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scale, in weights and measures

(Encyclopedia)scale, in weights and measures, instruments for determining weight, generally for other than laboratory use. For the principles of operation of all weighing devices, see balance. Platform scales utili...

Rosenquist, James

(Encyclopedia)Rosenquist, James, 1933–2017, American painter, b. Grand Forks, N.Dak., studied Univ. of Minnesota (1952–54), Art Students League, New York City (1955). An important figure in the pop art movement...

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 ...

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...

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...

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...

entropy

(Encyclopedia)entropy ĕnˈtrəpē [key], quantity specifying the amount of disorder or randomness in a system bearing energy or information. Originally defined in thermodynamics in terms of heat and temperature, e...