An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 86 Search : rate
mass loss rate
  نرخ ِ دسترفت ِ جرم   
nerx-e dastraft-e jerm

Fr.: taux de perte de masse   

The rate with which the → mass loss process takes place, usually expressed in → solar mass per year. → radiation-driven mass loss. The mass loss rate and the → terminal velocity are anti-correlated, since the → wind momentum is constant, → bi-stability jump.

mass loss; → rate.

Meteor Crater
  لاوک ِ شهاب‌سنگ، کندال ِ ~، ~ آسمان‌سنگ   
lâvak-e šahâbsang, kandâl-e ~, ~ âsmânsang

Fr.: Meteor Crater   

A → meteorite impact crater located about 55 km east of Flagstaff, near Winslow in the northern Arizona desert of the United States. Meteor Crater is about 1,200 m in diameter and some 170 m deep. It is thought to have formed between 20,000 to 50,000 years ago, by the impact of a small → asteroid about 25 m in diameter. Same as → Barringer Crater.

meteor; → crater.


Fr.: émigrer, immigrer   

1) To go from one country, region, or place to another.
2) To pass periodically from one region or climate to another, as certain birds, fishes, and animals.
3) Chem.: To move toward an electrode during electrolysis; (of atoms within a molecule) to change position (

From L. migratus p.p. of migrare "to move from one place to another," ultimately from PIE *meigh- "to move, go;" cf. Gk. ameibein "to change," Iranian muž-, as below.

Mužidan, ultimately from Proto-Ir. *maij- "to move (to places);" cf. Parachi muž-, muš-, Yazghulami mûž- "to go," mexw-/maxwt- "to move, shake," Gilaki maxtan "to stroll," Gonâbâdi mejon "ague, shivering, shaking chills," Sangesari moj; cognate with L. migrare "to move, go," as below, Skt. niméghanāna- "moving down;" PIE *meigh- "to move, go."


Fr.: opérer   

To function or work; to make something function or work.

From L. operari "to work, labor," L. opus "a work, labor, exertion," Av. *āpah-, *apah- "to do, operate," see below, Skt. ápas- "work, action, religious act;" O.H.G. uoben "to start work, to practice, to honor;" Ger. üben "to exercise, practice;" Du. oefenen; O.E. æfnan "to perform, work, do," afol "power"); PIE base *op- "to work, perform."

Âpâridan, from âpâr-, from Av. *āp(ah)- "to do, operate," as above, + suffix -ar (as in vadar- "weapon," zafar- "jaw," baēvar- "thousand," and so on), shifted to -âr, + -idan suffix of infinitives. The Av. *āpah- "to do, operate," is extant in Mod.Pers. xub "good;" Mid.Pers. hwp, xub "good;" from Av. huuāpah- "doing good work, masterly," from huu-, hv- "good" → eu- + āpah- "work, deed," hauuapanha- "creativity;" cf. Skt. sv-ápas- "doing good work, skillful;" PIE base *op-, as above.


Fr.: péjorer   

To make worse; to cause to deteriorate. To endow (a word) with a less favorable meaning.

Back formation from → pejorative.

Pastârdan, literally "to render low, vile, bring down" from past "low, vile, abject," → platykurtic, + ârdan, short for âvardan, "to cause or produce; to bring," → cause.

perklorât (#)

Fr.: perchlorate   

Any salt of perchloric acid.

per-; → chlorate.

pre-degenerate star
  ستاره‌ی ِ پیش-واگن   
setâre-ye piš-vâgen

Fr.: étoile pré-dégénérée   

Same as → PG 1159 star.

post-; → degenerate; → star.


Fr.: taux   

The amount of change of some quantity during a time interval divided by the length of the time interval.

M.E. rate "monetary value," M.Fr. rate "price, value," from M.L. rata (pars) "fixed (amount)," from L. rata "fixed, settled," p.p. of reri "to reckon, think," → reason.

Nerx "rate, price, tariff."

reaction rate
  نرخ ِ واژیرش   
nerx-e vâžireš

Fr.: taux de réaction   

The speed with which a → chemical reaction takes place. In other words, the change in → concentration of a → substance divided by the → time interval during which the change is observed.

reaction; → rate.

reading rate
  نرخ ِ خوانش   
nerx-e xâneš

Fr.: vitesse de lecture   

In computing and data processing, the number of words, characters, fields, etc. sensed by an input sensing device per unit of time.

