For each
question, the first answer is the correct answer.
1. An object whose gravitational
field is so strong that light cannot escape is called a
A. black hole
B. pulsar
C. neutron star
D. black dwarf
E. dark nebula
2. How does the General Theory of
Relativity describe gravity?
A. As a stretching and bending of
the geometry of space.
B. As a force that acts from a
distance.
C. As a law passed by the Michigan
state legislature.
D. As a particle that travels
between objects.
E. By the fact that light moves at
a constant speed.
3. How did Newton describe gravity?
A. As a force that acts from a
distance.
B. As a stretching and bending of
the geometry of space.
C. As a law passed by the Michigan
state legislature.
D. As a particle that travels
between objects.
E. By the fact that light moves at
a constant speed.
4. When were most of the hydrogen
and helium found on Earth formed?
A. When the universe was only a few
minutes old.
B. By the radioactive decay of
uranium and iron.
C. When the Earth captured the
Moon.
D. When the collision of the earth
with an asteroid killed the dinosaurs.
E. In the center of the Sun after
it started to have thermonuclear reactions.
5. How do we know that the universe
is expanding from a very much smaller size?
A. From the combination of two of
the other answers.
B. Because the velocity of
recession of distant galaxies is proportional to their distance.
C. Because we see Cosmic Microwave
Background radiation coming from all directions.
D. Because it has a flat geometry.
E. None of the other answers are
correct.
6. The basic source of energy of
quasars is:
A. The release of gravitational
potential energy as gas falls onto a disk around the central black hole.
B. Matter-antimatter reactions.
C. High-energy particles escaping
from the central black hole.
D. Nuclear reactions inside the
black hole.
E. Nuclear reactions in stars.
7. The inflation model predicts
that the geometry of the universe should be
A. flat
B. closed (positive curvature; 4D
version of a ball)
C. open (negative curvature; 4D
version of a potato chip)
D. it does not make any prediction
about the geometry
E. obtuse
8. What force currently works to
SLOW DOWN the expansion of the universe?
A. Gravitational attraction of all
matter for all other matter.
B. The strong nuclear force.
C. The kinetic energy contained in
the motion of the galaxies.
D. Reluctance of small investors to
buy stocks even at today's depressed prices.
E. Electrostatic attraction between
atomic nuclei.
9. The Principle of Equivalence as
used in General Relativity says that that an observer cannot tell the
difference between acceleration and
A. gravity.
B. deceleration.
C. time.
D. a falling elevator.
E. being inside a black hole.
10. Oops! You take the wrong exit
on I96 and find yourself trapped $inside$ the Schwarzschild radius (event
horizon) of a black hole. You use your cell phone to try to send a radio SOS
message back to the AAA (who prudently have located their office outside the
Schwarzschild radius). What will be the fate of that message?
A. The message will never emerge
from the Schwarzschild radius.
B. The radio waves will emerge from
the Schwarzschild radius with a huge gravitational redshift.
C. The radio waves will emerge from
the Schwarzschild radius as gamma rays.
D. The message will make it to AAA
but all of its information will be randomly garbled.
E. The message will make it to the
AAA in fine shape with all information intact (but your call will be put on
hold).
11. Why do we think that quasars
are extremely luminous?
A. Their large redshifts plus
Hubble's Law indicate very large distances, so they must be very luminous to
produce the observed flux.
B. They are powered by black holes,
which always are very luminous objects.
C. We cannot measure any parallax
for them, so they must be far away and therefore very luminous.
D. Their high temperatures show
that they must be more luminous than any stars.
E. We can see that they are much
larger in diameter than any normal galaxy, so they must be much more luminous
as well.
12. Based on the variabilty of the
light, which is the best size estimate for the central light source in a
typical quasar?
A. Similar in size to our Solar
System
B. Larger than our Galaxy
C. 100 light years.
D. Smaller than a breadbox.
E. 1000 light years.
13. If we watch from afar as an
astronaut falls into a black hole, which of the following effects would we
$NOT$ be able to see even in principle?
A. The astronaut smashing into the infinitely
dense material at the singularity.
B. The astronaut being horribly
stretched out by tidal forces near the Schwarzschild radius.
C. The astronaut getting older at
an ever-slowing rate.
D. The astronaut never quite
reaching the Schwarzschild radius.
E. We could see all of these things
happen.
14. If the universe has a closed
geometry (positive curvature, described by the surface of a sphere in our 2D
analogy), which of the following would be true?
A. It would be possible to
construct triangles in which each angle is 90o.
B. Two lines which are parallel at
a given point would never cross each other at any other point.
C. It could not be expanding.
D. It would have infinite volume.
E. Hubble's Law could not occur.
15. What is the source of the Cosmic
Microwave Background radiation?
A. It is photons left over from a
time when the Universe was denser, and was filled by hot, opaque gas.
B. It is emitted by stars in
distant galaxies.
C. It comes from cold gas (3o
K) at the edge of the universe.
D. It comes from the disk of the
Milky Way.
E. It is emitted by supernovae in
galaxies in the Local Supercluster.
16. Which of the following best
describes the inflation model of the universe?
A. The scale factor increased by a
huge amount in a very short period of time early in the life of the universe,
then continued to increase at a much slower rate.
B. The universe has always been
expanding at a roughly constant rate.
C. The universe first swelled up to
an enormous size, then collapsed back down to the approximate size we see
today.
D. The universe expanded to a large
size very early on, and now is steadily collapsing back to a single point.
E. The amount that money can buy
steadily decreases with time.
17. The Doppler shift, measured
from the change in wavelength of emission or absorption lines in the spectrum
of a galaxy, tells us
A. the velocity of that galaxy
along the line of sight.
B. the velocity of that galaxy
perpendicular to the line of sight.
C. the temperature of that galaxy.
D. the speed of light in the
direction of that galaxy.
E. the chemical composition of that
galaxy.
18. A fairly massive black hole
appears to reside at the center of our own Galaxy. The evidence for this is:
A. We see from the orbits of stars
very close to the Galactic center that there must be a very massive object in
there.
B. We see gigantic radio jets
shooting out from the center of our Galaxy.
C. When we look at infra-red and
radio wavelengths, we see a full-fledged quasar shining away in the center of
our own Galaxy.
D. We see periodic bursts of
intense x-ray energy coming from the Galactic center.
E. Astronauts have been seen to
fall into the black hole.
19. When we look over very large
size scales in space, what is the distribution of galaxies and clusters of
galaxies?
A. They lie on the surfaces of
gigantic, intersecting bubbles.
B. They are smoothly distributed
throughout space.
C. They form the centers of large
spheres of completely empty space.
D. They all lie along one long line
that connects back to the center of the universe.
E. The density of these objects in
space gets to be less the farther you go away from Earth in any direction.
20. The Cosmic Microwave Background
radiation is systematically slightly brighter in one direction and slightly
fainter in the opposite direction. What is this due to?
A. Doppler shifting due to the
orbital motion of our galaxy about the local supercluster of galaxies.
B. Because we are located near the
edge of the universe, there is more material in one direction than in the other
direction.
C. The universe is sytematically
hotter in one direction and cooler in the opposite direction.
D. Dust has absorbed the CMB
radiation from one direction.
E. The Cosmic Microwave Background
comes from stars within our Galaxy.