<< < -sc Sag sam sat sca sca Sch sco sec sec sec sei sel sem sep set Sha she sho sid sig sim sin sip ske sli Smo soc sol sol sol sol son sou Spa spa spe spe spe sph spi spo squ sta sta sta sta ste ste sti sto str str sub sub sub sum sup sup sup sup sur sus sym syn > >>
spectroscopy binânnemâyi Fr.: spectroscopie The study of spectral lines from different atoms and molecules. Spectroscopy is an important part of studying the physical and chemical properties of astronomical objects. |
spectrum binâb (#) Fr.: spectre The → electromagnetic radiation divided into its constituting wavelengths or frequencies. From L. spectrum "appearance, image, apparition," from specere "to look at, view;" Gk. skopein "to behold, look, consider," skeptesthai "to look at;" PIE base *spek- "to see;" cf. Av. spas-, spaš- "to attend to; to serve; spy," spasiieiti "looks at, perceives" (Mod.Pers. sepâs "kindness, favor, thanksgiving," sepâsidan "to praise for benefits received);" Skt. paś- "to see, watch," spasati "sees;" L. specere "to look at;" O.H.G. spehônn "to spy," Ger. spähen "to spy." Binâb "a vision;" Mid.Pers. wênâb "vision," from wên-, present stem of didan "to see;" O.Pers. vain- "to see;" Av. vaēn- "to see;" cf. Skt. veda "I know;" Gk. oida "I know," idein "to see;" L. videre "to see;" PIE base *weid- "to know, to see." |
specular reflection bâztâb-e âyenevâr (#) Fr.: réflexion spéculaire The reflection of light waves in which the reflected waves travel in a definite direction, and the directions of the incident and reflected waves make equal angles with a line perpendicular to the reflecting surface. Same as → regular reflection; opposite of → diffuse reflection. From L. specularis, from speculum "mirror;" → reflection. Bâztâb, → reflection; âyenevâr "mirror-like," from âyené, → mirror + -vâr similarity suffix. |
speculate gâsidan Fr.: spéculer To guess possible answers to a question when there are not enough information to be certain. Back formation from O.Fr. speculation, from L. speculatus, p.p. of speculari "to watch over, observe," from specula "watch tower," from specere "to look at, regard," cognate with Av. spas- "to attend; to serve," spasiieiti "looks at, perceives;" Pers. sepâs "kindness, thanksgiving;" Skt. spasati "sees;" Gk. skopein "to behold, look, consider," skeptesthai "to look at;" O.H.G. spehhon "to spy;" Ger. spähen "to spy;" PIE *spek- "to look around, observe." Gâsidan infinitive from gâs, from Av. kas- "to look at, see," with extension of the vowel and change of the last phoneme from k to g, as in and cognate with negâh (Mid.Pers. nikâh), → look, âgâh (Mid.Pers. âkâh) "aware" (→ Space Situational Awareness), pargast "God forbid!," and maybe (Lori, Laki, Torbat-Heydarie-yi) gâs "perhaps," (Shirâzi, Fasâyi) gâsam "maybe;" cf. Skt. kāś- "to become visible, appear;" Gk. tekmor, tekmar "sign, mark;" PIE base *k^{w}ek- "to appear, show." |
speculation gâseš Fr.: spéculation The act or an instance of speculating. Verbal noun of → speculate. |
speech 1) soxan (#); 2) soxanrâni (#) Fr.: 1) parole; 2) discours, allocution 1) The faculty or power of speaking; oral communication; ability to
express one's thoughts and emotions by speech sounds and gesture (Dictionary.com). M.E. speche; O.E. spæc; cf. Dan. sprog, O.S. spraca, O.Fris. spreke, Du. spraak, O.H.G. sprahha, Ger. Sprache "speech." Soxan "speech, utterance, word;" Mid.Pers. saxwan "word, speech;" O.Pers. θa^{n}h- "to declare, say," aθaham "I said;" Av. səngh- "to declare," sənghāmi "I say;" cf. Skt. śams- "to praise, declare;" L. censere "to estimate, think; decide." |
speed tondi (#) Fr.: vitesse The ratio of the distance covered to the time taken by a moving body. Speed in a specified direction is → velocity. M.E. spede "good luck, prosperity, rapidity;" O.E. sped "success, prosperity, advancement;" cf. O.S. spod "success," Du. spoed "haste, speed," O.H.G. spuot "success," O.H.G. spuoten "to haste;" from PIE base *spe- "to thrive, prosper" (cf. Skt. sphā- "to increase, become fat;" L. sperare "to hope;" O.C.S. spechu "endeavor;" Lith. speju "to have leisure"). Tondi "speed," from tond "swift, rapid, brisk; fierce, severe" (Mid.Pers. tund "sharp, violent;" Sogdian tund "violent;" cf. Skt. tod- "to thrust, give a push," tudáti "he thrusts;" L. tundere "to thrust, to hit" (Fr. percer, E. pierce, ultimately from L. pertusus, from p.p. of pertundere "to thrust or bore through;" PIE base *(s)teud- "to thrust, to beat") + noun suffix -i. |
speed of light tondi-ye nur Fr.: vitesse de la lumière Same as → velocity of light. |
