Question 1

The "flatness" problem arises because the curvature of space seems remarkably close to:

Accepted Answer

A)  zero curvature, favoring a spherical cosmos. 
B)  exactly one. 
C)  0.5, suggesting we are split between open and closed universes. 
D)  2.73 K, in spite of the eddies and turbulence that led to galaxy formation. 
E)  infinity, suggesting an open universe is the only possible cosmology. 
A)  zero curvature, favoring a spherical cosmos. 
B)  exactly one. 
C)  0.5, suggesting we are split between open and closed universes. 
D)  2.73 K, in spite of the eddies and turbulence that led to galaxy formation. 
E)  infinity, suggesting an open universe is the only possible cosmology.

Question 2

When new particle pairs are being created as fast as they annihilate,it is:

Accepted Answer

A)  hydrostatic equilibrium. 
B)  thermal equilibrium. 
C)  the threshold equilibrium. 
D)  the cosmological constant. 
E)  the critical density. 
A)  hydrostatic equilibrium. 
B)  thermal equilibrium. 
C)  the threshold equilibrium. 
D)  the cosmological constant. 
E)  the critical density.

Question 3

Discounting the newly discovered role of dark energy,the universe we live in now is said to be ________ dominated.

Accepted Answer

The answer of Discounting the newly discovered role of dark...

Question 4

The period from about 100 seconds up to 15 minutes after the Big Bang is the:

Accepted Answer

A)  Radiation Era. 
B)  Lepton Epoch. 
C)  Nuclear Epoch. 
D)  Decoupling Epoch. 
E)  Matter Era. 
A)  Radiation Era. 
B)  Lepton Epoch. 
C)  Nuclear Epoch. 
D)  Decoupling Epoch. 
E)  Matter Era.

Question 5

How does the energy of the cosmic microwave background compare to the energy radiated by all the stars and galaxies that ever existed?

Accepted Answer

A)  They are very close to being equal. 
B)  73% cosmic background, 27% starlight. 
C)  About ten times more from the Big Bang than from stars and galaxies. 
D)  The starlight now dominates the background, as your eyes show clearly. 
E)  We have no way of comparing matter and energy this way. 
A)  They are very close to being equal. 
B)  73% cosmic background, 27% starlight. 
C)  About ten times more from the Big Bang than from stars and galaxies. 
D)  The starlight now dominates the background, as your eyes show clearly. 
E)  We have no way of comparing matter and energy this way.

Question 6

Before about 4 billion years ago the universe was:

Accepted Answer

A)  radiation dominated. 
B)  quark dominated. 
C)  lepton dominated. 
D)  matter dominated. 
E)  dark energy dominated. 
A)  radiation dominated. 
B)  quark dominated. 
C)  lepton dominated. 
D)  matter dominated. 
E)  dark energy dominated.

Question 7

At this time,the universe is:

Accepted Answer

A)  radiation dominated. 
B)  quark dominated. 
C)  lepton dominated. 
D)  matter dominated. 
E)  dark energy dominated. 
A)  radiation dominated. 
B)  quark dominated. 
C)  lepton dominated. 
D)  matter dominated. 
E)  dark energy dominated.

Question 8

Relate the inflationary theory to the GUTs.

Accepted Answer

The "superforce" breaks up into the stro

Question 9

The ________ epoch explains how the uniformity of the 2.73K background could evolve into the clumpy cosmos we live in today.

Accepted Answer

The answer of The ________ epoch explains how the uniformity...

Question 10

Physicists have detected hot dark matter particles in terrestrial laboratories,but it is much harder to observe than cold dark matter.

Accepted Answer

A) True 
 B)False

Question 11

Gravity becomes separate from the other forces at the:

Accepted Answer

A)  decoupling Event, about a million years after the Big Bang. 
B)  end of the Planck Era, about 10⁻⁴³ seconds after the Big Bang. 
C)  end of the Inflationary Epoch, about 10⁻³² seconds into creation. 
D)  beginning of particle production, about .0001 seconds into the universe. 
E)  end of electron production, about a minute after creation. 
A)  decoupling Event, about a million years after the Big Bang. 
B)  end of the Planck Era, about 10⁻⁴³ seconds after the Big Bang. 
C)  end of the Inflationary Epoch, about 10⁻³² seconds into creation. 
D)  beginning of particle production, about .0001 seconds into the universe. 
E)  end of electron production, about a minute after creation.

