The three basic theories that ancient astronomers believed to be true are as follows:

All motion in the heavens is uniform circular motion.

The objects in the heavens are made from perfect material, and cannot change their intrinsic properties (their brightness).

The Earth is at the center of the Universe.

Though nowadays we know these to be false, at the time these theories were never even questioned. As I said above, they believed that planetary motion was in the form of perfect circles (diagram 4) and by adjusting the velocity of these concentric spheres most of the planetary motion could be explained. However, there was still the problem of varying brightness in stars and apparent retrograde motion. To solve thi

The orbit of planets are ellipses, with the sun at one center of the ellipse

As you can see between the time of Ptolemy and Kepler there were great leaps and bounds made in how we perceived the Universe. Ptolemy’s view of the universe was basically that it was geocentric and all the planets orbited about the Earth on a perfectly circular path. He as well thought that the planets were made of some heavenly material that would not change in brightness. Since Ptolemy was one of the first Astronomers and he had little equipment and at that time in the world there was not much known about Mathematics; I find it very impressive that he could even come to those conclusions. However, those predictions were not correct and thanks to Johannes Kepler we finally know how the Universe works. The major differences between Kepler’s view of the Universe and Ptolemys is that the Sun is the center of the Universe and the planets follow a slightly ecliptic path not a circular one. As far as brightness is concerned, stars and other heavenly bodies are not made of a perfect material but they are made of many gases and other elements.

Not only did Kepler solve the mystery as to how the planets orbited the sun, he as well made many other contributions to society in the field of optics. He was the first to investigate the formation of pictures with a pinhole camera and the first to explain the process of vision by refraction within the eye. He as well was the first to formulate eyeglass designed for people wi

Some topics in this essay:
Mathematical Collection, Deferents Ptolemaic, Planetary Motion, Brache Kepler, Ptolemys Sun, Universe Ptolemy’s, Aristotle Copernicus, Tycho Brache, Ptolemy Astronomers, Tycho Kepler, planetary motion, view universe, planets orbited, kepler believed, planets orbited sun, sun center, concentric spheres, perfect circles, created image, sphere stars, god created,