Wolf-Rayet-e WO Fr.: Wolf-Rayet WO A → Wolf-Rayet star whose spectrum shows emission lines of carbon and strong emission lines of oxygen O VI 3811-34 Å. In theoretical models, a W-R star whose carbon abundance at surface is larger than nitrogen abundance and has the abundance ratio (C + O) / He > 1 (in number). See also: W short for Wolf-Rayet star, O for → oxygen. |
Wolf-Rayet-e WO Fr.: Wolf-Rayet WO A → Wolf-Rayet star whose spectrum shows emission lines of carbon and strong emission lines of oxygen O VI 3811-34 Å. In theoretical models, a W-R star whose carbon abundance at surface is larger than nitrogen abundance and has the abundance ratio (C + O) / He > 1 (in number). See also: W short for Wolf-Rayet star, O for → oxygen. |
setâre-ye WO1 Fr.: étoile WO1 An oxygen-rich → Wolf-Rayet star whose spectrum shows the following emission
line characteristics: See also: W, from → Wolf-Rayet; O, from → oxygen; → star. |
setâre-ye WO1 Fr.: étoile WO1 An oxygen-rich → Wolf-Rayet star whose spectrum shows the following emission
line characteristics: See also: W, from → Wolf-Rayet; O, from → oxygen; → star. |
setâre-ye WO2 Fr.: étoile WO2 An oxygen-rich → Wolf-Rayet star whose spectrum shows the following emission line characteristics: No O IV 3400 Å, strong O VI 3811-34 Å, O V 5572-98 Å weaker than C IV 5801-12 Å, no C III 5696 Å. See also: W, from → Wolf-Rayet; O, from → oxygen; → star. |
setâre-ye WO2 Fr.: étoile WO2 An oxygen-rich → Wolf-Rayet star whose spectrum shows the following emission line characteristics: No O IV 3400 Å, strong O VI 3811-34 Å, O V 5572-98 Å weaker than C IV 5801-12 Å, no C III 5696 Å. See also: W, from → Wolf-Rayet; O, from → oxygen; → star. |
1) palâpelidan; 2) palâpel Fr.: chanceler, osciller, vaciller; chancellement, vacillement 1a) To incline to one side and to the other alternately, as a wheel, top, or
other rotating body when not properly balanced. 1b) To move unsteadily from side to side; vacillate; waver.
Etymology (EN): Probably from Low Ger. wabbeln “to wobble;” Etymology (PE): Palâpel “wobbling, unsteady motion” in štiyâni dialect, variant in colloquial Persian pilipili, pelpel (pilipili raftan, pilipili xordan). |
1) palâpelidan; 2) palâpel Fr.: chanceler, osciller, vaciller; chancellement, vacillement 1a) To incline to one side and to the other alternately, as a wheel, top, or
other rotating body when not properly balanced. 1b) To move unsteadily from side to side; vacillate; waver.
Etymology (EN): Probably from Low Ger. wabbeln “to wobble;” Etymology (PE): Palâpel “wobbling, unsteady motion” in štiyâni dialect, variant in colloquial Persian pilipili, pelpel (pilipili raftan, pilipili xordan). |
kamine-ye Wolf Fr.: minimum de Wolf A 70-year period of unusually low → solar activity, from about 1280 to 1350. See also the → Maunder minimum. See also: → Wolf number; → minimum. |
kamine-ye Wolf Fr.: minimum de Wolf A 70-year period of unusually low → solar activity, from about 1280 to 1350. See also the → Maunder minimum. See also: → Wolf number; → minimum. |
adad-e Wolf Fr.: nombre de Wolf A number indicating the degree of → sunspot → activity. Same as → sunspot number and → relative sunspot number. See also: Named after Johann Rudolf Wolf of Zurich who introduced the number in 1852; → number. |
adad-e Wolf Fr.: nombre de Wolf A number indicating the degree of → sunspot → activity. Same as → sunspot number and → relative sunspot number. See also: Named after Johann Rudolf Wolf of Zurich who introduced the number in 1852; → number. |
