An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -le Lag lam lan Lar lat law lea lem lep Lib lig lin lin lin liq Lit loc log lon lou low lun lun Lym > >>

Number of Results: 495
linear size
  اندازه‌ی ِ خطی   
andâze-ye xatti

Fr.: taille linéaire   

The real, physical size, as opposed to angular size.

linear; → size.

linear system
  راژمان ِ خطی   
râžmân-e xatti

Fr.: système linéaire   

Physics: A → dynamical system whose evolution is a linear process. If a change in any variable at some initial time produces a change in the same or some other variable at some later time, twice as large a change at the same initial time will produce twice as large a change at the same later time.

linear; → system.

linear velocity
  تندای ِ خطی   
tondâ-ye xatti

Fr.: vitesse linéaire   

The rate of change of the position of an object that is traveling along a straight path. In other words, the velocity of an object when its moving direction is not changing. For a given → angular velocity (ω), the linear velocity v of the particle is directly proportional to the distance of the particle from the center of the circular path: v = ω ×r.

linear; → velocity.


Fr.: linéarité   

The property, condition, or state of being linear.
Math.: A relationship between two variables so that when plotted on a graph they yield a straight line.

linear; → -ity.

  خطش، خطانش   
xatteš, xattâneš

Fr.: linéarisation   

A process of reduction to linear form by appropriate change of variables or by approximation.

Verbal noun of → linearize.

  خطیدن، خطانیدن   
xattidan, xattânidan

Fr.: linéariser   

To make linear; give linear form to.

linear + → -ize.

linearized differential equation
  هموگش ِ دگرسانه‌ای ِ خطی   
hamugeš-e degarsâneyi-ye xatti

Fr.: équation différentielle linéarisée   

A differential equation that has been derived from an original nonlinear equation.

Linearized, p.p. of → linearize; → differential; → equation.


Fr.: linéairement   

In a manner characterized by first-degree algebraic terms.

Adverb of → linear.

linearly dependent
  خطانه وابسته   
xattâné vâbasté

Fr.: linéairement dépendant   

A set of objects x1, x2, ..., xn (→ vectors, → matrices, → polynomials, etc.) on a given set if there is a linear combination of them: a1x1 + a2x2 + ... + anxn, which is zero, but at least one of the coefficients is non-zero. For example the binomials (2x + y) and (6x + 3y) are linearly dependent, since 3(2x + y) - (6x + 3y) = 0.

linearly; → dependent.

linearly independent
  خطانه ناوابسته   
xattâné nâvâbasté

Fr.: linéairement indépendant   

1) A set of objects x1, x2, ..., xn (→ vectors, → matrices, → polynomials, etc.) if it si not → linearly dependent.
2) Of two particular solutions (y1, y2) of a → homogeneous linear differential equation of the second order (y'' + a1 y' + a2y = 0) on an interval [a, b], if their ratio in this interval is not a constant: y1/y2≠ constant.

linearly; → independent.

linearly polarized light
  نور ِ قطبیده‌ی ِ خطی   
nur-e qotbide-ye xatti

Fr.: lumière polarisée linéairement   

Light exhibiting → linear polarization.

linearly; → polarized; → light.

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).

  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.

  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.

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."

  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.

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 (

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.


Fr.: liquéfaction   

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

liquefy; → -tion.

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