Question 1

What is the temperature of the blackbody radiation that we receive from the Big Bang (the cosmic microwave background radiation)?

Accepted Answer

A)  30 K 
B)  30 billion K 
C)  3 K 
D)  3000 K 
A)  30 K 
B)  30 billion K 
C)  3 K 
D)  3000 K

Question 2

When the Big Bang began,all the fundamental forces were unified and behaved like a single force.As the universe expanded and cooled during the Big Bang,when did gravity first become a separate force?

Accepted Answer

A)  at the start of quark confinement, when the universe was about 10-⁶ s old 
B)  at the start of the inflationary period, when the universe was about 10-³⁵ s old 
C)  at the end of the inflationary period, when the universe was about 10-³³ s old 
D)  at the Planck time, when the universe was about 10-⁴³ s old 
A)  at the start of quark confinement, when the universe was about 10-⁶ s old 
B)  at the start of the inflationary period, when the universe was about 10-³⁵ s old 
C)  at the end of the inflationary period, when the universe was about 10-³³ s old 
D)  at the Planck time, when the universe was about 10-⁴³ s old

Question 3

The weak force:

Accepted Answer

A)  acted only during the Big Bang and has no known role in the universe at the present time. 
B)  holds the quarks together inside a proton or neutron. 
C)  attracts the electrons to the nucleus, holding the atom together. 
D)  acts during certain kinds of radioactive decay. 
A)  acted only during the Big Bang and has no known role in the universe at the present time. 
B)  holds the quarks together inside a proton or neutron. 
C)  attracts the electrons to the nucleus, holding the atom together. 
D)  acts during certain kinds of radioactive decay.

Question 4

In a primordial,pre-galactic gas cloud,what is believed to have been the MOST important condition that caused the cloud to become an elliptical galaxy (as opposed to some other type of galaxy)?

Accepted Answer

A)  The initial rate of star formation was high. 
B)  The cloud started off with a lot of dust and heavy elements. 
C)  The cloud started off flattened and disk-shaped before it collapsed. 
D)  The initial rate of star formation was low. 
A)  The initial rate of star formation was high. 
B)  The cloud started off with a lot of dust and heavy elements. 
C)  The cloud started off flattened and disk-shaped before it collapsed. 
D)  The initial rate of star formation was low.

Question 5

Which two forces are infinite in extent?

Accepted Answer

A)  gravity and electromagnetism 
B)  gravity and the strong nuclear force 
C)  electromagnetism and the strong nuclear force 
D)  the two nuclear forces, strong and weak 
A)  gravity and electromagnetism 
B)  gravity and the strong nuclear force 
C)  electromagnetism and the strong nuclear force 
D)  the two nuclear forces, strong and weak

Question 6

What caused the Big Bang and the expansion of the universe?

Accepted Answer

A)  the separation of the strong nuclear force as a distinct force 
B)  the decoupling of radiation from matter 
C)  an unknown cause, with expansion starting suddenly and continuing to this time 
D)  a universal repulsive force stronger than the gravitational attraction between matter in the universe 
A)  the separation of the strong nuclear force as a distinct force 
B)  the decoupling of radiation from matter 
C)  an unknown cause, with expansion starting suddenly and continuing to this time 
D)  a universal repulsive force stronger than the gravitational attraction between matter in the universe

Question 7

Who developed the steady-state theory of the universe?

Accepted Answer

A)  Dicke and Peebles 
B)  Alpher and Gamow 
C)  Hoyle, Bondi, and Gold 
D)  Penzias and Wilson 
A)  Dicke and Peebles 
B)  Alpher and Gamow 
C)  Hoyle, Bondi, and Gold 
D)  Penzias and Wilson

Question 8

What appears to be the relationship between the distribution of dark matter and the distribution of luminous matter?

