Relativity, theory of
Relativity, theory of
A mathematical theory of space-time (q.v.), of profound epistemological as well as physical importance, comprising the special theory of relativity (Einstein, 1905) and the general theory of relativity (Einstein, 1914-16). The name arises from the fact that certain things which the classical theory regarded as absolute — e.g. , the simultaneity of spatially distant events, the time elapsed between two events (unless coincident in space-time), the length of an extended solid body, the separation of four-dimensional space-time into a three-dimensional space and a one-dimensional time — are regarded by the relativity theory as relative (q.v.) to the choice of a coordinate system in space-time, and thus relative to the observer. But on the other hand the relativity theory represents as absolute certain things which are relative in the classical theory — e.g., the velocity of light in empty space. See Non-Euclidean geometry. — A.C.
Albert Einstein,
Relativity, The Special & The General Theory, A Popular Exposition, translated by R. W. Lawson, London, 1920.
A. S. Eddington,
Space, Time, and Gravitation, Cambridge, England, 1920.
A. V. Vasihev,
Space, Time, Motion, translated by H. M. Lucas and C. P. Sanger, with an introduction by Bertrand Russell, London. 1924, and New York, 1924.