An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 1298
saturation
  انجال، انجالش   
anjâl, anjâleš

Fr.: saturation   

Physics: Degree of magnetization of a substance which cannot be exceeded however strong the applied magnetizing field.
Detectors: The condition of a detector or a pixel when it is submitted to a signal so strong that it cannot handle it properly; the result is a non-linear, useless response.

Verbal noun of → saturate.

saturation current
  جریان ِ انجال، ~ انجالش   
jarayân-e anjâl, ~ anjâleš

Fr.: courant de saturation   

The maximum current that can be obtained in a specific circuit under specified conditions.

saturation; → current.

saturation induction
  درهازش ِ انجال، ~ انجالش   
darhâzeš-e anjâl, ~ anjâleš

Fr.: induction à saturation   

The maximum intrinsic magnetic induction possible in a material.

saturation; → induction.

saturation signal
  نشال ِ انجال، ~ ِ انجالش   
nešâl-e anjâl, ~ anjaalesh

Fr.: signal de saturation, ~ saturé   

In radar, a signal whose amplitude is greater than the dynamic range of the receiving system.

saturation; → signal.

Saturn
  کیوان   
Keyvân (#)

Fr.: Saturne   

The sixth → planet from the Sun and the second largest with an equatorial diameter of 120,536 km orbiting at an average distance of 1,429,400,000 km (9.54 → astronomical units) from Sun. With an → eccentricity of 0.05555, its distance from the Sun ranges from 1.35 billion km (9.024 AU) at its → perihelion to 1.509 billion km (10.086 AU) at its → aphelion. Its average orbital speed being 9.69 km/s, it takes Saturn 29.457 Earth years (or 10,759 Earth days) to complete a single revolution around the Sun. However, Saturn also takes just over 10 and a half hours (10 hours 33 minutes) to rotate once on its axis. This means that a single year on Saturn lasts about 24,491 Saturnian solar days. Saturn has a mass of 5.6836 × 1026 kg (95.159 → Earth masses) and a mean density of 0.687 g cm-3. Like Jupiter, Saturn is about 75% → hydrogen and 25% → helium with traces of → water, → methane, and → ammonia, similar to the composition of the primordial Solar Nebula from which the solar system was formed. The temperature on Saturn is ~ -185 °C. Like Jupiter, Saturn has a solid core of iron-nickel and rock (silicon and oxygen compounds). The core has an estimated mass of 9-22 Earth Masses and a diameter of about 25,000 km (about 2 Earth diameter). The core is enveloped by a liquid → metallic hydrogen layer and a → molecular hydrogen layer. Saturn's interior is hot (12,000 K at the core). The planet radiates more energy into space than it receives from the Sun. Most of the extra energy is generated by the → Kelvin-Helmholtz mechanism as in Jupiter. Saturn has 62 known satellites. → Saturn's ring. On 1 July 2004 NASA/ESA's → Cassini-Huygens became the first to orbit Saturn, beginning a 13 year mission that revealed many secrets and surprises about Saturn and its system of rings and moons.

O.E. Sætern "Italic god," also "most remote planet" (then known), from L. Saturnus, Italic god of agriculture, possibly from Etruscan.

Keyvân Mid.Pers. Kêwân, borrowed from Aramean kâwân, from Assyrian kaiamânu.

Saturn Nebula
  میغ ِ کیوان   
miq-e Keyvân

Fr.: nébuleuse Saturne   

A planetary nebula in the Aquarius constellation discovered by William Herschel in 1782. It has a size of about 0.3 x 0.2 light-years and lies about 1400 light-years away. Also known as NGC 7009.

Saturn, such named by Lord Rosse in the 1840s, because the object has a vague resemblance to the planet Saturn in low-resolution telescopes; → nebula.

Saturn's rings
  حلقه‌های ِ کیوان   
halqehâ-ye Keyvân (#)

Fr.: anneaux de Saturne   

A system of rings around Saturn made up of countless small particles, ranging in size from micrometers to meters, that orbit the planet. The ring particles are made almost entirely of → water ice, with some contamination from → dust and other chemicals. The ring system is divided into six major components: D, C, B, A, F, and G rings, listed from inside to outside. But in reality, these major divisions are subdivided into thousands of individual → ringlets. The large gap between the A and B rings is called the Cassini division. Saturn's rings are extraordinarily thin: though they are 250,000 km or more in diameter, they are less than one kilometer thick. → A ring, → B ring, → C ring, → D ring, → F ring, → G ring.

Saturn; → ring.

SB1 binary
  درین ِ SB1   
dorin-e SB1

Fr.: binaire SB1   

Same as → single-lined binary.

SB, for → spectroscopic binary; 1, for → single-lined; → binary.

SB2 binary
  درین ِ SB2   
dorin-e SB2

Fr.: binaire SB2   

Same as → double-lined binary.

