Measure what is measurable, and make measurable what is not so.

The 17th century was a revolutionary period in the development of modern science. In 1610 Galileo Galilei began a detailed study of the moons of Jupiter using the cutting edge technology of the telescope. By 1619 Johannes Kepler (implementing the detailed data he inherited after Tycho Brahe's death) had published his three laws of planetary motion, the first of which made the inflammatory assertion that the orbit of each planet in the solar system is an ellipse with the sun at one focus.