GEO 1111 Lecture Notes - Lecture 2: Planetary Nebula, Orbital Period, Meteoroid

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: David Schneider

Document Summary

Lecture 2: cosmology and the birth of the earth. Motion of the stars: there is order in the movement of celestial objects, when viewed over a whole night, stars in the northern hemisphere appear to revolve around polaris, the north star. The numbers give dates (month/day) when the planet shown was at a given location: geocentric (ptolemy model) earth at the center; aristotle, challenged by aristarchus (church doctrine) The sun revolving around earth did not explain the retrograde motion of planets. Ptolemy: planets following a smaller circular orbit (called epicycles) : heliocentric (copernicus model to galilei to kepler) - sun at the center predictable periods of retrograde motion. Copernicus: suggested that because mars has the larger retrograde motion it is the closest to earth while saturn, having the smallest retrograde motion is the furthest from the earth. Proposed that the earth spins on its axis leading to sunrise and sunset. Kepler: law of ellipses, orbital harmony, equal areas.