Minkowski spacetime cone. Diagram showing the light cone for a worldline in Minkowski spacetime. The observer is at the junction between two light cones, the past (bottom) and the future (top). The plane (blue) is the hypersurface of present time. Minkowski spacetime was proposed by the German mathematician Hermann Minkowski (1864-1909) as a four-dimensional spacetime that could be used to described the consequences of Einstein's theory of special relativity.