Question 1

The ________ background radiation in fact far exceeds all the energy radiated by all the starsand galaxies that formed since then.

Accepted Answer

The answer of The ________ background radiation in fact far...

Question 2

The collision of two gamma rays can result in a single particle.

Accepted Answer

A) True 
 B)False

Question 3

What factors would determine that we live in a matter-dominated universe?

Accepted Answer

The density of matter can be approximate

Question 4

Not taking dark energy into account, we seem to live now in a matter dominated universe,since the observed matter density exceeds the observed energy density.

Accepted Answer

A) True 
 B)False

Question 5

There is observational evidence that supports the theoretical conditions of the universe. Thefarthest back in the history of the universe this evidence goes is:

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 6

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

Accepted Answer

A) True 
 B)False

Question 7

The flatness problem is the fact that the observed density of matter is unexpectedly differentfrom the critical density predicted by the inflationary epoch.

Accepted Answer

A) True 
 B)False

Question 8

The critical temperature for nucleosynthesis to begin was the:

Accepted Answer

A) triple alpha reaction at 100 million K. 
B) deuterium bottleneck at about 900 million K. 
C) proton-proton cycle at 10 million K. 
D) iron production at 10 billion K. 
E) formation of lithium at 50 million K. 
A) triple alpha reaction at 100 million K. 
B) deuterium bottleneck at about 900 million K. 
C) proton-proton cycle at 10 million K. 
D) iron production at 10 billion K. 
E) formation of lithium at 50 million K.

Question 9

Before about 50,000 years after the Big Bang, 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 10

The ________ epoch has dominated the last ten billion years of universal evolution.

Accepted Answer

The answer of The ________ epoch has dominated the last...

Question 11

Why do Population II stars contain almost nothing but hydrogen and helium?

Accepted Answer

This first generation of stars

Question 12

Oscillations in the early universe are most similar to:

Accepted Answer

A) water waves. 
B) sound waves. 
C) light waves. 
D) seismic waves. 
E) oscillations of stars in the instability strip of the H-R diagram. 
A) water waves. 
B) sound waves. 
C) light waves. 
D) seismic waves. 
E) oscillations of stars in the instability strip of the H-R diagram.

Question 13

At what point do the weak nuclear and electromagnetic forces split?

Accepted Answer

A) never, they are still united 
B) at $10^{12} \mathrm {~K} \text {, }$ when pair production starts for neutrons and protons 
C) at $10 ^{- 43}$ seconds, when all four forces separate as the Planck Era ends 
D) at about four seconds, when at millions of degrees hydrogen forms helium 
E) after about $10 ^ { - 10 }$ seconds, when the temperature drops below $10 ^ { - 15 } \mathrm {~K}$ 
A) never, they are still united 
B) at $10^{12} \mathrm {~K} \text {, }$ when pair production starts for neutrons and protons 
C) at $10 ^{- 43}$ seconds, when all four forces separate as the Planck Era ends 
D) at about four seconds, when at millions of degrees hydrogen forms helium 
E) after about $10 ^ { - 10 }$ seconds, when the temperature drops below $10 ^ { - 15 } \mathrm {~K}$

Question 14

Pair production is how a proton and electron are formed together from two photons, withneutrinos also given off.

Accepted Answer

A) True 
 B)False

Question 15

The universe was ________ old when electrons and positrons formed.

Accepted Answer

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

Question 16

When an electron is formed from a gamma-ray collision, a positron is also made.

Accepted Answer

A) True 
 B)False

Question 17

What happened in the Planck Era? At what temperature did it end?

Accepted Answer

The Planck Era was the first @#IMG-DLM& seconds of

Question 18

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 19

Concerning dark energy, we do know:

Accepted Answer

A) that it is created when matter annihilates anti-matter. 
B) its density remains constant over time, so it is not important in the early Universe. 
C) combined with dark matter, it will ultimately produce a closed universe. 
D) that it was revealed with Type II supernovae distances in the late 1990s. 
E) that it makes up 90% of all the matter and energy in the whole universe. 
A) that it is created when matter annihilates anti-matter. 
B) its density remains constant over time, so it is not important in the early Universe. 
C) combined with dark matter, it will ultimately produce a closed universe. 
D) that it was revealed with Type II supernovae distances in the late 1990s. 
E) that it makes up 90% of all the matter and energy in the whole universe.

Question 20

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.

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

The ________ background radiation in fact far exceeds all the energy radiated by all the starsand galaxies that formed since then.

The collision of two gamma rays can result in a single particle.

What factors would determine that we live in a matter-dominated universe?

Not taking dark energy into account, we seem to live now in a matter dominated universe,since the observed matter density exceeds the observed energy density.

There is observational evidence that supports the theoretical conditions of the universe. Thefarthest back in the history of the universe this evidence goes is:

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

The flatness problem is the fact that the observed density of matter is unexpectedly differentfrom the critical density predicted by the inflationary epoch.

The critical temperature for nucleosynthesis to begin was the:

Before about 50,000 years after the Big Bang, the universe was:

The ________ epoch has dominated the last ten billion years of universal evolution.

Why do Population II stars contain almost nothing but hydrogen and helium?

Oscillations in the early universe are most similar to:

At what point do the weak nuclear and electromagnetic forces split?

Pair production is how a proton and electron are formed together from two photons, withneutrinos also given off.

The universe was ________ old when electrons and positrons formed.

When an electron is formed from a gamma-ray collision, a positron is also made.

What happened in the Planck Era? At what temperature did it end?

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

Concerning dark energy, we do know:

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

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: Earths 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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