Lectures (Video)

- 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 II
- 18. Hubble's Law and the Big Bang III
- 19. Omega and the End of the Universe
- 20. Dark Matter
- 21. Dark Energy and the Accelerating Universe and the Big Rip
- 22. Supernovae
- 23. Other Constraints: The Cosmic Microwave Background
- 24. The Multiverse and Theories of Everything

## Frontiers and Controversies in Astrophysics - Lecture 20

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Lecture 20 - Dark Matter
This lecture introduces an important concept related to the past and future of the universe: the Scale factor, which is a function of time. With reference to a graph whose coordinates are the Scale factor and time, the problem of dark matter is addressed again. Cosmological redshifts are measured to determine the scale of the universe. The discovery of the repulsive, anti-gravitational force of dark energy is explained. The lecture concludes with discussion of Einstein's biggest mistake: the invention of the cosmological constant to balance gravity.
Prof. Charles Bailyn
ASTR 160 - Frontiers and Controversies in Astrophysics, Spring 2007 (Yale University: Open Yale) http://oyc.yale.edu Date accessed: 2009-05-12 License: Creative Commons BY-NC-SA |

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