Question : 1.The resolution of Olbers' paradox suggests that it gets dark : 1777273

1.The resolution of Olbers' paradox suggests that it gets dark at night because
A.the universe is not infinite in age.
B.the universe is static.
C.the universe is closed.
D.a and b
E.all of the above

2.The assumption of isotropy states that
A.the universe looks the same at all epochs.
B.the universe looks the same from all locations over sufficiently great distances.
C.the universe looks the same in all directions over sufficiently great distances.
D.all of the above
E.none of the above

3.The assumption of homogeneity states that
A.the universe looks the same at all epochs.
B.the universe looks the same from all locations over sufficiently great distances.
C.the universe looks the same in all directions over sufficiently great distances.
D.all of the above
E.none of the above

4.Quintessence is the name of the
A.force that lead to the inflationary period of the universe.
B.five dimensional space of the universe.
C.force suspected to cause the current acceleration in the rate of expansion of the universe.
D.one of the particles of dark matter related to WIMPs.
E.the force that holds the proton together.

5.During the first moments of the big bang when elements could be created, nuclear fusion reactions made few heavy elements because
A.all heavy nuclei are unstable.
B.no stable nuclei exist with masses of 5 or 8 hydrogen masses.
C.the helium nucleus is unstable.
D.the temperature and density were too low.
E.no nuclei heavier than helium could form since there weren't any electrons formed.

6.The Hubble time is
A.the time it takes a galaxy moving at 1000 km/sec to move 1 Mpc.
B.the time it takes the galaxy to double its size.
C.the time since recombination occurred.
D.the time remaining before the universe stops expanding and begins to contract.
E.an estimate of the age of the universe based on the Hubble constant.

7.The ________ theory was based on the assumption that the universe was eternal and unchanging.
A.inflationary
B.accelerating
C.steady-state
D.big bang

8.When a proton and an antiproton collide
A.they destroy each other and produce energy in the form of gamma rays.
B.one of the protons is converted to a neutron and they form nucleus of one proton and one neutron.
C.one of the protons is converted to an electron and they form a hydrogen atom.
D.one proton is converted to a neutron and the other is converted to an electron.
E.A proton and an antiproton can not collide because the Coulomb barrier is too great.

9.As the universe cooled, it eventually reached a temperature of 3,000 K and protons were able to capture and hold electrons to form neutral hydrogen. This process is known as
A.ionization.
B.isotropy.
C.annihilation.
D.recombination.
E.hydration.

10.The cosmological principle states that the universe is

I.	expanding.
II.	accelerating.
III.	homogeneous.
IV.	isotropic.

A.I and II
B.III and IV
C.I and III
D.II and IV
E.I, II, III, and IV