Question 1

Explain why the principle of homogeneity is an important aspect of the cosmological principle.

Accepted Answer

The answer of Explain why the principle of homogeneity is...

Question 2

According to the steady state theory,the universe did not expand.

Accepted Answer

A) True 
 B)False

Question 3

In 1998,it was announced that the expansion of the universe is accelerating.What does this imply from the perspective of the Big Bang?

Accepted Answer

A) The acceleration is caused by a previously unknown force. 
B) The universe must be closed. 
C) The amount of dark matter must be far less than the amount of normal matter. 
D) The universe must be infinitely old. 
A) The acceleration is caused by a previously unknown force. 
B) The universe must be closed. 
C) The amount of dark matter must be far less than the amount of normal matter. 
D) The universe must be infinitely old.

Question 4

Describe how we know that the expansion rate of the universe is currently accelerating.

Accepted Answer

We know that the expansion rate of the u

Question 5

What is the Hubble time?

Accepted Answer

A) the time it takes a galaxy moving at 1000 km/sec to move 1 Mpc 
B) the time it takes the galaxy to double its distance from us 
C) the time remaining before the universe stops expanding and begins to contract 
D) an estimate of the age of the universe based on the Hubble constant 
A) the time it takes a galaxy moving at 1000 km/sec to move 1 Mpc 
B) the time it takes the galaxy to double its distance from us 
C) the time remaining before the universe stops expanding and begins to contract 
D) an estimate of the age of the universe based on the Hubble constant

Question 6

What does the flatness problem state?

Accepted Answer

A) that the density of the universe is very close to the critical density 
B) that the density of the universe is much greater than the critical density 
C) that the universe is two-dimensional 
D) that the universe is one-dimensional 
A) that the density of the universe is very close to the critical density 
B) that the density of the universe is much greater than the critical density 
C) that the universe is two-dimensional 
D) that the universe is one-dimensional

Question 7

The night sky is dark because the universe is not infinitely old.

Accepted Answer

A) True 
 B)False

Question 8

What is the assumption of isotropy?

Accepted Answer

A) that the large-scale appearance of the universe is the same in all epochs 
B) that the large-scale appearance of the universe is the same from any point 
C) that the large-scale appearance of the universe is the same in every direction 
D) that the large-scale appearance of the universe is the same at any temperature 
A) that the large-scale appearance of the universe is the same in all epochs 
B) that the large-scale appearance of the universe is the same from any point 
C) that the large-scale appearance of the universe is the same in every direction 
D) that the large-scale appearance of the universe is the same at any temperature

Question 9

What is the assumption of homogeneity?

Accepted Answer

A) that the large-scale appearance of the universe is the same in all epochs 
B) that the large-scale appearance of the universe is the same from any point 
C) that the large-scale appearance of the universe is the same in every direction 
D) that the large-scale appearance of the universe is the same at any temperature 
A) that the large-scale appearance of the universe is the same in all epochs 
B) that the large-scale appearance of the universe is the same from any point 
C) that the large-scale appearance of the universe is the same in every direction 
D) that the large-scale appearance of the universe is the same at any temperature

Question 10

What is the point of the raisin bread analogy for the expanding universe?

Accepted Answer

A) to show that all observers see other raisins (galaxies) expanding away from them 
B) to show that the raisins (galaxies) at the centre of the loaf have a special viewpoint 
C) to show that there is an edge to the universe (the crust) 
D) to show that the expansion is faster near the edges and slower in the centre 
A) to show that all observers see other raisins (galaxies) expanding away from them 
B) to show that the raisins (galaxies) at the centre of the loaf have a special viewpoint 
C) to show that there is an edge to the universe (the crust) 
D) to show that the expansion is faster near the edges and slower in the centre

Question 11

What is quintessence?

Accepted Answer

A) the name of the force that led to the inflationary period of the universe 
B) the name of the theoretically-hypothesized five-dimensional space of the universe 
C) the name of the force suspected to cause the current acceleration in universe's expansion 
D) the name of one of the particles of dark matter related to WIMPs 
A) the name of the force that led to the inflationary period of the universe 
B) the name of the theoretically-hypothesized five-dimensional space of the universe 
C) the name of the force suspected to cause the current acceleration in universe's expansion 
D) the name of one of the particles of dark matter related to WIMPs

Question 12

How could the inflationary universe solve the horizon problem?

Accepted Answer

The inflationary universe model proposes

Question 13

What property of the cosmic microwave background indicates that the universe is flat?

