A physical process occurring in stellar atmospheres whereby → radiation pressure selectively pushes certain elements outward, leading to an atmospheric overabundance of such elements.
from levitate modeled on gravitate, from L. levitas "lightness," from levis "light."
A combining form meaning "left" and "counterclockwise," used in the formation of compound words, such as → levorotation, levocardia, levoglucose, etc. The variant lev- occurs before vowels. Compare → dextro-.
From L. laevo-, from laevus, cf. Gk. laios, Russ. levyj, + epenthetic vowel -o-.
Cap-, from cap "left," of unknown etymology.
The counterclockwise rotation of the → plane of polarization of light (as observed when looking straight through the incoming light) by certain substances.
Adj. related to → levorotation.
Adj. related to → levorotation.
A branch of → linguistics that deals with the principle and methods of writing dictionaries.
A branch of → linguistics that studies the formation, meaning, and use of words and their idiomatic combinations. In contrast to → terminology, lexicology is based on words and does not conceive of meaning unless it is related to the word.
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
xatt-e Li I
Fr.: raie Li I
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).
An effect 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.
L. libration- "a balancing."
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").
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."
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").
1) (n.) nur (#), rowšanâyi (#); 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.
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);
1) Nur, from Ar.
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.
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.
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).
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.
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.
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.
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.