An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A vapor at the pressure and temperature at which it can exist in dynamical equilibrium with its liquid. Any compression of its volume at constant temperature causes it to condense to liquid at a rate sufficient to maintain a constant pressure. The term "saturated" is a misnomer, since it does not have the same meaning as a → saturated solution in chemistry. There is no question of one substance being dissolved in another.

→ saturate; → vapor.

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.

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

→ saturation; → current.

The maximum intrinsic magnetic induction possible in a material.

→ saturation; → induction.

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

→ saturation; → signal.

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.

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.

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.

1) To rescue from danger or possible harm, injury, or loss.
2) To keep safe, intact, or unhurt; safeguard; preserve.
3) Computers: To copy (a file) from RAM onto a disk or other storage medium (Dictionary.com).

M.E. sa(u)ven, from O.Fr. sauver "keep (safe), protect, redeem," from L.L. salvare "make safe, secure," from L. salvus "safe;" ultimately from PIE root *sol- "whole," → general.

Bužidan, variants buxtan, boxtan "to save, liberate;" boxt "saved, redeemed;" Mid.Pers. bôz- "to free, to release;" Bactrian βoγ "to save;" Av. bûj- "to save, redeem;" cf. Baluci bôtk / bôj "to open", butk / busk "to be released (from jail), be fired (a gun), be emptied;" Pers. buzidan/buz- "to pluck off hair, wool;" cf. Gk. phugo, L. fugio "I flee", Goth. us-baugjan "to wipe off" (Cheung 2007).

Same as → single-lined binary.

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

Same as → double-lined binary.

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

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

→ scalable; → -ity.

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.

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.

A → tensor density of → order 0.

→ scalar; → density.

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.

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.

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.

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.

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

→ scalar; → wave.