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 aca acc acc acr act ada adh Adr aer AGB air Alf Alg all alp alt AM amo ana And ang ani ano Ant Ant apa apo app app Ara Arc ari Arr ash ass ast ast asy atm ato att aut ave axi Bab bal Bal bar bar bea Bek Bes bia Big bin bin bip biv bla bli blu Boh Bol Bos bou bra bri bro buo cal cal can cap car Car cat cat CCD Cen cen CH cha cha che Che chr cir cir cit 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 con Cop Cor cor cor cos cos cou cou Cow cre cri cro cry cur cya Cyg dan dar dat de- deb dec dec ded def deg del dem den dep des det dev dia dif dif dih dio Dir dis dis dis dis dis dis DO don dou dow dro dur dwa dyn Dys ear ebb ecl edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ esc eth Eur Eve exa exc exe exi exp exp ext ext ext fac fal far fed Fer fer fie fin fir fis fla flo flu fol for for fou fra fre Fre fro fut G-t gal gal gam gas Gau Gem gen geo geo geo gia Gli Gol gra gra gra gra gre gri gui H I Hag hal har hat He- hea hel Hel her Hes hie hig his hom hor hot Hub Hug hur hyd hyd hyg hyp ice ide ima Ima imp imp inc inc ind ine inf inf inf ing inn ins ins int int int int int int int int inv Io ion iro isl iso iso Jac jet jud jur Kel Kep kil Klo Kui Lag lam Lap Lar lat law lea len lep Lib lig lim lin lin Lio lit loc LOF lon Lor low lum lun Lup Lyo mac mag mag mag mag mag mai man Mar mas mas mat Max mea mec Meg Mer Mer met met Met mic Mid Mil min Mir mit mod mod mol mon Mor mou mul mul mys nan Nat nau nec neo neu nev New NGC no nom non non nor not nuc nuc num nut obj obs obs occ ocu oft ome Oor ope opp opt opt orb ord ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per per pha phi pho pho pho phy pio Pla pla pla pla Pla plu Poi pol pol pol poo pos pos pot pra pre pre pre pre pri pri pro pro pro pro pro Pro pro pse pul pur qua qua qua qua que rac rad rad rad rad rad rad ran rar ray rea rea rec rec red red ref ref reg rel rel rel ren res res res res ret rev Ric rig rin roc roo rot rot Rus Sac sal sat sca sca Sch sci Scu sec sec Sed sel Sel sen ser Sex Sha she sho sid sig sil sim sin siz sla Sma sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spi spr squ sta sta sta sta ste ste ste Sto Str str str sub sub suc sun sup sup sup sup sur swa syn syn tab tar tek tem ter tes the the the the Tho thr tid tim Tis Too Tor tra tra Tra tra tra tri tri tru Tul tur two Typ ult un- und uni uni unk upp Urc utt val var vec vel ver vib vio vir vis voi vor wan wat wav wax wea Wei whi Wil win WN9 wor X-r yel you zer zod > >>

Number of Results: 13048 Search : far
phase difference
  دگرسانی ِ فاز   
degarsâni-ye fâz

Fr.: différence de phase   

The difference of phase (usually expressed as a time or an angle) between two periodic quantities which vary sinusoidally and have the same frequency.

phase; → difference.

phase equilibrium
  ترازمندی ِ فاز   
tarâzmandi-ye fâz

Fr.: équilibre de phases   

The condition of temperature and pressure under which different phases (e.g. gas, liquid, and solid) of a substance coexist.

phase; → equilibrium.

phase function
  کریای ِ فاز   
karyâ-ye fâz

Fr.: fonction de phase   

The variation in brightness of a target as the phase angle (the angle between Sun and observer as seen from the target) varies between 0° and 180°. The directional distribution of reflected (or scattered) radiation. The phase angle is the supplement of the scattering angle (the angle between the incident ray and the emerging ray); in other words, the sum of the phase angle and the scattering angle is always 180° (Ellis et al., 2007, Planetary Ring Systems, Springer).

