1. Is there gravity outside our atmosphere where there is no air? If your answer is yes, then explain why we see astronauts floating about the cabin in the Shuttle as if they were in outer space. If your answer is no then explain why the shuttle does not move at constant speed in a straight line.
2. According to general relativity our expanding universe should describe
a) The motion of galaxies away from the location of the Big Bang
b) The contraction of space itself as matter expands form the location of the Big Bang
c) The expansion of space as matter is kept in place by its mutual gravitational attraction
d) The expansion of space itself which carries along matter
e) An effect now known not to be correct.
3. Two twins are born on Earth, when they are 20 years old twin A makes a trip to a distant and very massive and compact planet traveling in a spaceship that moves close to the speed of light. Twin B stays at home. Upon return
a) A is older than B
b) A and B are the same age
c) B is older that A by a larger amount than if A had not stayed on the planet
d) Who is older depends on how long was A on the planet and how fast was he traveling
e) B is older than A by a smaller amount than if A had not stayed on the planet
4. Imagine
a spacecraft that is in orbit around the Earth and this orbit is such that the
ship is always above
a) Exactly the same color as seen by an observer on Earth
b) Slightly more yellow than what an observer on Earth sees
c) Slightly redder
d) Slightly bluer than what an observer on Earth sees
5. An observer on an accelerating spacecraft with no windows finds that there are
a) No experiments he can perform inside the craft that can determine whether it is moving
b) Experiments that can be done inside that demonstrate it is moving, but these cannot determine whether the ship is moving at constant speed or whether it is accelerating
c) No experiments that can tell him whether he is accelerating in space and not standing on top of a planet
d) Experiments that can show him he is accelerating, but he cannot tell whether this is due to the rockets or whether he standing on some planet.
e) No experiments that can tell whether he is accelerating, but there are ways of finding out whether he is moving.
6. Light takes about 500 seconds to travel from the Sun to Earth and about 43 minutes to get to Jupiter. If the sun were to suddenly disappear the associated effects would be noticed
a) On Earth only after 500 seconds and on Jupiter after 43 minutes
b) Instantaneously on Earth and Jupiter
c) Instantaneously on Earth and a short time later on Jupiter
d) First on Jupiter and then on Earth because Jupiter is moving so much closer
e) Simultaneously on Jupiter and Earth after the average of 500 seconds and 43 minutes.
7. When Einstein modified his gravitational equations to include the cosmological constant
a) He violated the steps of the scientific method since he modified his theory
b) He did not follow Ockham’s razor as a guiding principle since the final theory is more complicated than the original one
c) He had no other motivation than seeing what kind of universes could be described in this way
d) He followed both the scientific method and Ockham’s razor in modifying his theory to accommodate the data, and doing so in the simplest possible way.
e) He was able to finally describe an expanding universe.
8. When a light beam goes by a black hole
a) It will be bent towards the black hole to a larger or lesser degree depending on how close the light beam comes to the hole.
b) It will be bent away form the black hole due to the repulsion effects of gravity
c) It will necessarily be sucked into the black hole horizon
d) It will be bent towards or away from the black hole depending on how close the light beam comes to the hole.
e) It will not be affected
9. A rock is moving above Earth at very high speed. It starts in a direction parallel to the surface, then
a) It will keep on going in a straight line at constant speed
b) It will fall faster than when it has no initial velocity because it’s mass is larger and the gravitational force is also larger
c) It will fall at the same rate than when it has no initial speed because gravitational acceleration is independent of the mass
d) It will fall slower than when it has no initial velocity because in its reference frame time flows slower than on Earth
e) The gravitational force on the rock is identical to when the rock has no initial speed.
10. One peculiarity of the gravitational force is that
a) It is sometimes repulsive and sometimes attractive
b) It is always attractive and is experienced by all bodies
c) It has the exact same strength between any two bodies
d) It acts only over very short distances
e) It is independent of the distance between any two objects