An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 411

Fr.: glycolaldéhyde   

The organic compound with the formula HOCH2-CHO. It is the simplest → sugar and the first intermediate product in the formose reaction that begins with formaldehyde (H2CO) and leads to the (catalyzed) formation of sugars and ultimately ribose, the backbone of RNA, under early Earth conditions. The presence of glycolaldehyde is therefore an important indication that the processes leading to biologically relevant molecules are taking place. However, the mechanism responsible for its formation in space is still unclear. Glycolaldehyde has been detected toward the → Galactic Center cloud Sgr B2, in the high-mass → hot molecular core G31.41+0.31, and more recently in the gas surrounding a young binary star with similar mass to the Sun (IRAS 16293-2422). See Jorgensen et al. 2012, astro-ph/1208.5498, and references therein.

From glycol, from glyc(erin) + (alcoh)ol + → aldehyde.


Fr.: gnomon   

1) A rod oriented in such a way that its shadow, cast by the Sun's rays, shows the hours on a → sundial; a style.
2) A device used in ancient times consisting of a vertical shaft used to measure the altitude of the Sun and hence to determine the time of day.

From L. gnomon, from Gk. gnomon "carpenter's square, rule; indicator," literally "one who discerns," from gignoskein "to know, think, judge," cognate with L. gnoscere, noscere "to come to know" (Fr. connaître; Sp. conocer); O.Pers./Av. xšnā- "to know, learn, come to know, recognize;" Mid.Pers. šnâxtan, šnâs- "to know, recognize," dânistan "to know;" Mod.Pers. šenâxtan, šenâs- "to recognize, to know," dânestan "to know;" Skt. jñā- "to recognize, know," jānāti "he knows;" P.Gmc. *knoeanan; O.E. cnawan, E. know; Rus. znat "to know;" PIE base *gno- "to know."

Bâhu "stick, staff; arm (from the elbow to the shoulder)," related to bâzu "arm," Mid.Pers. bâzûk "arm;" Av. bāzu- "arm;" cf. Skt. bāhu- "arm, forearm," also "the shadow of the gnomon on a sundial; the bar of a chariot pole;" Gk. pechys "forearm, arm, ell;" O.H.G. buog "shoulder;" Ger. Bug "shoulder;" Du. boeg; O.E. bôg, bôh "shoulder, bough;" E. bough " a branch of a tree;" PIE *bhaghu- "arm."

gnomonic projection
  فراشانش ِ باهویی   
farâšâneš-e bâhu-yi

Fr.: projection gnomonique   

The projection of a spherical surface onto a plane through a point. A gnomonic → map projection displays all great circles as straight lines, and therefore indicates the shortest path between two points. Small circles are projected as conic sections.

gnomon; → -ic; → projection.

xodâ (#)

Fr.: dieu   

1) The Being perfect in power, wisdom, and goodness who is worshipped as creator and ruler of the Universe.
2) (lowercase) A being or object believed to have more than natural attributes and powers and to require human worship ( See also: → fingers of God

M.E. from O.E. akin to O.H.G. got, Ger. Gott, O.N. guð, Goth. guþ, from PIE *gheuH- "to call upon;" cf. Av. zu- "to call, invoke;" O.Pers. (upa)zu- "to proclaim;" Skt. hu-, variant hve- "to call upon, invoke," huta- "invoked," an epithet of Indra, from root *gheu(e)- "to call, invoke."

Xodâ, xodây "god, lord, master;" Mid.Pers. xwadây "king, master;" Av. xvadāta- "autonomous" (darego.xvadāta- "highly autonomous"), from xva-, → self- + dā- "to give, grant, yield" (Pers. dâdan, → datum); cf. Skt. svadhā- "inherent power, habitual power, self-placed," from sva- "self," + dhā- "to place, fix, maintain"

Godunov method
  روش ِ گودونوف   
raveš-e Godunov

Fr.: méthode de Godunov   

In numerical analysis and fluid dynamics, a conservative scheme for solving → partial differential equations based on utilizing the solution of the local → Riemann problem at each time step.

