Question 1

The cosmic background radiation comes from a particular time after the origin of the universe.What was that time?

Accepted Answer

A) when protons and neutrons were first formed 
B) when the Big Bang first began to expand 
C) when gamma rays had enough energy to destroy nuclei 
D) when electrons began to recombine with nuclei to form atoms 
A) when protons and neutrons were first formed 
B) when the Big Bang first began to expand 
C) when gamma rays had enough energy to destroy nuclei 
D) when electrons began to recombine with nuclei to form atoms D

Question 2

Which of the following best describes the horizon problem?

Accepted Answer

A) the nearness of the universe to critical density 
B) the isotropy of the cosmic microwave background 
C) the existence of the inflationary Big Bang 
D) the limited size of the observable universe 
A) the nearness of the universe to critical density 
B) the isotropy of the cosmic microwave background 
C) the existence of the inflationary Big Bang 
D) the limited size of the observable universe B

Question 3

What characteristic of the universe governs whether the universe is open,closed,or flat?

Accepted Answer

A) density 
B) temperature 
C) radius 
D) rotation rate 
A) density 
B) temperature 
C) radius 
D) rotation rate A

Question 4

What does the resolution of Olbers' paradox say about why it gets dark at night?

Accepted Answer

A) It gets dark at night because the universe is not infinite in age. 
B) It gets dark at night because the universe is static. 
C) It gets dark at night because the universe is closed. 
D) It gets dark at night because the universe contains dust. 
A) It gets dark at night because the universe is not infinite in age. 
B) It gets dark at night because the universe is static. 
C) It gets dark at night because the universe is closed. 
D) It gets dark at night because the universe contains dust.

Question 5

Why is the primordial background radiation visible in all directions?

Accepted Answer

The answer of Why is the primordial background radiation visible...

Question 6

The cosmological principle states that any observer in any galaxy will see the same general features of the universe.

Accepted Answer

A) True 
 B)False

Question 7

What do current observations indicate about the amount of baryonic matter and dark matter in the universe?

Accepted Answer

A) The total amount detected is sufficient to overcome the expansion of the universe. 
B) The total amount detected implies that the universe is closed. 
C) The amounts of the two kinds of matter are roughly equal. 
D) The total amount detected implies that the universe is open. 
A) The total amount detected is sufficient to overcome the expansion of the universe. 
B) The total amount detected implies that the universe is closed. 
C) The amounts of the two kinds of matter are roughly equal. 
D) The total amount detected implies that the universe is open.

Question 8

Where did the cosmic microwave background (CMB)come from?

Accepted Answer

A) photons emitted from the first stars 
B) photons released from hydrogen in our galaxy 
C) light scattered by dust in our solar system 
D) photons released when electrons and nuclei combined for the first time 
A) photons emitted from the first stars 
B) photons released from hydrogen in our galaxy 
C) light scattered by dust in our solar system 
D) photons released when electrons and nuclei combined for the first time

Question 9

The ____________________ is that the universe is both isotropic and homogeneous.

Accepted Answer

cosmologic

Question 10

How does the geometry of a gravity-dominated universe relate to its density?

Accepted Answer

A) If the universe is closed, the density is equal to the critical density. 
B) If the universe is flat, the density is equal to the critical density 
C) If the universe is open, the density is equal to the critical density. 
D) if the universe is open, the density is greater than the critical density. 
A) If the universe is closed, the density is equal to the critical density. 
B) If the universe is flat, the density is equal to the critical density 
C) If the universe is open, the density is equal to the critical density. 
D) if the universe is open, the density is greater than the critical density.

Question 11

Which of the following applies if the universe is closed?

Accepted Answer

A) The universe will expand forever. 
B) The universe has a centre. 
C) The universe has an edge. 
D) The universe has a high density. 
A) The universe will expand forever. 
B) The universe has a centre. 
C) The universe has an edge. 
D) The universe has a high density.

Question 12

Why is the cosmic microwave background (CMB)so cold,if the early universe was so hot?

Accepted Answer

A) Enough time has passed for matter in the universe to release enough heat to cool down. 
B) The CMB constantly interacts with atoms, which effectively cools down the photons. 
C) The expansion of the universe has redshifted those photons to an effectively cooler temperature. 
D) The Big Bang was initially hot but the CMB was released from cold material much later on. 
A) Enough time has passed for matter in the universe to release enough heat to cool down. 
B) The CMB constantly interacts with atoms, which effectively cools down the photons. 
C) The expansion of the universe has redshifted those photons to an effectively cooler temperature. 
D) The Big Bang was initially hot but the CMB was released from cold material much later on.

Question 13

Under what conditions will space-time be flat?

Accepted Answer

A) if the universe is expanding 
B) if the universe is finite 
C) if the average density of the universe is equal to the critical density 
D) if the universe is homogeneous and isotropic 
A) if the universe is expanding 
B) if the universe is finite 
C) if the average density of the universe is equal to the critical density 
D) if the universe is homogeneous and isotropic

Question 14

Why would a value of 100 km/sec/Mpc for the Hubble constant contradict theories of stellar evolution?

