L. ansa "handle."
Dastak "handle," from dast "hand" (Mid.Pers. dast; O.Pers. dasta-; Av. zasta-; cf. Skt. hásta-; Gk. kheir; L. praesto "at hand;" Arm. jern "hand;" Lith. pa-žastis "arm-pit;" PIE *ghes-to-) + -ak suffix denoting relation, affinity, similarity.
In physics and mathematics an a priori assumption that is used to establish the form of an equation or a system of equations. The ansatz, which is verified later by the result, is meant to facilitate the solution. → Bethe ansatz.
From Ger. Ansatz "attempt, approach, beginning."
The direction in the sky (in → Columba) away from which the Sun seems to be moving (at a speed of 19.4 km/s) relative to general field stars in the Galaxy.
Daštargân, Jonubgân (#)
The south polar area, south of latitude 66° 33' 8'' S.
Daštargân, from daštar, → south, +
-gân suffix indicating the direction.
Antares (α Scorpii)
A → red supergiant star (→ spectral type M1 Ib) in the constellation → Scorpius, lying about 500 → light-years (170 (+35/-25) → parsecs) from Earth. It has a dwarf massive companion (B3 V), which is a → radio source.
Antares, in Gk. "rival of Mars," from Gk. → anti + Ares "the Gk. god of War, called Mars by the Romans." The comparison with the planet Mars is because they are both red in color and have the same brightness.
Každom-del "the heart of the Scorpion," from každom "scorpion" + del, → heart. Qalb-ol-'Aqrab "the heart of the Scorpion," from Ar. Qalb "heart" + 'aqrab "scorpion".
M.E., from from L. antecedentem, from antecedere "go before, precede," from ante- "before" + cedere "to yield, to go," → process.
1) General: A device or a set of wires that receives or sends out
L. antenna "sail yard," the long yard that sticks up on some sails, of unknown origin, perhaps from PIE base *temp- "to stretch, extend." In this sense, it is a translation of Gk. keraiai "horns" (of insects).
Âten, from Fr. antenne, from L. as above.
Fr.: gain d'antenne
A measure of the directivity of a radio telescope. It is the ratio of the amount of power received in the direction the dish is pointing to the smaller amount of power from other directions in the sidelobes.
Fr.: lobe d'antenne
A three-dimensional section of the → radiation pattern ofa directional antenna, bounded by one or more cones of nulls or by regions of diminished irradiance.
Fr.: diagramme de rayonnement
The response of an antenna to incident radiation as a function of the direction of incidence of the radiation. A generic antenna pattern consists of a → main lobe and a number of smaller → side lobes. Also called → radiation pattern.
Fr.: température d'antenne
In radio astronomy, a measure of the power absorbed by the antenna. In an ideal, loss-free radio telescope, the antenna temperature is equal to the brightness temperature if the intensity of the received radiation is constant within the main lobe. → antenna; → temperature.
antenna; → temperature.
Fr.: galaxies des Antennes
The pair of colliding galaxies NGC4038 and NGC4039 and the long arcing insect-like "antennae" of luminous matter revealed by optical telescopes. The "antennae" are believed to have been produced by the collision between the galaxies that began about 100 million years ago and is still occurring. The Antennae Galaxies, about 60 million → light-years from Earth, lie in the constellation → Corvus.
Kahkešânhâ, plural of kahkešân→ galaxy; šâxak "insect antenna," from šâx "horn" (Mid.Pers šâk, cf. Skt. sakha- "a branch, a limb," Arm. cax, Lit. šaka, O.S. soxa, PIE *kakhâ "branch") + -ak suffix denoting relation, affinity, similarity (as in dastak, pos(tak, pas(mak, xarak, nâxonak, mus(ak, eynak);
Fr.: principe anthropique
The idea that the existence of → life and, in particular, our presence as → intelligent → observers, → constrains the nature of the → Universe. It is an attempt to explain the observed fact that the → fundamental constants of nature are just right or fine-tuned to allow the Universe and life to exist. This is not however a "principle." See also → weak anthropic principle, → strong anthropic principle. Compare → Copernican principle.
Parvaz, → principle; ensân-hasti, from ensân, → anthropo-, + Mod.Pers. hasti "existence, being," Mid.Pers. astih, O.Pers. astiy; Av. asti "is," O.Pers./Av. root ah- "to be;" cf. Skt. as-; Gk. esti; L. est; PIE *es-.
Frpm Gk. anthropos "man, human being," from aner "man" (as opposed to a woman, a god, or a boy), from PIE *hner "man;" cf. Pers. nar "male," Skt. nara-, Welsh ner "man."
Ensân-, from ensân "mankind," loan from Ar. insân.
Fr.: anti-, ant-
L. anti- from Gk. anti "against, opposite, instead of," from PIE *anti "against".
Pâd- "agaist, contrary to," from Mid.Pers. pât- "to, at, for, in," from O.Pers. paity "agaist, back, opposite to, toward, face to face, in front of;" Av. paiti; cf. Skt. práti "toward, against, again, back, in return, opposite;" Pali pati-; Gk. proti, pros "face to face with, toward, in addition to, near;" PIE *proti.
The point in the → Galactic plane that lies directly opposite the → Galactic center. It lies in → Auriga at approximately R.A. 5h 46m, Dec. +28° 56'; the nearest bright star to it is → Alnath in → Taurus.
Meteorology: Small, faintly colored rings of light surrounding the → antisolar point, seen when looking down at a water cloud. Same as glory.
Pâdafsar, from pâd-, → anti- + afsar
Statistics: The correlation coefficient of two random variables X and Y is in general defined as the ratio of the Cov(X,Y) to the two standard deviations of X and Y. It varies between 1 and -1 corresponding to complete correlation or anticorrelation.
Fr.: rayons anticrépusculaires
Rays of → sunlight that appear to converge at the → antisolar point. Like → crepuscular rays, they are parallel beams of sunlight from holes in the clouds, and their apparently odd directions are a perspective effect.