longitude : Dictionary / Wörterbuch (BEOLINGUS, TU Chemnitz)

English Dictionary: longitude	by the DICT Development Group
4 results for longitude
From WordNet (r) 3.0 (2006) [wn]:
longitude n the angular distance between a point on any meridian and the prime meridian at Greenwich
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Longitude \Lon"gitude\, n. [F., fr. L. longitudo, fr. longus long.] 1. Length; measure or distance along the longest line; -- distinguished from breadth or thickness; as, the longitude* of a room; rare now, except in a humorous sense. --Sir H. Wotton. The longitude of their cloaks. --Sir. W. Scott. Mine [shadow] spindling into longitude immense. --Cowper. 2. (Geog.) The arc or portion of the equator intersected between the meridian of a given place and the meridian of some other place from which longitude is reckoned, as from Greenwich, England, or sometimes from the capital of a country, as from Washington or Paris. The longitude of a place is expressed either in degrees or in time; as, that of New York is 74[deg] or 4 h. 56 min. west of Greenwich. 3. (Astron.) The distance in degrees, reckoned from the vernal equinox, on the ecliptic, to a circle at right angles to the ecliptic passing through the heavenly body whose longitude is designated; as, the longitude of Capella is 79[deg]. {Geocentric longitude} (Astron.), the longitude of a heavenly body as seen from the earth. {Heliocentric longitude}, the longitude of a heavenly body, as seen from the sun's center. {Longitude stars}, certain stars whose position is known, and the data in regard to which are used in observations for finding the longitude, as by lunar distances.
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Refraction \Refrac"tion\ (r?fr?k"sh?n), n. [F. r[82]fraction.] 1. The act of refracting, or the state of being refracted. 2. The change in the direction of ray of light, heat, or the like, when it enters obliquely a medium of a different density from that through which it has previously moved. Refraction out of the rarer medium into the denser, is made towards the perpendicular. --Sir I. Newton. 3. (Astron.) (a) The change in the direction of a ray of light, and, consequently, in the apparent position of a heavenly body from which it emanates, arising from its passage through the earth's atmosphere; -- hence distinguished as atmospheric refraction, or astronomical refraction. (b) The correction which is to be deducted from the apparent altitude of a heavenly body on account of atmospheric refraction, in order to obtain the true altitude. {Angle of refraction} (Opt.), the angle which a refracted ray makes with the perpendicular to the surface separating the two media traversed by the ray. {Conical refraction} (Opt.), the refraction of a ray of light into an infinite number of rays, forming a hollow cone. This occurs when a ray of light is passed through crystals of some substances, under certain circumstances. Conical refraction is of two kinds; external conical refraction, in which the ray issues from the crystal in the form of a cone, the vertex of which is at the point of emergence; and internal conical refraction, in which the ray is changed into the form of a cone on entering the crystal, from which it issues in the form of a hollow cylinder. This singular phenomenon was first discovered by Sir W. R. Hamilton by mathematical reasoning alone, unaided by experiment. {Differential refraction} (Astron.), the change of the apparent place of one object relative to a second object near it, due to refraction; also, the correction required to be made to the observed relative places of the two bodies. {Double refraction} (Opt.), the refraction of light in two directions, which produces two distinct images. The power of double refraction is possessed by all crystals except those of the isometric system. A uniaxial crystal is said to be optically positive (like quartz), or optically negative (like calcite), or to have positive, or negative, double refraction, according as the optic axis is the axis of least or greatest elasticity for light; a biaxial crystal is similarly designated when the same relation holds for the acute bisectrix. {Index of refraction}. See under {Index}. {Refraction circle} (Opt.), an instrument provided with a graduated circle for the measurement of refraction. {Refraction of latitude}, {longitude}, {declination}, {right ascension}, etc., the change in the apparent latitude, longitude, etc., of a heavenly body, due to the effect of atmospheric refraction. {Terrestrial refraction}, the change in the apparent altitude of a distant point on or near the earth's surface, as the top of a mountain, arising from the passage of light from it to the eye through atmospheric strata of varying density.
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Heliocentric \He`liocen"tric\, Heliocentrical \He`liocen"tric"al\, a. [Helio- + centric, centrical: cf. F. h[82]liocentrique.] (Astron.) pertaining to the sun's center, or appearing to be seen from it; having, or relating to, the sun as a center; -- opposed to geocentrical. {Heliocentric parallax}. See under {Parallax}. {Heliocentric place}, {latitude}, {longitude}, etc. (of a heavenly body), the direction, latitude, longitude, etc., of the body as viewed from the sun.