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.

1. Introduction
2. Planetary Orbits
3. Our Solar System and the Pluto Problem
4. Discovering Exoplanets: Hot Jupiters
5. Planetary Transits
6. Microlensing, Astrometry and Other Methods
7. Direct Imaging of Exoplanets
8. Introduction to Black Holes
9. Special and General Relativity
10. Tests of Relativity
11. Special and General Relativity (cont.)
12. Stellar Mass Black Holes
13. Stellar Mass Black Holes (cont.)
14. Pulsars
15. Supermassive Black Holes
16. Hubble's Law and the Big Bang
17. Hubble's Law and the Big Bang (cont.)
18. Hubble's Law and the Big Bang (cont.)
19. Omega and the End of the Universe
20. Omega and the End of the Universe
21. Dark Matter
22. Dark Energy and the Accelerating Universe and the Big Rip
23. Supernovae
24. Other Constraints: The Cosmic Microwave Background
25. The Multiverse and Theories of Everything

In this course, Yale Prof. Charles Bailyn focuses on three particularly interesting areas of astronomy that are advancing very rapidly: Extra-Solar Planets, Black Holes, and Dark Energy. Particular attention is paid to current projects that promise to improve our understanding significantly over the next few years. The course explores not just what is known, but what is currently not known, and how astronomers are going about trying to find out.



This Yale College course, taught on campus twice per week for 50 minutes, was recorded for Open Yale Courses in Spring 2007.