," Av. gaya- "life," gaeθâ- "being, world, mankind," jivya-, jva- "aliving, alive;" cf. Skt. jiva- "alive, living;" Gk. bios "life;" L. vivus "living, alive," vita "life;" O.E. cwic "alive;" E. quick; Lith. gyvas "living, alive;" PIE base *gweie- "to live."

lift
  بالابر   
bâlâbar (#)

Fr.: portance   

In fluid mechanics, the component of aerodynamical force which is perpendicular to the oncoming flow direction. In aeronautics, the perpendicular component of the force of the air against an airplane; the component that is effective in supporting the plane's weight. → drag; → thrust.

M.E. liften, from O.N. lypta "to raise;" cf. M.L.G. lüchten, Du. lichten, Ger. lüften "to lift;" O.E. lyft "heaven, air."

Bâlâbar "lift," from bâlâ "up, above, high, elevated, height" (variants boland "high," borz "height, magnitude" (it occurs also in the name of the mountain chain Alborz), Lori dialect berg "hill, mountain;" Mid.Pers. buland "high;" O.Pers. baršan- "height;" Av. barəz- "high, mount," barezan- "height;" cf. Skt. bhrant- "high;" L. fortis "strong" (Fr. & E. force); O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg); PIE base *bhergh- "high") + bar present stem of bordan "to carry, transport" (Mid.Pers. burdan; O.Pers./Av. bar- "to bear, carry," barəθre "to bear (infinitive);" Skt. bharati "he carries;" Gk. pherein "to carry;" PIE base *bher- "to carry").

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.

<< < -le Lag lam Lan Lar las law lea Lem Leo Ley lig lim lin lin lin lit Loc Loc Lom Lor low lum lun lun Lym > >>