Question 1

Describe how the inflationary model of the early universe,a current matter density equal to the critical density,and dark matter are related.

Accepted Answer

According to the flatness problem,it is

Question 2

Why was deuterium so critical in the primordial nucleosynthesis?

Accepted Answer

Formed at 900 million K,when p

Question 3

The Big Bang formed:

Accepted Answer

A)  only hydrogen. 
B)  only helium. 
C)  hydrogen and helium, but nothing else. 
D)  all elements up to iron. 
E)  all elements found in nature now. 
A)  only hydrogen. 
B)  only helium. 
C)  hydrogen and helium, but nothing else. 
D)  all elements up to iron. 
E)  all elements found in nature now.

Question 4

What is the antimatter problem in pair production?

Accepted Answer

Where did the antiparticles go

Question 5

The stellar epoch,which we are still in today,began:

Accepted Answer

A)  with the end of the quark epoch, when neutrons and protons fused into deuterium. 
B)  with the end of the lepton epoch, when neutrinos were formed and escaped from matter. 
C)  with the liberation of the dark energy. 
D)  about 100 million years after the Big Bang, with the making of galaxies. 
E)  about three billion years after the Big Bang, with Population I stars forming. 
A)  with the end of the quark epoch, when neutrons and protons fused into deuterium. 
B)  with the end of the lepton epoch, when neutrinos were formed and escaped from matter. 
C)  with the liberation of the dark energy. 
D)  about 100 million years after the Big Bang, with the making of galaxies. 
E)  about three billion years after the Big Bang, with Population I stars forming.

Question 6

Most of the deuterium that formed right after the Big Bang:

Accepted Answer

A)  is still around today. 
B)  broke down into electrons and neutrons. 
C)  turned into dark matter. 
D)  quickly burned into helium nuclei. 
E)  was found in the globular clusters. 
A)  is still around today. 
B)  broke down into electrons and neutrons. 
C)  turned into dark matter. 
D)  quickly burned into helium nuclei. 
E)  was found in the globular clusters.

Question 7

Observed temperature fluctuations in the Cosmic Microwave Background Radiation are:

Accepted Answer

A)  millions of kelvins. 
B)  hundreds of kelvins. 
C)  a few kelvins. 
D)  tens of millionths of a kelvin. 
E)  immeasurably small. 
A)  millions of kelvins. 
B)  hundreds of kelvins. 
C)  a few kelvins. 
D)  tens of millionths of a kelvin. 
E)  immeasurably small.

Question 8

In GUTs,the electromagnetic force and weak nuclear force were the first to separate; then came gravity.

Accepted Answer

A) True 
 B)False

Question 9

The period from about one to 100 seconds after the Big Bang is called the:

Accepted Answer

A)  pair-production era. 
B)  atomic epoch. 
C)  nuclear epoch. 
D)  quark epoch. 
E)  lepton epoch. 
A)  pair-production era. 
B)  atomic epoch. 
C)  nuclear epoch. 
D)  quark epoch. 
E)  lepton epoch.

Question 10

Why didn't elements heavier than helium form in the first minutes of creation?

Accepted Answer

A)  The first generation of stars used them up too quickly to observe them. 
B)  There was not enough matter in the universe at that time. 
C)  When He-4 was formed, the expansion cooled the cosmos below 100 million K. 
D)  The electrons slowed down enough to be captured into orbits by protons. 
E)  Only type I supernovae can produce iron and heavier elements. 
A)  The first generation of stars used them up too quickly to observe them. 
B)  There was not enough matter in the universe at that time. 
C)  When He-4 was formed, the expansion cooled the cosmos below 100 million K. 
D)  The electrons slowed down enough to be captured into orbits by protons. 
E)  Only type I supernovae can produce iron and heavier elements.

Question 11

The period before the separation of the gravitational force is the Planck Epoch.

Accepted Answer

A) True 
 B)False

Question 12

The universe expanded by a factor of 10⁵⁰ during inflation,when the strong force separated from the electromagnetic and weak nuclear forces.

Accepted Answer

A) True 
 B)False

Question 13

How do astronomers define the "superforce"?

