An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < -es -iv -ti 217 a- abe abs abs acc acc ach act act ada adi adv aff agg Alc Alf ali all alp alt Ama amp ana ang ang ann ano ant ant ape apo app aps arc arg arm art ass ast ast ast atm ato att aur aut axi B-t bai Bal bar bar Be bee Bes bi- bif bin bin bio bis bla bli blu Boe Bol bor bou bra bri Bro bum CAI cal Can cap car car cat cat CCD Cel cen CGS cha cha che che chr cir cir civ cla clo clo CMB coa coe coh col col col Com com com com com com com com com con con con con con con con con con con con coo cor cor cor cos cos cos cou cov cra cri cro cry cum cur cyc d'A dar dat DC dea dec dec dec def def deh Del den dep des det dev dia dif dif dif dim dip dir dis dis dis dis dis div dom dou dou dri dup dus dyn dyn ear eas ecl Edd eff Ein Ekm ele ele ele ele ell emb emi enc ene ent eph equ equ equ eru eth eup eve EX exc exe exi exo exp ext ext ext fac fal far fec Fer fer fie fin fir fis fla flo flu fog for for Fou fra fre Fre Fro fus G-t gal gal Gam gas Gau Gem gen geo geo geo gia gla gol gra gra gra gra Gre Gre gui H a haf Hal har har He- hea hel Hel her Her hie hig his hom hor hot Hub Hug hur hyd hyd hyl hyp ice ide ima imp imp imp inc ind ind ine inf inf Inf inj InS ins int int int int int int int int inv inv ion iro Isl iso iso Jac jet jud jur Kel Kep kil kly L d Lag lam Lap lar lat law Lea len lep lib lig lin lin lin liq lit loc log lon Los low lum lun Lut Lyr mac mag mag mag mag mag maj man Mar mas mas mat mea mec mem mer mes met met met mic mid mil min Mir Miz mod mol mon moo MOS mul mul mut nai nas nat neb neg Neu neu New New Nih noi non non non nor nuc nuc nul nut obj obl obs occ oct off old one ope opp opt opt orb ord org Ori osc oth ove oxi pac Pal par par Par par pas Pau Pel per per per per per per pha phi pho pho pho phy pip Pla pla pla pla pla Plu Poi pol pol pol pop pos pos pot Pra pre pre pre Pri pri pri pro pro pro pro pro pro pro Pto pul puz qua qua qua qua qui rad rad rad rad rad rad rai ran Ras Ray rea rec rec rec red red ref reg reg rel rel rel rep res res res res rev rhe Rie Rig Rit roe Ros rot Ruf Ryd Sag sam sat sca sca Sch Sco sec sec sec seg sel sem sen set sha SHB sho sib sie sil sim sin sit sky slo sno sod sol sol sol sol sor sou Spa spa spe spe spe sph spi Spi spr sta sta sta sta sta ste ste Ste sto str str sub sub sub suf sun sup sup sup sup sur swo syn sys tak Tay Tel ten ter tet the the the thi Tho thu tid tim toa top tot tra tra tra tra tri tri tro Tru tur twi Typ UBV ult unb uni uni uni up ura uti val var vec Vel ver ver vig vir vis VLT vol wad was wav wav wea wei Whe Wie win WN5 Wol X-r yea You zer zod > >>

Number of Results: 12929 Search : far
Foucault's Marseille reflector
  بازتابگر ِ فوکو‌ی ِ مارسی   
bâztâbgar-e Foucault-ye Marseille

Fr.: réflecteur marseillais de Foucault   

The first functioning → reflecting telescope with a silvered glass mirror. It was built by Léon Foucault in 1826 for the Marseille Observatory. The mirror of 80-cm in diameter (f/d = 5) had an excellent quality. The telescope was used for a century as a visual instrument. Edouard Stéphan (1837-1923) used it from 1871 to 1884 to find 800 high-brightness galaxies, among which the → Stephan's Quintet. From 1906 to 1962 the telescope was used by Robert Jonckheere (1888-1927) to discover 3,350 new binary stars. In 1873, following an idea of Hippolyte Fizeau (1819-1896), Stéphan attempted to use it as an → interferometer to measure the diameter of a number of stars. In 1914 Charles Fabry (1867-1945) and Henri Buisson (1873-1944) used the telescope to obtain the first astronomical Fabry-Pérot interferogram, on the → Orion Nebula.

