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: 474
LINER
  لاینر   
lâyner (#)

Fr.: LINER   

A type of galactic nucleus that is defined by its spectral line emission. The lines are very weak, the most prominent ones being from low ionization states (such as [O II], [N II], [S II] and [OI]). There is so far no generally accepted interpretation of the spectra of liners. It is likely that galaxies of different histories may have their nuclei with liner-type spectra. → retired galaxy.

Short for → Low-Ionization Nuclear Emission-line Region. The term liner was first introduced by T. M. Heckman (1980, A&A 87, 152).

linewidth
  خط-پهنا، پهنای ِ خط   
xatt-pahnâ (#), pahnâ-ye xatt (#)

Fr.: largeur de raie   

1) The range of frequencies or wavelengths over which radiations are absorbed or emitted in a transition between a specific pair of atomic energy levels. The full width is determined between half-power points of the line.
2) In a laser, the range of frequencies over which most of the beam energy is distributed.

line; → width.

linguistic variable
  ورتنده‌ی ِ زبانیک   
vartande-ye zabânik

Fr.: variable linguistique   

One of several → input or → output variables of a → fuzzy logic system whose values are → words or → sentences from a natural language, instead of numerical values.

linguistic; → variable.

linguistics
  زبانیک، زبانشناسی   
zabânik (#), zabânšenâsi (#)

Fr.: linguistique   

The study of the structure and evolution of → language, including → phonetics, → morphology, syntax, semantics.

From linguistic, from linguistic, from linguist, from L. lingua, → language, + → ics.

Zabânik, from zabân, → language, + -ik, → -ics. Zabânšenâsi, from zabân + šenâsi, → -logy.

link
  پیوند   
peyvand (#)

Fr.: lien   

1) General: Anything serving to connect one part or thing with another; a bond or tie.
2) A direct connection in a hypertext document to the Internet address (URL) of another document.

From M.E. link(e), of Scandinavian origin; akin to O.Dan. lænkia "chain;" Old Norse hlekkr "chain;" Ger. Gelenk "joint."

Peyvand "join, union," from peyvandidan, peyvastan "to join, connect;" Mid.Pers. peywand, peywastan "connection, offspring; to join, connect, attach," from *pati-basta-, from suffix pati- (Mid.Pers. pât-,from O.Pers. paity "agaist, back, opposite to, toward, face to face, in front of," Av. paiti, akin to Skt. práti "toward, against, again, back, in return, opposite," Pali pati-, Gk. proti, pros "face to face with, toward, in addition to, near;" PIE *proti) + basta- "tied, shut" (Av./O.Pers. band- "to bind, fetter," banda- "band, tie," Skt. bandh- "to bind, tie, fasten," PIE *bhendh- "to bind," cf. Ger. binden, E. bind), cf. Skt. prati-bandh- "to tie."

linkage
  پیوند، هم‌پیوندی   
peyvand, ham-payvandi (#)

Fr.: liaison   

1) General: An act or mode of linking; the fact of being linked.
2) Physics: The amount of magnetic flux passing through a coil of wire or other electric circuit.

From → link + -age a suffix of abstract nouns from O.Fr.

From ham-, → com-, + peyvand, → link, + noun suffix -y.

lion
  شیر   
šir (#)

Fr.: lion   

A large, usually tawny-yellow cat, Panthera leo, native to Africa and southern Asia, having a tufted tail and, in the male, a large mane (dictionary.com).

M.E., from O.Fr., variant of leon, from L. leon- (stem of leo), from Gk. leon.

Mid.Pers. šagr "lion;" cf. Parth. šarg; Sogd. šarγu "lion;" its O.Pers. and Av. forms are not extant. Šir may be cognate with Skt. kēsarin- "lion; literally maned," from kēsar- "mane;" PIE *kaisar- "mane; hairs." If so, šir could be related to PIE *kaisaraka-, provided that the the initial *kai- is dropped and *saraka- has transformed in *sarg, šarg, šir.

Liouville's theorem
  فربین ِ لیوویل   
farbin-e Liouville

Fr.: théorème de Liouville   

A key theorem in statistical mechanics of classical systems which states that the motion of phase-space points defined by Hamilton's equations conserves phase-space volume.

After Joseph Liouville (1809-1882), a French mathematician; → theorem.

liquefaction
  آوش   
âveš

Fr.: liquéfaction   

1) The act or process of liquefying or making liquid.
2) The state of being liquefied.

liquefy; → -tion.

liquefy
  آویدن   
âvidan

Fr.: liquéfier   

1) To reduce to a liquid state.
2) To become liquid.

