Synonyms and related words :
Einstein theory, balance, coequality, communion, community, contingency, continuum theory, corelation, correlation, correlativism, correlativity, correspondence, cosmic constant, dependence, equilibrium, equipollence, equivalence, four-dimensional geometry, four-dimensional space, fourth dimension, interrelation, inverse proportion, inverse ratio, inverse relationship, mutuality, other continuums, principle of equivalence, principle of relativity, proportionality, reciprocality, reciprocation, reciprocity, space-time, space-time continuum, symmetry, theory of relativity, time-space