PHY 102 Lecture Notes - Lecture 2: Circular Motion, Geocentric Model, Nicolaus Copernicus
Document Summary
Thought year was 360 days because there are 360 degrees in a circle. 1st rising of sirius at dawn signals the flooding of the nile. Sun rides by in a boat (explains rising and setting sun) Bubble of water on the back to a turtle. First to claim numbers can describe the universe. Don"t accelerate except to go in a circle. Earth is at the center of the universe. Kept postulates (the original ideas) through changes in model. Earth is fixed at the center of the universe. Sun, moon, stars have separate crystal spheres around the earth. Earth is at the center of everything. Can"t feel the earth move so everything else has to orbit it. Retrograde motion: planets seems to occasionally reverse direction, then reverse direction again. No longer constant motion, uniform speed and motion. Need to keep circles and uniform motion. 1st to link math with cosmological theory. Not for brightness change (sun rising and setting)
