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tachyon

(Encyclopedia)tachyon tăkˈēŏnˌ [key], hypothetical elementary particle that travels only at speeds exceeding that of light. According to the theory of relativity, the speed of light is the limiting velocity fo...

Beaufort scale

(Encyclopedia)Beaufort scale, a scale of wind velocity devised (c.1805) by Admiral Sir Francis Beaufort of the British navy. An adaptation of Beaufort's scale is used by the U.S. National Weather Service; it employ...

electromotive series

(Encyclopedia)electromotive series, list of metals whose order indicates the relative tendency to be oxidized, or to give up electrons (see oxidation and reduction); the list also includes the gas hydrogen. The ele...

calculus

(Encyclopedia)CE5 The derivative f″(x) of the function f(x) at the point P represents the slope of the tangent line at that point. CE5 The area under the curve y=f(x) may be found by calculating the sum of ...

Montreal Protocol

(Encyclopedia)Montreal Protocol, officially the Protocol on Substances That Deplete the Ozone Layer, treaty signed on Sept. 16, 1987, at Montreal by 25 nations; 197 nations are now parties to the accord. The protoc...

infinity

(Encyclopedia)infinity, in mathematics, that which is not finite; it is often indicated by the symbol ∞. A sequence of numbers, a1, a2, a3, … , is said to “approach infinity” if the numbers eventually b...

solar time

(Encyclopedia)solar time, time defined by the position of the sun. The solar day is the time it takes for the sun to return to the same meridian in the sky. Local solar time is measured by a sundial. When the cente...

neutrino

(Encyclopedia)neutrino no͞otrēˈnō [key] [Ital.,=little neutral (particle)], elementary particle with no electric charge and a very small mass emitted during the decay of certain other particles. The neutrino wa...

uncertainty principle

(Encyclopedia)uncertainty principle, physical principle, enunciated by Werner Heisenberg in 1927, that places an absolute, theoretical limit on the combined accuracy of certain pairs of simultaneous, related measur...

Miyazaki, Hayao

(Encyclopedia)Miyazaki, Hayao mēyäˈzäˌkē [key], 1941–, Japanese animator. Japan's preeminent maker of animated films (anime), Miyazaki is thought by many to be the world's finest living animator. He draws, ...