An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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<< < -es -iv -ti 21- A r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir cla clo clo clu 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 cou Cra Cre cri cro cub cur cyc cyl dar dat daw de- Deb dec dec dee def deg del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis div dog Dop dou dra dua dus dwa dyn e-m ear ecl eco eff ein Ein elb ele ele ele ele Els emi emp ene enr env epi equ equ Eri est Euc eva evo exc exc exh exo exp exp ext ext f-n Fah fam fau fee Fer fib fil fin fir fix fle flu foc for for for fra fre fre fri fun fuz gal gal gal Gan gau GCN gen geo geo geo geo Gl glo gra gra gra gra gra gre gro GW1 hab hal han HAR haz hea hel hel Hen Her heu Hig Hil hol hop hor hou Hub Hum Hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind ine inf inf inf inh INP ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos Jun K2 Kep key kin Kol lag lam Lan lar las lav lea leg len lev lig lim lin lin lin lis lob loc log lor low lum lun lun Lym Mac mag mag mag mag mag mai Mal mar mas mas mat max mea mea mee Men mer met met met mic mid Mil min Mir mix mod mod mol mon Mor mou mul muo mys nan nat nav nec Nep neu New New NGC nob nom non non nor not nuc nuc num Nyq obj obs obs oce oen OH omn opa ope opt opt opt orb ord Ori ort osc out ove oxy pal pan par Par par par pas pea Pen per per per per per pet pha pho pho pho phy pie Pit Pla pla pla pla ple Poi pol pol pol pol pop pos pos 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 Sah san Sat sca Sch Sch scr sec sec sec sei sel sem sep set sha she sho sid sig sil sim sin sit sky slu sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spl spr sta sta sta sta sta ste ste sti sto str str sub sub sub sug sun sup sup sup sup sur syl syn sys tal Tay tel ten ter tex the the the thi tho thu tid tim tod top tot tra tra tra tra tri tri tro tru tur twi Typ UFO ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis voc von wak Was wav wax wea wei whi Wie win WN6 wom X-r yel you zer zod > >>

Number of Results: 12948 Search : far
forbidden band
  باند ِ بژکم   
bând-e bažkam

Fr.: bande interdite   

In → solid state physics, a range of → energy levels which is not attained by any electrons in a → crystal. In the energy level diagram forbidden bands appear as gaps between → allowed bands.

forbidden; → band .

forbidden emission line
  خط ِ گسیلی ِ بژکم   
xat-e gosili-ye bažkam

Fr.: raie d'émission interdite   

A → forbidden line in → emission.

forbidden; → emission; → line.

forbidden line
  خط ِ بژکم   
xatt-e bažkam

Fr.: raie interdite   

A spectral line emitted by atoms undergoing energy transitions not normally allowed by the → selection rules of → quantum mechanics. Forbidden emission lines form in low-density interstellar gas and are collisionally excited. They are designated by enclosing in brackets, e.g. [O III] and [N II], O and N representing oxygen and nitrogen atoms respectively.

forbidden; → line.

forbidden transition
  گذرش ِ بژکم   
gozareš-e bažkam

Fr.: transition interdite   

A transition between two quantum mechanical → states that → violates the quantum mechanical → selection rules.

forbidden; → transition.

Forbush decrease
  کاهش ِ فورباش   
kâheš-e Forbush

Fr.: effet Forbush   

A decrease in the Galactic cosmic flux around sunspot maximum as a consequence of Solar flare activity. When sunspots explode, they often hurl massive clouds of hot gas away from the Sun, a phenomenon called → coronal mass ejections (CME). The CMEs contain not only gas but also magnetic fields. So when a CME sweeps past Earth, it also sweeps away many of the electrically-charged cosmic rays.

After Scott E. Forbush, American physicist who studied cosmic rays in the 1930s and 40s; → effect; decrease, from O.Fr. stem of descreistre, from L. decrescere, from → de- "away from" + crescere "to grow."

Kâheš, verbal noun of kâstan, kâhidan "to decrease," from Mid.Pers. kâhitan, kâstan, kâhênitan "to decrease, diminish, lessen;" Av. kasu- "small, little" (Mod.Pers. keh), Proto-Iranian *kas- "to be small, diminish, lessen."

force
  نیرو   
niru (#)

Fr.: force   

1) The cause of a change in motion or shape of a body.
2) A → vector quantity defined by → Newton's second law as the rate of change of → momentum or, equivalently, as the product of → mass and → acceleration. A force is completely specified by giving its magnitude, direction, and point of application. In mechanics, force represents the quantitative measure of the mechanical interaction of material bodies.

From O.Fr. force, from L.L. fortia, from neut. pl. of L. fortis "strong," from forctus, from PIE base *bhergh- "high" (cf. Av. barəz- "high, mount," barezan- "height;" O.Pers. baršan- "height;" Mod.Pers. borz in (the mountain chain) Alborz, and borz "height, magnitude," bâlâ "up, above, high, elevated, height," Lori dialect berg "hill, mountain;" Skt. bhrant- "high;" O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg).

