Question 1

Ripples in the Cosmic Microwave Background correspond to:

Accepted Answer

A) matter density fluctuations. 
B) temperature fluctuations. 
C) energy fluctuations. 
D) fluctuations in both matter and radiation. 
E) imperfections in measurement techniques or equipment. 
A) matter density fluctuations. 
B) temperature fluctuations. 
C) energy fluctuations. 
D) fluctuations in both matter and radiation. 
E) imperfections in measurement techniques or equipment. D

Question 2

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

Accepted Answer

A) after $10^{ - 43}$ seconds, at the Planck Era. 
B) at $1032 \mathrm {~K}$ at the end of the Inflationary Era. 
C) at $1013 \mathrm {~K} \text {, }$ , bout .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 $1032 \mathrm {~K}$ at the end of the Inflationary Era. 
C) at $1013 \mathrm {~K} \text {, }$ , bout .0001 seconds after the Big Bang. 
D) after about a minute of expansion. 
E) about 50,000 years after the Big Bang. C

Question 3

Collectively, electrons, muons, and neutrinos are called:

Accepted Answer

A) hadrons. 
B) baryons. 
C) photons. 
D) leptons. 
E) pions. 
A) hadrons. 
B) baryons. 
C) photons. 
D) leptons. 
E) pions. D

Question 4

The universe we live in now is said to be ________ dominated.

Accepted Answer

The answer of The universe we live in now is...

Question 5

Describe what occurred during the period of decoupling.

Accepted Answer

During decoupling, about 400,000 years a

Question 6

Sound waves in the early universe traveled faster than half of the speed of light.

Accepted Answer

A) True 
 B)False

Question 7

In pair production, the heaviest particles are formed in reactions that have the highesttemperatures.

Accepted Answer

A) True 
 B)False

Question 8

Why was deuterium so critical in the primordial nucleosynthesis?

Accepted Answer

Formed at 900 million K, when

Question 9

In GUTs, gravity was the first force to take on a separate identity at the Planck Time.

Accepted Answer

A) True 
 B)False

Question 10

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 11

What are the important relics of the lepton epoch? Why are they important?

Accepted Answer

Electrons and neutrinos; elect

Question 12

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) .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) .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 13

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

Accepted Answer

A) True 
 B)False

Question 14

The quark epoch is when ________ was/were created.

Accepted Answer

A) all known matter 
B) everything in normal atoms 
C) only dark energy 
D) protons and neutrons that still survive 
E) the rapid inflation of the cosmos 
A) all known matter 
B) everything in normal atoms 
C) only dark energy 
D) protons and neutrons that still survive 
E) the rapid inflation of the cosmos

Question 15

Which of these orderings of the epochs is correct?

Accepted Answer

A) nuclear, stellar, galactic 
B) quark, lepton, atomic 
C) Planck, lepton, quark 
D) nuclear, lepton, quark 
E) Planck, stellar, galactic 
A) nuclear, stellar, galactic 
B) quark, lepton, atomic 
C) Planck, lepton, quark 
D) nuclear, lepton, quark 
E) Planck, stellar, galactic

Question 16

Including all energy and mass, both dark and traditional, we seem to live now in a matterdominated universe, since the observed matter density exceeds the observed energy density.

Accepted Answer

A) True 
 B)False

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

About how hot was the Big Bang when matter and energy "decoupled"?

Accepted Answer

A) 900 million K 
B) 15 million K 
C) 3,000 K 
D) 300 K 
E) 2.73 K 
A) 900 million K 
B) 15 million K 
C) 3,000 K 
D) 300 K 
E) 2.73 K

Question 20

Before the Planck time of $10 ^{- 43}$ seconds, the Big Bang must be treated as a singularity, witheven general relativity yielding no information about it.

Accepted Answer

A) True 
 B)False

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

Ripples in the Cosmic Microwave Background correspond to:

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

Collectively, electrons, muons, and neutrinos are called:

The universe we live in now is said to be ________ dominated.

Describe what occurred during the period of decoupling.

Sound waves in the early universe traveled faster than half of the speed of light.

In pair production, the heaviest particles are formed in reactions that have the highesttemperatures.

Why was deuterium so critical in the primordial nucleosynthesis?

In GUTs, gravity was the first force to take on a separate identity at the Planck Time.

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

What are the important relics of the lepton epoch? Why are they important?

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

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

The quark epoch is when ________ was/were created.

Which of these orderings of the epochs is correct?

Including all energy and mass, both dark and traditional, we seem to live now in a matterdominated universe, since the observed matter density exceeds the observed energy density.

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

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

About how hot was the Big Bang when matter and energy "decoupled"?

Before the Planck time of 10−4310 ^{- 43}10−43 seconds, the Big Bang must be treated as a singularity, witheven general relativity yielding no information about it.

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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Before the Planck time of $10 ^{- 43}$ seconds, the Big Bang must be treated as a singularity, witheven general relativity yielding no information about it.