half-spherical
21Moons of Saturn — Artist s concepts of the Saturnian ring–moon system Saturn, its rings and major icy moons from Mimas to Rhea …
22nuclear fission — fission (def. 2). [1885 90] * * * Division of a heavy atomic nucleus into two fragments of roughly equal mass, accompanied by the release of a large amount of energy, the binding energy of the subatomic particles. The energy released in the… …
23radioactivity — /ray dee oh ak tiv i tee/, n. Physics, Chem. the phenomenon, exhibited by and being a property of certain elements, of spontaneously emitting radiation resulting from changes in the nuclei of atoms of the element. Also called activity. [1895… …
24sound — sound1 soundable, adj. /sownd/, n. 1. the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other medium. 2. mechanical vibrations transmitted through an elastic medium, traveling in air at a… …
25Sound — /sownd/, n. The, a strait between SW Sweden and Zealand, connecting the Kattegat and the Baltic. 87 mi. (140 km) long; 3 30 mi. (5 48 km) wide. Swedish and Danish, Oresund. * * * I Mechanical disturbance that propagates as a longitudinal wave… …
26Lune (mathematics) — In geometry, a lune is either of two figures, both shaped roughly like a crescent Moon. The word lune derives from luna, the Latin word for Moon. Contents 1 Plane geometry 2 Spherical geometry 3 Lune of Hippocrates …
27cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …
28Pythagorean theorem — See also: Pythagorean trigonometric identity The Pythagorean theorem: The sum of the areas of the two squares on the legs (a and b) equals the area of the square on the hypotenuse (c) …
29Differential geometry of surfaces — Carl Friedrich Gauss in 1828 In mathematics, the differential geometry of surfaces deals with smooth surfaces with various additional structures, most often, a Riemannian metric. Surfaces have been extensively studied from various perspectives:… …
30Curvilinear coordinates — Curvilinear, affine, and Cartesian coordinates in two dimensional space Curvilinear coordinates are a coordinate system for Euclidean space in which the coordinate lines may be curved. These coordinates may be derived from a set of Cartesian… …
