NATS 1740- Midterm Exam Guide - Comprehensive Notes for the exam ( 38 pages long!)

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Tatiana Paulin

Document Summary

Geocentric model places earth at the centre of the universe. Ptolemaic model- geocentric model proposed by ptolemy. Each planet moves around a small circle that turns upon a larger circle. The backwards portion of the loop mimics retrograde motion. Copernican revolution- sun centered model proposed and modern science emerged. Kepler-discovered that planets do not orbit in a circle. Ellipse- special type of oval that is the shape of planetary orbits. Eccentricity- how much an ellipse if stretched compared to a perfect circle. The orbit of each planet about the sun is an ellipse with the sun at one focus. Planets closest point to the sun is called perihelion and farthest is called aphelion. A planet moves faster in the part of it"s orbit near the sun and slower farther from the sun, sweeping out equal areas in equal time. More distant planets orbit the sun at slower av. speeds. p^2=a^3.