After the French physicist and optician Léon Foucault (1819-1868); Marseille (Observatory), the second largest city of France, located on the south east coast of the Mediterranean Sea, from L. Massalia, from Gk. Massalia; → reflector.

four
  چهار   
cahâr (#)

Fr.: quatre   

O.E. feower, from P.Gmc. *petwor- (cf. O.S. fiwar, Du. and Ger. vier, O.N. fjorir, Dan. fire, Sw. fyra), cognate with Pers. cahâr, as below, from PIE *qwetwor.

Cahâr, variant câr, from Mid.Pers. cahâr; Av. caθwarô, catur-; cf. Skt. catvārah; Gk. tessares; cognate with L. quattuor; E. four, as above.

four-dimensional operator
  آپارگر ِ چهار-وامونی   
âpârgar-e cahâr-vâmuni

Fr.: opérateur à quatre dimensions   

An operator defined as: ▫ = (∂/∂x, ∂/∂y, ∂/∂z, 1/(jc∂/∂t).

four; → dimensional; → operator.

Fourier analysis
  آنالس ِ فوریه   
ânâlas-e Fourier

Fr.: analyse de Fourier   

The process of decomposing any function of time or space into a sum of sinusoidal functions using the → Fourier series and → Fourier transforms. In other words, any data analysis procedure that describes or measures the fluctuations in a time series by comparing them with sinusoids. Fourier analysis is an essential component of much of modern applied and pure mathematics. It forms an exceptionally powerful analytical tool for solving various problems in many areas of mathematics, physics, engineering, biology, finance, etc. and has opened up new realms of knowledge.

After the French mathematician Baron Jean Baptiste Joseph Fourier (1768-1830), whose work had a tremendous impact on the physical applications of mathematics; → analysis.

Fourier coefficient
  همگر ِ فوریه   
hamgar-e Fourier

Fr.: coefficient de Fourier   

One of the coefficients an or bn of cos (nx) and sin (nx) respectively in the → Fourier series representation of a function. They are expressed by:
an = (1/π) ∫f(x) cos nx dx, for n≥ 0, summed over 0 to 2π
bn = (1/π) ∫f(x) sin nx dx, for n≥ 1, summed over 0 to 2π.

Fourier analysis; → series.

Fourier integral
  درستال ِ فوریه   
dorostâl-e Fourier

Fr.: intégrale de Fourier   

An integral used in the → Fourier transform.

Fourier analysis; → integral.

Fourier series
  سری ِ فوریه   
seri-ye Fourier

Fr.: séries Fourier   

A mathematical tool used for decomposing a → periodic function into an infinite sum of sine and cosine functions. The general form of the Fourier series for a function f(x) with period 2π is:
(1/2) a0 + Σ (an cos (nx) + bn sin (nx), summed from n = 1 to ∞,
where an and bn are the → Fourier coefficients, measuring the strength of contribution from each harmonic. The functions cos (nx) and sin (nx) can be used in this way because they satisfy the → orthogonality conditions. For the problem of convergence of the Fourier series see → Dirichlet conditions. The Fourier series play a very important role in the study of periodic phenomena, because they allow one to decompose a large number of complex problems into simpler ones. The generalization of this method, called the → Fourier transform, makes it possible to also decompose non-periodic functions into harmonic components. See also → complex Fourier series, → Parseval's theorem.

Fourier analysis; → series.

Fourier theorem
  فربین ِ فوریه   
farbin-e Fourier

Fr.: théorème de Fourier   

Any finite periodic motion may be analyzed into components, each of which is a simple harmonic motion of definite and determinable amplitudes and phase.

Fourier analysis; → theorem.

Fourier transform
  ترادیس ِ فوریه   
tarâdis-e Fourier

Fr.: transformée de Fourier   

A powerful mathematical tool which is the generalization of the → Fourier series for the analysis of non-periodic functions. The Fourier transform transforms a function defined on physical space into a function defined on the space of frequencies, whose values quantify the "amount" of each periodic frequency contained in the original function. The inverse Fourier transform then reconstructs the original function from its transformed frequency components. The integral F(α) = ∫ f(u)e-iαudu is called the Fourier transform of F(x) = (1/2π)∫ f(α)eiαxdx, both integrals from -∞ to + ∞.

