GEO 1111 Lecture Notes - Lecture 4: Distant Star, World Egg, Orbital Period

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: Robert Jack Cornett

Document Summary

Lec 4 solar system geocentric perspective: ptolemy proposed that planets also follow a smaller circular orbit (epicycles) and. Every planet orbit around the sun in a elliptical orbit: law of orbital harmony. For any planet, the square of the orbital period in years is propotional to the cube of the planets averge distance from the sun. Essentially, this means that planets orbit the sun in a regular and predictable fashion: law of equal ares. A line drawn from a planet to the sun sweeps out equal areas in equal time. This means that planets speed increase and decrease depending on where they are in the orbit. Closer to the star, the faster it moves, flinging it further away. While further it decelerates and then falls back towards the sun. Olbers paradox why is the night sky black: a stionary fnite universe should collapse on itself due to gravity.