1. Cosmology: what we now know, and what we don’t

2. What is found for Type Ia SN

3. The Expansion of the Universe is Accelerating Not explicable in terms of a Friedmann universe Behavior requires addition of “Cosmological Constant” to the theory Physically, corresponds to “Dark Energy”, an energy field the produces long range, repulsive force Dark energy can contribute to Omega, make it 1

4. Contemporary “Precision” Cosmology Omega of Baryonic matter = 0.02 – 0.05 Omega of all matter = 0.33 Omega of Dark Energy = 0.67 Age of Universe = 13.7 Gyr Inflation occurred 1E-34 sec after Big Bang, during which universe puffed up by factor of 1E+25 Total = 1

5. In spite of precision, still some (very) unsatisfactory aspects Nature of the Dark Matter unknown. When (if ever) will we confirm its existence in a laboratory? Nature of the “Dark Energy” is completely unknown

6. Implications for our view of ourselves “The Realization that the majority of the matter in the universe might be non-Baryonic is the ultimate Copernican viewpoint; not only are we in no special place in the universe, but we aren’t even made out of the same stuff as dominates the matter density of the universe.” Andrew Liddle – An Introduction to Modern Cosmology

7. What we discussed this semester The solar system, to place stars and galaxies In context. Scale: the astronomical unit

8. Space filled with stars Interstellar space Scale: light year Or parsec

9. The nature of stars Stars: similarities and differences, how they work, how they form

10. The Milky Way Galaxy Vast city of stars, scale: kiloparsec

11. Galaxies and the Universe Scale: megaparsecs, hundreds of megaparsecs, thousands of megaparsecs

12. Cosmology We can see the beginning of everything

13. “The Truth is out there”