newtonian focus
1Newtonian telescope — The Newtonian telescope is a type of reflecting telescope invented by the British scientist Sir Isaac Newton (1642–1727), using a concave primary mirror and a flat diagonal secondary mirror. Newton’s first reflecting telescope was completed in… …
2Optical telescope — Eight Inch refracting telescope (Chabot Space and Science Center) An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for… …
3Dominion Astrophysical Observatory — For the observatory in Ottawa, see Dominion Observatory. Dominion Astrophysical Observatory Alternative names Observatoire fédéral d astrophysique …
4Reflecting telescope — 24 inch convertible Newtonian/Cassegrain reflecting telescope on display at the Franklin Institute. A reflecting telescope (also called a reflector) is an optical telescope which uses a single or combination of curved mirrors that reflect light… …
5Orbit — This article is about orbits in celestial mechanics, due to gravity. For other uses, see Orbit (disambiguation). A satellite orbiting the Earth has a tangential velocity and an inward acceleration …
6gravitation — gravitational, adj. gravitationally, adv. /grav i tay sheuhn/, n. 1. Physics. a. the force of attraction between any two masses. Cf. law of gravitation. b. an act or process caused by this force. 2. a sinking or falling …
7science, philosophy of — Branch of philosophy that attempts to elucidate the nature of scientific inquiry observational procedures, patterns of argument, methods of representation and calculation, metaphysical presuppositions and evaluate the grounds of their validity… …
8Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
9science, history of — Introduction the history of science from its beginnings in prehistoric times to the 20th century. On the simplest level, science is knowledge of the world of nature. There are many regularities in nature that mankind has had to… …
10mechanics — /meuh kan iks/, n. 1. (used with a sing. v.) the branch of physics that deals with the action of forces on bodies and with motion, comprised of kinetics, statics, and kinematics. 2. (used with a sing. v.) the theoretical and practical application …
