The Scientific Revolution

Lesson 2: Columbus and Copernicus

Copernicanism after Copernicus

It took over a century after On the Revolutions of the Heavenly Spheres for Copernican astronomy to win wide acceptance throughout Europe. The principal obstacles Copernicanism faced in the sixteenth century were not the religious ones that became more prominent later, but objections based on commonsense and Aristotelian physics.

A moving earth, not one just revolving around the sun but also rotating, seemed to defy the evidence of the senses. If you drop something, you notice that (in the absence of wind) it falls where you drop it, and not some point to the west as the earth moves under it. Nor does the earth’s motion generate a mighty wind.

Displacing the earth from the center of the universe also threatened a basic Aristotelian tenet, the idea of natural place. Aristotelians argued that objects sought their natural place in the universe, and that this seeking explained "natural" motion.

Heavy objects fell to earth because they sought their natural place at the center of the universe. If earth was not at the center of the universe, this explanation fell apart, and much of Aristotelian physics with it. Nor was the astronomical argument for Copernicanism overwhelming.

Although the Copernican system required fewer mathematical devices than did the previous earth-centered Ptolemaic system, it also seemed less elegant. While everything revolved around the earth in Ptolemaicism, in Copernicanism the moon continued to revolve around the earth while the planets revolved around the sun. Some denied that the universe could have two centers of motion.

The fact that the apparent positions of the stars did not move when the earth moved around the sun–the lack of “stellar parallax”–also forced Copernicus and subsequent Copernicans to posit a much larger universe with the stars at a much greater distance from earth than was accepted.

For all these reasons, only about a dozen sixteenth century thinkers can be identified as accepting Copernicanism as a true picture of the universe. Oster’s documents 2.2, 3.1, and 3.2 show some early Copernicans. How convincing do you find them?

However, many astronomers accepted Copernicanism as a valid system for making astronomical calculations. Making calculations, rather than speculating on the structure of the universe, was considered by many to be the true task of astronomy anyway.

This computational use of Copernicanism was particularly influential among German Lutherans. Among those few who did accept Copernicanism as a true picture of physical reality, interpretations of the Copernican universe varied. Some, closely following Copernicus himself, kept the crystalline spheres of traditional astronomy, and simply shifted the center of the finite universe from the earth to the sun.

The more intellectually radical Italian magician Giordano Bruno carried out what could be considered the logical implications of the Copernican universe by putting a sun centered planetary system in an infinite universe with an infinite number of other stars and planets following the same arrangement. Bruno’s influence was limited by the fact that he was burned as a heretic (though not for his Copernicanism) in 1600.

  1  2  3  4  5  6  7