Chapter 28 The Structure of Space and Time
28.1 Looking Back in Time
1) Cosmology is the study of the overall structure and evolution of
A) the universe.
B) stars.
C) beauty.
D) galaxies.
Answer: A
2) The Big Bang occurred
A) at the tip of your nose.
B) at the center of each galaxy.
C) at some undetermined yet vastly distant point.
D) within an unusually large supernova.
Answer: A
3) Edwin Hubble discovered that the farther away a galaxy is the
A) faster it is receding from us.
B) more massive it is.
C) more energetic it is.
D) more black holes it contains.
Answer: A
4) The "Big Bang" refers to the
A) point in time in which the known (and perhaps knowable) universe came into being.
B) phenomenon of rapid chain reaction supernovae during the first 100 seconds of the universe.
C) time when our Sun will become a nova, rendering Earth into molten lava.
D) end of the universe when simultaneous supernovae will transform the universe into a
supergiant black hole.
Answer: A
5) The Big Bang
A) took place within space.
B) marked the beginning of space and time.
C) occurred as a result of disturbances within the Large Magellenic cloud.
D) took place within time.
Answer: B
6) Cepheids are types of stars that regularly change how bright they are over a period of a few
A) days.
B) months.
C) year.
D) decades.
Answer: A
7) The difference between lightwaves approaching and lightwaves receding is
A) when approaching, lightwaves have higher frequency; when receding their frequency is
lower.
B) when approaching, lightwaves have lower frequency; when receding their frequency is
higher.
C) the frequency of approaching lightwaves remain constant, while receding lightwaves are
invisible.
D) There is no difference
Answer: A
8) The "redshift" of a galaxy refers to the rate
A) at which is receding.
B) at which it is approaching.
C) at which it is spinning.
D) of its fusion.
Answer: A
9) "Cosmological Redshift" refers to
A) the expansion of space itself.
B) the expansion of galaxies.
C) the expansion of red giants.
D) the tendency of light to expand when free of gravitational influences.
Answer: A
10) How did Mr. Hubble calculate the age of the universe?
A) By measuring the rate of expansion of the universe
B) By looking at the age of the oldest stars
C) By measuring the redshift of stars within 360 degrees of the center of our galaxy
D) By measuring the rate of radioactive decay within the farthest galaxies
Answer: A
11) According to calculations made by modern astronomers, the age of the universe is close to
A) 14 billion years.
B) 7 billion years.
C) 21 billion years.
D) 6,000 years.
Answer: A
12) Cosmic background radiation refers to
A) uniformly distributed residual radiation that resulted from the Big Bang.
B) pockets of radiation found in certain quadrants of the observable universe.
C) the radiation emitted from galactic nuclei.
D) redshifted microwave radiation being emitted from the center of the universe.
Answer: A
13) The formation of more protons than neutrons (at about a 7:1. ratio) was favored in the early
universe because
A) it takes more energy to create a neutron from a proton than a proton from a neutron.
B) it takes more energy to create a proton from a neutron than a neutron from a proton.
C) the more massive neutrons made better targets for nucleon collisions.
D) the positively charged protons were repelled away from the explosion.
Answer: A
14) Astronomers who subscribe to the Big Bang theory believe the Big Bang occurred
A) about 14 billion years ago.
B) at the beginning of time.
C) both of these
D) neither of these
Answer: C
15) The Big Bang is regarded as the expansion of
A) space.
B) energy.
C) time.
D) matter.
Answer: A
16) We are actually looking into the past when we look at
A) a distant star.
B) our physics book.
C) actually, both of these
D) none of these
Answer: C
28.2 Cosmic Inflation
1) Cosmic Inflation refers to
A) an extremely rapid expansion of the early universe that occurred in an extremely brief period
of time.
B) the fact that there is an ever increasing energy cost in order for fusion within stars to occur.
C) the phenomenon of matter within the universe is becoming increasingly disordered.
D) is another way of referring to the Big Bang itself.
Answer: A
2) The currently accepted reasoning for why the cosmic background radiation is so uniform in
temperature is because
A) this temperature uniformity was achieved in the moments before cosmic inflation.
B) as the universe has had time to cool, the hotter parts transferred their heat to the cooler
regions.
C) microwaves can only function at a certain very limited range of temperature.
D) space is a vacuum and thus cannot retain heat very well.
