Introduction to Astrophysics

Lecture Details

FrontiersControversies in Astrophysics (ASTR 160)

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.

0000 - Chapter 1. The Expanding Universe -- Big Bang and Steady State Theories
0953 - Chapter 2. Quasars and the Rejection of the Steady State Theory
3221 - Chapter 3. Calculating the Duration of the Big Bang
4316 - Chapter 4. Calculating the Potential Future of the Universe

Complete course materials are available at the Open Yale Courses website httpopen.yale.educourses

This course was recorded in Spring 2007.