The Geocentric View of the Solar System
The geocentric theory is the belief that the Earth is the center of the universe and that all other objects orbit around it. This outdated and disproved theory is often attributed to Ptolemy. The belief was very popular in China and ancient Greece and widely expounded on by the leading thinkers of the day: Aristotle and Ptolemy. The theory was thought to be proved by to observations: that the stars, sun, and planets appear to revolve around the Earth each day, with the stars circling around the pole and those stars nearer the equator rising and setting each day and circling back to their rising point. Second, since the Earth is solid and stable, it is not moving, so being at rest other bodies must orbit around it. Geocentrism was not replaced until the 1600′s.
Clausius Ptolemy is the man widely credited with taking the geocentric theory mainstream. A few of the basic tenets had been published since the 6th century B.C and all of the basic components were established by Aristole’s time. Ptolemy’s influence was so extensive that his name became synonymous with geocentrism. Despite the popularity of the model, not everyone agreed with it. The Pythagorean school believed that the Earth was one of several planets going around a central fire. Martianus Capella put Mercury and Venus on epicycles around the Sun. Aristarchus of Samos wrote a work on heliocentrism saying that the Sun was at the center of the universe and the Earth and other planets revolved around it. His theory was not popular and he had one known follower. It was not until 1563, when Copernicus published his works, that a more workable heliocentric view was postulated. Still, it took until 1610, when Galileo Galilei was able to offer a more verifiable theory by using a telescope, for the heliocentric view to begin to overtake geocentrism.
What truly disproved the geocentric theory was the invention of the telescope. Observations with the unaided eye were too limited to show the true motions in the heavens. With the knowledge that we have accumulated; it is hard to understand that anyone ever believed in geocentrism, but we owe much of our knowledge base to the early theorists.
We have written many articles about the Geocentric Theory for Universe Today. Here’s an article about the Geocentric Model, and here’s an article about the difference between the Geocentric and Heliocentric Model.
If you’d like more info on the Geocentric Theory, check out an article about the Geocentric Theory, and here’s a link to an article about the center of the galaxy.
We’ve also recorded a series of episodes of Astronomy Cast about the center of the universe. Listen here, Episode 77: Where is the Centre of the Universe.
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