Text: In his Astronomia Nova 1609, Kepler pronounced (as quoted verbatim in Pair Spolter Graviational Forces of the Sun, ISBN 0-9638107-5-8) 1st Law - The orbit of a planet is elliptical and the Sun the source of motion is in one of the foci of this ellipse. 2nd Law - The apparent diurnal arcs of one eccentric are almost exactly proportional to the square of their distances from the Sun. 3rd Law - The periodic times of any two planets are to each other exactly as the cubes of the square roots of their mean distance.

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