Niru, from Mid.Pers. nêrok, Av. nairya- "manly, male" (cf. Skt. nárya-), from nar- "man, male" (Mid./Mod.Pers. nar- "male," Skt. nár- "male").

force field
  میدان ِ نیرو   
meydân-e niru (#)

Fr.: champ de force   

Same as → field of force.

force; → field.

force multiplier parameter
  پارامون ِ بستاگر ِ نیرو   
pârâmun-e bastâgar-e niru

Fr.: paramètre de multiplicateur de force   

One of the three quantities (k, α, and δ) which are used in the → radiation-driven wind theory to express the radiation pressure due to spectral lines. These coefficients parametrize the radiation acceleration as: grad≅ k(dv/dr)αge, where ge = σeL/4πcR*2 is the radiative acceleration by electron scattering. The parameter k is dependent on the number of lines that produce the radiation pressure. The parameter α depends on the optical depth of the driving lines and varies between 0 (optically thin) and 1 (optically thick). The parameter δ describes the dependence of k on the density with k ≅ ρδ. The velocity law of radiation-driven winds depends on α and δ, but not on k. The → mass loss rate depends on k, α, and δ (Castor et al. 1975, ApJ 195, 157; Lamers et al., 1995, ApJ 455, 269 and references therein).

force; → multiplier; → parameter.

force system
  راژمان ِ نیروها   
râžmân-e niruhâ

Fr.: système de forces   

Any set of forces acting on a → rigid body.

force; → system.

force-free magnetic field
  میدان ِ مغناتیسی ِ بی‌نیرو   
meydân-meqnâtisi-ye bi-niru

Fr.: champ magnétique sans force   

The condition in a plasma when the → Lorentz force is zero, that is when the electric current flows along the magnetic field. Force-free magnetic fields are encountered in astrophysical plasmas with negligible gas pressure. The solar corona is the best available example of such fields in action in a plasma.

force; → free; → magnetic; → field.

forced
  زوری   
zuri (#)

Fr.: forcé   

1) Physics: Caused by an external force. → forced oscillation.
2) General: Subjected to force, compulsory.

Adjective from → force.

Adjective from zur, → strength.

forced flow
  تچان ِ زوری   
tacân-e zuri

Fr.: écoulement forcé   

A fluid flow generated when external forces cause the fluid to flow, for example when a flow is caused by a pump. It contrasts with → free flow.

forced; → flow.

forced oscillation
  نوش ِ زوری   
naveš-e zuri

Fr.: oscillation forcée   

The oscillation of a system or object induced by an external periodic force. See also → free oscillation.

forced; → oscillation.

forearm
  ارش   
araš (#)

Fr.: avant bras   

The part of the arm between the → elbow and the → wrist.

From fore- a prefix meaning "before; front; superior," related to → per-; → arm.

Araš, variant ârenj "elbow;" Mid.Pers. âranj; O.Pers. arašan- "cubit;" Av. arəθnâ- "elbow;" Skt. aratni- "elbow," Iranian stem aratan-, araθn-, borrowed from Iranian into General Slavic as aršin "ell."

foreground
  پیش-زمینه   
pišzaminé

Fr.: avant-plan   

The ground or parts situated, or represented as situated, in the front; the portion of a scene or stellar field nearest to the viewer. → background.

From fore, from O.E. fore (prep.) "before, in front of;" (adv.) "before, previously" (cf. O.H.G. fora, Ger. vor, Goth. faiura); from PIE *per-/*pr- (cf. Skt. pura "before, formerly;" Av. paro "before;" Hittite para- "on, forth;" Gk. paros "before," para "from beside, beyond," peri "around, about, toward," pro "before;" L. pro "before, for, instead of," prae "before," per "through, for") + ground, from M.E., from O.E. grund; akin to O.H.G. grunt "ground."

Pišzaminé, from piš- "before; in front," from Mid.Pers. pêš "before, earlier;" O.Pers. paišiya "before; in the presence of" + ziminé "ground," from zamin "earth, ground" → earth.

foreground absorption
  درشم ِ پیش-زمینه   
daršam-e pišzaminé

Fr.: absorption d'avant-plan   

Loss of radiant energy received from an astronomical object due to the presence of absorbing matter situated between the object and observer.

foreground; → absorption.

forest
  جنگل   
jangal (#)

Fr.: forêt   

1) A large tract of land covered with trees and underbrush; woodland (Dictionary.com).
2) In → graph theory, a → graph which contains no → cycles. The connected components of a forest are → trees.

M.E., from O.Fr. forest, probably from L.L. forestis (silva) "the outside woods," from L. foris "outside."

