constructions: the eccentric, epicycle, and the equant. The eccentric construction is the only one of the three not centered on the earth. The epicycle says that the planet moves in a small circle, which in itself is moving around a bigger circle. The last of the three constructions, the equant, suggested that the center of motion on a large circle was separated from the center of the circle. The contributions of Ptolomy are numerous, and today he is known as one of the greatest astronomers and mathematicians of the ancient world. The father of modern astronomer, Nicolaus Copernicus, was born in Poland in 1743. All that is known of his childhood is that his father died when Nicolaus was ten years old, so he was raised by his uncle. Copernicus was lucky that his uncle was a prominent Bishop and made sure that Nicolaus received a good education. He enrolled in the University of Cracow to study mathematics, astronomy, astrology, and philosophy. After completing his studies there, Copernicus traveled abroad and also enrolled in the Universities of Bologna and Padua to study both medicine and law. After his return to Poland, he was elected as canon, due greatly to his uncles influence, so Copernicus devoted his time to astronomy. In 1512, Copernicus began a critical study of all the proposed models of the universe and decided that the model that Ptolomy was too complicated to be possible. He then created the Copernican system, in which the sun was the center of the universe and all the planets were in constant orbit around it. But Copernicus deemed it necessary to include two of Ptolomys constructions, the epicycle and the eccentric, to explain The constant variable in the movement of the planets because he believed that all planets were in a circular orbit around the sun. Since Copernicus used two of Ptolomys ideas, his model was about as inaccurate. Before Nicolaus Copernicus died in 1543, he finished his book De Revoliutionibus, which ...
