PHYS 182 Lecture Notes - Lecture 2: Copernican Principle, Neutrino, Copernican Revolution
24 Jan 2018
School
Department
Course
Professor
Document Summary
Radius of sun is 7 * 105. Observable universe: 100 of billions of galaxies. Scale of universe reduced by 10 billion. Sun orbits the center of the milky ay (230 million year orbit) at 800,000km/hr. Moves randomly with respect to nearby stars. Light takes 8 minutes to reach earth. Neart star takes 4 years for light to reach earth. Further apart the galaxies are - the faster they are moving away from each other (receding) Galaxies that are close together have such strong gravitational field. Milky ay and nearest galaxy (andromeda) are on a collision course. Takes 2 million years of light from andromeda galaxy to reach earth. Solar system is constantly moving in relation to other stars. Light-year = speed of light x 1 year. Explain a wide variety of observations with a few principles. Must be supported by large and compelling evidence. Must not have failed any crucial test of validity.