Answer: A
3) How is it possible that today's diverse universe was able to arise from that which was very
homogenous at its first moments?
A) Inflation magnified ultrasmall quantum variations in position and momenta.
B) There is evidence of a second, slightly smaller Big Bang that took place very shortly after the
initial Big Bang, which would account for the variation in structure.
C) The rapidly cooling universe created massive quantities of hydrogen, and then helium, which
interacted with each other to create regions of relative structure.
D) Entropy immediately came into effect, slowing down some areas of expansion, while
increasing others.
Answer: A
4) In a flat universe parallel lines
A) never converge.
B) are concentric to each other.
C) are mirror images.
D) eventually meet.
Answer: A
5) According to inflation theory, parallel lines appear to remain parallel because
A) the universe is so unbelievably large.
B) mass has the effect of balancing the natural curvature of space-time.
C) space is inherently flat.
D) the universe is so very old.
Answer: A
28.3 General Relativity
1) Relativity is the
A) study of how space, energy, and mass are related to time.
B) concept that there are no absolutes that can be postulated.
C) idea that space bends in relationship to the square of the mass contained within it.
D) study of wormholes and time travel.
Answer: A
2) Spacetime is curved by
A) mass.
B) the force of gravity.
C) quantum fluctuations.
D) the vacuum force.
Answer: A
3) The universe as a whole is
A) curved.
B) flat.
C) the shape of a saddle.
D) has yet to be determined, although most astrophysical data points to a flat universe.
Answer: D
4) If the Sun suddenly became less massive, what would happen to Earth's orbit?
A) Spacetime around the Sun would become flatter, and the Earth, with its current momentum,
would exit its orbit around the Sun.
B) Spacetime around the Sun would become less flat, and the Earth would go plunging into the
Sun.
C) The Earth's orbital distance from the Sun would increase correspondingly.
D) The Earth's orbital distance from the Sun would decrease correspondingly
Answer: A
5) According to Einstein, gravity is not the force exerted by one object on another, but rather the
A) effect we witness when a large mass causes a curvature in the shape of spacetime.
B) force of attraction that exists between two objects.
C) effects of the graviton particle.
D) curvature of space caused by objects reaching the speed of light.
Answer: A
6) "Local observations made in an accelerated frame of reference cannot be distinguished from
observations made in a gravitational field" is known as the principle of
A) equivalence.
B) equality.
C) equanimity.
D) interchangeability.
Answer: A
7) Light is without mass, so how can gravity have an effect on light?
A) The space through which the light passes is curved.
B) Photons actually have a very small mass, so gravity does have an effect on them.
C) When light interacts with particles, it loses some energy, and thus takes on some mass.
D) Gravity has no effect on light.
Answer: A
8) Precession is
A) when the elliptical orbits of planets slip forward with each revolution.
B) the process of planetary evolution.
C) the stage before planets stabilize into a stationary orbit.
D) the wobbling of a planet's axis of rotation.
Answer: A
9) Technically, its not mass that causes the curvature of spacetime, but
A) mass density.
B) energy density.
C) thermal mass.
D) thermal mass fluctuations.
Answer: A
10) A greater gravitational field causes time to
A) speed up.
B) slow down.
C) fluctuate.
D) Gravity has no measurable effect on time.
Answer: B
11) Space and time are
A) bound together.
B) independent entities.
Answer: A
12) General relativity is most concerned with
A) acceleration.
B) gravitation.
C) space-time geometry.
D) all of these
E) none of these
Answer: D
13) Suppose at the surface of the Earth a person can do 20 pushups. In a spaceship far away from
any gravitational influence, accelerating at g, the same person could do
A) less than 20 pushups.
B) 20 pushups.
C) more than 20 pushups.
Answer: B
14) Fire a cannonball from a cannon and it curves due to gravity. Shine a light from a flashlight
and it
A) curves per second the same as the cannonball.
B) follows a straight-line path with no curvature at all.
C) curves half as much as the cannonball.
D) curves slightly, but not as much per second as the cannonball.
Answer: A
15) A person on the ground floor of a skyscraper ages
A) faster than a person on the top floor.
B) slower than a person on the top floor.
C) at the same speed as a person on the top floor.
Answer: B
16) A strong gravitational field
A) slows a clock.
B) speeds up a clock.
C) has no effect on the speed of a clock.
