spacetime

{{physics}} An ''n''-dimensional continuum consisting of dimensions of both space & time. Normally spacetime is considered as having 4 dimensions (''x'', ''y'', ''z'', ''t''), but higher-dimensional spacetimes are often encountered in theoretical physics, e.g. the 5-dimensional spacetime of Kaluza-Klein theory or the 11 dimensions of spacetime in M-theory.