The Ptolemaic System

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he Ptolemaic System, or geocentric model, is the theory that the earth is the stationary center of the universe, with the planets moving in epicyclic orbits within surrounding concentric spheres. This theory, a mathematically based extension of astronomical facts proposed by other Greek scientists at the time persisted with minor adjustments until the 16th and 17th centuries when other scientists like Copernicus, Brahe, Kepler, Galileo, and Newton would examine it, some in support, some not. These men would either manipulate and or reimagine the principles of the system to develop the basis of modern astronomy.

The Ptolemaic system was a mathematical model, based on Aristolian physics, of the universe formulated by the Alexandrian astronomer …show more content…

Like Ptolemy, Copernicus’s model would still assume that the Earth traveled in an epicycle around the Sun. However, Copernicus assumed the epicycles were smaller and proposed that the irregularities of planetary motion were optical illusions caused by the fact that the Earth was moving at the same time as the other planets. Furthermore, it proposed that the farther the planets were from the Sun, the longer it took them to travel around it which would make it possible to determine the order of the planets from the sun. Although Copernicus’s model was no more accurate than Ptolemy’s System it did succeed in getting other intellectuals of the time to challenge the concepts of the Ptolemaic system and the mathematics of Aristotle’s cosmology.

One such intellectual was Tycho Brahe (1546-1601). Unlike Copernicus, Brahe did not believe the Earth revolved around the Sun. Instead, he proposed that Mars and Venus moved around the Sun and the other heavenly bodies moved around the Earth. Although still misguided, Brahe’s contribution to the astronomy world was his means of supporting his theory. To prove his ideas Brahe constructed instruments which would help him make more naked-eye observations of the heavens than anyone had done before. When he died, his assistant Johannes Kepler (1571-1630) used …show more content…

Galileo was one of the first people to use the newly developed telescope to look into the heavens. What he saw there, from stars to features of the Moon, proved to him that the heavens were much more complicated than was realized at the time. A philosopher and a mathematician in the court of the Duke of Tuscany, Galileo presented his findings to the court, gaining favor for his theories with shrewd political skills and persuasive discussion. Despite the fact that Galileo could not prove his Copernican based model of heliocentricity, he banked on the fact that few people would understand enough Ptolemaic mathematics to dispute his claims. Galileo, a naturalist, further proposed that the universe was not a disorganized mess, but rather a place subject to mathematical laws. He also proposed that all of life could be described in terms of orderly mathematical patterns. Because the people of the time were anxious to find an orderly explanation to the world around them rather than some esoteric theory few could understand, Galileo’s Copernican system became popularized. But the question of why and how the planets moved

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