Wolf-Lundmark-Melotte (WLM) Fr.: Wolf-Lundmark-Melotte A → dwarf irregular galaxy that is a remote and rather isolated member of the → Local Group. Also known as DDO 221 and LEDA 143. It is a dim galaxy located in the constellation → Cetus, about three million → light-years from the → Milky Way. Its nearest neighbor, the → dwarf galaxy IC 1613, is one million light-years away. Quite elongated, with a largest extension of more than 8,000 light-years, WLM is about 12 times smaller than the Milky Way, a measurement that includes a → halo of extremely → old stars. WLM has a → metallicity only about one-tenth that of the Milky Way. See also: Named after astronomer Max Wolf (1863-1932), who discovered the galaxy in 1909, and astronomers Knut Lundmark (1889-1958) and Philibert Jacques Melotte (1880-1961), who identified it as a galaxy some fifteen years later. |
Wolf-Lundmark-Melotte (WLM) Fr.: Wolf-Lundmark-Melotte A → dwarf irregular galaxy that is a remote and rather isolated member of the → Local Group. Also known as DDO 221 and LEDA 143. It is a dim galaxy located in the constellation → Cetus, about three million → light-years from the → Milky Way. Its nearest neighbor, the → dwarf galaxy IC 1613, is one million light-years away. Quite elongated, with a largest extension of more than 8,000 light-years, WLM is about 12 times smaller than the Milky Way, a measurement that includes a → halo of extremely → old stars. WLM has a → metallicity only about one-tenth that of the Milky Way. See also: Named after astronomer Max Wolf (1863-1932), who discovered the galaxy in 1909, and astronomers Knut Lundmark (1889-1958) and Philibert Jacques Melotte (1880-1961), who identified it as a galaxy some fifteen years later. |
kahkešân-e Wolf-Rayet Fr.: galaxie Wolf-Rayet A subset of → starburst galaxies whose integrated spectra show
broad emission features attributed to the presence of hundreds to thousands See also: → Wolf-Rayet star; → galaxy. |
kahkešân-e Wolf-Rayet Fr.: galaxie Wolf-Rayet A subset of → starburst galaxies whose integrated spectra show
broad emission features attributed to the presence of hundreds to thousands See also: → Wolf-Rayet star; → galaxy. |
setâre-ye Wolf-Rayet Fr.: étoile Wolf-Rayet A type of very luminous, very hot (as high as 50,000 K) stars whose spectrum is characterized by broad emission lines (mainly He I and He II), which are presumed to originate from material ejected from the star at very high (~ 2000 km s-1) velocities. The most massive → O stars (M > 25 → solar masses for → solar metallicity) become W-R stars around 2 and 3 million years after their birth, spending only some few hundreds of thousands of years (≤ 106 years) in this phase until they explode as → type Ib and → type Ic supernovae. The minimum stellar mass that an O star needs to reach the W-R phase and its duration is dependent on → metallicity. → WC Wolf-Rayet; → WNE Wolf-Rayet; → WNL Wolf-Rayet; → WO Wolf-Rayet. For a review see: P. A. Crowther, 2007, Annu. Rev. of Astron. Astrophys. 45, 177. See also: Named after the French astronomers Charles Wolf (1827-1918) and
Georges Rayet (1839-1906), of the Paris Observatory. |
setâre-ye Wolf-Rayet Fr.: étoile Wolf-Rayet A type of very luminous, very hot (as high as 50,000 K) stars whose spectrum is characterized by broad emission lines (mainly He I and He II), which are presumed to originate from material ejected from the star at very high (~ 2000 km s-1) velocities. The most massive → O stars (M > 25 → solar masses for → solar metallicity) become W-R stars around 2 and 3 million years after their birth, spending only some few hundreds of thousands of years (≤ 106 years) in this phase until they explode as → type Ib and → type Ic supernovae. The minimum stellar mass that an O star needs to reach the W-R phase and its duration is dependent on → metallicity. → WC Wolf-Rayet; → WNE Wolf-Rayet; → WNL Wolf-Rayet; → WO Wolf-Rayet. For a review see: P. A. Crowther, 2007, Annu. Rev. of Astron. Astrophys. 45, 177. See also: Named after the French astronomers Charles Wolf (1827-1918) and
Georges Rayet (1839-1906), of the Paris Observatory. |
manšur-e Wollaston (#) Fr.: prisme de Wollaston An optical device for producing and analyzing polarized light. It divides See also: After the English scientist William Hyde Wollaston (1766-1828); → prism. |