M.E. lyquefyen, from O.Fr. liquefier, from L. liquefacere "make → liquid, melt," from liquere "be fluid" + facere "to make," → -fy.

liquid
  آوه، آبگون   
âvé, âbgun (#)

Fr.: liquide   

The state of matter in which a substance exhibits a characteristic readiness to flow, little or no tendency to disperse, and relatively high incompressibility.

O.Fr. liquide, from L. liquidus "fluid, liquid, moist," from liquere "be fluid," related to liqui "to melt, flow."

Âvé, from âv, variant of âb "→ water" + nuance suffix -e.
Âbgun literally "resembling water," from âb "water," + gun "resembling; manner, fashion; color" (Mid.Pers. gônak "kind, species;" Av. gaona- "color").

liquid crystal
  بلور ِ آوه   
bolur-e âvé (#)

Fr.: cristaux liquides   

A type of material that possesses less geometrical regularity or order than normal solid crystals, and whose order varies in response to alterations in temperature, electric field, and other quantities.

liquid; → crystal.

liquid helium
  هلیوم ِ آوه   
heliom-e âvé

Fr.: hélium liquide   

The state of helium (4He) below its boiling point of 4.2 K. Its normal form is called → helium I, but converts into superfluid → helium II below 2.17 K (→ lambda point). Liquid helium is colorless and transparent so that it is impossible to see the surface of the liquid with the naked eye. Helium was first liquefied in 1911 by the Dutch physicist Heike Kamerlingh Onnes (1853-1936), Physics Nobel Prize 1913.

liquid; → helium.

liquid mirror
  آینه‌ی ِ آوه   
âyene-ye âvé

Fr.: miroir liquide   

A mirror composed of liquid, taking advantage of the parabolic shape of a spinning liquid and the fact that the mirror's focal length can be adjusted by altering the velocity at which the liquid's container spins.

liquid; → mirror.

liquid water
  آب ِ آوه   
âb-e âvé

Fr.: eau liquide   

Water in a state that is neither ice nor vapor.

liquid; → water.

liquidus
  آوگان   
âbvegân

Fr.: liquidus   

In the → phase diagram of a → mixture (such as an → alloy) at constant pressure, the → curve that separates the all liquid phase from the liquid+solid phase. Below the liquidus the mixture will be partly or entirely → solid. See also → solidus.

From L. liquidus, → liquid.

LISA Pathfinder
  رهیاب لایزا   
rahyâb LISA

Fr.: LISA Pathfinde   

An → ESA spacecraft that was launched on December 3, 2015 to test technologies needed for the Evolved Laser Interferometer Space Antenna (eLISA), an ESA → gravitational wave observatory planned to be launched in 2034. LISA Pathfinder paves the way for future missions by testing in flight the very concept of gravitational wave detection.

LISA, short for → Laser Interferometer Space Antenna; → pathfinder.

Lissajous figure
  خم ِ لیساژو   
xam-e Lissajous (#)

Fr.: courbe de Lissajous, figure de ~   

A curve traced out by a point which is oscillating simultaneously in two mutually perpendicular directions. In general, the amplitude and frequency may be different in the two directions, and the two oscillations may have an arbitrary initial phase difference. The simplest pattern is a straight line, being obtained from two oscillations of equal frequency in phase with each other. The patterns can become very involved if the ratio of the frequencies is not a simple one.

After the French physicist Jules Antoine Lissajous (1822-1880), who first demonstrated such curves (Comptes-Rendus, 1857, 44, 727); → figure.

Xam, → curve.

Lissajous orbit
  مدار ِ لیساژو   
madâr-e Lissajous

Fr.: orbite de Lissajous   

A quasi-periodic path resembling a → Lissajous figure around the L1 or L2 → Lagrangian points of a two-body system. Lissajous orbits, resulting from a combination of planar and vertical components, are used by certain space telescopes (such as → WMAP, → Planck Satellite, and → Herschel Satellite) that are required to be in a stable position relative to the Earth and Sun while making long-term observations.

Lissajous figure; → orbit.

list
  ۱) لیست؛ ۲) لیستیدن   
1) list; 2) listidan

Fr.: 1) liste; 2) faire (dresser) la liste de   

1a) A series of names or other items written or printed together in a meaningful grouping or sequence so as to constitute a record.
1b) Computers: A series of records in a file.
2) To set down together in a list; make a list of (Dictionary.com).

From M.E. liste "border, edging, stripe," from O.Fr. liste "border, band, row," also "strip of paper," or from O.It. lista "border, strip of paper, list," both from Germanic sources (compare O.H.G. lista "strip, border, list," O.Norse lista "border."

List, loan from Fr. liste, as above.

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