celestial+sphere
91Lie sphere geometry — is a geometrical theory of planar or spatial geometry in which the fundamental concept is the circle or sphere. It was introduced by Sophus Lie in the nineteenth century. [The definitive modern textbook on Lie sphere geometry is Harvnb|Cecil|1992 …
92armillary sphere — Astron. an ancient instrument consisting of an arrangement of rings, all of which are circles of the same sphere, used to show the relative positions of the celestial equator, ecliptic, and other circles on the celestial sphere. [1550 60] * * * ▪ …
93hem|i|sphere — «HEHM uh sfihr», noun. 1. a half sphere or globe, formed by a plane passing through the center. 2. a) half of the earth s surface. North America and South America are in the Western Hemisphere; Europe, Asia, Africa, and Australia are in the… …
94Riemann sphere — The Riemann sphere can be visualized as the complex number plane wrapped around a sphere (by some form of stereographic projection – details are given below). In mathematics, the Riemann sphere (or extended complex plane), named after the 19th… …
95armillary sphere — ar′millary sphere′ n. astron. an ancient astronomical instrument consisting of an arrangement of metal rings used to show the relative positions of the celestial equator and other circles on the celestial sphere …
96parallel sphere — noun : the celestial sphere seen from either the north or the south pole of the earth where all the celestial bodies seem to move in small circles parallel to the horizon …
97plan|i|sphere — «PLAN uh sfihr», noun. a projection or representation of the whole or a part of a sphere on a plane, especially a map of half or more of the celestial sphere with an adjustable device to show the part of the heavens visible at a given time.… …
98Armillary sphere — Armillary Ar mil*la*ry, a. [LL. armillarius, fr. L. armilla arm ring, bracelet, fr. armus arm: cf. F. armillaire. See {Arm}, n.] Pertaining to, or resembling, a bracelet or ring; consisting of rings or circles. [1913 Webster] {Armillary sphere},… …
99armillary sphere — noun Etymology: French sphère armillaire, from Medieval Latin armilla, from Latin, bracelet, iron ring, from armus shoulder more at arm Date: 1664 an old astronomical instrument composed of rings showing the positions of important circles of the… …
100armillary sphere — /aˌmɪləri ˈsfɪə/ (say ah.miluhree sfear) noun Astronomy an arrangement of rings, all circles of a single sphere, showing the relative positions of the principal circles of the celestial sphere …