manšur-e Wollaston (#) Fr.: prisme de Wollaston An optical device for producing and analyzing polarized light. It divides See also: After the English scientist William Hyde Wollaston (1766-1828); → prism. |
teleskop-e Wolter Fr.: télescope Wolter A → grazing incidence telescope designed to observe → X-ray emission from astronomical objects. Wolter telescopes use a combination of two elements, a parabolic mirror followed by a hyperbolic mirror and come in three different optical configurations. The design most commonly used by X-ray astronomers is the Type I since it has the simplest mechanical configuration. In addition, the Type I design offers the possibility of nesting several telescopes inside one another, thereby increasing the useful reflecting area. This is an extremely important attribute, since virtually all X-ray sources are weak, and maximizing the light-gathering power of a mirror system is critical. The → Chandra X-Ray Observatory is a Wolter Type I telescope that has four thick nested mirrors coated in iridium. The Japanese X-ray observatory Suzuki uses a conical approximation of the Wolter Type I design. Its mirrors are coated in gold, and they are far thinner than the ones used in Chandra. This allows for denser nesting, so there are 700 mirrors instead of four. The result is a much higher collecting efficiency at a reduced weight. For comparable apertures and grazing angles, the primary advantage of Type II over Type I is that higher magnifications are attainable. This is because the second reflection is off the outside of a surface, which allows longer focal lengths. However, since off-axis images suffer much more severely from blurring in Type II configurations, the Wolter Type II is useful only as a narrow-field imager or as the optic for a dispersive spectrometer. The Wolter Type III has never been employed for X-ray astronomy (NASA Imagine the Universe!). See also: Named after Hans Wolter (1911-1978), a German physicist who designed the optical configuration. |
teleskop-e Wolter Fr.: télescope Wolter A → grazing incidence telescope designed to observe → X-ray emission from astronomical objects. Wolter telescopes use a combination of two elements, a parabolic mirror followed by a hyperbolic mirror and come in three different optical configurations. The design most commonly used by X-ray astronomers is the Type I since it has the simplest mechanical configuration. In addition, the Type I design offers the possibility of nesting several telescopes inside one another, thereby increasing the useful reflecting area. This is an extremely important attribute, since virtually all X-ray sources are weak, and maximizing the light-gathering power of a mirror system is critical. The → Chandra X-Ray Observatory is a Wolter Type I telescope that has four thick nested mirrors coated in iridium. The Japanese X-ray observatory Suzuki uses a conical approximation of the Wolter Type I design. Its mirrors are coated in gold, and they are far thinner than the ones used in Chandra. This allows for denser nesting, so there are 700 mirrors instead of four. The result is a much higher collecting efficiency at a reduced weight. For comparable apertures and grazing angles, the primary advantage of Type II over Type I is that higher magnifications are attainable. This is because the second reflection is off the outside of a surface, which allows longer focal lengths. However, since off-axis images suffer much more severely from blurring in Type II configurations, the Wolter Type II is useful only as a narrow-field imager or as the optic for a dispersive spectrometer. The Wolter Type III has never been employed for X-ray astronomy (NASA Imagine the Universe!). See also: Named after Hans Wolter (1911-1978), a German physicist who designed the optical configuration. |
