Models of the Universe
1. List the observations and other evidence that could be used to support a geocentric view of the solar system:
Many cultures studied astrology for different purposes, however, the Greeks studied astrology simply because they were interested in how the system worked. The Greeks believed in the symmetry and unity of the cosmos. It was this charactertistic that made it a need for them to create a unified model of the universe.
The development of the geocentric model began when Aristotle (384-322 BC) rejected the Pythagoreans’ idea that earth moved around a central ball of fire. His major reason for the earth being the centre of the model was that if the earth was in fact moving, he would be able to observe the change in the relative positions of stars (now known as parallax). This information is important because generally, when an observation point changes, the distance of far away objects in relation to nearby objects would appear to change this is seen in diagram 1 which shows the apparent motion of stars in relation to a moving earth. However, after observing the stars for a peirod of time, Aristotle found that the stars showed no such shift and concluded that the earth was stationary. However, modern scientists now know that the displacement of stars can only be measured with a very large telescope this effect is hard to be observed purely by naked eye.
Aristotle also noticed that the sun, moon, celestial bodies and stars moved across the sky in a circular motion, therefore he concluded that each celestial body was attached to a crystalline sphere that had the earth as the centre and each celestial body (crystalline sphere) would move about the earth at different but constant speeds. In order of distance from the earth, Aristotle arranged his model as such: moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn and a celestial sphere of stars that was moved by the Prime Mover (god).
Another prominent observation that...