Reasons for the expansion of the universe are addressed at the start of this lecture, focusing especially on the acceleration of dark energy. Supernovae were the first evidence for the existence of dark energy. Two other proofs are presented. The first is the Cosmic Microwave Background, which is a form of electromagnetic radiation that is perfectly smooth and equal in all directions. It firmly supports the Big Bang theory. Projects attempting to measure it, such as COBE and WMAP, are discussed. Secondly, Large-Scale Clustering is introduced: by measuring the degree of clustering, astronomers hope to advance their understanding of dark energy and dark matter. Computer simulations of the evolution of the universe are shown.

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.