farbin-e Woltjer Fr.: théorème de Woltjer In → magnetohydrodynamics, in the limit of zero → resistivity, the → magnetic field B satisfies the → induction equation ∂B/∂t = ∇ x (v x B), then for a → plasma confined by a perfectly conducting boundary, the → magnetic helicity is conserved. If the normal field is fixed on the boundary, the minimum-energy state is the linear → force-free magnetic field that conserves the total magnetic helicity. See also: Named after the Dutch astrophysicist Lodewijk Woltjer (1930-2019), who discovered the phenomenon in 1958 while studying the → Crab Nebula; → theorem. |
farbin-e Woltjer Fr.: théorème de Woltjer In → magnetohydrodynamics, in the limit of zero → resistivity, the → magnetic field B satisfies the → induction equation ∂B/∂t = ∇ x (v x B), then for a → plasma confined by a perfectly conducting boundary, the → magnetic helicity is conserved. If the normal field is fixed on the boundary, the minimum-energy state is the linear → force-free magnetic field that conserves the total magnetic helicity. See also: Named after the Dutch astrophysicist Lodewijk Woltjer (1930-2019), who discovered the phenomenon in 1958 while studying the → Crab Nebula; → theorem. |
zan (#) Fr.: femme The → female human being. Etymology (EN): M.E. womman, wimman, O.E. wifman, from wif “female” + man “human being.” Etymology (PE): Zan “woman, wife” (variants Baluci, Zâzâ jan, Gorgâni cen, Baxtiyâri zine, Sangesari, Tâti, Kurd. žen, Kurd. kenâ, Karingâni yan); Mid.Pers. zan “woman, wife;” kaniz “maid, virgin, girl;” Av. jəni- “woman, wife;” cf. Skt. jáni- “woman, wife;” Gk. gyne “woman, wife;” O.E. cwen “queen, woman, wife” (E. queen; Arm. kin “woman;” PIE base *gwenh- “woman, wife.” |
zan (#) Fr.: femme The → female human being. Etymology (EN): M.E. womman, wimman, O.E. wifman, from wif “female” + man “human being.” Etymology (PE): Zan “woman, wife” (variants Baluci, Zâzâ jan, Gorgâni cen, Baxtiyâri zine, Sangesari, Tâti, Kurd. žen, Kurd. kenâ, Karingâni yan); Mid.Pers. zan “woman, wife;” kaniz “maid, virgin, girl;” Av. jəni- “woman, wife;” cf. Skt. jáni- “woman, wife;” Gk. gyne “woman, wife;” O.E. cwen “queen, woman, wife” (E. queen; Arm. kin “woman;” PIE base *gwenh- “woman, wife.” |
vâžé (#) Fr.: mot A unit of language, consisting of one or more sounds or their written representation, that communicates a meaning. → stopword Etymology (EN): M.E., from O.E. word; cf. Du. woord, O.H.G., Ger. wort, Goth. waurd; related to verb, from L. verbum “verb;” from PIE *wer- “to speak, say.” Etymology (PE): Vâžé “word;” Mid.Pers. vâc, vâcak “word, speech;”
related to âva “voice, sound,” âvâz “voice, sound, song,”
bâng “voice, sound, clamour” (Mid.Pers. vâng);
Av. vacah- “word,” vaocanghê “to decalre” (by means of speech), from
vac- “to speak, say;” cf. Skt. vakti “speaks, says,” vacas- “word;” |
vâžé (#) Fr.: mot A unit of language, consisting of one or more sounds or their written representation, that communicates a meaning. → stopword Etymology (EN): M.E., from O.E. word; cf. Du. woord, O.H.G., Ger. wort, Goth. waurd; related to verb, from L. verbum “verb;” from PIE *wer- “to speak, say.” Etymology (PE): Vâžé “word;” Mid.Pers. vâc, vâcak “word, speech;”
related to âva “voice, sound,” âvâz “voice, sound, song,”
bâng “voice, sound, clamour” (Mid.Pers. vâng);
Av. vacah- “word,” vaocanghê “to decalre” (by means of speech), from
vac- “to speak, say;” cf. Skt. vakti “speaks, says,” vacas- “word;” |
kâr (#) Fr.: travail If a force F acting on a body moves its point of application through a distance r, the work is defined by the product F.r.cosθ, where θ is the angle between the line of action of the force and the displacement. Work can be positive, negative, or zero. Etymology (EN): M.E.; O.E. weorc, worc “something done, action, military fortification,” from P.Gmc. *werkan (cf. O.S., O.Fris., Du. werk, O.N. verk, O.H.G. werah, Ger. Werk), from PIE base *werg- “to work;” cognate with Pers. varz-, varzidan “to labor, practise,” → erg. Etymology (PE): Kâr “work,” Mid.Pers kâr; Mod./Mid.Pers.
