Question 1

Even with infinitely powerful telescopes,we can look back in time only until

Accepted Answer

A)  when galaxies were first formed. 
B)  when hydrogen and helium were formed. 
C)  when gravity was quantum mechanical. 
D)  the time of recombination. 
A)  when galaxies were first formed. 
B)  when hydrogen and helium were formed. 
C)  when gravity was quantum mechanical. 
D)  the time of recombination.

Question 2

Observations of Type I supernovae in distant galaxies confirm that the expansion of the universe is decreasing over time.

Accepted Answer

A) True 
 B)False

Question 3

The theory of inflation assumes that at some point in time dark energy will decay and the universe will expand rapidly by a factor of   .

Accepted Answer

A) True 
 B)False

Question 4

The four fundamental forces of nature are gravity,electromagnetism,the weak force,and the strong force.

Accepted Answer

A) True 
 B)False

Question 5

By the time the universe was 5 minutes old,approximately 24 percent of the normal matter in it had been turned into

Accepted Answer

A)  protons. 
B)  neutrons. 
C)  hydrogen. 
D)  helium. 
A)  protons. 
B)  neutrons. 
C)  hydrogen. 
D)  helium.

Question 6

What is the "flatness problem" in cosmology?

Accepted Answer

If the mass and energy density of the un

Question 7

Observations of Type I supernovae in distant galaxies have shown that

Accepted Answer

A)  the star formation rate in galaxies decreases with increasing redshift. 
B)  the expansion rate of the universe is increasing. 
C)  the cosmological constant is zero. 
D)  dark energy is negligible at the present time. 
A)  the star formation rate in galaxies decreases with increasing redshift. 
B)  the expansion rate of the universe is increasing. 
C)  the cosmological constant is zero. 
D)  dark energy is negligible at the present time.

Question 8

How would astronomers describe the antiparticle of an electron?

Accepted Answer

A)  It would have the same mass but opposite charge. 
B)  It would have the same charge but opposite spin. 
C)  It would have the opposite charge and higher mass. 
D)  It would have the opposite spin and higher mass. 
A)  It would have the same mass but opposite charge. 
B)  It would have the same charge but opposite spin. 
C)  It would have the opposite charge and higher mass. 
D)  It would have the opposite spin and higher mass.

Question 9

Describe the four fundamental forces of nature by listing their names and describing what effect each force has on objects in the universe.

Accepted Answer

The four fundamental forces of nature ar

Question 10

What can solve the flatness and horizon problem in cosmology,and why?

Accepted Answer

The concept of inflation in the very ear

Question 11

The ratio of the average density in all forms of matter (luminous and dark)in our universe to the critical density is approximately 0.3.

Accepted Answer

A) True 
 B)False

Question 12

If   today and dark energy was a cosmological constant,the universe will

Accepted Answer

A)  expand forever. 
B)  slow its expansion but never reverse it. 
C)  stop expanding and eventually collapse. 
D)  oscillate between expansion and collapse. 
A)  expand forever. 
B)  slow its expansion but never reverse it. 
C)  stop expanding and eventually collapse. 
D)  oscillate between expansion and collapse.

Question 13

In some particle physics theories,the universe must have more than three spatial dimensions,but we experience only three.Why would we not see the other spatial dimensions?

Accepted Answer

A)  The other seven spatial dimensions are tightly wrapped around each other and have not expanded. 
B)  The other nine spatial dimensions are too small to be noticeable. 
C)  The other seven spatial dimensions undergo inflation and flatten themselves out. 
D)  The other nine spatial dimensions wrap around each another and form the temporal dimension. 
A)  The other seven spatial dimensions are tightly wrapped around each other and have not expanded. 
B)  The other nine spatial dimensions are too small to be noticeable. 
C)  The other seven spatial dimensions undergo inflation and flatten themselves out. 
D)  The other nine spatial dimensions wrap around each another and form the temporal dimension.

Question 14

Why does the critical mass density of the universe depend on the value of Hubble's constant,   ?

