Fr.: image fantôme
A faint false image caused by reflection that is sometimes seen in an optical system. In spectroscopy, a false image of a spectral line formed by irregularities in the ruling of diffraction gratings.
Ghost, from O.E. gast "soul, spirit, breath," from P.Gmc. *ghoizdoz (cf. M.Du. gheest, Ger. Geist "spirit, ghost"), from PIE base *ghois- "to be excited, frightened;" cf. Av. zaēša- "horrible, frightful," zôiždišta- "the most loathsome;" Mid./Mod.Pers. zešt "ugly, disgusting;" Goth. usgaisjan "to be afraid;" O.E. gæstan "to frighten."
Parhib "ghost," Pers. word of Xorâsâni dialect.
Ghost Head Nebula
miq-e sar-e parhib
Fr.: Nébuleuse de la Tête de Fantôme
A star forming region in the → Large Magellanic Cloud, a satellite of our Galaxy, as pictured by the → Hubble Space Telescope. It spans about 50 light-years and contains several young, → massive stars.
qul, qulpeykar, kalân (#)
From O.Fr. géant, from V.L. *gagantem, from L. gigas "giant," from Gk. gigas (gen. gigantos), huge and savage monsters, children of Gaia and Uranus, who fought the Olympians but were eventually destroyed by the gods, probably from a pre-Gk. language. The Gk. word was used in Septuagint (the Greek translation of the Jewish Scriptures) to refer to men of great size and strength, hence the expanded use in Western languages.
Qul "an imaginary hideous demon, supposed to devour men and animals," Pers. word
probably related to Skt. grábha- "a demon causing diseases, one who seizes,"
grahila- "possessed by a demon," from
grah-, grabh- "to seize, take," graha
"seizing, holding, perceiving," Av./O.Pers. grab- "to take, seize;"
Mid.Pers. griftan; Mod.Pers. gereftan
"to take, seize;" cf. M.L.G. grabben "to grab,"
from P.Gmc. *grab, E. grab "to take or grasp suddenly;"
PIE base *ghrebh- "to seize."
šâxe-ye qulân, ~ qulpeykarân (#)
Fr.: branche des géantes
giant H II region
nahiye-ye H II-ye qulpeykar
Fr.: région H II géante
An → H II region emitting at least 1050 → Lyman continuum photons per second, or about 10 times → Orion nebula. Such an H II region should be powered by at least one O3V star or by at least a dozen → O-type and tens → B-type stars. Our nearest giant H II region is → NGC 3603. Some other Galactic giant H II regions are: → Lagoon Nebula, M17, W31, W51A, and NGC 3576.
giant magnetoresistance (GMR)
meqnât-istâdegi-ye kalân, istâdegi-ye meqnâtisi-ye ~
Fr.: magnétorésistance géante
A quantum mechanical phenomenon where the resistance of certain materials drops dramatically upon application of a magnetic field in certain structures composed of alternating layers of magnetic and nonmagnetic metals. The basis of the GMR is the dependence of the electrical resistivity of electrons in a magnetic metal on the direction of the electron spin, either parallel or anti-parallel to the magnetic moment of the layers. The 2007 Nobel Prize in physics was awarded to the French physicist Albert Fert (1938-) and German physicist Peter Grünberg (1939-) for the discovery of GMR.
giant molecular cloud (GMC)
abr-e molekuli-ye qulpeykar (#)
Fr.: nuage moléculaire géant
A massive complex of → interstellar gas and → dust, consisting mostly of → molecular hydrogen, that typically stretches over 150 light-years and contains several hundred thousand → solar masses. Giant molecular clouds are the principal sites of star formation. → molecular cloud.
sayyâre-ye qulpeykar (#)
Fr.: planète géante
setâre-ye qulpeykar (#)
Fr.: étoile géante
kuž, kužmâh (#)
An adjective applied to the phase of the Moon (or a planet) when it is more than half full, but less than entirely full.
From L.L. gibbous "hunchbacked," from L. gibbus "hump, hunch;" cf. Mod.Pers. kaž "crooked, bent, being aside;" Skt. kubja- "hump-backed, crooked;" Pali kujja- "bent;" Lith. kupra "hump."
Kuž "humped," Mid.Pers. kôf "hill, mountain; hump" (Mod.Pers. kuh, "mountain"), kôfik "humpbacked," O.Pers. kaufa-, Av. kaofa- "mountain;" mâh, → moon.
Gibbs canonical distribution
vâbâžeš-e hanjârvâr-e Gibbs
Fr.: distribution canonique de Gibbs
The probability distribution of the various possible states of a certain → quasi-closed subsystem.
Gibbs free energy
kâruž-e âzâd-e Gibbs
Fr.: énergie libre de Gibbs
The total energy needed to create a thermodynamic system minus the energy provided the environment. It is defined by G = U + PV -TS, where U is the → internal energy, T the → absolute temperature, S the → entropy, P the → pressure, and V is the final → volume. Same as the → Gibbs function and → thermodynamic potential.
Fr.: fonction de Gibbs
Same as → Gibbs free energy.
Named after Josiah Willard Gibbs (1839-1903), an American physicist who played an important part in the foundation of analytical thermodynamics; → function.
A prefix that is used to represent 109 in the SI system.
From Gk. gigas, → giant.
A unit of → frequency, equal to 106 Hz.
Fr.: monture à la Cardan, cardan
1) A support component of a gyroscope, which allows the axis to move freely.
Gimbal, alteration of gemel "twin," from M.E., gemelles, from O.Fr. gemeles (Fr. jumeau, jumelle), from L. gemellus, diminutive of geminus "twin;" cf. Pers. Kermâni dialect jomoli "twin;" → Gemini.
Doqâb, from do "two" (Mid.Pers. do; Av. dva-; cf. Skt. dvi-; Gk. duo; L. duo; O.E. twa; Ger. zwei) + qâb "frame," from Turkish.
Fr.: Gl 229B
The prototype of → T dwarfs discovered by Nakajima et al. (1995, Nature 378, 463). This → brown dwarf lies 21.8 → light-years away and orbits a primary star of type M1 V every about 40 years. It has a temperature of less than 1,200 K, and a mass approximately 20-50 times that of Jupiter. Its luminosity is about 2 x 10 -6 that of the Sun.
Gl, referring to the → Gliese catalogue.
An extended mass of ice formed from snow falling and accumulating over the years and moving very slowly, either descending from high mountains, as in valley glaciers, or moving outward from centers of accumulation, as in continental glaciers (Dictionary.com).
From Fr. glacier, from O.Fr. glace "ice," from V.L. glacia, from L. glacies "ice," probably from PIE root *gel-, → cold.
Yaxzâr, from yax, → ice, + -zâr suffix denoting profusion and abundance, as in šurezâr "infertile, salty ground; nitrous earth," xoškzâr "arid land," kârzâr "a field of battle; combat," marqzâr "a place abounding with the grass," and so forth.
Fr.: lumière éblouissante
1) A very harsh, bright, dazzling light.
M.E. glaren; cognate with M.Du., M.L.G. glaren; akin to glass.
Xirtâv, literally "dazzling light," from xir, from xiré konandé, "dazzling," from xiré "much, many; obstinate; perverse; unwilling;" + tâv, variant tâb, tâbidan "to shine," → luminous.