kardan “to do, to work,” Mid.Pers. kardan; O.Pers./Av. kar-
“to do, make, build,” Av. kərənaoiti “he makes;”
cf. Skt. kr- “to do, to make,” krnoti “he makes, he does,” |
kâr (#) Fr.: travail If a force F acting on a body moves its point of application through a distance r, the work is defined by the product F.r.cosθ, where θ is the angle between the line of action of the force and the displacement. Work can be positive, negative, or zero. Etymology (EN): M.E.; O.E. weorc, worc “something done, action, military fortification,” from P.Gmc. *werkan (cf. O.S., O.Fris., Du. werk, O.N. verk, O.H.G. werah, Ger. Werk), from PIE base *werg- “to work;” cognate with Pers. varz-, varzidan “to labor, practise,” → erg. Etymology (PE): Kâr “work,” Mid.Pers kâr; Mod./Mid.Pers.
kardan “to do, to work,” Mid.Pers. kardan; O.Pers./Av. kar-
“to do, make, build,” Av. kərənaoiti “he makes;”
cf. Skt. kr- “to do, to make,” krnoti “he makes, he does,” |
karyâ-ye kâr Fr.: travail d'extraction The least amount of energy required to remove an electron from the surface of a solid, to a point just outside the solid where the electron has zero kinetic energy. See also → photoelectric effect. |
karyâ-ye kâr Fr.: travail d'extraction The least amount of energy required to remove an electron from the surface of a solid, to a point just outside the solid where the electron has zero kinetic energy. See also → photoelectric effect. |
parvaz-e kâr-kâruž Fr.: principe travail-énergie |
parvaz-e kâr-kâruž Fr.: principe travail-énergie |
kâr-goruh (#) Fr.: groupe de travail |
kâr-goruh (#) Fr.: groupe de travail |
zonâr-e andar-âžireš Fr.: zone d'interaction The double shock structure formed in any two fluids that collide supersonically. A working surface consists of two → shocks, a → bow shock where the ambient material is shocked and accelerated, and a jet shock or → Mach disk, where the → jet material is decelerated. It is common to find multiple working surfaces along the axis of an → Herbig-Haro jet, testifying to recurrent eruptions of the underlying source. |
zonâr-e andar-âžireš Fr.: zone d'interaction The double shock structure formed in any two fluids that collide supersonically. A working surface consists of two → shocks, a → bow shock where the ambient material is shocked and accelerated, and a jet shock or → Mach disk, where the → jet material is decelerated. It is common to find multiple working surfaces along the axis of an → Herbig-Haro jet, testifying to recurrent eruptions of the underlying source. |
kârgâh (#) Fr.: atelier
Etymology (EN): → work + shop M.E. shoppe, O.E. sceoppa; Etymology (PE): Kârgâh “workshop,” from kâr, → work, + gâh “place; time” (Mid.Pers. gâh, gâs “time;” O.Pers. gāθu-; Av. gātav-, gātu- “place, throne, spot;” cf. Skt. gâtu- “going, motion; free space for moving; place of abode;” PIE *gwem- “to go, come”). |
kârgâh (#) Fr.: atelier
Etymology (EN): → work + shop M.E. shoppe, O.E. sceoppa; Etymology (PE): Kârgâh “workshop,” from kâr, → work, + gâh “place; time” (Mid.Pers. gâh, gâs “time;” O.Pers. gāθu-; Av. gātav-, gātu- “place, throne, spot;” cf. Skt. gâtu- “going, motion; free space for moving; place of abode;” PIE *gwem- “to go, come”). |
jahân (#) Fr.: monde