Accepted Answer

A value of 100 km/sec/Mpc for the Hubble

Question 15

What property of an antiproton is opposite to that of a proton?

Accepted Answer

A) mass 
B) velocity 
C) electric charge 
D) direction of spin 
A) mass 
B) velocity 
C) electric charge 
D) direction of spin

Question 16

What properties does the cosmological principle require the universe to have?

Accepted Answer

A) homogeneous and expanding 
B) homogeneous and isotropic 
C) isotropic and accelerating 
D) isotropic and expanding 
A) homogeneous and expanding 
B) homogeneous and isotropic 
C) isotropic and accelerating 
D) isotropic and expanding

Question 17

How do we know there was a Big Bang?

Accepted Answer

The Big Bang theory is the prevailing co

Question 18

As the universe cooled,it eventually reached a temperature of 3,000 K and protons were able to capture and hold electrons to form neutral hydrogen.What is this process called?

Accepted Answer

A) ionization 
B) isotropy 
C) annihilation 
D) recombination 
A) ionization 
B) isotropy 
C) annihilation 
D) recombination

Question 19

What happens when a proton and an antiproton collide?

Accepted Answer

A) They destroy each other and produce energy in the form of gamma rays. 
B) One of the protons is converted to a neutron and they form a nucleus of one proton and one neutron. 
C) One of the protons is converted to an electron and they form a hydrogen atom. 
D) One proton is converted to a neutron and the other is converted to an electron. 
A) They destroy each other and produce energy in the form of gamma rays. 
B) One of the protons is converted to a neutron and they form a nucleus of one proton and one neutron. 
C) One of the protons is converted to an electron and they form a hydrogen atom. 
D) One proton is converted to a neutron and the other is converted to an electron.

Question 20

What could be the origin of the galaxy seeds around which galaxies,clusters,and walls grew?

Accepted Answer

A) hot dark matter 
B) baryons 
C) the separation of the electromagnetic and weak forces 
D) quantum fluctuations in space-time 
A) hot dark matter 
B) baryons 
C) the separation of the electromagnetic and weak forces 
D) quantum fluctuations in space-time

The cosmic background radiation comes from a particular time after the origin of the universe.What was that time?

Which of the following best describes the horizon problem?

What characteristic of the universe governs whether the universe is open,closed,or flat?

What does the resolution of Olbers' paradox say about why it gets dark at night?

Why is the primordial background radiation visible in all directions?

The cosmological principle states that any observer in any galaxy will see the same general features of the universe.

What do current observations indicate about the amount of baryonic matter and dark matter in the universe?

Where did the cosmic microwave background (CMB)come from?

The ____________________ is that the universe is both isotropic and homogeneous.

How does the geometry of a gravity-dominated universe relate to its density?

Which of the following applies if the universe is closed?

Why is the cosmic microwave background (CMB)so cold,if the early universe was so hot?

Under what conditions will space-time be flat?

Why would a value of 100 km/sec/Mpc for the Hubble constant contradict theories of stellar evolution?

What property of an antiproton is opposite to that of a proton?

What properties does the cosmological principle require the universe to have?

How do we know there was a Big Bang?

As the universe cooled,it eventually reached a temperature of 3,000 K and protons were able to capture and hold electrons to form neutral hydrogen.What is this process called?

What happens when a proton and an antiproton collide?

What could be the origin of the galaxy seeds around which galaxies,clusters,and walls grew?

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Structure and Formation of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

Filters

Exam 11: Cosmology in the 21st Century

The cosmic background radiation comes from a particular time after the origin of the universe.What was that time?

Which of the following best describes the horizon problem?

What characteristic of the universe governs whether the universe is open,closed,or flat?

What does the resolution of Olbers' paradox say about why it gets dark at night?

Why is the primordial background radiation visible in all directions?

The cosmological principle states that any observer in any galaxy will see the same general features of the universe.

What do current observations indicate about the amount of baryonic matter and dark matter in the universe?

Where did the cosmic microwave background (CMB)come from?

The ____________________ is that the universe is both isotropic and homogeneous.

How does the geometry of a gravity-dominated universe relate to its density?

Which of the following applies if the universe is closed?

Why is the cosmic microwave background (CMB)so cold,if the early universe was so hot?

Under what conditions will space-time be flat?

Why would a value of 100 km/sec/Mpc for the Hubble constant contradict theories of stellar evolution?

What property of an antiproton is opposite to that of a proton?

What properties does the cosmological principle require the universe to have?

How do we know there was a Big Bang?

As the universe cooled,it eventually reached a temperature of 3,000 K and protons were able to capture and hold electrons to form neutral hydrogen.What is this process called?

What happens when a proton and an antiproton collide?

What could be the origin of the galaxy seeds around which galaxies,clusters,and walls grew?

The Scale of the Cosmos

User's Guide to the Sky

The Origin of Modern Astronomy

Astronomical Telescopes and Instruments

Sun Light and Sun Atoms

The Family of Stars

The Structure and Formation of Stars

The Deaths of Stars

The Milky Way Galaxy

Galaxies

The Origin of the Solar System

Comparative Planetology of the Terrestrial Planets

Comparative Planetology of the Jovian Planets

Life on Other Worlds

Filters