Accepted Answer

A)  There seems to be no correlation at all. 
B)  There seems to be a separate distribution of dark matter-dark-matter galaxy clusters, voids in the dark matter, and so on. But these formations all occur in regions of space far from luminous matter. 
C)  The distribution of dark matter seems to coincide with the distribution of luminous matter. 
D)  The distribution of dark matter seems to be just the reverse of the distribution of luminous matter: Dark-matter galaxy clusters occur in the voids of luminous matter; luminous galaxy clusters occur in the voids of dark matter. 
A)  There seems to be no correlation at all. 
B)  There seems to be a separate distribution of dark matter-dark-matter galaxy clusters, voids in the dark matter, and so on. But these formations all occur in regions of space far from luminous matter. 
C)  The distribution of dark matter seems to coincide with the distribution of luminous matter. 
D)  The distribution of dark matter seems to be just the reverse of the distribution of luminous matter: Dark-matter galaxy clusters occur in the voids of luminous matter; luminous galaxy clusters occur in the voids of dark matter.

Question 9

What is the range of the gravitational force (the maximum distance over which it acts)?

Accepted Answer

A)  10¹³ m, or roughly the size of the solar system 
B)  10²¹ m, or roughly the size of the Milky Way Galaxy 
C)  infinity 
D)  10²⁶ m, or roughly the distance to the farthest quasars 
A)  10¹³ m, or roughly the size of the solar system 
B)  10²¹ m, or roughly the size of the Milky Way Galaxy 
C)  infinity 
D)  10²⁶ m, or roughly the distance to the farthest quasars

Question 10

Which statement does NOT describe a characteristic of Population III stars?

Accepted Answer

A)  They were composed of almost pure hydrogen. 
B)  Most had very small masses. 
C)  They were formed soon after the Big Bang. 
D)  Most have long since disappeared. 
A)  They were composed of almost pure hydrogen. 
B)  Most had very small masses. 
C)  They were formed soon after the Big Bang. 
D)  Most have long since disappeared.

Question 11

We can determine the amount of mass in a cluster of galaxies by observing its gravitational interactions.How much of this mass is luminous matter?

Accepted Answer

A)  1-2% 
B)  10-20% 
C)  50% 
D)  80-90% 
A)  1-2% 
B)  10-20% 
C)  50% 
D)  80-90%

Question 12

Which element(s)was/were created during the Big Bang?

Accepted Answer

A)  hydrogen and helium 
B)  hydrogen, helium, lithium, and beryllium 
C)  hydrogen 
D)  hydrogen, helium, and lithium 
A)  hydrogen and helium 
B)  hydrogen, helium, lithium, and beryllium 
C)  hydrogen 
D)  hydrogen, helium, and lithium

Question 13

What makes gravity the main force determining the large-scale structure of the universe?

Accepted Answer

A)  Gravity is the strongest of the four fundamental forces. 
B)  Gravity is the only force that has an infinite range. 
C)  While the electromagnetic force of a charged particle has an infinite range, it is usually screened (and limited) by the existence of charges of the opposite sign. Ordinary matter has only one sign and therefore does not screen other gravitational forces. 
D)  The gravitational force, while short-ranged, is the only force that affects all particles: photons, quarks, changed particles, uncharged particles. 
A)  Gravity is the strongest of the four fundamental forces. 
B)  Gravity is the only force that has an infinite range. 
C)  While the electromagnetic force of a charged particle has an infinite range, it is usually screened (and limited) by the existence of charges of the opposite sign. Ordinary matter has only one sign and therefore does not screen other gravitational forces. 
D)  The gravitational force, while short-ranged, is the only force that affects all particles: photons, quarks, changed particles, uncharged particles.

Question 14

How many quarks are there in a proton or a neutron?

Accepted Answer

A)  three 
B)  one 
C)  six 
D)  four 
A)  three 
B)  one 
C)  six 
D)  four

Question 15

How do we know that the fundamental forces become unified as the energy of particle interactions increases?

