Question 1

Describe the large-scale structure of the universe.

Accepted Answer

The structure of the universe

Question 2

The critical mass density of the universe today is 8 × 10-27 kg/m3.Using the current observed value of  $\varOmega$luminous,what is the average density of protons in the universe? If they were spread evenly throughout the universe,what would be their typical separation? Note that the mass of the proton is 1.7 × 10-27 kg.

Accepted Answer

The average density of protons in the un

Question 3

Structure formation in the universe proceeds hierarchically,meaning that:

Accepted Answer

A)  large objects collapse then fragment to form smaller objects 
B)  large objects form at the same times as smaller objects 
C)  small objects collapse then merge to form larger objects 
D)  only small objects form and are stable over time 
A)  large objects collapse then fragment to form smaller objects 
B)  large objects form at the same times as smaller objects 
C)  small objects collapse then merge to form larger objects 
D)  only small objects form and are stable over time

Question 4

In the superstring theory that successfully unites gravity and quantum mechanics,the universe must have:

Accepted Answer

A)  11 dimensions (10 spatial and 1 temporal) 
B)  4 dimensions (3 spatial and 1 temporal) 
C)  9 dimensions (8 spatial and 1 temporal) 
D)  6 dimensions (3 spatial and 3 temporal) 
A)  11 dimensions (10 spatial and 1 temporal) 
B)  4 dimensions (3 spatial and 1 temporal) 
C)  9 dimensions (8 spatial and 1 temporal) 
D)  6 dimensions (3 spatial and 3 temporal)

Question 5

Even at its earliest moments,the universe had about as much structure in it as it has at the current time.

Accepted Answer

A) True 
 B)False

Question 6

As structure formed in the universe,galaxy-sized objects formed before cluster-sized objects.

Accepted Answer

A) True 
 B)False

Question 7

What is the name of the particle that mediates the electromagnetic force in quantum electrodynamics (QED)and the strong force in quantum chromodynamics (QCD)?

Accepted Answer

The photon is the particle tha

Question 8

The standard model of particle physics is incomplete because it leaves which question(s)unanswered?

Accepted Answer

A)  Why do neutrinos have mass? 
B)  Why is the strong nuclear force much stronger than the weak nuclear force? 
C)  How is gravity related to the other three fundamental forces? 
D)  All of the above 
A)  Why do neutrinos have mass? 
B)  Why is the strong nuclear force much stronger than the weak nuclear force? 
C)  How is gravity related to the other three fundamental forces? 
D)  All of the above

Question 9

Why does the overall mass and energy density of the universe decide its ultimate fate?

Accepted Answer

A)  The greater the density of the universe,the more black holes will form,which will devour surrounding material more quickly. 
B)  The greater the density of the universe,the more gravitationally bound the universe will be. 
C)  The greater the density of the universe,the more massive stars it will contain,and the faster it will evolve. 
D)  The greater the density of the universe,the more stars it will form over time and the longer the universe will last. 
A)  The greater the density of the universe,the more black holes will form,which will devour surrounding material more quickly. 
B)  The greater the density of the universe,the more gravitationally bound the universe will be. 
C)  The greater the density of the universe,the more massive stars it will contain,and the faster it will evolve. 
D)  The greater the density of the universe,the more stars it will form over time and the longer the universe will last.

Question 10

Structure formation in our universe:

Accepted Answer

A)  proceeds from the top down 
B)  proceeds from the bottom and moves up 
C)  begins on all spatial scales at the same time 
D)  begins after clusters form 
A)  proceeds from the top down 
B)  proceeds from the bottom and moves up 
C)  begins on all spatial scales at the same time 
D)  begins after clusters form

Question 11

What would the universe be like if there were complete symmetry between matter and antimatter?

Accepted Answer

A)  It would look similar to our universe,but half of it would be composed of antimatter. 
B)  We would observe two universes,one an antimatter reflection of the other. 
C)  There would be no universe because all of the matter and antimatter would have been annihilated. 
D)  There would be a universe,but it would be completely composed of energy. 
A)  It would look similar to our universe,but half of it would be composed of antimatter. 
B)  We would observe two universes,one an antimatter reflection of the other. 
C)  There would be no universe because all of the matter and antimatter would have been annihilated. 
D)  There would be a universe,but it would be completely composed of energy.

Question 12

If the quantum fluctuations imprinted on the dark matter halos at the time of the formation of the CBR were ten times larger,galaxies would likely be:

Accepted Answer

A)  smaller 
B)  larger 
C)  more numerous 
D)  nonexistent 
A)  smaller 
B)  larger 
C)  more numerous 
D)  nonexistent

Question 13

We expect the kinds of galaxies that we see at a redshift of 4 (that is,when the universe was much younger)to be:

Accepted Answer

A)  much like what we see today 
B)  smaller and much more irregular looking than today 
C)  smaller versions of what we see today 
D)  far more numerous but with fewer spiral galaxies 
A)  much like what we see today 
B)  smaller and much more irregular looking than today 
C)  smaller versions of what we see today 
D)  far more numerous but with fewer spiral galaxies

Question 14

Which was a triumph of quantum electrodynamics (QED)?

Accepted Answer

A)  QED predicted the existence of three carrier particles before they were discovered in laboratory experiments. 
B)  QED unites the strong and weak nuclear forces. 
C)  QED is an example of a theory of everything. 
D)  QED successfully explains the origin of quantum mechanical fluctuations in the CBR. 
A)  QED predicted the existence of three carrier particles before they were discovered in laboratory experiments. 
B)  QED unites the strong and weak nuclear forces. 
C)  QED is an example of a theory of everything. 
D)  QED successfully explains the origin of quantum mechanical fluctuations in the CBR.

