NATS 1740 Lecture Notes - Lecture 6: Geocentric Model

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Tatiana Paulin

Document Summary

Earth"s rotation makes them appear to rise in the east and set in the west. Apparent retrograde motion: the apparent motion of a planet, as viewed from earth, during the period of a few weeks or months when it moves westward relative to the stars in our sky. Mars never actually changes direction; it only appears to go backward as earth passes mars in its orbit. The idea that earth goes around the sun was suggested as early as 260 b. c. by the greek astronomer. Geocentric mode: any of the ancient greek models that were used to predict planetary positions under the assumptions that earth lay in the center of the universe. Ptolemaic model: the geocentric model of the universal developed by ptolemy in about 150 a. d. Copernican revolution: the dramatic change, initiated by copernicus that occurred when we learned that earth is a planet orbiting the sun rather than the center of the universe.