Fourier analysis; → transform.

fourth contact
  پرماس ِ چهارم   
parmâs-e cahârom

Fr.: quatrième contact   

The end of a solar eclipse marked by the disk of the Moon completely passing away from the disk of the Sun.

From M.E. fourthe, O.E. féowertha, from four, from O.E. feower, from P.Gmc. *petwor- (cf. Du. and Ger. vier, O.N. fjorir, Dan. fire, Sw. fyra), from PIE *qwetwor (cf. Mod.Pers. cahâr, Av. caθwar-, catur-, Skt. catvarah, Gk. tessares, L. quattuor) + -th a suffix used in the formation of ordinal numbers, from M.E. -the, -te, O.E. -tha, -the; cf. O.N. -thi, -di; L. -tus; Gk -tos; → contact.

Parmâs, → contact; cahârom cardinal form from cahâr "four," cognate with E. four, as above.

fovea
  لکه‌ی ِ زرد   
lake-ye zard (#)

Fr.: fovéa   

A small depression, approximately 1.5 millimeters in diameter, at the back of the → retina. It forms the area of the most acute vision.

Contraction of fovea centralis, from L. fovea "small pit," of unknown origin.

Lake-ye zard, literally "yellow spot," from laké, → spot, zard, → yellow.

fractal
  برخال   
barxâl (#)

Fr.: fractal   

A geometrical or physical structure that repeats itself or nearly repeats itself on many different scales of magnification.

From Fr. fractale, term coined by Benoit Mandelbrot (1975), from frac(tus) "broken, uneven", → fraction, + -ale-al.

Barxâl, from barx, → fraction, + -âl-al.

fractal cosmology
  کیهانشناخت ِ برخالی   
keyhânšenâxt-e barxâli

Fr.: cosmologie fractale   

The postulate that the concentrations of matter in the Universe follow a → fractal structure over a wide range of scales.

fractal; → cosmology.

fractal structure
  ساختار ِ برخالی   
sâxtâr-e barxâli

Fr.: structure fractale   

A → hierarchial structure that can be likened to fractals.

fractal; → structure

fraction
  برخه   
barxé (#)

Fr.: fraction   

A rational number of the form a/b where a is called the numerator and b is called the denominator.

From L.L. fractionem (nom. fractio) "a breaking in pieces," from frangere "to break," from PIE base *bhreg- "to break" (cf. Goth. brikan, O.E. brecan "to break;" Lith. brasketi "crash, crack").

Barxé, from barx "lot, portion," variant bahr, from Mid.Pers. bahr "lot, share, portion," Av. baxəδra- "portion."

fractional
  برخه‌ای   
barxe-yi

Fr.: fractionnaire, fractionné, partiel   

1) Math.: Pertaining to fractions; constituting a fraction.
2) Chemistry: Of or relating to any process by which parts of a mixture are separated by exploiting differences in their physical properties, such as their boiling points, solubility, or other characteristics.

fraction; → -al.

fractional sky coverage
  پوشش ِ برخه‌ای ِ آسمان   
pušeš-e barxe-yi-ye âsmân

Fr.: couverture partielle du ciel   

The portion of the 4π → steradians of the sky that a radiotelescope can observe from a given location on Earth over a 24-hour time interval.

fractional; → sky; → coverage.

fractionate
  برخاندن   
barxândan

Fr.: fractionner   

1) To break something up into smaller parts.
2) To separate a mixture into ingredients or portions having different properties, as by distillation or otherwise.

From → fraction + -ate a suffix forming verbs or nouns, from L. -atus, -ata, -atum.

Barxândan, from barx, barxé, → fraction, + -ândan suffix of transitive verbs.

fractionation
  برخانش   
barxâneš

Fr.: fractionnement   

1) Any of various methods of separating the components of a mixture into fractions of different properties.
2) → isotope fractionation

Verbal noun from → fractionate.

fragment
  ۱) لته، لت، پاره؛ ۲) لتپار شدن؛ ۳) لتپاریدن   
1) latté (#), latt (#), pâré (#); 2) latpâr šodan (#); 3) latpâridan

Fr.: 1) fragment; 2) se fragmenter; 3) fragmenter   

1) (n.) A part broken off or detached.
2) (v.intr.) To collapse or break into pieces.
3) (v.tr.) To break something into pieces.

