ASTR 3 Lecture 5: ASTRO LEC-10/10
Document Summary
Compiled most accurate observations using the naked eye. The orbit of each planet around the sun is an ellipse with the sun at one focus. As a planet moves around its orbit, it sweeps out equal areas in equal times. A planet travels faster when it is nearer to the sun and slower when it is farther from the sun. More distant planets orbit the sun at slower average speeds, obeying the relationship. Galileo galilei(1564-1642) overcame major objections to the copernican view. Overcoming the first objection (nature of motion); overcoming the second objection (heavenly perfection); overcoming the third objection(parallax) Galileo saw four moons orbiting jupiter, proving that not all objects orbit earth and his observations of phases of venus proved that venus orbits the sun and not earth. Modern science seeks explanations for observed phenomena that rely solely on natural causes. A scientific model must make testable predictions about natural phenomena.
