AS101 Lecture Notes - Lecture 7: Apparent Retrograde Motion, Deçan, Deferent And Epicycle
Document Summary
A carved bone shows pictographs of the crescent moon: this allowed them to determine when to plant seeds and grow their crops, 4000 bc: egyptians institute the 365 day calendar based on periodic rising of. Also recorded solar, lunar eclipses continuously from 4 bc: 1054 ad: supernova explosion recorded by anasazi tribes as well as in china. The greeks were the first to observe without resorting to natural supernatural and gods. Thales of miletus- first assumed that the world was understandable and proposed a model of the earth. He successfully predicted a solar eclipse: 500bc: pythagoras suggests that the earth is a sphere and not flat as had. The most sophisticated geocentric model was that of ptolemy (ad 100-170): the. Ptolemaic model: planets move on small circles called epicycles, attached to big circle in which planets go backward in this model.