Etymology (EN): M.E.; O.E. woruld, weorold; cf. O.S. werold, O.Fris. warld, Du. wereld, O.N. verold, O.H.G. weralt, Ger. Welt. Etymology (PE): Jahân, variants keyhân, geyhân “world,” giti “world, material world, time;” Mid.Pers. gêhân “world,” gêtig “the material world; wordly,” Manichean Mid.Pers. gyh “world,” gyh’n “worlds;” Av. gaēθā- “being, world, matter, mankind” (O.Pers. gaiθā- “livestock”), gaya- “life, manner of living,” root gay- “to live” (present tense jiva-), cognate with Skt. jīv- “to live,” jīva- “alive, living;” Gk. bios “life,” L. vivus “living, alive,” vita “life;” PIE base *gwei- “to live” (cf. O.E. cwic “alive;” O.C.S. zivo “to live;” Lith. gyvas “living, alive;” O.Ir. bethu “life,” bith “age, life, world;” Welsh byd “world”). The Pers. words zistan “to live,” zendé “alive,” zendegi “life,” and jân “vital spirit, soul; mind” belong to this family. |
jahân (#) Fr.: monde
Etymology (EN): M.E.; O.E. woruld, weorold; cf. O.S. werold, O.Fris. warld, Du. wereld, O.N. verold, O.H.G. weralt, Ger. Welt. Etymology (PE): Jahân, variants keyhân, geyhân “world,” giti “world, material world, time;” Mid.Pers. gêhân “world,” gêtig “the material world; wordly,” Manichean Mid.Pers. gyh “world,” gyh’n “worlds;” Av. gaēθā- “being, world, matter, mankind” (O.Pers. gaiθā- “livestock”), gaya- “life, manner of living,” root gay- “to live” (present tense jiva-), cognate with Skt. jīv- “to live,” jīva- “alive, living;” Gk. bios “life,” L. vivus “living, alive,” vita “life;” PIE base *gwei- “to live” (cf. O.E. cwic “alive;” O.C.S. zivo “to live;” Lith. gyvas “living, alive;” O.Ir. bethu “life,” bith “age, life, world;” Welsh byd “world”). The Pers. words zistan “to live,” zendé “alive,” zendegi “life,” and jân “vital spirit, soul; mind” belong to this family. |
xatt-e jahân, jahân-xatt (#) Fr.: ligne d'univers In relativity, the path traced out in four-dimensional → space-time that represents a continuous sequence of events relating to a given particle. A point on a world line is called an → event. Any straight world line corresponds to an → inertial motion. Curved world lines represent → accelerated motion. A world line that curves corresponds to an accelerated observer. World lines are shown on space-time diagrams. |
xatt-e jahân, jahân-xatt (#) Fr.: ligne d'univers In relativity, the path traced out in four-dimensional → space-time that represents a continuous sequence of events relating to a given particle. A point on a world line is called an → event. Any straight world line corresponds to an → inertial motion. Curved world lines represent → accelerated motion. A world line that curves corresponds to an accelerated observer. World lines are shown on space-time diagrams. |
kerm-surâx, surâx-e kerm Fr.: trou de ver A hypothetical topological feature, based on
→ general relativity, that connects two different points
like a “tunnel” in → space-time. Etymology (EN): The term was coined by the Princeton physicist John Wheeler (1911-2008), from worm, M.E., O.E. wurm “serpent, dragon;” cf. O.S., O.H.G., Ger. wurm, O.Fris., Du. worm, Goth. waurms “serpent, worm;” akin to Pers. kerm “worm,” as below; → hole. Etymology (PE): Kerm “worm;” Mid.Pers. kirm “worm, snake, dragon;” cf.
Skt. krmi- “worm, maggot;” O.Ir. cruim “worm;” Lith. kirmis
“worm;” L. vermis “worm;” E. worm, as above; surâx, |
kerm-surâx, surâx-e kerm Fr.: trou de ver A hypothetical topological feature, based on
→ general relativity, that connects two different points
like a “tunnel” in → space-time. Etymology (EN): The term was coined by the Princeton physicist John Wheeler (1911-2008), from worm, M.E., O.E. wurm “serpent, dragon;” cf. O.S., O.H.G., Ger. wurm, O.Fris., Du. worm, Goth. waurms “serpent, worm;” akin to Pers. kerm “worm,” as below; → hole. Etymology (PE): Kerm “worm;” Mid.Pers. kirm “worm, snake, dragon;” cf.
Skt. krmi- “worm, maggot;” O.Ir. cruim “worm;” Lith. kirmis
“worm;” L. vermis “worm;” E. worm, as above; surâx, |