An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 699

Fr.: réguler   

To control, direct, or adjust by a rule, principle, method, etc.

From L.L. regulatus, p.p. of regulare "to control by rule, direct," from L. regula, cognate with Pers. râstright.

Razanidan, verbal form of razan, → rule, cognate with L. regula.


Fr.: régulé, réglementé   

Controlled or governed according to a rule or principle or law.

Past participle of → regulate.


Fr.: régulation   

1) The act of regulating; the state of being regulated.
2) A law, rule, or other order prescribed by authority.
3) Electronics: The degree by which a voltage source is held near its no-load amplitude when a load is applied.

Verbal noun of → regulate.


Fr.: régulateur   

A person or thing that regulates.
A governor mechanism for regulating the flow of fuel, steam, etc., to an engine in order to maintain constant speed under varying load or resistance.

Agent noun of → regulate.

Regulus (α Leonis)

Fr.: Régulus   

The brightest star in the constellation → Leo (V = 1.35). Regulus is approximately 77.5 light-years from Earth. It is a triple star system composed of a hot, bluish-white star with a pair of small, faint companions. The main star (Regulus A) is a main sequence of type B7, with a luminosity 140 times brighter than the Sun. Its equatorial rotation speed being 317 kilometers per second, the fast rotation distorts Regulus into an oblate spheroid with an equatorial diameter about 30 percent larger than the polar diameter. As a result, the poles, with a temperature of 15,400 Kelvin, are much hotter than the equator, which glows at 10,200 Kelvin.

L., literally "little king," diminutive of rex "king," related to regere "to keep straight, guide, lead, rule," from PIE base *reg- "to rule, to lead straight, to put right;" akin to Pers. râst "right, straight, correct," → right.

Širdel, literally "the Lion's heart," on the model of Ar. Qalb al-Asad (قلب‌الاسد), from šir "lion;" Mid.Pers. šagr "lion" + del "heart;" Mid.Pers. dil; Av. zərəd- "heart;" cf. Skt. hrd-; Gk. kardia; L. cor Arm. sirt; PIE base *kerd- "heart;" O.E. heorte; E. heart; Ger. Herz; Bret. kreiz "middle."


Fr.: réionisation   

An early epoch in the Universe's history, but after → recombination, when the → first stars formed and their ultraviolet light began to ionize the → neutral hydrogen gas that filled the Universe. The epoch of reionization is estimated to last between → redshifts of 12 to 6 (or when the Universe had between 2 and 5% of its age). Reionization marks the end of the → Dark Age in cosmic history.

re- + → ionization.

Reissner-Nordstrom black hole
  سیه‌چال ِ رایسنر-نوردستروم   
siyah câl-e Reissner-Nordström

Fr.: tou noir de Reissner-Nordström   

A type of electrically charged → black hole that is spherically symmetric and non-rotating. Another type of such objects is the → Kerr-Newman black hole.

Named after the German physicist Hans Jacob Reissner (1874-1967) in 1916 and the Finnish Gunnar Nordstrom (1881-1923) in 1918 independently worked out solutions different from those of Schwarzschild; → black hole.


Fr.: rejeter   

To refuse to accept, take, consider, recognize, etc.

re- + jec-, combining form of jacere "to throw" + -tus p.p. suffix, → project.

  ۱) بازانیدن؛ ۲) بازانش داشتن   
1) bâzânidan; 2) bâzâneš dâštan

Fr.: 1) établir un rapport entre, rapprocher; 2) se rapporter   

1) (tr.) To find or show a connection between two or more people or things.
2) (intr.) To have a significant connection with or bearing on something.

From O.Fr. relater, from L. relatus literally "carried, brought back," from re- "back, again" + latus "carried, brought," used as p.p. of referre, from re- "back, again" + ferre "carry, bear," cognate with Pers. bordan "to carry, bear" (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").

Bâzânidan, literally "to bring, lead back," from bâz- "back, again," → re- + ân stem of ânidan "to bring; to lead; to guide," cf. dialectical Kurd. ânin "to bring, to lead to," Tâleši ânân, ânoe "to bring together two edges;" Mid.Pers. ônidan, nidan, nay- "to lead; to bring;" O.Pers. nay- "to lead; to bring" anaya "leads;" Av. nay- "to lead; to bring," naiieiti "leads;" cf. Skt. nī- "to lead," náyati "leads," aorist s. anait.


Fr.: apparenté   

Connected; associated.

P.p. of → relate.


Fr.: relation   

General: A connection or association between two or more things.
Math.: A property that associates two quantities in a definite order, as equality or inequality.

Verbal noun of → relate.

relation symbol
  نماد ِ باز‌آنش   
nemâd-e bâzâneš

Fr.: symbole de relation   

Same as → predicate symbol.

relation; → symbol.


Fr.: relationnel   

Of or pertaining to relations.

relation + → -al.

relational data structure
  ساختار ِ داده‌های ِ بازانشی   
sâxtâr-e dâdehâ-ye bâzâneši

Fr.: structure de données relationnelle   

A type of data structure in which data are represented as tables in which no entry contains more than one value.

relational; → data; → structure.

relational system
  راژمان ِ بازانشی   
râžmân-e bâzâneši

Fr.: système relationnel   

A database management system in which a relational data structure is used.

relational; → system.


Fr.: relatif   

(adj.): Existing or having its specific nature only by relation to something else; not absolute or independent.
See also: → relative azimuth, → relative dating, → relative density, → relative error, → relative frequency, → relative humidity, → relative invariant, → relative tensor, → relative vector, → relative permeability, → relative refractive index, → relative sunspot number, → relative velocity, → relatively, → relativity.

From M.E. relatif (n.), from O.Fr. relatif, from L.L. relativus "having reference or relation," from L. relatus, suppletive p.p. of referre "to refer," → relate.

Bâzâni, from bâzân- present stem of bâzânidan, → relate, + -i adj. suffix.

relative azimuth
  سوگان ِ بازانی   
sugân-e bâzâni

Fr.: azimut relatif   

The difference in → azimuth between the → Moon and the → Sun.

relative; → azimuth.

relative dating
  سن‌یابی ِ بازانی   
senn-yâbi-ye bâzâni

Fr.: datation relative   

A method of dating that can only tell us whether an event or object is older or younger than another event or object. In geology, different layers of rock are compared to determine an ordered sequence of events in geologic history. In contrast to → absolute dating, relative dating cannot give the actual age of a rock. See also → stratigraphy.

relative; → dating.

relative density
  چگالی ِ بازانی   
cagâli-ye bâzâni

Fr.: densité relative   

The ratio of the density of a substance to the density of a given reference material. For a solid or liquid, it is the density (at 20°C) relative to the maximum density of water (at 4°C). For a gas is its density divided by the density of hydrogen (or sometimes dry air) at the same temperature and pressure. Also called → specific density.

relative; → density.

relative error
  ایرنگ ِ بازانی   
irang-e bâzâni

Fr.: erreur relative   

The → absolute error divided by the true value x, that is: Δx/x. The result may be expressed as a percentile and is useful when we want to determine the error relative to the value of the exact quantity.

relative; → error.

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