Why Johannes Kepler? Kepler is the astronomer who first worked out the true nature of how planets move.  This is covered in virtually all astronomy textbooks.  What is generally not covered is how he worked this out.  Faith is part of that story. Since the time of the ancient Greeks, astronomers had believed that the observed motions of planets through the constellations resulted from them moving around the Earth in perfect, steady circles, or some combination of circles.  This idea reached its peak in the work of the ancient astronomer Ptolemy, whose work was based on the ideas of the philosopher Aristotle.  In the early sixteenth century Nicolaus Copernicus proposed that Venus, Earth, Mars, etc. all revolve about the sun, but (a) he still assumed they moved in circular orbits and (b) the ancient Greek Aristarchus had proposed this idea nearly two thousand years earlier.  Kepler, by contrast, determined that planetary motion was the result of them all revolving around … Continue reading →