From L. fragmentum, from frangere "to break."

1) Latté, lat, variant laxt, laxté "piece, part;" pâré "piece, part, portion, fragment;" Mid.Pers. pârag "piece, part, portion; gift, offering, bribe;" Av. pāra- "debt," from par- "to remunerate, equalize; to condemn;" PIE *per- "to sell, hand over, distribute; to assigne;" cf. L. pars "part, piece, side, share," portio "share, portion;" Gk. peprotai "it has been granted;" Skt. purti- "reward;" Hitt. pars-, parsiya- "to break, crumble."
2) and 3) Verbal forms.

<< < -es -iv -ti 217 a- abe abs abs acc acc ach act act ada adi adv aff agg Alc Alf ali all alp alt Ama amp ana ang ang ann ano ant ant ape apo app aps arc arg arm art ass ast ast ast atm ato att aur aut axi B-t bai Bal bar bar Be bee Bes bi- bif bin bin bio bis bla bli blu Boe Bol bor bou bra bri Bro bum CAI cal Can cap car car cat cat CCD Cel cen CGS cha cha che che chr cir cir civ cla clo clo CMB coa coe coh col col col Com com com com com com com com com con con con con con con con con con con con coo cor cor cor cos cos cos cou cov cra cri cro cry cum cur cyc d'A dar dat DC dea dec dec dec def def deh Del den dep des det dev dia dif dif dif dim dip dir dis dis dis dis dis div dom dou dou dri dup dus dyn dyn ear eas ecl Edd eff Ein Ekm ele ele ele ele ell emb emi enc ene ent eph equ equ equ eru eth eup eve EX exc exe exi exo exp ext ext ext fac fal far fec Fer fer fie fin fir fis fla flo flu fog for for Fou fra fre Fre Fro fus G-t gal gal Gam gas Gau Gem gen geo geo geo gia gla gol gra gra gra gra Gre Gre gui H a haf Hal har har He- hea hel Hel her Her hie hig his hom hor hot Hub Hug hur hyd hyd hyl hyp ice ide ima imp imp imp inc ind ind ine inf inf Inf inj InS ins int int int int int int int int inv inv ion iro Isl iso iso Jac jet jud jur Kel Kep kil kly L d Lag lam Lap lar lat law Lea len lep lib lig lin lin lin liq lit loc log lon Los low lum lun Lut Lyr mac mag mag mag mag mag maj man Mar mas mas mat mea mec mem mer mes met met met mic mid mil min Mir Miz mod mol mon moo MOS mul mul mut nai nas nat neb neg Neu neu New New Nih noi non non non nor nuc nuc nul nut obj obl obs occ oct off old one ope opp opt opt orb ord org Ori osc oth ove oxi pac Pal par par Par par pas Pau Pel per per per per per per pha phi pho pho pho phy pip Pla pla pla pla pla Plu Poi pol pol pol pop pos pos pot Pra pre pre pre Pri pri pri pro pro pro pro pro pro pro Pto pul puz qua qua qua qua qui rad rad rad rad rad rad rai ran Ras Ray rea rec rec rec red red ref reg reg rel rel rel rep res res res res rev rhe Rie Rig Rit roe Ros rot Ruf Ryd Sag sam sat sca sca Sch Sco sec sec sec seg sel sem sen set sha SHB sho sib sie sil sim sin sit sky slo sno sod sol sol sol sol sor sou Spa spa spe spe spe sph spi Spi spr sta sta sta sta sta ste ste Ste sto str str sub sub sub suf sun sup sup sup sup sur swo syn sys tak Tay Tel ten ter tet the the the thi Tho thu tid tim toa top tot tra tra tra tra tri tri tro Tru tur twi Typ UBV ult unb uni uni uni up ura uti val var vec Vel ver ver vig vir vis VLT vol wad was wav wav wea wei Whe Wie win WN5 Wol X-r yea You zer zod > >>