quadrantal sphere

См. также в других словарях:

• Armillary sphere — An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of the celestial sphere. Description and use of the armillary sphere The exterior parts of this machine are a compages of brass rings, which represent …   Wikipedia

• The vector of a quaternion — In the 19th century, the vector of a quaternion written Vq was a well defined mathematical entity in the classical quaternion notation system. This article is written using classical nomenclature. In this article the word vector means the… …   Wikipedia

• astronomical map — Introduction       any cartographic representation of the stars, galaxies, or surfaces of the planets and the Moon. Modern maps of this kind are based on a coordinate system analagous to geographic latitude and longitude. In most cases, modern… …   Universalium

• Classical Hamiltonian quaternions — For the history of quaternions see:history of quaternions For a more general treatment of quaternions see:quaternions William Rowan Hamilton invented quaternions, a mathematical entity in 1843. This article describes Hamilton s original treatment …   Wikipedia

• quadrant — n. 1 a quarter of a circle s circumference. 2 a plane figure enclosed by two radii of a circle at right angles and the arc cut off by them. 3 a quarter of a sphere etc. 4 a a thing, esp. a graduated strip of metal, shaped like a quarter circle. b …   Useful english dictionary