Geocentric Theory This model is also called Ptolemaic system. It was created by philosophers in Ancient Greece and it was named after the philosopher Claudius Ptolemy, he lived during the 90 to 168 A.D. It was created to state how planets, the sun and the stars orbit around the Earth. This theory stated that the earth was in the center of universe. This theory existed even before Ptolemy; it has being named in many early Greek manuscripts and during the 4th century. There were some philosophers such as Aristotle and Plato that were writing about the geocentric system. Greeks created different interpretations of the geocentric model. The models show that the earth was in the center and planets and other orbital bodies moved in circles in their orbits around it. Each planet orbits around a circle. The geocentric theory holds up until the 16th century. This happened because it fits with many observations Greeks had done. With time, theories evolved there was more evidence discovered and throughout time the geocentric theory was replaced by new models created by Copernicus and other astronomers. Copernicus proposed the heliocentric theory which showed that the sun was in the center of the universe. With advances in technology the heliocentric theory was proposed and with the help of the telescope they could convince people that the earth was not in the center. This proved the Ancient theories wrong.
The heliocentric theory was given by Nicolaus Copernicus. The theory says that the sun is the center of the universe and the planets orbit around it. He published his theory in his book On the Revolution of the Heavenly Bodies.(1543) It was not until the 16th century that the theory gained popularity because technology was developing and he had more evidence on his favor. Heliocentric theory replaced geocentrism model. Aristarchus of Samos developed a form of heliocentric model in 200 BC saying that the earth and the other planets moved around a central object which he believed to be the sun. Copernicus published his theory when he was dying because of the power of the church. Galileo contributed with the theory but it was Newton who produced the first convincing proof that supported the heliocentric theory.
"Heliocentric Model." Heliocentric Model. N.p., n.d. Web. 10 Dec. 2014. <http://www.universetoday.com/33113/heliocentric-model/>. Dictionary.com. Dictionary.com, n.d. Web. 10 Dec. 2014. <http://dictionary.reference.com/browse/heliocentric+theory>. "Geocentric Model." Geocentric Model. N.p., n.d. Web. 10 Dec. 2014.