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: 394
granulation
  دانه‌بندی   
dâne-bandi

Fr.: granulation   

The mottled appearance of the solar → photosphere, caused by → convective cells, resembling → granules, which rises from the interior of the Sun. Each granule has a mean size of about 1,000 km and an upward velocity of about 0.5 km/sec. Granules are separated by intergranular walls about 400 K colder. They emerge from the fragments of the preceding granules and their lifetimes are about 20 minutes.

From → granule + -ation a combination of -ate and -ion, used to form nouns from stems in -ate.

Dâne-bandi, from dâné, → grain, + bandi verbal noun of bastan, vastan "to bind, shut;" O.Pers./Av. band- "to bind, fetter," banda- "band, tie" (cf. Skt. bandh- "to bind, tie, fasten;" PIE *bhendh- "to bind;" Ger. binden; E. bind).

granule
  دانول   
dânul

Fr.: granule   

A tiny grain; a small particle.
One of the convective cells constituting the solar → granulation.

From L.L. granulum "small grain," from → gain + → -ule.

grape
  انگور   
angur (#)

Fr.: raisin   

The edible, pulpy, smooth-skinned berry or fruit that grows in clusters on vines of the genus Vitis, and from which wine is made (Dictionary.com).

M.E., from O.Fr. grape "bunch of grapes, grape."

Angur "grape," from Mid.Pers. angur "grape;" cf. Khwarazmi 'nkyδ, Yidgha agidro, Munji aglero, Shughni angûrδ, related to quré "unripe grape."

graph
  نگاره   
negâré (#)

Fr.: diagramme, graphique, graphe   

A visual representation of data that displays the relationship among variables, usually cast along X and Y axes.

Short for graphic (formula), from L. graphicus "of painting or drawing," from Gk. graphikos "able to draw or paint," from graph(ein) "to draw, write" + -ikos, → ic.

Negâré, from negâr "picture, figure" (verb negârdan, negâštan "to paint"), from prefix ne-, O.Pers./Av. ni- "down; into," → ni-, + gâr, from kar-, kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build;" Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base *kwer- "to do, to make").

graphic
  نگاریک   
negârik

Fr.: graphique   

(Adj.) Pertaining to the use of diagrams, graphs, mathematical curves, or the like.
Math.: Pertaining to the determination of values, solution of problems, etc., by direct measurement on diagrams instead of by ordinary calculations.
(n.) A product of the graphic arts, as a drawing or print. A computer-generated image.

graph + → -ic.

graphite
  گرافیت   
gerâfit (#)

Fr.: graphite   

A particular crystalline form of → carbon occurring as a soft, black, lustrous mineral. The carbon atoms in graphite are strongly bonded together in sheets. Because the bonds between the sheets are weak, other atoms can easily fit between them, causing graphite to be soft and slippery to the touch. Graphite conducts electricity and is used in lead pencils and electrolytic anodes, as a lubricant, and as a moderator in nuclear reactors. If graphite is subjected to high pressure, it will be transformed into → diamond.
Graphite is present in the → interstellar medium; it forms in circumstellar shells and supernova ejecta. In particular, the 2175 Å interstellar extinction feature is accounted for by small graphite grains.

From Ger. Graphit, from Gk. graph(ein) "to write, draw," so called because it was used for pencils, → graph + -it a suffix of chemical compounds, equivalent to E. -ite.

grating
  توری، ~ ِ پراش   
turi, ~ -e parâš (#)

Fr.: réseau   

Same as → diffraction grating.

M.E. grating, M.L. grata "a grating," variant of crata, from crat-, stem of cratis "wickerwork."