Accepted Answer

A)  a force connecting electromagnetism with the strong and the weak nuclear forces 
B)  the GUT, with all five forces combined 
C)  the GUT, but with no dark energy added in 
D)  a force connecting gravity and the electroweak force 
E)  a force including only dark energy and gravity 
A)  a force connecting electromagnetism with the strong and the weak nuclear forces 
B)  the GUT, with all five forces combined 
C)  the GUT, but with no dark energy added in 
D)  a force connecting gravity and the electroweak force 
E)  a force including only dark energy and gravity

Question 14

The scarcity of what isotope is a critical test of the density of the present cosmos?

Accepted Answer

A)  carbon 14 
B)  deuterium 
C)  helium 3 
D)  helium 4 
E)  lithium 5 
A)  carbon 14 
B)  deuterium 
C)  helium 3 
D)  helium 4 
E)  lithium 5

Question 15

At decoupling,the electrons and protons were made from neutron decay.

Accepted Answer

A) True 
 B)False

Question 16

The one theory of the early universe before the Recombination Epoch and after the Planck Epoch that was developed to resolve a conflict between observation and theory is:

Accepted Answer

A)  the Grand Unified Theory. 
B)  the theory of inflation. 
C)  the theory of nucleosynthesis. 
D)  the theory of recombination. 
E)  the quantum quark theory. 
A)  the Grand Unified Theory. 
B)  the theory of inflation. 
C)  the theory of nucleosynthesis. 
D)  the theory of recombination. 
E)  the quantum quark theory.

Question 17

Scientists are able to use the theories of physics to describe the conditions of the universe back to:

Accepted Answer

A)  the moment of the Big Bang. 
B)  the end of the Planck Epoch. 
C)  the beginning of GUT. 
D)  the end of the Radiation Era. 
E)  the Recombination Epoch. 
A)  the moment of the Big Bang. 
B)  the end of the Planck Epoch. 
C)  the beginning of GUT. 
D)  the end of the Radiation Era. 
E)  the Recombination Epoch.

Question 18

Both protons and neutrons (and their anti-particles)froze out:

Accepted Answer

A)  after 10⁻⁴³ seconds, at the Planck Era. 
B)  at 10³² K, at the end of the Inflationary Era. 
C)  at 10¹³ K, about .0001 seconds after the Big Bang. 
D)  after about a minute of expansion. 
E)  about 50,000 years after the Big Bang. 
A)  after 10⁻⁴³ seconds, at the Planck Era. 
B)  at 10³² K, at the end of the Inflationary Era. 
C)  at 10¹³ K, about .0001 seconds after the Big Bang. 
D)  after about a minute of expansion. 
E)  about 50,000 years after the Big Bang.

Question 19

Deuterium was made only in primordial nucleosynthesis,since stars destroy it.

Accepted Answer

A) True 
 B)False

Question 20

In the process of pair production,which of the following is a possible product pair?

Accepted Answer

A)  electron-neutron 
B)  proton-neutron 
C)  electron-positron 
D)  proton-positron 
E)  electron-proton 
A)  electron-neutron 
B)  proton-neutron 
C)  electron-positron 
D)  proton-positron 
E)  electron-proton

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

Describe how the inflationary model of the early universe,a current matter density equal to the critical density,and dark matter are related.

Why was deuterium so critical in the primordial nucleosynthesis?

The Big Bang formed:

What is the antimatter problem in pair production?

The stellar epoch,which we are still in today,began:

Most of the deuterium that formed right after the Big Bang:

Observed temperature fluctuations in the Cosmic Microwave Background Radiation are:

In GUTs,the electromagnetic force and weak nuclear force were the first to separate; then came gravity.

The period from about one to 100 seconds after the Big Bang is called the:

Why didn't elements heavier than helium form in the first minutes of creation?

The period before the separation of the gravitational force is the Planck Epoch.

The universe expanded by a factor of 10⁵⁰ during inflation,when the strong force separated from the electromagnetic and weak nuclear forces.

How do astronomers define the "superforce"?

The scarcity of what isotope is a critical test of the density of the present cosmos?

At decoupling,the electrons and protons were made from neutron decay.

The one theory of the early universe before the Recombination Epoch and after the Planck Epoch that was developed to resolve a conflict between observation and theory is:

Scientists are able to use the theories of physics to describe the conditions of the universe back to:

Both protons and neutrons (and their anti-particles)froze out:

Deuterium was made only in primordial nucleosynthesis,since stars destroy it.

In the process of pair production,which of the following is a possible product pair?

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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