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Sinai Billiard
A dynamical billiard is a dynamical system in which a particle alternates between free motion (typically as a straight line) and specular reflections from a boundary. When the particle hits the boundary it reflects from it without loss of speed (i.e. elastic collisions). Billiards are Hamiltonian idealizations of the game of billiards, but where the region contained by the boundary can have shapes other than rectangular and even be multidimensional. Dynamical billiards may also be studied on non-Euclidean geometries; indeed, the first studies of billiards established their ergodic motion on surfaces of constant negative curvature. The study of billiards which are kept out of a region, rather than being kept in a region, is known as outer billiard theory. The motion of the particle in the billiard is a straight line, with constant energy, between reflections with the boundary (a geodesic if the Riemannian metric of the billiard table is not flat). All reflections are specular: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stadium Billiard
A stadium (: stadiums or stadia) is a place or venue for (mostly) outdoor sports, concerts, or other events and consists of a field or stage completely or partially surrounded by a tiered structure designed to allow spectators to stand or sit and view the event. Pausanias of Athens, Pausanias noted that for about half a century the only event at the ancient Greek Olympic festival was the race that comprised one length of the Stadion (unit), stadion at Olympia, Greece, Olympia, where the word "stadium" originated. Most of the stadiums with a capacity of at least 10,000 are used for association football. Other popular stadium sports include gridiron football, baseball, cricket, the various codes of Rugby football, rugby, field lacrosse, bandy, and bullfighting. Many large sports venues are also used for concerts. Etymology "Stadium" is the Latin form of the Greek word "Stadion (unit), stadion" (''στάδιον''), a measure of length equalling the length of 600 human feet. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