Turi, from tur "fishing net, net, snare," variants târ "thread, warp, string," tâl "thread" (Borujerdi dialect), cognate with tanidan, tan- "to spin, twist, weave" (Mid.Pers. tanitan; Av. tan- to stretch, extend;" Skt. tan- to stretch, extend;" tanoti "stretches," tantram "loom;" tántra- "warp; essence, main point;" Gk. teinein "to stretch, pull tight;" L. tendere "to stretch;" Lith. tiñklas "net, fishing net, snare," Latv. tikls "net;" PIE base *ten- "to stretch").

grating angle
  زاویه‌ی ِ توری   
zâviye-ye turi (#)

Fr.: angle de réseau   

The angle between the incident optical beam and the normal to the grating. It is the angle to which the grating must be set to place the desired wavelength at the center of the detector.

grating; → angle.

grating efficiency
  کار‌آیی ِ توری   
kârâyi-ye turi (#)

Fr.: efficacité de réseau   

The measure of the light intensity diffracted from a grating.

grating; → efficiency.

grating groove
  شیار ِ توری   
šiyâr-e turi (#)

Fr.: trait du réseau, sillon ~ ~   

One of thousands of long, narrow indentations in the surface of a → diffraction grating.

grating; → groove.

gravitate
  گرانیدن   
gerânidan (#)

Fr.: graviter   

To move or tend to move under the influence of gravitational force.

From L. gravitatus, p.p. of gravitâre, from gravis "heavy," → gravity.

Gerânidan, infinitive of gerân, → gravity.

gravitation
  گرانش   
gerâneš (#)

Fr.: gravitation   

1) The universal phenomenon of attraction between material bodies. → Newton's law of gravitation.
2) The act or process of moving under the influence of this attraction.

Verbal noun of → gravitate.

gravitational
  گرانشی   
gerâneši (#)

Fr.: gravitationnel   

Of or relating to or caused by → gravitation.

Adj. of → gravitation.

gravitational acceleration
  شتاب ِ گرانشی   
šetâb-e gerâneši (#)

Fr.: accélération gravitationnelle   

The acceleration caused by the force of gravity. At the Earth's surface it is determined by the distance of the object form the center of the Earth: g = GM/R2, where G is the → gravitational constant, and M and R are the Earth's mass and radius respectively. It is approximately equal to 9.8 m s-2. The value varies slightly with latitude and elevation. Also known as the → acceleration of gravity.

gravitational; → acceleration.

gravitational attraction
  درکشش ِ گرانشی   
darkešeš-e gerâneši

Fr.: attraction gravitationnelle   

The force that pulls material bodies toward one another because of → gravitation.

gravitational; → attraction.

gravitational collapse
  رمبش ِ گرانشی   
rombeš-e gerâneši (#)

Fr.: effondrement gravitationnel   

Collapse of a mass of material as a result of the mutual → gravitational attraction of all its constituents.

gravitational; → collapse.

gravitational constant
  پایای ِ گرانشی   
pâyâ-ye gerâneši (#)

Fr.: constante gravitationnelle   

A fundamental constant that appears in → Newton's law of gravitation. It is the force of attraction between two bodies of unit mass separated by unit distance: G = 6.673 x 10-8 dyn cm2 g-2 or 6.673 x 10-8 cm3s-2g-1, or 6.673 x 10-11 N m2 kg-2 or 6.673 x 10-11 m3s-2kg-1. It was first measured in 1798 by Henry Cavendish (1731-1810), 71 years after Newton's death. Same as the → Newtonian constant of gravitation.

gravitational; → constant.

gravitational contraction
  ترنگش ِ گرانشی   
terengeš-e gerâneši

Fr.: contraction gravitationnelle   

Decrease in the volume of an astronomical object under the action of a dominant, central gravitational force.

gravitational; → contraction.

gravitational encounter
  رویارویی ِ گرانشی   
ruyâruyi-ye gerâneši

Fr.: rencontre gravitationnelle   

An encounter in which two moving bodies alter each other's direction and velocity by mutual → gravitational attraction.

gravitational; → encounter.

gravitational energy
  کاروژ ِ گرانشی   
kâruž-e gerâneši

Fr.: énergie gravitationnelle   

Same as → gravitational potential energy.

gravitational; → energy.

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