Accepted Answer

A) the temperature of 2.7 K 
B) the distribution of sizes of tiny irregularities 
C) the isotropic nature of the radiation 
D) the peak wavelength of 0.1 cm 
A) the temperature of 2.7 K 
B) the distribution of sizes of tiny irregularities 
C) the isotropic nature of the radiation 
D) the peak wavelength of 0.1 cm

Question 14

A universe is finite in time if its expansion will eventually stop,and finite in space if it does not extend indefinitely.What would a closed universe be?

Accepted Answer

A) infinite in both time and space 
B) finite in both time and space 
C) infinite in time but finite in space 
D) finite in time but infinite in space 
A) infinite in both time and space 
B) finite in both time and space 
C) infinite in time but finite in space 
D) finite in time but infinite in space

Question 15

What was the temperature of the universe when the recombination took place that produced the cosmic background radiation we observe today?

Accepted Answer

A) about 2.7 K 
B) about 300 K 
C) about 3,000 K 
D) about 3 billion K 
A) about 2.7 K 
B) about 300 K 
C) about 3,000 K 
D) about 3 billion K

Question 16

What is the difference between homogeneity and isotropy?

Accepted Answer

The answer of What is the difference between homogeneity and...

Question 17

When people hear the phrase "Big Bang," they often think of an explosion.What word would be a better description than "explosion"?

Accepted Answer

A) expansion 
B) compression 
C) combustion 
D) extension 
A) expansion 
B) compression 
C) combustion 
D) extension

Question 18

What evidence do we have that the universe is expanding?

Accepted Answer

The evidence for the expansion of the un

Question 19

The deuterium in distant quasars and in the interstellar medium suggests that the universe is open.

Accepted Answer

A) True 
 B)False

Question 20

How could the measurement of the Hubble constant at great distances tell us whether the universe is open or closed?

Accepted Answer

The Hubble constant, denoted as H0, is a

Explain why the principle of homogeneity is an important aspect of the cosmological principle.

According to the steady state theory,the universe did not expand.

In 1998,it was announced that the expansion of the universe is accelerating.What does this imply from the perspective of the Big Bang?

Describe how we know that the expansion rate of the universe is currently accelerating.

What is the Hubble time?

What does the flatness problem state?

The night sky is dark because the universe is not infinitely old.

What is the assumption of isotropy?

What is the assumption of homogeneity?

What is the point of the raisin bread analogy for the expanding universe?

What is quintessence?

How could the inflationary universe solve the horizon problem?

What property of the cosmic microwave background indicates that the universe is flat?

A universe is finite in time if its expansion will eventually stop,and finite in space if it does not extend indefinitely.What would a closed universe be?

What was the temperature of the universe when the recombination took place that produced the cosmic background radiation we observe today?

What is the difference between homogeneity and isotropy?

When people hear the phrase "Big Bang," they often think of an explosion.What word would be a better description than "explosion"?

What evidence do we have that the universe is expanding?

The deuterium in distant quasars and in the interstellar medium suggests that the universe is open.

How could the measurement of the Hubble constant at great distances tell us whether the universe is open or closed?

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

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Exam 11: Cosmology in the 21st Century

Explain why the principle of homogeneity is an important aspect of the cosmological principle.

According to the steady state theory,the universe did not expand.

In 1998,it was announced that the expansion of the universe is accelerating.What does this imply from the perspective of the Big Bang?

Describe how we know that the expansion rate of the universe is currently accelerating.

What is the Hubble time?

What does the flatness problem state?

The night sky is dark because the universe is not infinitely old.

What is the assumption of isotropy?

What is the assumption of homogeneity?

What is the point of the raisin bread analogy for the expanding universe?

What is quintessence?

How could the inflationary universe solve the horizon problem?

What property of the cosmic microwave background indicates that the universe is flat?

A universe is finite in time if its expansion will eventually stop,and finite in space if it does not extend indefinitely.What would a closed universe be?

What was the temperature of the universe when the recombination took place that produced the cosmic background radiation we observe today?

What is the difference between homogeneity and isotropy?

When people hear the phrase "Big Bang," they often think of an explosion.What word would be a better description than "explosion"?

What evidence do we have that the universe is expanding?

The deuterium in distant quasars and in the interstellar medium suggests that the universe is open.

How could the measurement of the Hubble constant at great distances tell us whether the universe is open or closed?

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