spend ziyâmidan Fr.: dépenser 1) To pay out, disburse, or expend; dispose of (money, wealth, resources, etc.). M.E. spenden, from O.En. -spendan (in forspendan "use up"), from M.L. spendere, from expendere "to pay out, weigh out money," from → ex- "out" + pendere "to pay, weigh." Ziyâmidan, from Sogd. zyâm "to consume, spend," ultimately from Proto-Ir. *uz-iam-, from *uz- "out, away," → ex-, + *iam- "to hold, take; stretch, reach out;" cf. Av. yam- "to hold, keep," (+ *apa-) "to take away;" Skt. yam- "to hold, restrain." |
sphere koré (#), sepehr (#) Fr.: sphère A solid geometric figure generated by the revolution of a semicircle about its diameter; equation: x^{2} + y^{2} + z^{2} = r^{2}. M.E. spere, from O.Fr. espere, from L. sphæra "globe, ball, celestial sphere," from Gk. sphaira "globe, ball," of unknown origin. Koré, loan from Ar. kurat. |
sphere of influence sepehr-e hanâyeš Fr.: sphère d'influence The region of space around one of the bodies in a system of two celestial bodies where a third body of much smaller mass is influenced by the gravitational field of that body. The sphere of influence of a planet with respect to the Sun has a radius given by: R = R_{P}(M_{P}/M_{S})^{2/3}, where R_{P} is the radius of the planet's orbit around the Sun, M_{P} is the mass of the planet, and M_{S} is the solar mass. The sphere of influence of the Earth has a radius of about 927,000 km or slightly under 150 Earth radii. Beyond this limit, a space probe will come under the influence of the Sun. |
spheres of Eudoxus sepehrhâ-ye Eudoxus Fr.: sphères d'Eudoxe A series of spheres with varying radii centred on the Earth, each rotating uniformly about an axis fixed with respect to the surface of the next larger sphere, all comprising a model in Greek astronomy to describe the motions of the heavenly bodies. The spheres turned with different speeds about axes with different orientations. The fixed stars revolved around the Earth by the motion of the most distant sphere to which the stars were thought to be attached. Each of the five planets' (Mercury, Venus, Mars, Jupiter, and Saturn) motion could be described using four spheres. The Sun and the Moon required three spheres each to explain their motions. Therefore, a total of 27 spheres described the behavior of the heavenly bodies in terms of circular motion. Eudoxus was the first person to devise a model that could explain the → retrograde motion of the planets in the sky along a looped curve known as the → hippopede. → sphere; Eudoxus (Ευδοξοσ) of Cnidus (c 408 BC - c 355 BC), Greek astronomer and mathematician. |
spherical kore-yi Fr.: sphérique Having the form of a sphere; of or pertaining to a sphere or spheres. |
spherical aberration birâheš-e koreyi Fr.: aberration sphérique, ~ de sphéricité An aberration of a spherical lens or mirror in which light rays converge not to a single point but to a series of points with different distances from the lens or mirror. Spherical aberration is corrected by using parabolic reflecting and refracting surface → spherical; → aberration. |
spherical angle zâviye-ye koreyi Fr.: angle sphérique An angle formed on the surface of a sphere by the intersection of two great circles of the sphere. |
spherical astrolabe ostorlâb-e sepehri, ~ kore-yi Fr.: astrolabe sphérique A type of → astrolabe in which the observer's horizon is drawn on the surface of a globe, mounted with a freely rotating spherical lattice work or 'spider' representing the celestial sphere. The earliest description of the spherical astrolabe dates back to the Iranian astronomer Nayrizi (865-922). |
spherical astronomy axtaršenâsi-ye kore-yi Fr.: astronomie sphérique The branch of astronomy that is concerned with determining the apparent positions and motions of celestial bodies on the celestial sphere. Same as → positional astronomy. |
spherical coordinates hamârâhâ-ye kore-yi Fr.: coordonnées sphériques A coordinate system using an origin (O) and three perpendicular axes (Ox, Oy, Oz), in which the position of a point (P) is given by three numbers (r, θ, φ). The coordinate r is the distance from the origin, θ the angle between the z-axis and the r direction, and φ the angle between the projection of r on the xy-plane and the Ox-axis. The coordinate φ is also called the → azimuthal angle. → spherical; → coordinate. |
spherical excess fozuni-ye sepehri, ~ kore-yi Fr.: excès sphérique The difference between the sum of the three angles of a → spherical triangle and 180° (π radians). |
spherical geometry hendese-ye kore-yi Fr.: géométrie sphérique The branch of geometry that deals with figures on the surface of a sphere (such as the spherical triangle and spherical polygon). It is an example of a non-Euclidean geometry. |
<< < -sc Sag sam sat sca sca Sch sco sec sec sec sei sel sem sep set Sha she sho sid sig sim sin sip ske sli Smo soc sol sol sol sol son sou Spa spa spe spe spe sph spi spo squ sta sta sta sta ste ste sti sto str str sub sub sub sum sup sup sup sup sur sus sym syn > >>