(North, the Fontana History).
Ptolemy used the term epicycle to describe the small circle around which he claimed objects in space move. To make his theory of epicycles appear sound, he had to introduce variations from traditional mathematics. This departure from traditional assumptions was one reason the Polish astronomer Nicolas Copernicus rejected Ptolemy's system in the 16th century and developed his own heliocentric theory, which correctly stated that the sun was located at the center of the solar system. Even so, Copernicus retained an elaborate system of epicycles.
"It was not until the 16th century that Nicolas Copernicus developed a model for the universe in which the sun was at the center instead of the earth. The new model was rejected by the church, but it gradually gained popular acceptance because it provided better explanations for observed phenomena." (Crowe, 91) Ironically, Copernicus" initial measurements were no more accurate than Ptolemy's were, they just made more sense.
During Copernicus" time, humankind mind was set that all people were the chosen species of God, and this point strongly influenced his work. Ptolemy had already demonstrated that the geo-centric model would require complex mathematical re-interpretation to keep up with astronomical discoveries. Yet one of the Renaissance ideals was that of harmony in mathematics, and the complexity (and sometimes obvious failure) of Ptolemaic theorem caused doubt in the mind of Copernicus. So, he developed his own model of Universe that eventually became the basis for a Copernican Revolution. (North, The reluctant revolutionaries) One important point in the development of Copernicus' new theory is its basis in philosophy first, rather than science. Copernicus did rely on math and astronomical data to uphold his theory, but the reasoning behind his heliocentric model lie in the school of Neo-Platonism.
