The solar mass of the star at the center of our solar system has been decreasing.
 Kepler discovered that the square of the orbital period of each planet is directly proportional to the cube of the semi-major axis of its orbit, or equivalently, that the ratio of these two values is constant for all planets in the Solar System
 As of 2008, no deviation from universality, and thus from Galilean equivalence, has ever been found, at least to the precision 106