phase; → function.

phase lag
  دگرسانی ِ فاز   
degarsâni-ye fâz

Fr.: différence de phase   

1) General: Same as → phase difference.
2) Cepheids: The observed phase difference between luminosity and velocity in classical (radially pulsating) → Cepheids. On the basis of adiabatic pulsation theory, one would expect the maximum luminosity to occur when the radius of the star is minimal. This means that the maximum outward velocity would be one quarter period out of phase with the maximum velocity. However, in the observations the maximum luminosity and maximum outward velocity are nearly in phase. This effect is due to the → kappa mechanism which is responsible for driving the → pulsations. The pulsations in Cepheids are excited by the helium → partial ionization zone, He+↔ He++, which is located below the He ↔ He+ and H ↔ H+ zones. These latter two regions are too shallow to contribute significantly to the driving of the fundamental modes of Cepheids; so their only effect is to introduce a phase shift.

phase; lag, possibly from a Scandinavian source; cf. Norw. lagga "go slowly."

Degarsâni, → difference; fâzphase.

phase lock
  فازبست   
fâz bast

Fr.: blocage de phase   

In electronics, a technique of adjusting the phase of an oscillator signal so that it will follow the phase of a reference signal.

phase; lock, from O.E. loc "bolt, fastening, enclosure;" cf. O.N. lok "fastening, lock," Goth. usluks "opening," O.H.G. loh "dungeon," Ger. Loch "opening, hole," Du. luck "shutter, trapdoor."

Fâz, → phase; bast "fastening, lock," from bastan, from Mid.Pers. bastan/vastan "to bind, shut," Av./O.Pers. band- "to bind, fetter," banda- "band, tie," Skt. bandh- "to bind, tie, fasten," PIE *bhendh- "to bind," cf. Ger. binden, E. bind, → band.

phase modulation
  دگر‌آهنگش ِ فاز   
degarâhangeš-e fâz (#)

Fr.: modulation de phase   

Modulation in which the phase angle of a sine-wave carrier is caused to depart from the carrier angle by an amount proportional to the instantaneous magnitude of the modulating wave.

phase; → modulation.

phase reversal
  واگردانی ِ فاز، وارونش ِ ~   
vâgardâni-ye fâz, vâruneš-e ~

Fr.: inversion de phase   

An angular shift in phase by 180°.

phase; → reversal.

phase shift
  کیب ِ فاز   
kib-e fâz

Fr.: décalage de phase   

Any change in the phase of a periodic quantity or in the phase difference between two or more periodic quantities.

phase; → shift.

phase space
  فضای ِ فاز   
fazâ-ye fâz

Fr.: espace des phases   

Of a dynamical system, a six-dimensional space consisting of the set of values that the position and velocity can take together (x, y, z, vx, vy, vz). → velocity space.

phase; → space.

phase transfer function (PTF)
  کریای ِ تراوژ ِ فاز   
karyâ-ye tarâvaž-e fâz

Fr.: fonction de transfert de phase   

A measure of the relative phase in the image as function of frequency. It is the phase component of the → optical transfer function. A relative phase change of 180°, for example, results in an image with the black and white areas reversed.

phase; → transfer; → function.

phase transition
  گذرش ِ فاز   
gozareš-e fâz

Fr.: transition de phase   

The changing of a substance from one phase to another, by → freezing, → melting, → boiling, → condensation, or → sublimation. Also known as phase transformation. A well known phase transition is the transition from → water to → ice. Phase transitions are often associated with → symmetry breaking. In water there is a complete symmetry under rotations with no preferred direction. Ice has a crystal structure, in which certain orientations in space are preferred. Therefore, in transition from water to ice the continuous rotational symmetry is lost.

phase; → transition.

phase velocity
  تندای ِ فاز   
tondâ-ye fâz

Fr.: vitesse de phase   

The speed at which any fixed phase (individual wave) in a → wave packet travels. It is expressed as vph = ω/k, where ω is the → angular frequency and k the → wave number. See also the → group velocity.

