1. Why do we see distant galaxies receding from us?
2. According to General Relativity
a) The speed of light depends on the motion of the source
b) The acceleration of light depends on the motion of the source
c) Gravity is unaffected by the shape of space
d) Gravity is sometimes repulsive
e) Gravity affects everything that has mass and/or energy
3. According to General Relativity the Earth’s orbit about the Sun
a) Will look the same indefinitely
b) Will slowly become larger due to the emission gravitational radiation
c) Will slowly become smaller and smaller due to the emission gravitational radiation
d) Should be much smaller than what it is
e) Should precess at a faster rate than Mercury’s
4. The cosmological principle assumes that the universe is homogeneous and isotropic
a) And since our solar system is neither this principle is wrong
b) And is verified at all distances, in particular our solar system is homogeneous and isotropic
c) And this implies that observers at different location in the universe would measure different average properties of the cosmos
d) But this is supposed to be true only for the average properties of the universe when measured over long distances
e) And this implies that observers at different location in the universe would measure similar properties of the cosmos, but that these properties will depend on the direction along which the observations are made.
5. According to the current theory of cosmology the fate of the universe is determined by the amount of matter-energy it contains:
a) If this amount is above a critical value then the current expansion will eventually grind to a stop and the universe will re-collapse
b) If this amount is above a critical value then the current expansion will eventually grind to a stop and remain at that size forever
c) If this amount is below a critical value then the universe will re-collapse
d) If this amount is precisely equal to a critical value the universe will be static, neither expanding nor contracting.
e) But the curvature of space is independent of this amount.
6. Imagine that in the future a place in the universe is found from which all distant galaxies are seen to be approaching. In this case
a) General relativity would be proved wrong
b) Special relativity would be proved wrong
c) The assumption that the universe is uniform and isotropic would have to be abandoned
d) The principle of equivalence would have to be abandoned
e) No changes would be necessary in our current cosmological theories
7. When we observe distant galaxies we see them receding from us.
a) This is because the Big Bang happened near the Milky Way and all galaxies were expelled from this location
b) Any other observer on any part of the universe would also find that all galaxies are moving away form him (her? it?)
c) But this is because the Milky Way is moving; any other observer would find that the universe is static
d) Then a very far observer would find galaxies moving towards him
e) This is produced by the acceleration of the Milky Way, so that the distance between us and the distance galaxies is being more and more length-contracted
8. S and R are identical twins, they are remarkably obese and their waist is perfectly circular. R is spinning very fast while S is stationary (an inertial observer). When S measures R’s waistline he finds it to be 50 inches, when R measures his own waistline as he spins he will get
a) Also 50 inches
b) More or less than 50 inches depending on the direction of spin
c) More than 50 inches and the value increases the faster he spins
d) Less than 50 inches and the value will be independent of how fast he is spinning
e) Less than 50 inches the value decreases the faster he spins
9. One of the properties of gravity that allow it to be associated with the curvature of space is that
a) The acceleration induced by gravity is independent of the nature of the objects just as motion in a curved space.
b) That gravity propagates instantaneously
c) That the gravitational force is independent of the mass of the bodies
d) Gravity is sometimes repulsive
e) The gravitational force can be altered only by very massive objects
10. When an object is placed in space the curvature of space determines how it moves, on the other hand, the object warps space
a) Only if it’s mass is very large
b) As long as it has non-zero energy and/or mass, the effect is independent of the amount of mass-energy it possesses
c) Only if it has mass and no energy
d) As long as it has non-zero energy and/or mass, the effect is smaller the smaller the amount of mass-energy it possesses
e) Only if it is stationary