ASTR 5 Study Guide - Midterm Guide: Cosmic Microwave Background, Nuclear Fusion, Phase Transition
Document Summary
Topics: big bang: olber"s paradox- there should be no nights- as the infinite amount of light from stars should keep sky bright. We are not yet getting light from infinite stars, as there"s been finite time the stars have existed, so this is not the case. Plus, some other stars cancel out the light from other stars. Universe and its contents must have evolved from a smoother simpler state, to current complexity: hubble"s law: v = h d . Since separations between all galaxies are now increasing over time by the same proportion, we know they must have been closer together in the past. 1/h = hubble time since the beginning of the universe expansion: cosmic microwave background: playing the tape of expanding universe backwards, all material must have been together in simple (atomic) dense hot state. Some scientists found this idea way too much like creation. (but they turned out to be wrong. )
