1. The obejct that causes the lensing effect in the case of gravitational lensing
a) has to have large amounts of interstellar clouds so that refraction can occur
b) has to have large amounts of interstellar clouds so that reflection can occur
c) has to have a large mass
d) has to be large in size
e) Both A and D
2. Observations of microlensing of stars in the nearby Large Magellanic Clouds where used to show that:
a) dark matter is made up of very dim white dwarfs
b) dark matter is made up of small black holes
c) there are insufficient numbers of dim white and black dwarfs to account for all dark matter.
d) No microlensing events were found, showing that dark matter is not made up of white or black dwarfs
e) A and B are both possible
3. How do we determine whether a galaxy is moving toward or away from our galaxy?
a) We compare its spectrum to that of matter that is stationary with respect to us.
b) We compare its apprent size now to what it was years ago.
c) We compare its apprent brightness now to what it was years ago.
d) We compare its measured distance now to what it was years ago
e) None of the Above
a) has to have large amounts of interstellar clouds so that refraction can occur
b) has to have large amounts of interstellar clouds so that reflection can occur
c) has to have a large mass
d) has to be large in size
e) Both A and D
2. Observations of microlensing of stars in the nearby Large Magellanic Clouds where used to show that:
a) dark matter is made up of very dim white dwarfs
b) dark matter is made up of small black holes
c) there are insufficient numbers of dim white and black dwarfs to account for all dark matter.
d) No microlensing events were found, showing that dark matter is not made up of white or black dwarfs
e) A and B are both possible
3. How do we determine whether a galaxy is moving toward or away from our galaxy?
a) We compare its spectrum to that of matter that is stationary with respect to us.
b) We compare its apprent size now to what it was years ago.
c) We compare its apprent brightness now to what it was years ago.
d) We compare its measured distance now to what it was years ago
e) None of the Above