Question 1

Relate the inflationary theory to the GUTs.

Accepted Answer

The "superforce" breaks up into the stro...

Question 2

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.F) All of the above
G) B) and C)

Question 3

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 4

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.F) A) and B)
G) B) and C)

Question 5

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.F) C) and D)
G) A) and B)

Question 6

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 7

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.F) B) and D)
G) B) and C)

Question 8

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 9

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 10

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.F) None of the above
G) A) and E)

Question 11

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

Accepted Answer

Once helium was formed from de...

Question 12

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.F) C) and E)
G) B) and C)

Question 13

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.F) A) and B)
G) C) and E)

Question 14

The universe was ________ old when electrons and positrons formed.

Accepted Answer

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

Question 15

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 16

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...

Question 17

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 backgroundF) A) and B)
G) A) and C)

Question 18

At this time,the universe is:

Accepted Answer

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

Question 19

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.F) B) and E)
G) A) and C)

Question 20

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...

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

Before about 4 billion years ago the universe was:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The universe was ________ old when electrons and positrons formed.

Correct AnswerverifiedShow Answer

The redshift of the universe at decoupling was about:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedOnce helium was formed from de...View AnswerShow Answer

At this time,the universe is:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedSince stars tend to destroy deuterium,it...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Relate the inflationary theory to the GUTs.

Correct AnswerverifiedThe "superforce" breaks up into the stro...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

Gravity becomes separate from the other forces at the:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedThe higher the temperature,the greater t...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
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Once helium was formed from de...
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Since stars tend to destroy deuterium,it...
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The "superforce" breaks up into the stro...
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Correct Answer
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The higher the temperature,the greater t...
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Correct Answer
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