rotational drag
61Timeline of luminiferous aether — The timeline of luminiferous aether begins in the late 19th century with the concept of luminiferous aether ( light bearing aether ), or ether, as a medium for electromagnetic propagation. The aether was assumed to exist for much of the 19th… …
62Helicopter rotor — This article is about helicopter main rotor systems. For antitorque control, see tail rotor. Helicopter rotor The rotor head of a Sikorsky S 92 A helicopter main rotor or rotor system is a type of fan that is used to generate both the aerodynamic …
63TGV world speed record — The TGV (train à grande vitesse, French for high speed train ) holds a series of world speed records achieved in the context of an active research and development program pursued by SNCF, the French national railway, and its industrial partners.… …
64geomagnetic field — Magnetic field associated with the Earth. It is essentially dipolar (i.e., it has two poles, the northern and southern magnetic poles) on the Earth s surface. Away from the surface, the field becomes distorted. Most geomagnetists explain the… …
65Components 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… …
66Boomerang — A boomerang is a simple implement used for various purposes. It is primarily associated with Australian Aborigines, but has been found amongst peoples of North East Africa, Sardinia, Arizona, southern California Native Americans, and in India.… …
67Phonograph — Turntable redirects here. For other uses, see Turntable (disambiguation). Edison cylinder phonograph ca. 1899 …
68Rotary engine — The rotary engine was an early type of internal combustion aircraft engine in which the crankshaft remains stationary and the entire cylinder block revolves around it. The design was used mostly in the years shortly before and during World War I… …
69Special relativity — (SR) (also known as the special theory of relativity or STR) is the physical theory of measurement in inertial frames of reference proposed in 1905 by Albert Einstein (after considerable contributions of Hendrik Lorentz and Henri Poincaré) in the …
70Spacecraft propulsion — A remote camera captures a close up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Spacecraft propulsion is any method used to accelerate spacecraft and artificial… …
