4. What would happen if all the dark energy in the universe suddenly disappeared?

4.     What would happen if all the dark energyin the universe suddenly disappeared?  Explain your reasoning.  (3 points)

5.     Explain why the discovery of the CMB was a major milestone in the development of modern cosmology.  (2 points)

6.     Which elements existed at the time the CMB was emitted?  Where did the other elements come from?  (1 point)