phase; → velocity.

phases of the Moon
  سیماهای ِ مانگ   
simâhâ-ye Mâng

Fr.: phases de la lune   

Lunar phase.

phase; → Moon.

phases of Venus
  سیماهای ِ ناهید   
simâhâ-ye Nâhid

Fr.: phases de Vénus   

The gradual variation of the apparent shape of → Venus between a small, full → disk and a larger → crescent. The first telescopic observation of the phases of Venus by Galileo (1610) proved the → Ptolemaic system could not be correct. The reason is that with the → geocentric system the phases of Venus would be impossible. More specifically, in that model Venus lies always between Earth and Sun. Hence its fully bright surface would always be toward the Sun; so Venus could not be seen in full phase from Earth. Only slim crescents would be possible. On the other hand, this phenomenon could not prove the → heliocentric system, because it could equally be explained with the → Tychonic model.

phase; → Venus.

phenology
  زیست‌چرخه‌شناسی   
zistcarxe-šenâsi

Fr.: phénologie   

The study of the biological recurring phenomena in plants and animals (such as blossoming, hibernation, reproduction, and migration) and of their relation to changes in season and climate.

From L. phaeno-, from Gk. phaino-, from phainein "bring to light, cause to appear, show," from PIE root *bha- "to shine" + → -logy.

Zistcarxe-šenâsi, literally study of "life cycle," from zistcarxe "life cycle," from zist, → bio-, + carxe, → cycle, + -šenâsi, → -logy.

phenomenon
  پدیده   
padidé (#)

Fr.: phénomène   

1) An occurrence, circumstance, or fact, in matter or spirit, which can be perceived by human senses. → physical phenomenon.
2) Philosophy: For Kant, a thing as it is apprehended by the human senses as distinguished from a noumenon, or thing-in-itself.

From L.L. phænomenon, from Gk. phainomenon "that which appears or is seen," from phainesthai "to appear," passive of phainein "to bring to light; to show," from PIE base *bhhā- "to shine;" cf. Skt. bhāati "shines, glitters;" Av. bā- "to shine, appear, seem," bāmya- "light, luminous, bright," bānu- "light, ray;" Mid.Pers. bâm "beam of light, splendor," bâmik "brilliant," bâmdâd "morning, dawn."

Padidé, noun from padid "manifest, evident, conspicuous, in sight," variant padidâr, from Mid.Pers. pad didâr "visible," from pad "to, at, for, in," evolved to "to; for; in; on; with; by" in Mod.Pers. (O.Pers. paity; Av. paiti "to, toward, in, at;" cf. Skt. práti, Gk. poti) + did past stem of didan "to see, regard, catch sight of, contemplate, experience" (O.Pers. dī- "to see;" Av. dā(y)- "to see," didāti "sees;" cf. Skt. dhī- "to perceive, think, ponder; thought, reflection, meditation," dādhye; Gk. dedorka "have seen").

Pherkad (γ Ursae Minoris)
  فرقد   
Farqad (#)

Fr.: Pherkad (γ UMi)   

A blue → giant star in the constellation → Ursa Minor, also known as HR 5735, HD 137422, HIP 75097, BD+72°79, and SAO 8220. It has an → apparent visual magnitude of +3.0, → color indices of B -V = +0.09, U - B = +0.08, and a → spectral type of A2 III. Pherkad has a → luminosity of 1,100 Lsun, a radius of 15 Rsun, and a → surface temperature of 8,200 K. It lies 487 → light-years away from Earth.

From Ar. Al-Farqad (الفرقد) "calf."

Phillips relation
  بازانش ِ فیلیپس   
bâzâneš-e Phillips

Fr.: relation de Phillips   

A correlation between the peak brightness of → Type Ia supernovae and the decline rate of their → light curve (15 days after the maximum). The decline rate is also correlated to the width of the peak brightness of the supernova. The brightest events are the broadest in time and brighter SNe Ia decline more slowly than dimmer ones. Applying the Phillips relation reduces the dispersion in the light curves of Type Ia SNe thus making them precise distance indicators which can be observed over large distances.

