Astronom Johan Kepler dokazao je nekih 80 godina ranije, da orbite planeta oko Sunca nisu savršene kružnice, nego da su u stvari elipse, i da se planeta što je bliža Suncu, brže krece.
The astronomer Johannes Kepler had demonstrated, some 80 years before, that the orbits of the planets around the Sun were not perfect circles, but actually ellipses, and that the closer a planet was to the Sun,