Reading, verbal noun of read, from M.E. reden, O.E. rædan, redan "to counsel, read;" cf. Du. raden, Ger. raten "to advise, counsel, guess;" akin to Skt. rādh- "to succeed, accomplish;" Gk. arithmos "number amount;" L. ratio; Pers. rây, râ "because of, for the sake of;" → reason; → rate.

Nerx, → rate; xâneš verbal noun of xândan "to read; to sing; to call;" Mid.Pers. xwân- "to resound; to call;" Av. xvan- "to sound," Proto-Iranian *huan- "to call;" cf. Skt. svan-, sváranti "to sound, make a sound, sing;" L. sonus "sound," sonare "to sound;" O.E. swinn "music, song," PIE base *suen- "to sound" (Cheung 2007).

recombination rate
  نرخ ِ بازمیازش   
nerx-e bâzmiyâzeš

Fr.: taux de recombinaison   

In → H II regions the rate at which free electrons recombine with → ionized hydrogen atoms (protons).

recombination; → rate.


Fr.: regénérer   

1) To produce anew; bring into existence again; to bring new and more vigorous.
2) Biology: To renew or restore (a lost, removed, or injured part).
3) Physics: To restore (a substance) to a favorable state or physical condition.
4) Electronics: To magnify the amplification of, by relaying part of the output circuit power into the input circuit (

re-; → generate.


Fr.: saturer   

1) Chem.: To add as much of a liquid, solid, or gas to a solution as it can absorb at a given temperature.
2) To fill something with so many things that no more can be added.

From L. saturatus, p.p. of saturare "to fill full, sate, drench," from satur "sated, full," from PIE base *sā- "to satisfy."

Anjâlidan "to saturate, to fill" (Dehxodâ, Steingass), ultimately from Proto-Iranian *ham-gar-, from *ham- "together," denoting "much, many," → syn-, + *gar- "to soak, moisten;" cf. Sogdian wγyr- "to soak, steep," from *aua-gar-, from which derives Pers. âqâridan, âqeštan "to steep, soak; mix."


Fr.: saturé   

1) Chem.: The qualifier of a solution that has as much solute as possible.
2) (Of colors) Of maximum chroma or purity.

Past participle of → saturate (v..

saturated air
  هوای ِ انجالیده   
havâ-ye anjâlidé

Fr.: air saturé   

Air that contains the maximum amount of → water vapor that is possible at the given → temperature and → pressure, i.e. air in which the → relative humidity is 100%.

saturated; → air.

saturated liquid
  آوه‌ی ِ انجالیده   
âve-ye anjâlidé

Fr.: liquide saturé   

A liquid whose temperature and pressure are such that any decrease in pressure without change in temperature causes it to boil.

saturate; → liquid.

saturated solution
  لویش ِ انجالیده   
luyeš-e anjâlidé

Fr.: solution saturée   

A solution which can exist in equilibrium with excess of solute. The saturation concentration is a function of the temperature.

saturate; → solution.

saturated vapor
  بخار ِ انجالیده   
boxâr-e anjâlidé

Fr.: vapeur saturante   

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.

Search for Extraterrestrial Intelligence (SETI)
  جستجوی ِ هوش ِ اُسترزمینی   
jost-o-ju-ye huš-e ostar-zamini

Fr.: recherche d'intelligence extra-terrestre   

The scientific attempt to detect → intelligent extraterrestrial → life by surveying the sky to find the existence of → transmissions, especially → radio waves or → light, from a → civilization on a distant → planet. The SETI Institute, that carries out the project, is a private non-profit center founded in 1984. There are many methods that SETI scientific teams use to search for extraterrestrial intelligence. Many of these search billions of radio frequencies that reach Earth from all over the → Universe, looking for an intelligent → radio signal. Other SETI teams search by looking for signals in pulses of light emanating from the stars.

search; → extraterrestrial; → intelligence.

secondary crater
  لاوک ِ دومان، کندال ِ ~   
lâvak-e dovomân, kandâl-e ~

Fr.: cratère secondaire   

A crater formed by the relatively low-velocity impact of fragments ejected from a large primary crater. Secondary craters tend to cluster in a ring around the primary crater.

secondary; → crater.

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