Jangal "a wood, forest, a vast land with plenty of trees;" cf. Skt. jangala- "arid , sparingly grown with trees and plants."

fork
  دوشاخ، دوشاخه؛ چنگال   
došâx, došâxé; cangâl

Fr.: fourche; forchette   

1) An instrument having two or more prongs or tines, for holding, lifting, etc., as an implement for handling food or any of various agricultural tools (dictionary.com).
2) Something resembling or suggesting this in form. → fork mounting.

Fork, from O.E. forca, from L. furca "pitchfork," of uncertain origin; → mounting.

Došâx, došâxé "two-pronged; fork," from do "two" (Mid.Pers. do, Av. dva-, Skt. dvi-, Gk. duo, L. duo, E. two, Ger. zwei, Fr. deux) + šâx "branch; horn," from Mid.Pers. šâk "branch;" cf. Lith. šaka "branch;" O.S. soxa "plough;" Gothic hoha "plough."
Cangâl "claws, fingers," from cang "claws, fingers," + -al, → -al.

fork mounting
  برنشاند ِ دوشاخه   
barnešând-e došâxé

Fr.: monture à fourche   

A type of → equatorial mounting consisting of a two-pronged fork, which forms the → polar axis, with the → telescope pivoted between the prongs of the fork on a → declination axis.

fork; → mounting.

form
  ۱) دیس، دیسه؛ ۲) دیسیدن؛ ۳) دیساندن   
1) dis, disé (#); 2) disidan (#); 3) disândan (#)

Fr.: 1) forme; 2) se former; 3) former   

1) (n.) General: The shape and structure of something as distinguished from its material.
Philosophy: The structure, pattern, organization, or essential nature of anything. Structure or pattern as distinguished from matter.
Logic: The abstract relations of terms in a proposition, and of propositions to one another.
2) (v.intr.) of form.
3) (v.tr.) of form.

From O.Fr. forme, from L. forma "form, mold, shape, case," origin unknown.

1) Dis, disé "form, appearance," variants -diz, -diš (tandis "body form, like a body; effigy;" mâhdis "moon-like;" šabdiz "night color; a horse of dark rusty color;" andiš- "to think, contemplate"), from Mid.Pers. dêsag "form, appearance," dêsidan "to form, build;" Av. daēs- "to show," daēsa- "sign, omen;" cf. Skt. deś- "to show, point out;" PIE *deik- "to show" (cf. Gk. deiknumi "to show," dike "manner, custom;" L. dicere "to utter, say;" O.H.G. zeigon, Ger. zeigen "to show;" O.E. teon "to accuse," tæcan "to teach").
2) and 3) corresponding infintives of dis, as above.

<< < -es -iv -ti 21- A r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir cla clo clo clu 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 cou Cra Cre cri cro cub cur cyc cyl dar dat daw de- Deb dec dec dee def deg del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis div dog Dop dou dra dua dus dwa dyn e-m ear ecl eco eff ein Ein elb ele ele ele ele Els emi emp ene enr env epi equ equ Eri est Euc eva evo exc exc exh exo exp exp ext ext f-n Fah fam fau fee Fer fib fil fin fir fix fle flu foc for for for fra fre fre fri fun fuz gal gal gal Gan gau GCN gen geo geo geo geo Gl glo gra gra gra gra gra gre gro GW1 hab hal han HAR haz hea hel hel Hen Her heu Hig Hil hol hop hor hou Hub Hum Hyd hyd hyd hyp hys ide ign ima imp imp inc inc ind ine inf inf inf inh INP ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jos Jun K2 Kep key kin Kol lag lam Lan lar las lav lea leg len lev lig lim lin lin lin lis lob loc log lor low lum lun lun Lym Mac mag mag mag mag mag mai Mal mar mas mas mat max mea mea mee Men mer met met met mic mid Mil min Mir mix mod mod mol mon Mor mou mul muo mys nan nat nav nec Nep neu New New NGC nob nom non non nor not nuc nuc num Nyq obj obs obs oce oen OH omn opa ope opt opt opt orb ord Ori ort osc out ove oxy pal pan par Par par par pas pea Pen per per per per per pet pha pho pho pho phy pie Pit Pla pla pla pla ple Poi pol pol pol pol pop pos pos 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 Sah san Sat sca Sch Sch scr sec sec sec sei sel sem sep set sha she sho sid sig sil sim sin sit sky slu sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spl spr sta sta sta sta sta ste ste sti sto str str sub sub sub sug sun sup sup sup sup sur syl syn sys tal Tay tel ten ter tex the the the thi tho thu tid tim tod top tot tra tra tra tra tri tri tro tru tur twi Typ UFO ult unc uni uni uni upg ura uti val var vec vel ver ver vig vir vis voc von wak Was wav wax wea wei whi Wie win WN6 wom X-r yel you zer zod > >>