Suggested by Sergei K. Godunov (1929-) in 1959, Math. Sbornik, 47, 271, translated 1969, US Joint Publ. Res. Service, JPRS 7226; → method.

  تلا، طلا، زر   
talâ (#), zarr (#)

Fr.: or   

A yellow, ductile → metal which occurs naturally in veins and alluvial deposits associated with quartz or pyrite; symbol Au (L. aurum "shining dawn"). → Atomic number 79; → atomic weight 196.9665; → melting point 1,064.43 °C; → boiling point 2,808 °C; → specific gravity 19.32 at 20 °C.

M.E., from O.E. gold, from P.Gmc. *gulth- (cf. O.H.G. gold, Ger. Gold, Du. goud, Dan. guld, Goth. gulþ), from PIE base *ghel-/*ghol- "yellow, green;" cf. Mod.Pers. zarr "gold," see below.

Talâ "gold," variants tala, tali.
Zarr "gold;" Mid.Pers. zarr; Av. zaranya-, zarənu- "gold;" O.Pers. daraniya- "gold;" cf. Skt. hiranya- "gold;" also Av. zaray-, zairi- "yellow, green;" Mod.Pers. zard "yellow;" Skt. hari- "yellow, green;" Gk. khloe literally "young green shoot;" L. helvus "yellowish, bay;" Rus. zeltyj "yellow;" P.Gmc. *gelwaz; Du. geel; Ger. gelb; E. yellow.

Goldbach's conjecture
  هاشن ِ گلدباخ   
hâšan-e Goldbach

Fr.: conjecture de Goldbach   

Every number greater than 2 is the sum of two → prime numbers. Goldbach's number remains one of the most famous unsolved mathematical problems of today.

Named after the German mathematician Christian Goldbach (1690-1764); → conjecture.

golden number
  عدد ِ زرّین   
adad-e zarrin (#)

Fr.: nombre d'or   

1) The number giving the position of any year in the lunar or → Metonic cycle of about 19 years. Each year has a golden number between 1 and 19. It is found by adding 1 to the given year and dividing by 19; the remainder in the division is the golden number. If there is no remainder the golden number is 19 (e.g., the golden number of 2007 is 13).
2) Same as → golden ratio.

Golden, adj. of → gold; → number.

golden ratio
  وابر ِ زرین   
vâbar-e zarrin

Fr.: nombre d'or   

If a line segment is divided into a larger subsegment (a) and a smaller subsegment (b), when the larger subsegment is related to the smaller exactly as the whole segment is related to the larger segment, i.e. a/b = (a + b)/a. The golden ratio, a/b is usually represented by the Greek letter φ. It is also known as the divine ratio, the golden mean, the → golden number, and the golden section. Its numerical value, given by the positive solution of the equation φ2 - φ - 1 = 0, is approximately 1.618033989. The golden ratio is closely related to the → Fibonacci sequence.

golden; → ratio.

gossamer ring
  حلقه‌ی ِ تنته   
halqe-ye tanté

Fr.: anneau ténu   

An extremely faint and broad ring (in fact two rings) of tiny particles around → Jupiter lying just outside the main ring.

Gossamer "a film of cobwebs floating in air in calm clear weather; an extremely delicate variety of gauze, used esp. for veils," from M.E. gossomer, from gos "goose" + somer "summer." Possibly first used as name for late, mild autumn, a time when goose was a favorite dish, then transferred to the cobwebs frequent at that time of year; → ring.

