dowrân-e leptoni (#)
Fr.: ère leptonique
The era following the hadronic era, when the Universe consisted mainly of leptons and photons. It began when the temperature dropped below 1012 degrees kelvin some 10-4 seconds after the Big Bang, and it lasted until the temperature fell below 1010 degrees kelvin, at an era of about 1 second.
adad-e leptoni (#)
Fr.: nombre leptonique
In particle physics, a quantum number attributed to elementary particles which is conserved in nuclear reactions. It is +1 for a lepton, -1 for an antilepton and 0 for other particles.
The Hare. A small → constellation in the southern hemisphere at about 6h right ascension, 20° south declination. Abbreviation: Lep; genitive: Leporis.
L. lepus "hare."
Xarguš "rabbit, hare," literally "ass-ear," Mid.Pers. xargôš, from xar "donkey, ass" (Mid.Pers. xar "donkey;" Av. xara- "donkey;" cf. Skt. khára- "donkey, mule") + guš, → ear.
Lesath (Upsilon Scorpii)
A bright blue star of → apparent visual magnitudeV = 2.70, that with → Shaula (Lambda Scorpii) makes up the Scorpion's stinger. Among its other designations: HR 6508 and HIP 85696. Lesath is 580 → light-years away. Lesath and Shaula appear very close on the sky (less than a degree apart), but they are not physically related. Lesath is a → subgiant of → spectral type B2 IV with a → luminosity of about 7,380 Msun. It has a radius of about 6 Rsun, and a → surface temperature of about 22,000 K.
Lesath, from Ar. al-Las'ah (
1) vât (#); 2) nâmé (#)
1) A symbol or character representing a sound of which words are formed
used in writing and printing a language.
M.E., from O.Fr. letre "character, letter; missive," from L. littera "letter of the alphabet," litterae (plural) "epistle, literature"
1) Vât "letter, word," from vat- "to speak, say;" cf. (Kurd.) wittin
"to speak, say," → article,
(Nâyin) vâte, (Qohrud) vâta, (Sangesar) -vât-/vân,
(Zazaki) vâtiš, (Awromani) wâtay/wâc-,
(Farizand) -vât/-vaj, (Gaz) vâ-/vât, related to Pers.
vâžé "word;" Mid.Pers. vâc, vâcak "word, speech;"
âva "voice, sound," âvâz "voice, sound, song,"
bâng "voice, sound, clamour" (Mid.Pers. vâng);
Av. vacah- "word," vaocanghê "to decalre" (by means of speech), from
vac- "to speak, say;" cf. Skt. vakti "speaks, says," vacas- "word;"
Gk. epos "word;" L. vox "voice;" PIE base *wek- "to speak."
A position with respect to a given or specified base. → energy level.
From O.Fr. livel, from L. libella "a balance, level," diminutive of libra "balance, scale."
Tarâz "level; a level," from 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).
level of significance
Fr.: niveau de significativité
Same as → significance level.
A rigid bar that pivots about a point and is used to move or lift a load at one end by applying force to the other end. → lever arm.
M.E. levere, levour; O.Fr. levier "a lifter, a lever," agent noun from lever "to raise," from L. levare "to raise," from levis "light" in weight.
Ahrom, of unknown etymology.
bâzu-ye ahrom (#)
Fr.: bras de levier
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."