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 21- a p abe abs abs acc acc acc act act ada adi ads aes Age Alb Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app app arb are ari art ass ast ast ast Atl ato ato Aug aut Avo azi bac bal ban bar bas bea bel Bet bia Big bin bio bir bla bla blo blu Boh Bon bot Bow bre Bri bro but cal cal Can Cap car cas cat cau cel cen cen cha cha cha che Chi chr cir cir civ Cla clo clu CNO coa coe coi 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 cou cra Cre cro Cru cub cur cyc cyl dar dat Daw de- Deb dec dec def def deg Del den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis diu dog Dop dou Dra dua dus dwa dyn e-f Ear ecl eco edu eig Ein ela ele ele ele Ele elo emi emp ene Enl env epi equ equ erg est Euc eva evo exa exc exe exo exp exp ext ext f m fac fal fas fee Fer fib fie fin Fir fix fle flu foc for for For fou Fra fre Fri ful fuz Gal Gal gal Gam gas Gau gen geo geo geo geo Gib glo gov gra gra gra gra gre gro gul H-b hal Ham har Hay hea hel hel hem her het Hig hik hol hom hor hot Hub hum hyb hyd hyd hyp hyp ide ign ima imp imp imp inc ind ind ine inf inf inf ini ins ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos jun K-T Kep key kin Kol lad Lam lan lar las lat lea leg len lev lig lik lin lin lin Lis lob loc log loo low lum lun lun Lym Mac Mag mag mag mag mag Mag mak map Mar mas mat mat mea mea med mem mer MES met met MHD mic mid mil min mis mix mod mol mom Moo mos Mu mul mus nab nar nat neb neg nes neu New New nig nod non non non Nor noz nuc nul num OB obl obs Occ oct off Ohm on- ope Opp opt opt orb orb org Ori ort osm out ove ozo pal pap par par par pas pat pec pen per per per per per pH pha pho pho pho phy pie pla Pla Pla pla pla Plo poi pol pol pol pol por pos pot pow pre pre pre Pre pri pri pri pro pro pro pro pro pro Pro pub pul pyr qua qua qua qua Qui rad rad rad rad rad rad ram ran rat rea rec rec rec red ref ref reg reg rel rel rem rep res res res ret rev rho Rie rim riv rol Ros rot rul S a Sag sam sat sca Sch Sch sco sec sec sec seg sel sem sen set sha Sha sho SI sid sil sim sin sis sky slo sna Soc sol sol sol Sol Som sou spa spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste sto sto str str sub sub sub sum sup sup sup sup sur sus sym syn sys tan Tay Tem ten ter The the the the thi thr tic tid tim Tol tor tot tra tra tra tra Tri tri tro tru tur two Typ UHE ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis VLT vol wad was wav wav wea wei Whe Wie win WN5 Wol WZ Yag yot zen zir > >>

Number of Results: 13033 Search : far
curvature constant
  پارامون ِ خمیدگی   
pârâmun-e xamidegi

Fr.: paramètre de courbure   

A parameter occurring in the → Friedmann equations of → general relativity describing the geometry of → space-time. A spatially → open Universe is defined by k = -1, a → closed Universe by k = + 1 and a → flat Universe by k = 0. See also the → Robertson-Walker metric. See also → curvature of space-time.

curvature; → parameter.

curvature of space-time
  خمیدگی ِ فضا-زمان   
xamidegi-ye fazâ-zamân (#)

Fr.: courbure de l'espace-temps   

According to → general relativity, → space-time is curved by the presence of → matter. The curvature is described in terms of → Riemann's geometry. In → cosmological models three types of curvature are considered: positive (spherical, → closed Universe), zero (Euclidean, → flat Universe), and negative (hyperbolic, → open Universe). See also → curvature constant.

curvature; → space-time.

curve
  خم   
xam (#)

Fr.: courbe   

A line that deviates from straightness in a smooth, continuous fashion. A line representing a variable on a graph.

From L. curvus "crooked, curved, bent;" cf. Av. skarəna- "round," Gk. kirkos, krikos "a ring;" PIE base *sker- "to turn, bend."

Xam, variant kamân "arc," Mid.Pers. kamân, probably from PIE *kamb- "to bend, crook," cf. Breton kamm "curved, bent."

curve fitting
  سز ِ خم، سزکرد ِ ~   
saz-e xam, sazkard-e ~

Fr.: ajustement de courbe   

Construction of mathematical functions whose graphs are curves that "best" approximate a given collection of data points.

curve; → fitting.

curve of growth
  خم ِ رویش   
xam-e ruyeš

Fr.: courbe de croissance   

A plot showing how the → equivalent width of an → absorption line, or the radiance of an → emission line, increases as a → function of the → number of → atoms that produce the line.

curve; → growth.

curved
  خمیده   
xamidé (#)

Fr.: courbé   

Not straight.

Adj. from → curve.

curvilinear
  خم‌خط   
xam-xatt

Fr.: curviligne   

Consisting of, represented by, or bound by curved lines. → rectilinear.

