AST 10G Lecture Notes - Lecture 11: Galaxy Rotation Curve, Gravitational Lens, Black-Body Radiation
Document Summary
Large scale distribution of galaxies: clusters, filaments, voids. 14 billion year age of the the universe from the hubble law: v = Evidence for dark matter comes from galaxy rotation curves, the motions of galaxies in clusters, and analysis of gravitational lensing images. Hod ; t = 1/ho at time = 0. Expansion implies hot big bang, infinite density and temperature. Cosmic microwave background is the blackbody radiation of the big bang, proof that the universe started in a hot, dense state. Present temperature of the cmb is about 3k; the cmb is very smooth and uniform everywhere; tiny fluctuations in the cmb are from the seeds of galaxy and cluster formation matter vs. critical density. Future expansion vs. possible recollapse; present density of. Creation of particles and light elements in the first 5 (cid:883)(cid:882) minutes; Universe begins as about 75% hydrogen, 25% helium, almost nothing else. All heavier elements come from the evolution of massive stars.
