AS101 Lecture Notes - Lecture 9: Orbital Period, De Revolutionibus Orbium Coelestium, Ancient Greek Astronomy
Document Summary
France: cave paintings from 15, 000 bc may suggest knowledge of lunar phases (29 dots) and some star patterns. Ancient people of central africa apparently used the orientation of the crescent moon to mark the seasonal. A carved bone shows pictographs of the crescent moon. This helped them to determine when to plant crops. Alignments of the stones mark the rising and setting points of the sun at the solstices. China: earliest known records of supernova explosion od a day start. Also recorded solar, lunar eclipses continuously from 4 bc. Eratosthenes measured the earths circumference by observing the sun from two places on the same day of the year: measurements: At noon on the first day of summer, Alexandria: sun at 7 from vertical (zenith) Distance from syene to alexandria must be 7/360 of the circumference. Other greek astronomer figured out distances and size of moon an sun, using careful observations and geometrical reasoning.
