1. If a star formation switched off in a spiral galaxy, which part of it would get fainter? Bulge, disk, halo, dark matter or globularclusters?
2. What is the essential dissimilarity between formation of spiral and elliptical galaxies?
a. random motions of stars are larger in elliptical ?
b. spiral galaxies had a more recent tidal encounter with another galaxy?
c. elliptical form stars before they collapse; spiral form stars after they collapse?
d. spiral galaxies rotate faster
e. elliptical had a more recent violent encounter with another galaxy?
3. The temperature of the background radiation is almost the similar in all directions
a. this is surprising, because the radiation from opposite directions in the sky is coming from places that are beyong each others light travel horizon
b. this is expected because the big bang was a very homogenous explosion
c. this was a measurement error in early observations now discredited.
d. the statement is not true, the temperature shows a large fluctuation all over the sky
e. none