theory of relativity
relativity el`a*tiv"i*ty (-t?v"?-t?), n. 1. The state of being relative; as, the relativity of a subject. --Coleridge. [1913 Webster]

2. One of two theories (also called {theory of relativity}) proposed by Albert Einstein, the {special theory of relativity}, or the {general theory of relativity}. The {special theory of relativity} or {special relativity} is based on the proposition that the speed of light is a constant no matter how observed, and is independent of the motion of the observer. From this follows several principles, such as the increase of mass with velocity (which has been confirmed: see {relativistic mass equation}) and the impossibility of acceleration to a speed greater than that of light; the equivalence of mass and energy, expressed by the famous equation E = mc^{2}; and time dilation, which is the apparent slowing of a clock in a system, as observed by an observer in a system moving relative to the clock. The {general theory of relativity} is based on the proposition that there is no physical difference between gravitational force and the force produced by acceleration. From this follow several results, of which the bending of light rays in a gravitational field and the equivalence of the inertial and gravitational masses have been verified. The possible existence of {black holes} (believed by many astronomers to have been adequately proven) is another consequence of the theory. [PJC]

The Collaborative International Dictionary of English. 2000.

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• Theory of relativity — This article is about the scientific concept. For philosophical or sociological theories about relativity, see Relativism. For the silent film, see The Einstein Theory of Relativity. Two dimensional projection of a three dimensional analogy of… …   Wikipedia

• theory of relativity — noun (physics) the theory that space and time are relative concepts rather than absolute concepts • Syn: ↑relativity, ↑relativity theory, ↑Einstein s theory of relativity • Derivationally related forms: ↑relativistic (for: ↑ …   Useful english dictionary

• theory of relativity — noun The generic term of the special relativity and the general relativity, two theories in physics developed mainly by at the beginning of the 20th century from which several important results such as the equivalence of matter and energy and the …   Wiktionary

• theory of relativity — Physics. relativity (def. 2). [1960 65] * * * …   Universalium

• theory of relativity — method pertaining to science and specifically physics, Einstein s theory …   English contemporary dictionary

• general theory of relativity — relativity el a*tiv i*ty ( t?v ? t?), n. 1. The state of being relative; as, the relativity of a subject. Coleridge. [1913 Webster] 2. One of two theories (also called {theory of relativity}) proposed by Albert Einstein, the {special theory of… …   The Collaborative International Dictionary of English

• general theory of relativity — relativity el a*tiv i*ty ( t?v ? t?), n. 1. The state of being relative; as, the relativity of a subject. Coleridge. [1913 Webster] 2. One of two theories (also called {theory of relativity}) proposed by Albert Einstein, the {special theory of… …   The Collaborative International Dictionary of English

• special theory of relativity — relativity el a*tiv i*ty ( t?v ? t?), n. 1. The state of being relative; as, the relativity of a subject. Coleridge. [1913 Webster] 2. One of two theories (also called {theory of relativity}) proposed by Albert Einstein, the {special theory of… …   The Collaborative International Dictionary of English

• special theory of relativity — relativity el a*tiv i*ty ( t?v ? t?), n. 1. The state of being relative; as, the relativity of a subject. Coleridge. [1913 Webster] 2. One of two theories (also called {theory of relativity}) proposed by Albert Einstein, the {special theory of… …   The Collaborative International Dictionary of English

• special theory of relativity — noun a physical theory of relativity based on the assumption that the speed of light in a vacuum is a constant and the assumption that the laws of physics are invariant in all inertial systems • Syn: ↑special relativity, ↑special relativity… …   Useful english dictionary