31.The flatness problem states thatA.the density of the universe very : 1777276
31.The flatness problem states that
A.the density of the universe is very close to the critical density.
B.the density of the universe is much larger than the critical density.
C.the density of the universe is much less than the critical density
D.the universe is two dimensional
E.the universe is one-dimensional
32.If galaxy A is four times more distant than galaxy B, then according to the Hubble Law, galaxy A will recede ____ than galaxy B.
A.16 times faster
B.4 times faster
C.2 times faster
D.1.2 times faster
E.0.25 times faster
33.If a galaxy is located at a distance of 18 Mpc and is found to have recessional velocity of 1170 km/sec, what is Hubble's constant based only on this galaxy?
34.If gravity is unimportant, and H equals 75 km/sec/Mpc, then the age of the universe is about
A.8.9 billion years.
B.13 billion years.
C.16.6 billion years.
D.26 billion years.
E.74 billion years.
35.If a galaxy is found receding from us at 894 km/sec and it is located at a distance of 12 Mpc, what is the age of the universe if the universe is flat?
A.about 20 billion years
B.about 1.3 billion years
C.about 13 billion years
D.about 9 billion years
E.about 90 billion years
36.What is the fate of an open universe?
C.Gradual halt to the expansion
D.Can't be known without density information.
37.What observational evidence supports the fact that our universe is static and unchanging?
A.Detection of the cosmic microwave background (CMB)
B.Dark sky at night
C.Redshift of galaxies
D.Evolution of galaxies with distance
E.None of the above
38.Where did the cosmic microwave background (CMB) come from?
A.Photons emitted from the first stars
B.Photons released from hydrogen in our galaxy
C.Light scattered by dust in our Solar System
D.Photons released when electrons and nuclei combined for the first time.
39.Why is the cosmic microwave background (CMB) so cold if the early universe was so hot?
A.Enough time has passed for matter in the universe to release enough heat to cool down.
B.The CMB constantly interacts with atoms, which effectively cool down the photons.
C.The expansion of the universe has redshifted those photons to an effectively cooler temperature.
D.Misleading; The Big Bang was initially hot but the CMB was released from cold material much later on.
40.Which of the following is not an assumption of cosmology?
41.What observation has prompted astronomers to ponder the possible existence of dark energy?
A.Discovery of quasars
B.Discovery of superclusters
C.Supernovae appear fainter than expected at large redshifts.
D.Uniform nature of the cosmic microwave background (CMB).