An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 742

Fr.: reionisation   

1) The act or process of reionizing a gas; an instance of this action.
2) The → ionization of → neutral hydrogen atoms formed during → recombination epoch in the → early Universe. See also → reionization epoch.

re-; → ionize.

reionization epoch
  زیمه‌ی ِ بازیونش   
zime-ye bâzyoneš

Fr.: époque de réionisation   

An early epoch in the → Universe's history, but after the → recombination epoch, 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.

reionization; → epoch.


Fr.: reioniser   

1) To become → ionized again.
2) To → ionize again.

re-; → ionize.

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 atomic mass, → 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 atomic mass
  جرم ِ اتمی ِ بازانی   
jerm-e atomi-ye bâzâni

Fr.: masse atomique relative   

The ratio of the mass of an atom of the → chemical element to one-twelfth the mass of an atom of carbon-12. Because an element in nature is usually a mixture of isotopes, the relative atomic mass is also the weighted mean of the atomic masses of all the atoms in a particular sample of the element, weighted by isotopic abundance. In this sense, relative atomic mass was once known as → atomic weight.

relative; → atomic; → mass.

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.

relative frequency
  بسامد ِ بازانی   
basâmad-e bâzâni

Fr.: fréquence relative   

Statistics: The number of the occurrences of an event divided by the number of observations.

relative; → frequency.

relative humidity
  نم ِ بازانی   
nam-e bâzâni

Fr.: humidité relative   

The amount of moisture in the air compared to what the air can "hold" at that temperature. It is given by the ratio of the partial pressure of water vapor in the mixture to the saturated vapor pressure of water at a specific temperature.

relative; → humidity.

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