1) Give two pieces of evidence that can be used to argue that the Universe has a finite age. Do not just name the observations, but also explain how they lead us to the finite age conclusion.

2) Below is the graph showing the situation in a car race after a certain amount of time has passed. Each large dot represents one of the cars on the track. You may assume that all cars in the race are moving at a constant velocity.

a) (6 pts) How long has this race been going on? Show your work.

b) (8 pts) On the graph above, draw a line representing the situation in the race as of one hour ago. It doesn't have to be precisely correct. If the graph doesn't change, just write "no change" on the graph. Briefly explain below your answer for this part.

3) Name and explain two pieces of evidence that can be used to argue that the overall average density of matter in the Universe (including dark matter) is about 20% of the critical density.

4) Two of the most distant objects in the Universe are quasars and Gamma Ray Bursters (GRB).

a) (5 pts) Explain the evidence that leads us to believe quasars are extremely far away from the Earth.

b) (9 pts) What do we think is the mechanism that causes GRB's? Explain the evidence that leads us to believe GRB's are extremely far away from the Earth.

5) The graph below represents a Hubble Law diagram for a Universe with no cosmological constant (the dashed line is for an empty Universe) and a matter density about equal to the critical density.

a) (7 pts) Explain why this graph is shaped differently from a straight line Hubble's Law.

b) (7 pts) On the graph above, draw in what you would expect the graph to look like if the matter density were only about 20% of the critical density (again, assume there is no cosmological constant). Explain why you drew the graph the way you did. If you don't think the graph would change, write "no change" and explain your answer.

6) Give two examples of Anthropic Coincidences, then state two different definitions for versions of the Anthropic Principle.

7) Two factors in the Drake equation are fp (fraction of suitable planets on which life develops) and L (lifetime of an average civilization).

a) (7 pts) How will current research of Mars and Jupiter's moon Europa affect our estimate of the value of fp? Explain.

b) (7 pts) Why is L relevant in the Drake equation? Explain.

8) The discovery of the Cosmic Background Radiation (CBR) has been an important milestone in our study of the Universe.

a) (7 pts) Explain why Astronomers felt that the CBR had to have a lumpy nature (which it was subsequently shown to have).

b) (7 pts) Explain why the observations of the CBR have lent so much credibility to the Big Bang theory, more so than Hubble's discovery of the expanding universe.