An Etymological Dictionary of Astronomy and Astrophysics

The → metric that belongs to a four-dimensional → flat manifold and is given
by ds² = - dt² + dx² + dy² + dz². Three coordinates represent → space and the fourth coordinate is devoted to → time. The Minkowski metric underlies the → geometry of → special relativity. Compare → Robertson-Walker metric.

See also: In honor of Hermann Minkowski (1864-1909), Russian-born German mathematician, who introduced the concept of the four-dimensional nature of space-time; → metric.