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phlogiston theory

(Encyclopedia)phlogiston theory flōjĭsˈtŏn [key], hypothesis regarding combustion. The theory, advanced by J. J. Becher late in the 17th cent. and extended and popularized by G. E. Stahl, postulates that in all...

electroweak theory

(Encyclopedia)electroweak theory, a unified field theory that describes two of the fundamental forces in nature, electromagnetism (see electromagnetic radiation) and the weak interaction. The electroweak theory der...

quantum theory

(Encyclopedia)quantum theory, modern physical theory concerned with the emission and absorption of energy by matter and with the motion of material particles; the quantum theory and the theory of relativity togethe...

string theory

(Encyclopedia)string theory, description of elementary particles based on one-dimensional curves, or “strings,” instead of point particles. Superstring theory, which is string theory that contains a kind of sym...

information theory

(Encyclopedia)information theory or communication theory, mathematical theory formulated principally by the American scientist Claude E. Shannon to explain aspects and problems of information and communication. Whi...

communication theory

(Encyclopedia)communication theory: see information theory. ...

chaos theory

(Encyclopedia)chaos theory, in mathematics, physics, and other fields, a set of ideas that attempts to reveal structure in aperiodic, unpredictable dynamic systems such as cloud formation or the fluctuation of biol...

domino theory

(Encyclopedia)domino theory, the notion that if one country becomes Communist, other nations in the region will probably follow, like dominoes falling in a line. The analogy, first applied (1954) to Southeast Asia ...

planetesimal theory

(Encyclopedia)planetesimal theory plănˌĭtĕsˈəməl [key]: see solar system. ...

BCS theory

(Encyclopedia)BCS theory: see superconductivity. ...