SB, for → spectroscopic binary; 2, for → double-lined; → binary.

scalability
  مرپل-پذیری   
marpel-paziri

Fr.: scalibilité, extension graduelle, évolutivité, facteur d'échelle, extensibilité   

The ability of something, especially a computer system, to adapt to increased demands.

scalable; → -ity.

scalable
  مرپل-پذیر   
marpel-pazir

Fr.: scalable, échelonnable, extensible, évolutif.   

The quality of a system that can be expanded or reduced in scale. Scalability allows computer equipment and software programs to be upgraded easily, rather than needing to be replaced.

scale; → -able.

scalar
  مرپلی، مرپل‌وار   
marpeli, marpelvâr

Fr.: scalaire   

Any quantity which is sufficiently defined only with its magnitude, when given in appropriate units. Compare → vector.
See also:
electric scalar potential, → scalar field, → scalar potential, → scalar processor, → scalar product, → scalar wave, → scalar-tensor theory, → tensor-vector-scalar (TeVeS) theory.

Of or pertaining to → scale.

scalar density
  چگالی ِ مرپلی   
cagâli-ye marpeli

Fr.: densité scalaire   

A → tensor density of → order 0.

scalar; → density.

scalar field
  میدان ِ مرپلی   
meydân-e marpeli

Fr.: champ scalaire   

A → field whose value at every point of space is independent of → direction and → position. Examples include → temperature distribution throughout space and → pressure distribution in a → fluid. Similarly, a → potential field, such as the Newtonian → gravitational field or the electric potential in → electrostatics are scalar fields. In quantum field theory, a scalar field is associated with → spin zero particles, such as → mesons or → bosons. Therefore, the → Higgs boson is associated with a scalar field. The → derivative of a scalar field results in a → vector field is called the → gradient. In contrast to a vector field, a scalar field is → invariant under the → rotation of the → coordinate system. The → inflation in the → early Universe is supposed to be driven by a scalar field, called the → inflaton field.

scalar; → field.

scalar perturbation
  پرتورش ِ مرپلی   
partureš-e marpeli

Fr.: perturbation scalaire   

The energy density fluctuations in the → photon-baryon plasma that bring about hotter and colder regions. This perturbation creates velocity distributions that are out of phase with the acoustic density mode. The fluid velocity from hot to cold regions causes blueshift of the photons, resulting in → quadrupole anisotropy.

scalar; → perturbation.

scalar processor
  آمایشگر ِ مرپلی   
âmâyeš:gar-e marpeli

Fr.: processeur scalaire   

Computers: A type of central processing unit in which only one operation on data is executed at a time. By contrast, in a vector processor, a single instruction operates simultaneously on multiple data items.

scalar; → processor.

scalar product
  فر‌آورد ِ مرپلی   
farâvard-e marpeli

Fr.: produit scalaire   

A multiplication of two vectors giving a scalar. The scaler product of V1 and V2 is defined by: V1.V2 = V1.V2 cos α, where V1 and V2 are the magnitudes of the vectors and α is the angle between them. Same as dot product. See also → vector product.

scalar; → product.

scalar wave
  موج ِ مرپلی   
mowj-e marpeli

Fr.: onde scalaire   

In theories of gravitation, a kind of → gravitational wave, transversal and/or longitudinal, characterized by → spin zero.

scalar; → wave.

scalar-tensor theory
  نگره‌ی ِ مرپلی-تانسوری   
negare-ye marpel-tânsori

Fr.: théorie scalaire-tensorielle   

An alternative to the standard → general relativity of gravity that contains not only the → tensor field (or → metric), but also a → scalar field. In this formalism, the → gravitational constant is considered to vary over time. As a consequence, the measured strength of the gravitational interaction is a function of time. Same as → Jordan-Brans-Dicke theory.

scalar; → tensor; → theory.

scale
  ۱) مرپل؛ ۲) مرپلیدن   
1) marpel; 2) marpelidan

Fr.: 1) échelle; 2) augmenter/réduire proportionnellement   

1a) A succession or progression of steps or degrees.
1b) A standard of measurement or estimation; point of reference by which to gauge or rate.
2) To reduce or increase according to a common proportion (often followed by down or up).

M.E., from L. scalae "ladder, stairs."

Marpel, literally "measuring stick, measuring step," on the model of Ger. Maßstab from Mass "measure" + Stab "stick, bar, pole, baton." The first element from Mod./Mid.Pers. mar "measure, count," from Av. mar- "to count, remember;" Skt. smr, smarati "to remember, he remembers;" L. memor, memoria; Gk. mermera "care," martyr "witness." The second element pel "stick, a bit of wood;" pel can also be interpreted as the contraction of pellé "staircase, ladder."

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