Accepted Answer

A)  The theory that says that they do is a very elegant one, and it would be nice if it were right. 
B)  Experiments have actually been done with high-energy particle accelerators where all four forces have been unified. 
C)  Although it is not possible to see unification in the laboratory, the theory of unification agrees with many of the observed properties of the universe. 
D)  We have actually seen the start of the unification in high-energy particle accelerators, where the electromagnetic and weak forces become unified. 
A)  The theory that says that they do is a very elegant one, and it would be nice if it were right. 
B)  Experiments have actually been done with high-energy particle accelerators where all four forces have been unified. 
C)  Although it is not possible to see unification in the laboratory, the theory of unification agrees with many of the observed properties of the universe. 
D)  We have actually seen the start of the unification in high-energy particle accelerators, where the electromagnetic and weak forces become unified.

Question 16

The cosmic microwave background radiation is not uniform over the sky-it is slightly hotter toward the constellation Leo and slightly cooler in the opposite direction,toward Aquarius.Why?

Accepted Answer

A)  The difference is probably a statistical fluctuation and therefore not real. 
B)  The background radiation really is uniform; the observed difference is due to Earth's motion through the universe. 
C)  Earth is slightly off-center in the universe, so one side of the universe is a bit closer and the other is a bit farther away. 
D)  That is the way the universe began-hotter in one direction and cooler in the other. 
A)  The difference is probably a statistical fluctuation and therefore not real. 
B)  The background radiation really is uniform; the observed difference is due to Earth's motion through the universe. 
C)  Earth is slightly off-center in the universe, so one side of the universe is a bit closer and the other is a bit farther away. 
D)  That is the way the universe began-hotter in one direction and cooler in the other.

Question 17

For any object moving uniformly,velocity = distance/time.So in the Hubble relationship for the expansion of the universe,v = H₀r,what is the significance of the constant 1/H₀?

Accepted Answer

A)  The Hubble constant represents the average spacing between objects in the universe at the present time. 
B)  The Hubble constant represents the time since the expansion began, or the age of the universe. 
C)  The Hubble constant is merely a constant of proportionality to allow for the different units in v and r. 
D)  The Hubble constant is the inverse of the velocity that the object would have at a standard distance of 10 parsecs. 
A)  The Hubble constant represents the average spacing between objects in the universe at the present time. 
B)  The Hubble constant represents the time since the expansion began, or the age of the universe. 
C)  The Hubble constant is merely a constant of proportionality to allow for the different units in v and r. 
D)  The Hubble constant is the inverse of the velocity that the object would have at a standard distance of 10 parsecs.

Question 18

Gravity holds galaxies together.What does the weak nuclear force hold together?

Accepted Answer

A)  leptons (particles including electrons and neutrinos) 
B)  nothing 
C)  nuclei 
D)  quarks inside protons and neutrons 
A)  leptons (particles including electrons and neutrinos) 
B)  nothing 
C)  nuclei 
D)  quarks inside protons and neutrons

Question 19

What is the electroweak force?

Accepted Answer

A)  This is a fifth force, distinct from the original four, which helps to explain dark energy. 
B)  When charged particles of both signs (positive and negative) are closely mixed, the electromagnetic force-generally infinite in extent-is limited in its practical range. Under these circumstances, it is termed electroweak. 
C)  At sufficiently high temperatures, the electromagnetic force and the weak nuclear force are indistinguishable. This composite force is called electroweak. 
D)  At sufficiently high temperatures, the strong nuclear force and gravitational force disappear. At even higher temperatures, the weak nuclear force and the electromagnetic force combine to form the electroweak force. It is the only force that exists at this temperature. 
A)  This is a fifth force, distinct from the original four, which helps to explain dark energy. 
B)  When charged particles of both signs (positive and negative) are closely mixed, the electromagnetic force-generally infinite in extent-is limited in its practical range. Under these circumstances, it is termed electroweak. 
C)  At sufficiently high temperatures, the electromagnetic force and the weak nuclear force are indistinguishable. This composite force is called electroweak. 
D)  At sufficiently high temperatures, the strong nuclear force and gravitational force disappear. At even higher temperatures, the weak nuclear force and the electromagnetic force combine to form the electroweak force. It is the only force that exists at this temperature.