Halqé, → ring; tanté "cobweb, spider's web," from tanidan "to spin, twist, weave" (Mid.Pers. tanitan; Av. tan- to stretch, extend;" cf. Skt. tan- to spin, stretch;" tanoti "stretches," tantram "loom;" Gk. teinein "to stretch, pull tight;" L. tendere "to stretch;" PIE base *ten- "to stretch"), Pers. târ "string," tur "fishing net, net, snare," and tâl "thread" (Borujerdi dialect) belong to this family; variants tanta "cobweb," tanadu, tafen, kartané, kârtané, kâtené, Pashtu tanistah "cobweb;" cf. Skt. tantu- "cobweb, thread, string."

Gould's Belt
  کمربند ِ گولد   
kamarband-e Gould (#)

Fr.: ceinture de Gould   

A band of hot, young stars (O and B types) and molecular clouds that stretches around the sky. It is tilted by about 20 degrees with respect to the Galactic plane, and has a diameter of about 3000 light-years.

Named after the American astronomer Benjamin A. Gould (1824-1896), who discovered it in 1879 by studying the distribution of the nearest luminous stars in space; → belt.


Fr.: gouverner   

General: To rule over, to exercise authority.
Science: To serve as or constitute a law for, e.g. physical laws governing star formation, the Universe, and so on.
To regulate the speed of (an engine) with a governor.

From O.Fr. governer "to govern," from L. gubernare "to direct, rule, guide," originally "to steer," from Gk. kybernan "to steer or pilot a ship" (the root of cybernetics).

Faršâyidan, from Av. fraxšā(y)- "to establish authority, to deploy lordship," from fra- "forward, forth" (Av. pouruua- "first"; cf. Skt. pūrva- "first," pra- "before, formerly," Gk. pro; L. pro; O.E. fyrst "foremost," superlative of fore, from P.Gmc. *furisto; E. fore) + xšā(y)- "to rule, have power," xšayati "has power, rules," xšāyô "power;" O.Pers. xša- "to rule," pati-xša- "to have lordship over," Xšyāršan- "hero among kings" or "ruling over heroes" the proper name of the Achaemenid emperor Hellenized as Xerxes, upari.xšay- "to rule over," xšāyaθiya- "king;" Mid.Pers. šâh "king," pâdixšâ(y) "ruler; powerful; authoritative;" Mod.Pers. šâh "king," pâdšâh "protecting lord, emperor, monarch, king," šâyestan "to be worth, suit, fit;" cf. Skt. ksā- "to rule, have power," ksáyati "possesses;" Gk. ktaomai "I acquire," ktema "piece of property;" PIE base *tkeh- "to own, obtain."


Fr.: régulateur   

A regulating device for maintaining uniform speed regardless of changes of load, as by controlling the supply of gas, steam, fuel, etc.

Agent noun from → govern.

foruzamin (#)

Fr.: graben   

A block of the Earth's crust, bounded by two normal faults, that has dropped downward in relation to adjacent portions.

Graben, from Ger. Graben "ditch, trench;" O.H.G. graban "ditch," grab "grave, tomb;" Goth. graban "ditch;" P.Gmc. *graban; cf. O.E. græf "grave, ditch;" E. a grave; PIE base *ghrebh-/*ghrobh- "to dig, to scratch, to scrape."

Foruzamin, from foru- + zamin. The first component foru- "down, downward; below; beneath;" Mid.Pers. frôt "down, downward;" O.Pers. fravata "forward, downward;" cf. Skt. pravát- "a sloping path, the slope of a mountain." The second component zamin, variant zami "earth, ground," from Mid.Pers. zamig "earth;" Av. zam- "the earth;" cf. Skt. ksam; Gk. khthôn, khamai "on the ground;" L. homo "earthly being" and humus "the earth" (as in homo sapiens or homicide, humble, humus, exhume); PIE root *dh(e)ghom "earth."

  ۱) پداک؛ ۲) پداکیدن   
1) padâk; 2) padâkidan

Fr.: 1) grade, échelon; 2) classer, noter, graduer   

1) A degree or step in a scale, as of rank, advancement, quality, value, or intensity.
2) To arrange in a series of grades; class; sort (

From Fr. grade "grade, degree," from L. gradus "step, pace, gait, walk;" figuratively "a step, stage, degree," related to gradi "to walk, step, go," and second element in congress, progress, etc.; from PIE *ghredh-; cf. Lith. gridiju "to go, wander," O.C.S. gredo "to come," O.Ir. in-greinn "he pursues."

