1. State the two underlying assumptions of Simple Relativity. First: The laws of physics are the same in all frames moving at a constant velocity with respect to another. Second: The speed of light will always be the same measured from any reference frame.

2. Velma is flying past Mort's swimming pool at 4/5 c speed. How would she view the length of the swimming pool: extended, shrunk or the same? By how much ? How will Velma view the breadth of the pool, perpendicular to the direction of her motion? She would observe the length of Mort's pool shrunk by the factor gamma, but the breadth will appear to be the same; gamma = 1/sqrt(1-v2/c2) = 1/sqrt(1-(4/5)2) = 1/sqrt(3/5)2 = 5/3, so L = L0/gamma, the pool will appear shrunk to 60% of its length to Velma.

3. What is Cosmic Background Radiation? The cosmic background radiation is the relic radiation from the BIG BANG that gave birth to our universe. Because the universe expanded, the CMB radiation now has a temperature of 2.7 Kelvin.