The Ptolemaic System of Universe

A thousand and eight hundred years ago, a Greek mathematician proposed the planet moves with constant velocity in certain pattern of orbit. Whilst the center of the path rotates uniformly. Then, he mentioned the movement pattern as a small circle which the Earth is moved slightly to one side of its centre.

His proposal has been surviving for 1400 years and it was considered as the planet geocentric theory. The Almagest is the title of his mathematical book he wrote. Claudius Ptolemaeus which is also known as Ptolemy is the name of that Greek mathematician. Even though, most of Greek scientists during that era were doing argument and discussion instead of observation and experimenting, they were able to produce fundamental principle for the developing of astronomy.

Ptolemy predicted that the movements of every space objects in one system is in an uniform condition. Those are including the speed of motion and the orbits. His description based on the system created by Aristotle which the universe is described as earth-centred system. It means that the use of geometry pattern in the movement of the system is carried the fixed stars, planets, moon and sun rotate the earth. He used the word of epicycles as the geometric models describing the combination of circular motion of those objects. However, the Earth's location is not exactly in the centre of the circle. In Ptolemaic system -- the term of universe created by Ptolemy -- was displaced from the centre of the big circular pattern and makes the planets around were able to interfere the others movements. Basically, in the real world the ptolemaic system allows the planets to increase of the possibility of collision.

The slightly location of the Earth inside the big circle is called as a deferent which makes the Earth does not moved at all in a pattern of orbit. So, the Ptolemaic system describes the Earth as pure rotation of movements. Interestingly, by taking the understanding of the epicycles system, we were able to make a mathematical principle from the radiant and surrounding. Overall, this theory helped scientists and astronomer to predict the location of many space objects including the Sun and the Planets several hundred years later. And the most interesting fact, by using the principle invented by Ptolemy, Copernicus presented the heliocentric theory.