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: 707
random access memory (RAM)
  بَرم با دسترسی ِ کاتوره   
barm bâ dastrasi-ye kâtruré

Fr.: mémoire à accès aléatoire   

In computer technique, a configuration of memory cells that hold data for processing by a central processing unit (CPU). The term random derives from the fact that the CPU can retrieve data from any individual location, or address, within RAM.

random; → access; → memory.

random error
  ایرنگ ِ کاتوره   
irang-e kâturé

Fr.: erreur fortuite   

The fluctuating part of the overall error that varies from measurement to measurement. Normally, the random error is defined as the deviation of the total error from its mean value; opposite of → systematic error.

random; → error.

random experiments
  آزمایش‌های ِ کاتوره   
âzmâyešhâ-ye kâturé (#)

Fr.: expériences aléatoires   

Statistics: Experiments in which results will not be essentially the same even though conditions may be nearly identical.

random; → experiment.

random noise
  نوفه‌ی ِ کاتوره   
nufe-ye kâture

Fr.: bruit aléatoire   

Unpredictable noise comprising large numbers of frequent, transient impulses occurring at statistically random time intervals. Thermal noise is a form of random noise.

random; → noise.

random sample
  نمونان ِ کاتوره   
nemunân-e kâturé

Fr.: échantillon aléatoire   

A sample selected at random from a population.

random; → sample.

random structure
  ساختار ِ کاتوره   
sâxtâr-e kâturé

Fr.: structure aléatoire   

Crystalline arrangement in which equivalent positions are not necessarily occupied by atoms of a single kind.

random; → structure.

random thermal motion
  جنبش ِ گرمایی ِ کاتوره   
jonbeš-e garmâyi-ye kâturé

Fr.: mouvement thermique aléatoire   

The agitated motion of molecular, atomic, or → subatomic particles in all possible directions at any temperature, except at → absolute zero, where → thermal motion would cease.

random; → thermal; → motion.

random variable
  ورتنده‌ی ِ کاتوره   
vartande-ye kâturé

Fr.: variable aléatoire   

A quantity that takes different real values as a result of the outcomes of a random event or experiment involving specified probabilities.

random; → variable.

random walk
  پویش ِ کاتوره   
puyeš-e kâturé

Fr.: marche aléatoire, ~ au hasard   

The trajectory consisting of a series of successive moves in which the direction and size of each move is randomly determined.

random; → walk.

randomization
  کاتورش   
kâtureš (#)

Fr.: aléation   

Arrangement of data in such a way as to simulate chance occurrence.

Verbal noun of → randomize.

randomize
  کاتوریدن   
kâturidan (#)

Fr.: répartir au hasard   

To arrange or select in a random manner in order to reduce bias and interference caused by irrelevant variables.

Verbal form of → random.

randomness
  کاتورگی   
kâturegi (#)

Fr.: hasard   

The property of being random.

State, condition noun of → random.

range
  ۱) بُرد؛ ۲)، ۳) گستره   
1) bord; (#) 2), 3) gostaré (#)

Fr.: 1) portée; 2), 3) étendue   

1) Physics: The maximum distance a projectile travels.
2) Math.: The → set of values that actually comes out of a → function. The range is a → subset of the → codomain.
3) Statistics: The interval between the largest and smallest values in a statistical distribution.

M.E., from O.Fr. range "range, rank," from rangier "to place in a row, arrange," from reng "row, line."

1) Bord past stem of bordan "to carry, transport" (Mid.Pers. burdan, O.Pers./Av. bar- "to bear, carry," barəθre "to bear (infinitive)," Skt. bharati "he carries," Gk. pherein, L. fero "to carry;" PIE base *bher- "to carry").
2) Gostaré, from gostar, gostardan "to expand; to spread; to diffuse" (Mid.Pers. wistardan "to extend; to spread;" Proto-Iranian *ui.star-; Av. vi- "apart, away from, out" (O.Pers. viy- "apart, away;" cf. Skt. vi- "apart, asunder, away, out;" L. vitare "to avoid, turn aside") + Av. star- "to spread," starati "spreads;" cf. Skt. star- "to spread out, extend, strew," strnati "spreads;" Gk. stornumi "I spread out," strotos "spread, laid out;" L. sternere "to spread;" Ger. Strahlung "radiation," from strahlen "to radiate," from Strahl "ray;" from M.H.G. strāle; from O.H.G. strāla "arrow," stripe; PIE base *ster- "to spread").

rank
  رتبه   
rotbé (#)

Fr.: rang   

Position, in a series arranged in order, on the basis of some principle of arrangement, with reference to the other items or values in the series.

