Ebook: Kepler's Harmonics and his Concept of Inertia

American Journal of Physics, July 1966, Volume 34, Issue 7, pages 610-613.Kepler's Harmonics of the Universe, the mature work in which he first enunciated his third law of planetary motion, was a consummation of some of his youthful ideas. He introduced the term inertia into physics and astronomy, extended its purview to the heavens, and contributed essential components to the fully developed concept of inertia.