Harmonices Mundi

Harmonice Mundi (Latin: The Harmony of the World, 1619) is a book by Johannes Kepler. In the work, written entirely in Latin, Kepler discusses harmony and congruence in geometrical forms and physical phenomena. The final section of the work relates his discovery of the so-called third law of planetary motion. The full title is Harmonices mundi libri V (The Five Books of The Harmony of the World), which is commonly but ungrammatically shortened to Harmonices mundi.