Accepted Answer

@#IMG-DLM& is an indication of how fast

Question 15

If   today and there were no dark energy,the universe would

Accepted Answer

A)  expand forever. 
B)  slow its expansion but never reverse it. 
C)  stop expanding and eventually collapse. 
D)  oscillate between expansion and collapse. 
A)  expand forever. 
B)  slow its expansion but never reverse it. 
C)  stop expanding and eventually collapse. 
D)  oscillate between expansion and collapse.

Question 16

The concept of inflation helps solve both the problems of the flatness of the universe and smoothness of the cosmic background radiation.

Accepted Answer

A) True 
 B)False

Question 17

Why would it be very improbable for our universe to have   ?

Accepted Answer

A)  It would quickly evolve to have a much different value of   . 
B)  In order to exist,every universe must have   . 
C)  We know   ,based on the average density of galaxies. 
D)  The fluctuation in the CBR tell us that   . 
A)  It would quickly evolve to have a much different value of   . 
B)  In order to exist,every universe must have   . 
C)  We know   ,based on the average density of galaxies. 
D)  The fluctuation in the CBR tell us that   .

Question 18

If dark energy is currently causing the expansion rate of the universe to increase with time,does this mean that you should worry that the Sun,the Earth,and your body itself are expanding? Why or why not?

Accepted Answer

Dark energy is indeed causing space to e

Question 19

Due to the fact that we live in a universe with an accelerating expansion rate,the actual age of the universe is __________ the Hubble time.

Accepted Answer

A)  larger than 
B)  smaller than 
C)  the same as 
D)  independent of 
A)  larger than 
B)  smaller than 
C)  the same as 
D)  independent of

Question 20

In the superstring theory that successfully unites gravity and quantum mechanics,the universe must have 11 dimensions (10 spatial and 1 temporal).

Accepted Answer

A) True 
 B)False

Exam 21: Modern Cosmology

Even with infinitely powerful telescopes,we can look back in time only until

Observations of Type I supernovae in distant galaxies confirm that the expansion of the universe is decreasing over time.

The theory of inflation assumes that at some point in time dark energy will decay and the universe will expand rapidly by a factor of .

The four fundamental forces of nature are gravity,electromagnetism,the weak force,and the strong force.

By the time the universe was 5 minutes old,approximately 24 percent of the normal matter in it had been turned into

What is the "flatness problem" in cosmology?

Observations of Type I supernovae in distant galaxies have shown that

How would astronomers describe the antiparticle of an electron?

Describe the four fundamental forces of nature by listing their names and describing what effect each force has on objects in the universe.

What can solve the flatness and horizon problem in cosmology,and why?

The ratio of the average density in all forms of matter (luminous and dark)in our universe to the critical density is approximately 0.3.

If today and dark energy was a cosmological constant,the universe will

In some particle physics theories,the universe must have more than three spatial dimensions,but we experience only three.Why would we not see the other spatial dimensions?

Why does the critical mass density of the universe depend on the value of Hubble's constant, ?

If today and there were no dark energy,the universe would

The concept of inflation helps solve both the problems of the flatness of the universe and smoothness of the cosmic background radiation.

Why would it be very improbable for our universe to have ?

If dark energy is currently causing the expansion rate of the universe to increase with time,does this mean that you should worry that the Sun,the Earth,and your body itself are expanding? Why or why not?

Due to the fact that we live in a universe with an accelerating expansion rate,the actual age of the universe is __________ the Hubble time.

In the superstring theory that successfully unites gravity and quantum mechanics,the universe must have 11 dimensions (10 spatial and 1 temporal).

Why Learn Astronomy

Patterns in the Skymotions of Earth

Gravity and Orbitsa Celestial Ballet

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Gravity Is More Than Keplers Laws

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

A Run-Of-The-Mill G-Type Starour Sun

Star Formation and the Interstellar Medium

Stars in the Slow Lanelow-Mass Stellar Evolution

Live Fast,die Younghigh-Mass Stellar Evolution

Our Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

The Origin of Structure

Life

Filters