Fr.: mécanique analytique
A branch of → mechanics based on → variational principle that describes systems by their → Lagrangian or → Hamiltonian. Analytical mechanics provides a formalism that is different from that of Newton and does not use the concept of force. Among other things, analytical mechanics gives a more simple description of continuous and constrained systems. Moreover, its mathematical structure allows it an easier transition to quantum mechanical topics.
Infinitive of → analysis.
The quality of an → anamorphic system.
râžmân-e ânârixt, ~ ânârixtmand
Fr.: système anamorphique
An optical system whose optical power, and imaging scale, differs in the two principal directions. See also → anamorphosis.
1) Optics: The formation of a distorted image by an
→ anamorphic system.
From Gk. anamorphosis "transformation," noun of action from anamorphoein "to transform," from → ana- "up," + morphe "form" + -sis a suffix forming abstract nouns of action, process, state, condition, etc.
Ananke [Jupiter XII]
The thirteenth of Jupiter's known satellites discovered by S.B. Nicholson in 1951. It orbits the planet at a mean distance of 21,200,000 km, and has a diameter of about 30 km.
In Gk. mythology, Ananke is the personification of destiny, unalterable necessity and fate; she is also the mother of Adrastea,
A lens designed to correct → astigmatism.
1) (Conjunction, used to connect grammatically coordinate words, phrases, or clauses)
Along or together with; as well as; in addition to; besides; also; moreover.
→ if and only if.
From M.E., from O.E., akin to O.H.G. unti "and."
Va "and," graphical corruption of o "and;" Mid.Pers. ut, u- "and;" O.Pers. utā; Av. uta- "and;" cf. Skt. utá; maybe also influenced by Av. vā a disjunctive particle (Skt. vā) "or," occasionally used in the sense of "and;" vā ... vā "either, or;" cf. Sogd. βa, fa "and, or," fā "or."
Fr.: pont d'Anderson
A. Anderson (1891, Phil. Mag. (5) 31, 329); → bridge.
Ândromedâ, Zan-e bé Zanjir Basté (#)
In Gk. mythology, Andromeda was the princess of Ethiopia, daughter of → Cepheus and → Cassiopeia. The queen Cassiopeia angered Poseidon by saying that Andromeda (or possibly Cassiopeia herself) was more beautiful than the Nereids. Poseidon sent a sea monster to prey upon the country; he could be appeased only by the sacrifice of the king's daughter. Andromeda in sacrifice was chained to a rock by the sea; but she was rescued by → Perseus, who killed the monster and later married her. Cassiopeia, Cepheus, and Andromeda were all set among the stars as constellations.
Zan-e bé Zanjir Basté "the chained woman," coined by the 11th century astronomer Biruni, from Ar. Emra'at al-mosalsalah "the chained woman," from the Gk. mythology.
Andromeda galaxy (M31, NGC 224)
kahkašân-e Ândromedâ (#), ~ Zan-e bé Zanjir Basté (#)
Fr.: galaxie d'Andromède
The nearest → spiral galaxy to our own and a major member of the → Local Group. It lies in the constellation → Andromeda and is the most remote object normally visible to the naked eye. The earliest known reference to this galaxy is by the Iranian astronomer Sufi who called it "the little cloud" in his Book of Fixed Stars (A.D. 964).
A meteor shower which appears about 25 November with its → radiant located in the constellation → Andromeda. The Andromedids are the debris of → Biela's comet. The short-period comet, discovered in 1826, split into two parts in the middle of the 19th century and later vanished. Hence their alternative name Bielids.
Andromedids, from Andromeda constellation + → -ids suffix denoting "descendant of, belonging to the family of."
Ândromedâiyân, from Ândromedâ + -iyân, → -ids.
An instrument for measuring and indicating the force or speed of the wind.
From Gk. anemos "wind" + → -meter.
Bâdsanj, from bâd "wind" + -sanj, → -meter.
The figure formed by two lines extending from a common point; the figure formed by two intersecting planes (dihedral angle).
L. angulum (nominative angulus) "corner," a dim. form from PIE *ang-/*ank- "to bend". Cf. Skt. ankah "hook, bent," Gk. angkon "elbow," angkura "anchor," Lith. anka "loop," O.E. ancleo "ankle," O.H.G. ango "hook," Av. ank- "curved, crooked," Av. angušta- "toe," Mod.Pers. angošt, angol, angul "finger".
Zâviyé from Ar. zâwiyat "corner, angle".
angle of deviation
Fr.: angle de déviation
The angle between the → incident ray of light entering an → optical system (such as a prism) and the → refracted ray that emerges from the system. Because of the different indices of refraction for the different wavelengths of visible light, the angle of deviation varies with wavelength.
angle of emergence
Fr.: angle d'émergence
The angle of the light coming out of a medium. For a medium with parallel sides (such as a glass slab) it is equal to the angle of incidence.
angle of incidence
Fr.: angle d'incidence
The angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence. Also called → incidence angle.
angle of inclination
Fr.: angle d'inclinaison
1) General: The angle between one plane and another, or
the angle formed by a reference axis and a given line.
angle of minimum deviation
zâviye-ye kažraft kaminé
Fr.: angle de déviation minimale
The angle between the light entering and exiting the prism when the light passing through the prism is parallel to the prism's base. Angle of minimum deviation (D) is used to measure the → index of refraction (n) of the prism glass, because: n = sin [(A + D)/2]/sin (A/2), where A is the → prism angle.