Named after Mark M. Phillips (1951-), American astronomer (Phillips et al. 1993, ApJ 413, L105); → relation.

philosopher
  فیلسوف، فلسفه‌دان   
filsuf (#), falsafedân (#)

Fr.: philosophe   

A person who engages in → philosophy.

M.E., from O.E. philosophe, from L. philosophus "philosopher," from Gk. philosophos "philosopher, sage," literally "lover of wisdom," → philosophy; the agent noun ending -er appears in early 14th century from an Anglo-French or O.Fr. variant of philosophe.

Filsuf, from Ar., from Gk., as above. Falsafedân, literally "philosophy knower," with -dân present stem of dânestan "to know," → science.

philosophize
  فلسفیدن   
falsafidan (#)

Fr.: philosopher   

To explain or argue in terms of philosophical speculations or theories.

philosophy; → -ize.

<< < -es -iv -ti 21 a p abe abs abs aca acc acc acr act ada adh Adr aer AGB air Alf Alg all alp alt AM amo ana And ang ani ano Ant Ant apa apo app app Ara Arc ari Arr ash ass ast ast asy atm ato att aut ave axi Bab bal Bal bar bar bea Bek Bes bia Big bin bin bip biv bla bli blu Boh Bol Bos bou bra bri bro buo cal cal can cap car Car cat cat CCD Cen cen CH cha cha che Che chr cir cir cit 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 con Cop Cor cor cor cos cos cou cou Cow cre cri cro cry cur cya Cyg dan dar dat de- deb dec dec ded def deg del dem den dep des det dev dia dif dif dih dio Dir dis dis dis dis dis dis DO don dou dow dro dur dwa dyn Dys ear ebb ecl edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ esc eth Eur Eve exa exc exe exi exp exp ext ext ext fac fal far fed Fer fer fie fin fir fis fla flo flu fol for for fou fra fre Fre fro fut G-t gal gal gam gas Gau Gem gen geo geo geo gia Gli Gol gra gra gra gra gre gri gui H I Hag hal har hat He- hea hel Hel her Hes hie hig his hom hor hot Hub Hug hur hyd hyd hyg hyp ice ide ima Ima imp imp inc inc ind ine inf inf inf ing inn ins ins int int int int int int int int inv Io ion iro isl iso iso Jac jet jud jur Kel Kep kil Klo Kui Lag lam Lap Lar lat law lea len lep Lib lig lim lin lin Lio lit loc LOF lon Lor low lum lun Lup Lyo mac mag mag mag mag mag mai man Mar mas mas mat Max mea mec Meg Mer Mer met met Met mic Mid Mil min Mir mit mod mod mol mon Mor mou mul mul mys nan Nat nau nec neo neu nev New NGC no nom non non nor not nuc nuc num nut obj obs obs occ ocu oft ome Oor ope opp opt opt orb ord ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per per pha phi pho pho pho phy pio Pla pla pla pla Pla plu Poi pol pol pol poo pos pos pot pra pre pre pre pre pri pri pro pro pro pro pro Pro pro pse pul pur qua qua qua qua que rac rad rad rad rad rad rad ran rar ray rea rea rec rec red red ref ref reg rel rel rel ren res res res res ret rev Ric rig rin roc roo rot rot Rus Sac sal sat sca sca Sch sci Scu sec sec Sed sel Sel sen ser Sex Sha she sho sid sig sil sim sin siz sla Sma sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spi spr squ sta sta sta sta ste ste ste Sto Str str str sub sub suc sun sup sup sup sup sur swa syn syn tab tar tek tem ter tes the the the the Tho thr tid tim Tis Too Tor tra tra Tra tra tra tri tri tru Tul tur two Typ ult un- und uni uni unk upp Urc utt val var vec vel ver vib vio vir vis voi vor wan wat wav wax wea Wei whi Wil win WN9 wor X-r yel you zer zod > >>