Question 15

The fact that $\varOmega$mass + $\varOmega$$\wedge$ is very close to 1 means that its value has always been very close to 1.

Accepted Answer

A) True 
 B)False

Question 16

In the 1990s,astronomers found that distant Type Ia supernovae were __________ than they expected,leading them to conclude that __________.

Accepted Answer

A)  brighter; the universe's expansion rate was decreasing with time 
B)  brighter; the universe was finite in size 
C)  fainter; the universe's expansion rate has been increasing with time 
D)  fainter; the universe was infinite in size 
A)  brighter; the universe's expansion rate was decreasing with time 
B)  brighter; the universe was finite in size 
C)  fainter; the universe's expansion rate has been increasing with time 
D)  fainter; the universe was infinite in size

Question 17

If the fate of the universe were determined SOLELY by what we currently know to be the total mass of the universe in luminous and dark matter (excluding dark energy),astronomers would predict that we live in a universe that will:

Accepted Answer

A)  expand forever 
B)  slow its expansion but never reverse it 
C)  stop expanding and eventually collapse 
D)  oscillate between expansion and collapse 
A)  expand forever 
B)  slow its expansion but never reverse it 
C)  stop expanding and eventually collapse 
D)  oscillate between expansion and collapse

Question 18

What can solve the flatness and horizon problem in cosmology,and why?

Accepted Answer

The concept of inflation in the very ear

Question 19

How much of the total mass of the universe is made up of hot dark matter?

Accepted Answer

A)  5 percent 
B)  25 percent 
C)  45 percent 
D)  90 percent 
A)  5 percent 
B)  25 percent 
C)  45 percent 
D)  90 percent

Question 20

Why do astronomers think that cold dark matter (as opposed to hot dark matter)is the primary component of dark matter in galaxies?

Accepted Answer

Because cold dark ma

Describe the large-scale structure of the universe.

Structure formation in the universe proceeds hierarchically,meaning that:

In the superstring theory that successfully unites gravity and quantum mechanics,the universe must have:

Even at its earliest moments,the universe had about as much structure in it as it has at the current time.

As structure formed in the universe,galaxy-sized objects formed before cluster-sized objects.

What is the name of the particle that mediates the electromagnetic force in quantum electrodynamics (QED)and the strong force in quantum chromodynamics (QCD)?

The standard model of particle physics is incomplete because it leaves which question(s)unanswered?

Why does the overall mass and energy density of the universe decide its ultimate fate?

Structure formation in our universe:

What would the universe be like if there were complete symmetry between matter and antimatter?

If the quantum fluctuations imprinted on the dark matter halos at the time of the formation of the CBR were ten times larger,galaxies would likely be:

We expect the kinds of galaxies that we see at a redshift of 4 (that is,when the universe was much younger)to be:

Which was a triumph of quantum electrodynamics (QED)?

The fact that $\varOmega$ _mass + $\varOmega$ _$\wedge$ is very close to 1 means that its value has always been very close to 1.

In the 1990s,astronomers found that distant Type Ia supernovae were than they expected,leading them to conclude that .

If the fate of the universe were determined SOLELY by what we currently know to be the total mass of the universe in luminous and dark matter (excluding dark energy),astronomers would predict that we live in a universe that will:

What can solve the flatness and horizon problem in cosmology,and why?

How much of the total mass of the universe is made up of hot dark matter?

Why do astronomers think that cold dark matter (as opposed to hot dark matter)is the primary component of dark matter in galaxies?

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: The Sun

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Life in the Universe

Filters

Exam 17: Modern Cosmology and the Origin of Structure

Describe the large-scale structure of the universe.

Structure formation in the universe proceeds hierarchically,meaning that:

In the superstring theory that successfully unites gravity and quantum mechanics,the universe must have:

Even at its earliest moments,the universe had about as much structure in it as it has at the current time.

As structure formed in the universe,galaxy-sized objects formed before cluster-sized objects.

What is the name of the particle that mediates the electromagnetic force in quantum electrodynamics (QED)and the strong force in quantum chromodynamics (QCD)?

The standard model of particle physics is incomplete because it leaves which question(s)unanswered?

Why does the overall mass and energy density of the universe decide its ultimate fate?

Structure formation in our universe:

What would the universe be like if there were complete symmetry between matter and antimatter?

If the quantum fluctuations imprinted on the dark matter halos at the time of the formation of the CBR were ten times larger,galaxies would likely be:

We expect the kinds of galaxies that we see at a redshift of 4 (that is,when the universe was much younger)to be:

Which was a triumph of quantum electrodynamics (QED)?

The fact that Ω\varOmegaΩ mass + Ω\varOmegaΩ ∧\wedge∧ is very close to 1 means that its value has always been very close to 1.

In the 1990s,astronomers found that distant Type Ia supernovae were __________ than they expected,leading them to conclude that __________.

If the fate of the universe were determined SOLELY by what we currently know to be the total mass of the universe in luminous and dark matter (excluding dark energy),astronomers would predict that we live in a universe that will:

What can solve the flatness and horizon problem in cosmology,and why?

How much of the total mass of the universe is made up of hot dark matter?

Why do astronomers think that cold dark matter (as opposed to hot dark matter)is the primary component of dark matter in galaxies?

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: The Sun

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Expansion of Space

The Realm of the Galaxies

Our Galaxy: The Milky Way

Life in the Universe

Filters

The fact that $\varOmega$ _mass + $\varOmega$ _$\wedge$ is very close to 1 means that its value has always been very close to 1.

In the 1990s,astronomers found that distant Type Ia supernovae were than they expected,leading them to conclude that .