ASTR 340 Study Guide - Midterm Guide: Velocity-Addition Formula, Equivalence Principle, Arthur Eddington
Document Summary
Ancient greeks: believed concepts of the world could be understood in material terms. Had wrong ideas but at least were testable. Ionian philosophy: demand logically self-consistent principles that would be dismissed if shown to be false. Aristotle"s cosmology: earth is spherical, motionless, center of universe, sun, moon, planets revolve around earth, heavenly bodies in transparent spheres (27) that revolve around earth. Ptolemy: added epicycles to aristotle"s model to explain retrograde motion. Equant: point near earth that other planets orbited, explained changes in speed. Copernicus: proposed heliocentric model, planets rotate sun on concentric spheres that orbit in circles. Tyco brahe: observed a supernova, shattered belief that heavens were perfect. Lack of parallax of supernova implied it was too far to be inside atmosphere. Law of orbits: planets move in ellipses, with sun at 1 focus. Law of areas: a line that connects the planet to the sun sweeps up equal area in equal time.
