The critical evidence for cosmic acceleration in 1998 came from two teams of astronomers, both observing
A) hypernovae.
B) gamma ray bursts.
C) type I supernovae.
D) type II supernovae.
E) ages of globular clusters.
Question 2
Suppose you claim that you are feeling the effects of a gravitational field. How can you explain the fact that Al is weightless?
A) She is weightless because she is moving at constant velocity.
B) She is weightless because she is in a free-float frame.
C) She is weightless because she is in free-fall.
D) If you are in a gravitational field, then she cannot be weightless.