Question 12

Why were elements heavier than helium not produced during the Big Bang?

Accepted Answer

Once helium was formed from de

Question 13

Describe qualitatively how the formation of deuterium and its current abundance is related to the critical density of the universe.

Accepted Answer

Since stars tend to destroy deuterium,it

Question 14

Of the normal elements around us,the Big Bang produced:

Accepted Answer

A)  none, only energy. 
B)  only hydrogen. 
C)  hydrogen and helium. 
D)  all elements up to iron. 
E)  all elements in much their present proportions. 
A)  none, only energy. 
B)  only hydrogen. 
C)  hydrogen and helium. 
D)  all elements up to iron. 
E)  all elements in much their present proportions.

Question 15

The universe was ________ old when electrons and positrons formed.

Accepted Answer

The answer of The universe was ________ old when electrons...

Question 16

The density of the cosmos at the end of the lepton epoch was comparable to iron,about ten times denser than water.

Accepted Answer

A) True 
 B)False

Question 17

The redshift of the universe at decoupling was about:

Accepted Answer

A)  Z = 1,000,000. 
B)  Z = 400,000. 
C)  Z = 1,100. 
D)  Z = 10. 
E)  Z = 4. 
A)  Z = 1,000,000. 
B)  Z = 400,000. 
C)  Z = 1,100. 
D)  Z = 10. 
E)  Z = 4.

Question 18

What would help scientists probe the period from zero time to 10⁻⁴³ second?

Accepted Answer

A)  discovery of a white hole, with matter and energy flowing out 
B)  more sophisticated gravity wave detectors 
C)  a theory incorporating the force of gravity into existing GUTs 
D)  a better understanding of the nature of dark energy 
E)  more detailed observations of the cosmic microwave background 
A)  discovery of a white hole, with matter and energy flowing out 
B)  more sophisticated gravity wave detectors 
C)  a theory incorporating the force of gravity into existing GUTs 
D)  a better understanding of the nature of dark energy 
E)  more detailed observations of the cosmic microwave background

Question 19

Relate the temperature of the Big Bang to pair production in the quark and lepton epochs.

Accepted Answer

The higher the temperature,the greater t

Question 20

The universe was two minutes old when ________ started to form from deuterium fusion.

Accepted Answer

The answer of The universe was two minutes old when...

Exam 27: The Early Universe: Toward the Beginning of Time

The "flatness" problem arises because the curvature of space seems remarkably close to:

When new particle pairs are being created as fast as they annihilate,it is:

Discounting the newly discovered role of dark energy,the universe we live in now is said to be ________ dominated.

The period from about 100 seconds up to 15 minutes after the Big Bang is the:

How does the energy of the cosmic microwave background compare to the energy radiated by all the stars and galaxies that ever existed?

Before about 4 billion years ago the universe was:

At this time,the universe is:

Relate the inflationary theory to the GUTs.

The ________ epoch explains how the uniformity of the 2.73K background could evolve into the clumpy cosmos we live in today.

Physicists have detected hot dark matter particles in terrestrial laboratories,but it is much harder to observe than cold dark matter.

Gravity becomes separate from the other forces at the:

Why were elements heavier than helium not produced during the Big Bang?

Describe qualitatively how the formation of deuterium and its current abundance is related to the critical density of the universe.

Of the normal elements around us,the Big Bang produced:

The universe was ________ old when electrons and positrons formed.

The density of the cosmos at the end of the lepton epoch was comparable to iron,about ten times denser than water.

The redshift of the universe at decoupling was about:

What would help scientists probe the period from zero time to 10⁻⁴³ second?

Relate the temperature of the Big Bang to pair production in the quark and lepton epochs.

The universe was two minutes old when ________ started to form from deuterium fusion.

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information from the Cosmos

Spectroscopy: The Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earth's Sister Planet

Mars: A Near Miss for Life?

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants,Dwarfs,and the Main Sequence

The Interstellar Medium: Gas and Dust among the Stars

Star Formation: A Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae,Supernovae,and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: A Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

Life in the Universe: Are We Alone?

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