M.E., from O.E. ranc "proud, overbearing, showy," from O.Fr. renc, ranc, rang "row, line;" cf. Dan. rank "right, upright," Ger. rank "slender," O.N. rakkr "straight, erect," perhaps from PIE *reg- "to stretch, straighten," cognate with Pers. râst, → right.

Rotbé, loan from Ar. ratbat "rank."

Rankine scale
  مرپل ِ رنکین   
marpel-e Rankine

Fr.: échelle Rankine   

A temperature scale in which the degree intervals are the same size as in the → Fahrenheit scale, but 0 is set at absolute zero, -459.69 °F. Therefore, 1 degree Rankine is equal to exactly 5/9 → kelvin. It was formerly used by engineers in English-speaking countries, but is now obsolete. See also → Celsius scale, → Kelvin scale, → Reaumur scale.

Named for the British physicist and engineer William John Rankine (1820-1872); → scale.

Rankine-Hugoniot conditions
  بوتارهای ِ رانکین-هوگونیو   
butârhâ-ye Rankine-Hugoniot

Fr.: conditions de Rankine-Hugoniot   

Hydrodynamics → conservation laws (which can be extended to → magnetohydrodynamics, MHD) which describe the physical conditions of material across a → shock front. A fluid is completely described by its velocity, density, pressure, specific heat ratio, and magnetic field (in the MHD case). Mass, momentum, and energy fluxes are conserved in the shock, leading to the Rankine-Hugoniot relations. Also called Rankine-Hugoniot jump conditions. See also → jump condition.

Named after William John Rankine, → Rankine scale, and Pierre Henri Hugoniot, → Hugoniot curve; → condition.

Raoult's law
  قانون ِ رایءول   
qânun-e Raoult (#)

Fr.: loi de Raoult   

The → vapor pressure of an ideal → solution is dependent on the vapor pressure of each chemical component and the → mole fraction of the component present in the solution. This means that the addition of → solute to a liquid lessens the tendency for the liquid to become a → solid or a → gas. For example, the addition of → salt to water causes the water to freeze below its normal → freezing point (0°C) and to boil above its normal → boiling point (100°C).

After François-Marie Raoult (1830-1901), the French chemist who studied the physical properties of chemical solutions; → law.

rapid
  تند   
tond (#)

Fr.: rapide   

Occurring within a short time; happening speedily; moving or acting with great speed; swift (Dictionary.com).

From L. rapidus "tearing away, seizing, swift," from rapere "to hurry away, seize, plunder;"

Tond "swift, rapid, brisk; fierce, severe" (Mid.Pers. tund "sharp, violent;" Sogdian tund "violent;" cf. Skt. tod- "to thrust, give a push," tudáti "he thrusts;" L. tundere "to thrust, to hit" (Fr. percer, E. pierce, ultimately from L. pertusus, from p.p. of pertundere "to thrust or bore through;" PIE base *(s)teud- "to thrust, to beat").

Rapid Burster
  بلکور ِ تند   
belkvar-e tond

Fr.: source à sursaut rapide   

An object with technical designation MXB 17302335 which is characterized by erratic and extremely intense → X-ray emissions. The Rapid Burster is a → binary system comprising a → low-mass star as its → primary and a → secondary  → neutron star. The → gravitational attraction of the neutron star strips its → companion of some of its gas, which then forms an → accretion disk and spirals toward the neutron star. The Rapid Burster is located at a distance of 110 kpc in the highly reddened → globular cluster Liller 1. It is a → low-mass X-ray binary (LMXB) and a recurrent → X-ray transient. So far less than 200 LMXBs have been detected in the → Galaxy and the → Magellanic Clouds. All produce a persistent flux of X-rays, the result of a release of → gravitational potential energy. Approximately 40 of them also exhibit → Type I bursts which are due to → thermonuclear flashes on the surface of a neutron star. The Rapid Burster is unique among the LMXBs in that it produces X-ray bursts in quick succession. These are called → Type II bursts, and they result from a spasmodic release of gravitational potential energy, which is due to some unknown → accretion disk instability (Lewin et al., 1996, ApJ 462, L39).

rapid; → burster.

rapidly oscillating Ap star
  ستاره‌ی Apی ِ تند نونده   

Fr.: étoile Ap à oscillation rapide   

A chemically peculiar star characterized by the presence of high-frequency non-radial oscillations, with periods that range between about 4 and 16 min. These variations have periods from about 5 to 20 minutes and low amplitudes (B < 10 mmag). They are consistent with acoustic (→ p mode) pulsations of low degree and high radial overtone.

rapid; → -ly; → oscillate; → -ing; → Ap star.

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