Fr.: holocauste, shoa
1) A great or complete devastation or destruction, especially by fire.
A three-dimensional image produced with the technique of → holography.
Of, relating to, or produced using → holography; three-dimensional.
Fr.: réseau holographique
A → diffraction grating produced from a series of constructive → interference fringes. The fringes, whose intensities vary in a sinusoidal pattern, correspond to the grooves of the grating. They are recorded on a photosensitive substrate and subsequently treated using a chemical procedure. Since the grooves are created by the interference of light, such a grating is free from the random and periodic errors present in → ruled gratings.
A technique for making three-dimensional images by recording → interference patterns from a split → laser beam on a medium such as photographic film. One of the → coherent beams irradiates the object, the second beam illuminates a recording medium. The two beams produce an interference pattern, called → hologram, on the film. The hologram contains information on both → phase and → amplitude of the object. However, this information is in a coded form, and the image must be reconstructed. When the object is removed and the hologram is illuminated by the laser from the original direction, a 3-dimensional image of the object appears where the object was originally, as if it were not removed. The visible object seems so real that the observer can detect → parallax by changing the position of one's head.
From → holo- "whole" + → -graphy. By using the term holography, Dennis Gabor (1900-1979), the Hungarian-British electrical engineer and inventor, wanted to stress that the technique records complete information about a wave, both about its amplitude and its phase, in contrast to the usual photography in which only the distribution of the amplitude is recorded.
Fr.: système holonomique
A material system in which the → constraints can be expressed in the form of an equation relating the coordinates.
1) Respect or reverence paid or rendered.
M.E. (h)omage, from O.Fr. homage "allegiance or respect for one's feudal lord," from homme "man," → human, + -age.
A combining form meaning "same" used in the formation of compound words. Also, especially before a vowel, hom-.
Homo-, from Gk. homos "one and the same," also "belonging to two or more jointly," from PIE *somos; cf. Pers. ham-, as below; Lith. similis "like," Goth. sama "the same," samana "together."
Ham- "together, with; same, equally, even," Mid.Pers. ham-, like L. com- and Gk. syn- with neither of which it is cognate. O.Pers./Av. ham-, Skt. sam-; also O.Pers./Av. hama- "one and the same," Skt. sama-, Gk. homos-; originally identical with PIE numeral *sam- "one," from *som-. The Av. ham- appears in various forms: han- (before gutturals, palatals, dentals) and also hem-, hen-.
Fr.: sphères homocentriques
Concentric → spheres of Eudoxus.
State or quality of having a uniform appearance or composition, being homogeneous
1) Of uniform composition or having a common property throughout.
Homogeneous, from M.L. homogeneus, from Gk. homogenes "of the same kind," from homos "same," → homo-, + genos "race, kind," gonos "birth, offspring," from PIE base *gen-/*gon-/*gn- "to produce, beget, be born," cf. Av. zan- "to bear, give birth to a child, be born," infinitive zazāite, zāta- "born," zana- "race" (in sruuô.zana- "belonging to the race of the horned ones"), O.Pers. zana- "tribe" (in paru-zana- "consisting of many tribes"), Skt. janati "begets, bears," jana- "creature, human being, race, tribe, people;" L. genus "race, stock, kind," gignere "to beget."
Hamgen "of the same kind, like each other; friend, partner," from ham-, → homo-, + gen "kind," O.Pers./Av. zana- "race; tribe," cognate with L. genus, as above). Alternatively, gen may be a variant of Mid./Mod.Pers. gôn/gun "kind, type; manner; color, skin color," from Av. gaona- "hair, hair color, color."
šârre-ye hamgen (#)
Fr.: fluide homogène
A fluid with uniform properties throughout, but meteorologists sometimes designate as homogeneous a fluid with constant density.
homogeneous linear differential equation
hamugeš-e degarsâne-yi-ye xatti hamgen
Fr.: équation différentielle linéaire homogène
A → linear differential equation if the right-hand member is zero, Q(x) = 0, on interval I.
âšubnâki-ye hamgen (#)
Fr.: turbulence homogène
→ Turbulence in which spatial derivatives of all mean turbulent quantities are negligible.
giti-ye hamgen (#)
Fr.: Univers homogène
A model Universe which is homogeneous and → isotropic on large scales. It is modeled by a → Robertson-Walker cosmology. A homogeneous Universe is filled with a constant density and negligible pressure. Any small spatial region is characteristic for the whole Universe.
Fr.: molécule homonucléaire
Fr.: nébuleuse de l'Homoncule
A nebula of gas and dust (about 17" x 12" in size), which surrounds the massive star Eta Carinae and lies about 7500 light-years away. The surrounding material was ejected by the massive star in 1843 during its violent eruption, and is now expanding at about 500 km/sec.
Homunculus, "a diminutive human being; little man" (since the nebula resembled a small human to early observers), from L. homin-, homun-, homo "eartly being," humus "the earth" (cf. Pers. zamin "earth, ground," Mid.Pers. zamig "earth;" Av. zam- "the earth;" Skt. ksam; Gk. khthôn, khamai "on the ground;" PIE root *dh(e)ghom "earth") + → -ula, -ule; → nebula.
Miq, → nebula; âdamak "little man."
1) A curved or bent piece of metal or other hard material for catching,
holding, or hanging something.
M.E. hoke, O.E. hoc "hook, angle;" cf. M.Du. hoek, Du. haak, Ger. Haken "hook."
Qollab "a hook, a hooked device," probably ultimately from Proto-Ir. gart- "to turn;" cf. Pers. gard-, gardidan, gaštan "to turn, to wind;" cognate with dialectal qellidan "to roll."