Lecture 18 - Hubble's Law and the Big Bang (cont.)

Professor Bailyn returns to the subject of the expansion of the universe to offer explanations that do not require belief in the Big Bang theory. One alternative is a theory that, in the past, the entire universe was reduced to an "initial singularity," in which everything was much closer, and therefore denser and hotter. Since the universe is in constant flux, however, it follows that in the future things will drift apart. The Steady State explanation for the expansion of the universe is then explained. Coined as a derogatory term meant to ridicule supporters of the Big Bang theory, Steady State purports that new energy and matter are constantly created as the universe expands, to fill in the void that results from the expansion. The discovery of quasars refuted the Steady State theory. The lecture ends with a discussion of how observing very distant objects allows us to look back in time, and also gives us a glimpse into the future of galaxies and the universe. **Reading assignment:** ;[[http://oyc.yale.edu/sites/default/files/problem_set_6_7.pdf|Problem Set 6 [PDF] ]] ;[[http://oyc.yale.edu/sites/default/files/problem_set_6_sol_1.pdf|Problem Set 6 Solutions [PDF] ]] **Resources** [[http://oyc.yale.edu/sites/default/files/astr160_lec18_0.pdf|Class Notes - Lecture 18 [PDF] ]]