constant pitch
61Logarithmic spiral — A logarithmic spiral, equiangular spiral or growth spiral is a special kind of spiral curve which often appears in nature. The logarithmic spiral was first described by Descartes and later extensively investigated by Jakob Bernoulli, who called… …
62Control line — Brodak Control Line Aerobatic Strega in flight Control line (also called U Control ) is a simple and light way of controlling a flying model aircraft. The aircraft is connected to the operator by a pair of lines, attached to a handle, that work… …
63speech — /speech/, n. 1. the faculty or power of speaking; oral communication; ability to express one s thoughts and emotions by speech sounds and gesture: Losing her speech made her feel isolated from humanity. 2. the act of speaking: He expresses… …
64Precession — For other uses, see Precession (disambiguation). Precession of a gyroscope Precession is a change in the orientation of the rotation axis of a rotating body. It can be defined as a change in direction of the rotation axis in which the second… …
65Helix — This article is about the shape. For other uses, see Helix (disambiguation). The helix (cos t, sin t, t) from t = 0 to 4π with arrowheads showing direction of increasing t …
66galaxy — /gal euhk see/, n., pl. galaxies. 1. Astron. a. a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space. b. (usually cap.) See Milky Way. 2. any large and brilliant or impressive… …
67turbine — /terr bin, buyn/, n. any of various machines having a rotor, usually with vanes or blades, driven by the pressure, momentum, or reactive thrust of a moving fluid, as steam, water, hot gases, or air, either occurring in the form of free jets or as …
68Supermarine Spitfire (early Merlin powered variants) — Infobox Aircraft name =Spitfire type =Fighter manufacturer =Supermarine caption =Spitfire Vc launching from USS Wasp designer =R. J. Mitchell first flight =5 March 1936 introduction =1938 retired =1955, RAF status = primary user =Royal Air Force… …
69literature — /lit euhr euh cheuhr, choor , li treuh /, n. 1. writings in which expression and form, in connection with ideas of permanent and universal interest, are characteristic or essential features, as poetry, novels, history, biography, and essays. 2.… …
70Breakthrough Propulsion Physics Program — The Breakthrough Propulsion Physics Project (BPP) was a research project funded by NASA from 1996 through 2002, to study various proposals for revolutionary methods of spacecraft propulsion which would require breakthroughs in physics before they …
