ASTR 2010 Lecture Notes - Lecture 1: Geocentric Model, Kaleidoscope, Orbital Period
Document Summary
If the earth is spinning on its axis, we"re moving. The earth is moving 7000 miles per hour. Had the planets orbiting the earth, instead of the sun. Made the first map of the world, latitude and longitude. He looked at ptolemy, and made the conclusion that the sun was the center and the earth orbited around the sun, instead of ptolemy"s theory that the sun orbited the earth. Published his work in the year 1543, as he was laying in his death bed. When christopher columbus sailed (1492), the earth was the center. In the late 1500"s accumulated the best observations of mars. Kepler began to look at tycho"s observations of mars (best observations) and measured. Kepler"s first law: ellipses, a planet moves in an elliptical orbit with the sun at one focus. Kepler"s second law: speed varies, a planet moves so that a line from it to the sun sweeps out equal areas in equal times.