Question 20

At about what time after the Big Bang did the universe pass through the transition from being radiation-dominated to being matter-dominated?

Accepted Answer

A)  at the Planck time, 10-⁴³ s 
B)  about 15 billion years, as stars began to form 
C)  500,000 years 
D)  30,000 years 
A)  at the Planck time, 10-⁴³ s 
B)  about 15 billion years, as stars began to form 
C)  500,000 years 
D)  30,000 years

What is the temperature of the blackbody radiation that we receive from the Big Bang (the cosmic microwave background radiation)?

When the Big Bang began,all the fundamental forces were unified and behaved like a single force.As the universe expanded and cooled during the Big Bang,when did gravity first become a separate force?

The weak force:

In a primordial,pre-galactic gas cloud,what is believed to have been the MOST important condition that caused the cloud to become an elliptical galaxy (as opposed to some other type of galaxy)?

Which two forces are infinite in extent?

What caused the Big Bang and the expansion of the universe?

Who developed the steady-state theory of the universe?

What appears to be the relationship between the distribution of dark matter and the distribution of luminous matter?

What is the range of the gravitational force (the maximum distance over which it acts)?

Which statement does NOT describe a characteristic of Population III stars?

We can determine the amount of mass in a cluster of galaxies by observing its gravitational interactions.How much of this mass is luminous matter?

Which element(s)was/were created during the Big Bang?

What makes gravity the main force determining the large-scale structure of the universe?

How many quarks are there in a proton or a neutron?

How do we know that the fundamental forces become unified as the energy of particle interactions increases?

The cosmic microwave background radiation is not uniform over the sky-it is slightly hotter toward the constellation Leo and slightly cooler in the opposite direction,toward Aquarius.Why?

For any object moving uniformly,velocity = distance/time.So in the Hubble relationship for the expansion of the universe,v = H₀r,what is the significance of the constant 1/H₀?

Gravity holds galaxies together.What does the weak nuclear force hold together?

What is the electroweak force?

At about what time after the Big Bang did the universe pass through the transition from being radiation-dominated to being matter-dominated?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Astrobiology

Filters

Exam 14: Cosmology

What is the temperature of the blackbody radiation that we receive from the Big Bang (the cosmic microwave background radiation)?

When the Big Bang began,all the fundamental forces were unified and behaved like a single force.As the universe expanded and cooled during the Big Bang,when did gravity first become a separate force?

The weak force:

In a primordial,pre-galactic gas cloud,what is believed to have been the MOST important condition that caused the cloud to become an elliptical galaxy (as opposed to some other type of galaxy)?

Which two forces are infinite in extent?

What caused the Big Bang and the expansion of the universe?

Who developed the steady-state theory of the universe?

What appears to be the relationship between the distribution of dark matter and the distribution of luminous matter?

What is the range of the gravitational force (the maximum distance over which it acts)?

Which statement does NOT describe a characteristic of Population III stars?

We can determine the amount of mass in a cluster of galaxies by observing its gravitational interactions.How much of this mass is luminous matter?

Which element(s)was/were created during the Big Bang?

What makes gravity the main force determining the large-scale structure of the universe?

How many quarks are there in a proton or a neutron?

How do we know that the fundamental forces become unified as the energy of particle interactions increases?

The cosmic microwave background radiation is not uniform over the sky-it is slightly hotter toward the constellation Leo and slightly cooler in the opposite direction,toward Aquarius.Why?

For any object moving uniformly,velocity = distance/time.So in the Hubble relationship for the expansion of the universe,v = H₀r,what is the significance of the constant 1/H₀?

Gravity holds galaxies together.What does the weak nuclear force hold together?

What is the electroweak force?

At about what time after the Big Bang did the universe pass through the transition from being radiation-dominated to being matter-dominated?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Astrobiology

Filters