Commentaries on the Exhibit’s Works




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A brief commentary prepared by Robert Brecha, PhD, Professor, Physics, on the following work:

Johannes Kepler
Astronomia Nova (New Astronomy)
Heidelberg or Prague, 1609; first edition


In Astronomia Nova, Johannes Kepler proposed that planetary orbits are not circular, but ellipses with the sun as a focal point. It was revolutionary—overthrowing deeply ingrained thinking about perfect cosmological geometry.Galileo, a scientist willing to break with traditional views, rejected Kepler’s theory of elliptical orbits; it was not until the later work of Isaac Newton that a more complete mathematical theory of planetary motion arose—along with a causal explanation for why planets should move in orbits of a particular shape. Modern physical science grew from this union of mathematics and generalizable, testable physical laws.In a sense, Kepler represents the end of a two-millennium tradition of linking geometrically based theory to careful observations, without the need to link it to laws of motion. Astronomia Nova was Kepler’s breakthrough proposal for laws of planetary motion.

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Robert Brecha, professor of physics, explains how Johannes Kepler advanced research on heliocentrism through his exploration of planetary motion.

Kepler: ‘Astronomia Nova’ (‘New Astronomy’)


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