Padâk, from Baluci padâk "step, stair, ladder" (ultimately from Proto-Ir. *padaka-), older form of Pers. pâyé "step, base," from Mid.Pers. pâd, pây; Av. pad-, cf. Skt. pat: Gk. pos, genitive podos; L. pes; PIE *pod-/*ped-.

ziné (#)

Fr.: gradient   

1) General: Degree of slope.
2) Physics: Change in the value of a quantity (as temperature, pressure) with change in a given variable.
3) Math.: A differential → operator (symbol → nabla, ∇) that, operating upon a function (f) of several variables, creates a → vector whose coordinates are the → partial derivatives of the function: ∇f = (∂f/∂x)i + (∂f/∂y)j + (∂f/∂z)k. The gradient of a → scalar function is a vector function.

From L. gradient-, gradiens, pr.p. of gradi "to walk, go," from grad- "walk" + -i- thematic vowel + -ent suffix of conjugation.

Ziné "ladder, steps, stair," may be related to ciné, from cidan "to place (something) above/upon (another similar thing);" cf. Lori râ-zina, Yazdi râ-cina "stairs," Nâyini orcen "stairs, ladder;" the phoneme change -c- into -z-, as in gozidan, gozin-/cidan, cin- both deriving from Proto-Ir. *cai- "to heap up, gather, collect."

  پداکوار، پای‌پایه   
padâkvâr, pâypâyé

Fr.: graduel   

Proceeding, taking place, changing by small degrees.

From M.L. gradualis, from L. gradus "step."

Padâkvâr, from padâk "grade," + -vâr a suffix which denotes "suiting, befitting, resembling, in the manner of, possession."
Pâypâyé "step by step," from pây, pâ "foot, step," → foot.

gradual burst
  بلک ِ پداکوار، ~ پای‌پایه   
belk-e padâkvâr, ~ pâypâyé

Fr.: sursaut graduel   

A burst that happens gradually, in contrast to a sudden burst.

gradual; → burst.

  ۱) پداک دادن، پداکیدن؛ ۲) پداک گرفتن، پداکیده شدن؛ ۳) پداک دادن، پداکیدن؛ ۴) پداکمند، پداکیده   
1) padâk dâdan, padâkidan; 2) padâk gereftan, padâkidé šodan; 3) padâk dâdan, padâkidan; 4) padâkmand, padâkidé

Fr.: 1) graduer; 2) obtenir son diplôme; 3) conférer un diplôme; 4) licencié, diplômé   

1) To divide into or mark with degrees or other divisions, as the scale of a thermometer.
2) To receive a degree or diploma on completing a course of study (often followed by from).
3) To confer a degree upon, or to grant a diploma to, at the close of a course of study, as in a university, college, or school.
4) A person who has received a degree or diploma on completing a course of study, as in a university, college, or school (

M.E., from M.L. graduatus, of graduari "to take a degree," from L. gradus "step, → grade."

1, 3) Padâk dâdan, compound infinitive, padâkidan simple infinitive, both from padâk, → grade, + dâdan "to give, grant," → datum, and -idan, → -fy.
2) Padâk gereftan, from padâk + gereftan "→ take, hold."
4) Padâkmand, from padâk + -mand suffix of possession and ability, → -al; padâkidé, p.p. of padâkidan, as above.

  پداکش، پداک‌دهی، پداک‌گیری   
padâkeš, padâk dehi, padâk giri

Fr.: graduation   

1) Marking the scale of an instrument, e.g. the stem of a thermometer is graduated in degrees.
2) An act of graduating; the state of being graduated.

Verbal noun of → graduate.

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