Answer: A
17) In a 1-g gravitational field, in 1 s, a light beam will curve beneath a perfectly straight line by
A) much less than 4.9 m.
B) about 4.9 m.
C) much more than 4.9 m.
Answer: B
18) Compared to a clock at the bottom of a very tall skyscraper, a clock at the top of this
skyscraper will appear to run
A) slower.
B) faster.
C) the same.
Answer: B
19) A clock on the surface of a shrinking star will run progressively
A) slower.
B) faster.
C) no difference
Answer: A
20) Light bends when it
A) passes a massive star.
B) passes through a gravitational field.
C) both of these
D) neither of these
Answer: C
21) The quantity that undergoes a red shift is
A) wave frequency.
B) wavelength.
C) both of these
D) neither of these
Answer: C
22) The elliptical orbit of Mercury measurably precesses because
A) Mercury moves in the gravitational field of the other planets.
B) Mercury travels faster than any other planet.
C) Mercury is closest to the Sun.
D) the Sun's gravitational field varies along Mercury's orbit.
E) none of these
Answer: D
23) According to relativity theory, it is possible to reverse time and grow younger when you
A) are near a black hole.
B) are near a very large gravitational field.
C) travel at nearly the speed of light.
D) you can never grow younger.
E) none of these
Answer: D
24) If the orbit of Mercury were perfectly circular, its rate of precession would be
A) larger than it is now.
B) smaller than it is now.
C) the same as it is now.
D) zero.
Answer: D
25) If the elliptical orbit of Mercury were more eccentric, its precession rate would be
A) larger than it is now.
B) smaller than it is now.
C) the same as it is now.
D) nonexistent.
Answer: A
28.4 Dark Matter
1) Dark Matter is matter that
A) cannot be seen, felt, or measured.
B) cannot be seen or felt, but can be measured through its gravitational effects.
C) is Dark Energy's complement.
D) is found within a black hole.
Answer: B
2) Evidence for dark matter is exhibited by the
A) relatively similar speeds at which all stars in a galaxy orbit the galactic nucleus.
B) speed at which galaxies orbit one another within clusters.
C) degree to which galaxy clusters exhibit gravitational lensing effects.
D) All of the above
Answer: D
3) According to dark matter theory, most of the mass of a spiral galaxy is found
A) within the central supermassive black hole.
B) within the luminescent spiral arms.
C) outside of the luminescent spiral arms.
D) in the form of dark energy.
Answer: C
28.5 Dark Energy
1) Dark energy
A) is the phenomenon responsible for the acceleration of the universe.
B) would be considered to be the opposite of gravity.
C) is energy that exerts an outward pressure, causing spacetime to expand.
D) All of the above
Answer: D
2) Dark energy bends the curvature of spacetime
A) in the exact same fashion as gravity.
B) in the opposite manner of gravity.
C) by absorbing all lightwaves that pass through it.
D) Dark energy does not bend the curvature of spacetime.
Answer: B
3) Distant galaxies are
A) growing closer to each other as they encounter the curvature of the universe.
B) accelerating away from each other.
C) slowing in their dispersal due to the effects of gravity.
D) connected to each other by dark energy.
Answer: B
28.6 The Fate of the Universe
1) Heat death refers to the universe
A) reaching the lowest energy state possible, which will mean the greatest level of entropy.
B) ending after a massive fire.
C) reaching a state where all stars expand and merge into each other.
D) reaching the point where the process of radioactive decay is no longer possible.
Answer: A
2) The Big Rip refers to the
A) accelerating influence of dark energy, causing all matter to become completely ripped apart.
B) phenomenon of dark energy causing the universe to rip into multiple spacetimes.
C) possibility that galactic centers may suddenly implode causing galactic disintegration.
D) phenomenon of dark energy decelerating, causing all matter to disintegrate.
Answer: A
3) Eternal Inflation refers to
A) the possibility that our universe is only a patch of a greater universe and that the process of
universe spawning will continue forever.
B) the observation that cosmic inflation could eventually curve back in on itself, causing its
opposite: the compression of space.
C) cosmic inflation inflating itself such that its own inflation is self-generating.
D) the presence of a distinct beginning of time.
Answer: A
Test Bank for Conceptual Physical Science
Paul Hewitt, John Suchocki, Leslie Hewitt
9780321752932, 9780134060491
