Kepler's Harmonices Mundi

Title page of Kepler's Harmony of the World (Harmonices Mundi). The book was completed in the spring of 1618 and finally published in Linz in 1619. Again of a rather mystical flavor at time, the book contains Kepler's first formulation of his Third Law of planetary motion:

• The square of a planet's orbital periods is proportional to the cube of its mean distance to the Sun.

Bibliography:

Stephenson, B. 1994, The Music of the Heavens, Princeton University Press.

Kepler           Copernicus           Newton