AP European History
Chapter 14: New Directions in Thought and Culture in the Sixteenth and Seventeenth Centuries Notes
Nicolaus Copernicus Rejects an Earth-Centered Universe
Biographical information
Polish priest and scientist educated at the University of Krakow wrote On the Revolutions of the Heavenly Spheres in 1543
Commissioned to find astronomical justification so that the papacy could change the calendar so that it could correctly calculate the date of Easter, Copernicus’s work provided an intellectual springboard from which scientist could posit questions about Earth’s position in the universe.
Ptolemaic System
Ptolemy, a Roman citizen of Greek ancestry, wrote the Almagest (150CE) was considered the authority on astronomy throughout the Middle Ages and it suggested a geocentric model of the universe.
Ptolemaic World System
Above the earth lay a series of concentric spheres, probably fluid in character, one of which contained the moon, another the sun, and still others the planets and the stars.
The outer realm contains God and angels
The problem of the motions of the planets was something astronomers struggled to chart.
Ptolemy believed that the planets moved uniformly about a small circle called an epicycle and the center of the epicycle moved about a larger circle—called a deferent—with the earth at or near its center.
The circles in Ptolemy’s system were not orbits but rather components of mathematical calculations meant to predict planetary positions.
Copernicus’s Universe
Copernicus’s Model adopted many elements in the Ptolemaic model, but transferred them to a heliocentric model, which assumed the earth moved about the sun in a circle.
He proposed that the farther planets are away from the sun, the longer they took to revolve around it which enabled astronomers to rank the planets in terms of distance from the sun.
Although very few astronomers embraced the Copernican system—at least for a century—it did allow other