late helium flash
deraxš-e heliom-e dirân
Fr.: flash de helium tardif
A → helium flash event that occurs during the → post-AGB phase. Some of the central stars of planetary nebulae (→ CSPN) experience a final → thermal pulse after having achieved a → white dwarf configuration and begun their descent along a → white dwarf cooling track of nearly constant radius. During such a pulse, most of the hydrogen remaining in the star at pulse onset is incorporated into the helium-burning convective shell and completely burned. Following the pulse, the star swells briefly to → red giant dimensions (Iben et al. 1983; ApJ 264, 605).
late thermal pulse
tape-ye garmâyi-ye dirân
Fr.: flash de l'hélium tardif
In evolutionary models of → low-mass and → intermediate-mass stars, the occurrence of a → helium shell flash on the → horizontal branch of the → post-AGB track, while → hydrogen shell burning is still going on.
late-type galaxy (LTG)
kahkešân-e gune-ye farjâmin
Fr.: galaxie de type tardif
setâre-ye gune-ye farjâmin
Fr.: étoile de type tardif
Present but not visible, apparent, or actualized; existing as potential (Dictionary.com). → latent heat.
From L. latentem (nominative latens), pr.p. of latere "to lie hidden."
Nahân "concealed, hid; clandestine;" Mid.Pers. nihân "secrecy, a secret place, a hiding place," nihânik "concealed;" Av. niδāti- "deposing, deposit."
garmâ-ye nahân (#)
Fr.: chaleur latente
The amount of → thermal energy that is absorbed or released by a unit amount of a substance in the process of a phase change under conditions of constant pressure and temperature.
bari, kenâri, pahluyi
Of or relating to the → side; situated at, proceeding from, or directed to a side (Dictionary.com).
M.E., from O.Fr. latéral and directly from L. lateralis "belonging to the side," from latus "the side, flank; lateral surface."
Kenâri, relating to kenâr, → side.
The angle between a perpendicular at a location, and the
→ equatorial plane of the Earth.
→ longitude. See also:
L. latitudo "breadth, width, size," from latus "wide," from PIE base *stela- "to spread" (cf. O.C.S. steljo "to spread out," Arm. lain "broad").
Varunâ, from var "breadth, side, breast," variant bar, Tabari vari "width," Mid.Pers. var "breast," Av. varah- "breast" (Sk. vara- "width, breadth") + -u a suffix forming adjectives; Av. vouru- "wide;" + -nâ a suffix of dimension.
1) A regular geometric arrangement of points in a plane or in space.
From O.Fr. latiz "lattice," from late "lath, board, plank, batten" (Fr. latte); cf. O.H.G. latta "lath."
Jâré, from jarra "net; snare," Afghan jâli "reticulated garment," Tabari jarazin "grilled apparatus used in a watercourse to gather thatch and trash;" cf. Skt. jāla- "net, snare, lattice."
Fr.: énergie réticulaire
Fr.: latus rectum
The chord through a focus and perpendicular to then major axis of a conic section.
L. latus "side;" rectum "straight," → right.
Târ "thread, warp, string" (related to tur "net, fishing net, snare," tâl "thread" (Borujerdi dialect), tân "thread, warp of a web," from tanidan, tan- "to spin, twist, weave;" Mid.Pers. tanitan; Av. tan- to stretch, extend;" cf. Skt. tan- to stretch, extend;" tanoti "stretches," tántra- "warp; essence, main point;" Gk. teinein "to stretch, pull tight;" L. tendere "to stretch;" Lith. tiñklas "net, fishing net, snare," Latv. tikls "net;" PIE base *ten- "to stretch."
Molten → magma released from a volcanic vent or fissure.
Lava, from It. lava "torrent, stream," from L. lavare "to wash;" PIE base *lou- "to wash;" cf. Persian Lori, Kurdi, Malâyeri laf "flood," variants Tabari lé, [Mo'in, Dehxodâ] lur, lây "flood;" Gk. louein "to wash."
qânun (#), arté (#)
1) A rule of conduct or procedure established by custom, agreement,
M.E., O.E. lagu, from O.N. *lagu, variant of lag "that which is laid down;" cf. Ger. liegen, E. lay, lie; PIE *legh- "To lie, lay;" compare with Hittite laggari "falls, lies," Gk. lekhesthai "to lie down," L. lectus "bed," O.Ir. lige "bed, tomb," Tokharian lake, leke "bed."
Qânun, from Ar., ultimately from Gk. kanon "rule."
law of cosines
Fr.: loi des cosinus
An expression that for any triangle relates the length of a side to the cosine of the opposite angle and the lengths of the two other sides. If a, b, and c are the sides and A, B, and C are the corresponding opposites angles: a2 = b2 + c2 - 2bc cos A; b2 = c2 + a2 - 2ca cos B; c2 = a2 + b2 - 2ab cos C.
law of excluded middle
qânun-e miyâni soklândé
Fr.: principe du milieu exclu
Same as → principle of excluded middle.
law of identity
Fr.: principe d'identité
Same as → principle of identity.
law of inertia
qânun-e laxti (#)
Fr.: loi d'inertie
law of non-contradiction
Fr.: principe de non-contradiction
Same as → principle of non-contradiction.
law of reflection
qânun-e bâztâb (#)
Fr.: loi de réflexion
One of the two laws governing reflection of light from a surface: a) The → incident ray, normal to surface, and reflected ray lie in the same plane. b) The → angle of incidence (with the normal to the surface) is equal to the → angle of reflection.
law of refraction
qânun-e šekast (#)
Fr.: loi de réfraction
One of the two laws governing → refraction of light when it enters another transparent medium: a) The → incident ray, normal to the surface, and refracted ray, all lie in the same plane. b) → Snell's law is satisfied.