Minkowski, Hermann (hĕrˈmän mĭnkôfˈskē) [key], 1864–1909, Russian mathematician. He was educated in Germany and was professor at the Univ. of Königsberg (1894–96), the Federal Institute of Technology, Zürich (1896–1902), and the Univ. of Göttingen (1902–9). He is well known for use of geometric methods in the theory of numbers and for having evolved a four-dimensional geometry of space and time that influenced the formulation of the general theory of relativity. He also contributed to the theory of quadratic forms.