From → curve + → linear.

cusp
  تیزه   
tizé (#)

Fr.: cuspide   

1) General: Pointed end. A point of transition. → polar cusp.
2) Either point of a → crescent moon.
3) A steep power-law representing the number density of stars in the central region of a galaxy. Cusps are characteristic of low-mass ellipticals. They are thought to result from the gravitational attraction of a central → supermassive black hole.
4) A peaked concentration of dark matter in the center of galaxies, as predicted by the → cold dark matter (CDM) model of galaxy formation. See also → cusp problem.
5) Math: A tooth-like meeting of two branches of a curve, with sudden change of direction.

L. cuspis "point, spear, pointed end."

Tizé, noun from tiz "sharp, pointed," from Mid.Pers. tēz, tēž, tigr "sharp," O.Pers. tigra- "pointed," Av. taēža-, tighra- "pointed," Skt. taējas- "the sharp edge (of a knife), piercing (flame)", from tij- "to be sharp, to pierce," Gk. stizein "to prick, puncture," stigma "mark made by a pointed instrument," L. instigare "to goad," P.Gmc. *stik- "to pierce, prick, be sharp," O.H.G. stehhan, Ger. stechen "to prick," O.E. stician "to pierce, stab," E. stick "to pierce;" PIE *st(e)ig- "to stick; pointed".

cusp problem
  پراسه‌ی ِ تیزه   
parâse-ye tizé

Fr.: problème des cuspides   

A problem encountered by the → cold dark matter (CDM) model of galaxy formation. The numerical simulations with CDM predict a large concentration of dark matter in the center of galaxies, with a peaked density distribution, in contrast to the real, observed galaxies. See also: → angular momentum catastrophe; → missing dwarfs.

cusp; → problem.

cut
  بریدن   
boridan (#)

Fr.: couper   

To penetrate or divide something, as with a sharp-edged instrument.

M.E. cutten, kytten, kitten; O.E. *cyttan, cognate with O.Swed. kotta "to cut;" O.N. kuti "little knife," or from O.Fr. couteau "knife."

Boridan "to cut off;" Mid.Pers. brin-, britan, brinitan "to cut off," brin "cut, delimitation, determined;" Av. (pairi-) brī- "to shave, shear;" cf. Skt. bhrī- "to hurt, injure," bhrinanti "they hurt."

cutoff
  بره   
boré

Fr.: coupure   

1) A designated limit beyond which the passage of something must be stopped.
2) A device that cuts off a transmission of photons.

cut; → off.

Boré, from bor- present stem of boridan "to → cut" + noun suffix .

cutoff filter
  پالایه‌ی ِ بره   
pâlâye-ye boré

Fr.: filtre à coupure   

Filter rejecting all light with wavelengths on one side of the cutoff wavelength.

cutoff; → filter.

cutoff voltage
  ولتاژ ِ بره   
voltâž-e boré

Fr.: tension de coupure   

The electrode voltage which reduces the value of a dependent variable, e.g. anode current, to a specified low value.

cutoff; → voltage.

cutoff wavelength
  موج-طول ِ بره   
mowj-tul-e boré

Fr.: longueur d'onde de coupure   

Wavelength at which the transmittance of a filter, or the detectivity of a detector, has fallen to one-half its peak value.

cutoff; → wavelength.

cyanide
  سیانور   
siyânur (#)

Fr.: cyanure   

A chemical compound that contains the → cyano radical, -CN. Most cyanides are highly toxic.

cyano-; → -ide.

cyano radical
  رادیکال ِ سیانو   
râdikâl-e siyâno

Fr.: radical cyano   

A diatomic chemical radical composed of carbon and nitrogen atoms. The triple bonds of C to H leave one electron available, which makes the CN radical very reactive. Organic molecules with the -CN group are potential sources of → prebiotic amino acids. Same as the → CN molecule. The CN radical was first identified by Gay-Lussac, who in 1815 published an extensive study of the derivatives of prussic acid (→ hydrogen cyanide). He showed that the cyano radical remained intact throughout a series of chemical transformations. Also called cyanogen radical.

cyano-; → radical.

cyano-
  سیانو-   
siyâno- (#)

Fr.: cyano-   

1) A combining form meaning "blue, dark blue," used in the formation of compound words. Also cyan- before a vowel.
2) A combining form representing → cyanide in the formation of chemical compounds.

