 The geodetic effect was first predicted by Willem de Sitter in 1916, who provided relativistic corrections to the Earth–Moon system's motion.De Sitter's work was extended in 1918 by Jan Schouten and in 1920 by Adriaan Fokker.It can also be applied to a particular secular precession of astronomical orbits, equivalent to the rotation of the Laplace–Runge–Lenz vector.