time varying coefficient
81test — 1. To prove; to try a substance; to determine the chemical nature of a substance by means of reagents. 2. A method of examination, as to determine the presence or absence of a definite disease or of some substance in any of the fluids, tissues,… …
82Components of jet engines — Diagram of a typical gas turbine jet engine. Air is compressed by the fan blades as it enters the engine, and it is mixed and burned with fuel in the combustion section. The hot exhaust gases provide forward thrust and turn the turbines which… …
83Electronic amplifier — A practical amplifier circuit An electronic amplifier is a device for increasing the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In… …
84Laser — For other uses, see Laser (disambiguation). United States Air Force laser experiment …
85Luminiferous aether — The luminiferous aether: it was hypothesised that the Earth moves through a medium of aether that carries light In the late 19th century, luminiferous aether or ether, meaning light bearing aether, was the term used to describe a medium for the… …
86Quantum superposition — is the fundamental law of quantum mechanics. It defines the allowed state space of a quantum mechanical system.In Probability theory, every possible event has a positive number associated to it, the probability, which gives the chance that it… …
87Earth's magnetic field — Computer simulation of the Earth s field in a normal period between reversals.[1] The tubes represent magnetic field lines, blue when the field points towards the center and yellow when away. The rotation axis of the Earth is centered and… …
88Exposure (photography) — Underexposure redirects here. For the 2005 film by Oday Rasheed, see Underexposure (2005 film). A long exposure showing stars rotating around the southern and northern celestial poles. Credit: European Southern Observatory …
89Digital divide — Graph of internet users per 100 inhabitants between 1997 and 2007 by International Telecommunication Union …
90Bearing (mechanical) — A bearing is a device to allow constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified broadly according to the motions they allow and according to their principle of operation as… …
