1. Explain how the detections of anamolous motions (e.g. Uranus, Mercury, rotation speeds of galaxies) are used to probe for the existence of new objects in the Universe or new models of the Universe.

2. Summarize the Shapley-Curtis debate and its implications on the overall size of our Galaxy and the size of the Universe. What arguments did Shapely make to insist that there were no objects outside of our Galaxy.

3. Briefly outline the procedure/experiment that Penzias And Wilson used to discover (accidentally) the Microwave Background

4. What was the COBE mission of NASA and what were its main results? What is the WMAP mission and how has it improved upon the COBE results?

5. Google on the term "quantum gravity" and describe what physicists think this is and why it may be applicable to the very early Universe.