Western Civilization I / Unit 17 WC1 1634 worked example, 60 to 90 seconds
Sorting Astronomers: What Each Kept and Each Broke
The idea
The exam names an astronomer and asks his contribution, or describes a contribution and asks whose. The method is two columns: what the man kept from Ptolemy, and what he broke. Copernicus kept the spheres and circles, broke the earth's centrality. Brahe kept the earth central, broke the reliance on old data with twenty years of his own. Kepler kept heliocentrism, broke the circles, by convention, and sensed a force. Galileo kept mathematics, broke the heavens' perfection with a telescope.
In practice
Four cases. A book published at its author's death moving the sun to the center while keeping crystal spheres: Copernicus. A castle observatory producing tables used by a rival to prove the opposite of the observer's belief: Brahe. A Protestant mathematician at a Catholic emperor's court proving the sun central from another man's data: Kepler. A public demonstration showing Jupiter's moons and the moon's mountains: Galileo. A fifth: a heliocentrist of the third century B.C.E. named on the witness is Aristarchus, unit 05's forerunner.
Where people slip
Copernicus was not persecuted and Galileo was, a century apart, because the backdrop had changed to religious war. Do not attribute the telescope's invention to Galileo; the anchor says he built one from a description.
Your place on the trail
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Builds on
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