From Gk. kyanos "dark blue, lapis lazuli," because of its presence in the Prussian blue, Fe7(CN)18, a dye which was first accidentally made around 1706, by heating substances containing iron and carbon and nitrogen.

cyanogen
  سیانوژن   
siyânožen (#)

Fr.: cyanogène   

1) A colorless, very poisonous, flammable gas with a smell of bitter almonds. Chemical formula: C2N2. It was discovered by Louis Joseph Gay-Lussac (1778-1850) in 1848.
2) A univalent radical, CN, found in simple and complex cyanide compounds. CN exists in → interstellar medium and is one of the main molecules detected in → comets. It has energy levels at 113 and 227 GHz (2.6 and 1.3 mm wavelength) above the ground level.

cyano- + → -gen.

cyanogen band
  باند ِ سیانوژن   
bând-e siyânožen (#)

Fr.: bande de cyanogène   

An → absorption band of molecular origin characterizing the spectra of → late-type stars (G0 and later, e.g. → S star). → Cyanogen absorption is an important → luminosity criterion for → low-mass stars, and is more pronounced in → giant stars than in → dwarf stars of the same → spectral type.

cyanogen; → band.

cycle
  چرخ، چرخه   
carx (#), carxé (#)

Fr.: cycle   

1) A sequence of changes that are repeated regularly, such as revolution, rotation, vibration, oscillation, wave motion.
2) One complete set of changes in the value of a → periodic function during one period.
3) A period of time at the end of which an event or sequence of events are repeated.
carbon cycle, → Carnot cycle, → CNO cycle, → hydrologic cycle, → Metonic cycle, → Milankovich cycle, → solar activity cycle, → solar cycle, → solar magnetic cycle, → sunspot cycle, → epicycle, → recycle.
4) In → graph theory, a closed → path with at least one → edge.

From L.L. cyclus, from Gk. kyklos "circle, wheel," from PIE base *kw(e)-kwl-o- "wheel, circle," from *kwel- "to turn, move around, sojourn, dwell," (cf. Av. caxra- "wheel," caraiti "he moves, approaches;" Mod.Pers. carx "wheel;" Skt. cakra- "wheel, circle; cycle," carati "he moves, wanders;" Gk. polos "axis of a sphere," polein "move around;" L. colere "to dwell in, to cultivate, move around," colonus "farmer, settler;" O.E. hweol "wheel;" Rus. koleso "awheel").

Carx "every thing performing a circulatory motion; a wheel; a cart," Mid.Pers. chr "wheel," Parthian cxr "wheel," Ossetic, Khotanese calx "wheel," Av. caxra- "wheel," cognate with Gk. kyklos "circle, wheel," as above. Carxé from carx + nuance suffix .

<< < -es -iv -ti 21- a p abe abs abs acc acc acc act act ada adi ads aes Age Alb Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app app arb are ari art ass ast ast ast Atl ato ato Aug aut Avo azi bac bal ban bar bas bea bel Bet bia Big bin bio bir bla bla blo blu Boh Bon bot Bow bre Bri bro but cal cal Can Cap car cas cat cau cel cen cen cha cha cha che Chi chr cir cir civ Cla clo clu CNO coa coe coi 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 cou cra Cre cro Cru cub cur cyc cyl dar dat Daw de- Deb dec dec def def deg Del den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis diu dog Dop dou Dra dua dus dwa dyn e-f Ear ecl eco edu eig Ein ela ele ele ele Ele elo emi emp ene Enl env epi equ equ erg est Euc eva evo exa exc exe exo exp exp ext ext f m fac fal fas fee Fer fib fie fin Fir fix fle flu foc for for For fou Fra fre Fri ful fuz Gal Gal gal Gam gas Gau gen geo geo geo geo Gib glo gov gra gra gra gra gre gro gul H-b hal Ham har Hay hea hel hel hem her het Hig hik hol hom hor hot Hub hum hyb hyd hyd hyp hyp ide ign ima imp imp imp inc ind ind ine inf inf inf ini ins ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos jun K-T Kep key kin Kol lad Lam lan lar las lat lea leg len lev lig lik lin lin lin Lis lob loc log loo low lum lun lun Lym Mac Mag mag mag mag mag Mag mak map Mar mas mat mat mea mea med mem mer MES met met MHD mic mid mil min mis mix mod mol mom Moo mos Mu mul mus nab nar nat neb neg nes neu New New nig nod non non non Nor noz nuc nul num OB obl obs Occ oct off Ohm on- ope Opp opt opt orb orb org Ori ort osm out ove ozo pal pap par par par pas pat pec pen per per per per per pH pha pho pho pho phy pie pla Pla Pla pla pla Plo poi pol pol pol pol por pos pot pow pre pre pre Pre pri pri pri pro pro pro pro pro pro Pro pub pul pyr qua qua qua qua Qui rad rad rad rad rad rad ram ran rat rea rec rec rec red ref ref reg reg rel rel rem rep res res res ret rev rho Rie rim riv rol Ros rot rul S a Sag sam sat sca Sch Sch sco sec sec sec seg sel sem sen set sha Sha sho SI sid sil sim sin sis sky slo sna Soc sol sol sol Sol Som sou spa spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste sto sto str str sub sub sub sum sup sup sup sup sur sus sym syn sys tan Tay Tem ten ter The the the the thi thr tic tid tim Tol tor tot tra tra tra tra Tri tri tro tru tur two Typ UHE ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis VLT vol wad was wav wav wea wei Whe Wie win WN5 Wol WZ Yag yot zen zir > >>