Question 1

The Cosmological Principle says that physical laws that are true in one part of the universe must be true in every part of the universe.

Accepted Answer

A) True 
 B)False

Question 2

In the Great Debate of 1920,Curtis argued that spiral nebulae were individual galaxies,while Shapley argued spiral nebulae must be part of the Milky Way because the Milky Way was very large in size.

Accepted Answer

A) True 
 B)False

Question 3

Charles Messier published the first galaxy catalog containing over 2,000 nearby galaxies.

Accepted Answer

A) True 
 B)False

Question 4

The standard Big Bang theory successfully predicts that the fraction of helium by mass in the primordial universe was 2 percent.

Accepted Answer

A) True 
 B)False

Question 5

The CBR is a snapshot of the radiation in the universe at a redshift of   when the universe was

Accepted Answer

A)  1,000 times smaller than it is today. 
B)  10 times smaller than it is today. 
C)  2 times smaller than it is today. 
D)  the same size as it is today. 
A)  1,000 times smaller than it is today. 
B)  10 times smaller than it is today. 
C)  2 times smaller than it is today. 
D)  the same size as it is today.

Question 6

If suddenly we find that the distance between Earth and the Sun is now 10 percent larger than we thought it was before,what else will change?

Accepted Answer

A)  The distances of stars 
B)  The size of our galaxy 
C)  The value of   
D)  All of the above 
A)  The distances of stars 
B)  The size of our galaxy 
C)  The value of   
D)  All of the above

Question 7

There is no special center to the expansion of the universe.

Accepted Answer

A) True 
 B)False

Question 8

The inverse of the value of   is a

Accepted Answer

A)  time. 
B)  mass. 
C)  density. 
D)  size. 
A)  time. 
B)  mass. 
C)  density. 
D)  size.

Question 9

If we lived on a galaxy one billion light-years from our own,what would we see?

Accepted Answer

A)  A universe 1 billion years younger than ours 
B)  A universe 1 billion years older than ours 
C)  Much the same universe we see today 
D)  Nothing-there are no galaxies one billion light-years away from us. 
A)  A universe 1 billion years younger than ours 
B)  A universe 1 billion years older than ours 
C)  Much the same universe we see today 
D)  Nothing-there are no galaxies one billion light-years away from us.

Question 10

We can measure the value of   directly with no intermediate steps.

Accepted Answer

A) True 
 B)False

Question 11

Name three "rungs" in the distance ladder that let us estimate the value of   .

Accepted Answer

Trigonometric parallax,period-

Question 12

What important event in the universe's history marked the creation of the cosmic background radiation?

Accepted Answer

The CBR is a relic of the time in the un

Question 13

What did Edwin Hubble study in the Andromeda Galaxy that proved it was an individual galaxy and not part of our own Milky Way?

Accepted Answer

A)  Cepheid stars 
B)  Type I supernovae 
C)  Globular clusters 
D)  Red Giant stars 
A)  Cepheid stars 
B)  Type I supernovae 
C)  Globular clusters 
D)  Red Giant stars

Question 14

The current temperature of the cosmic microwave background radiation is 17 K.

Accepted Answer

A) True 
 B)False

Question 15

When we measure distances to very faint galaxies with Type I supernovae,the accuracy of the measurement is only as good as that of the calibration of the Cepheids.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following lists distance indicators that are used to measure distances ranging from the very nearest to the very farthest?

Accepted Answer

A)  Cepheids,parallax,main-sequence fitting,Type I supernovae 
B)  Parallax,main-sequence fitting,Cepheids,Type I supernovae 
C)  Parallax,main-sequence fitting,Type I supernovae,Cepheids 
D)  Main-sequence fitting,parallax,Cepheids,Type I supernovae 
A)  Cepheids,parallax,main-sequence fitting,Type I supernovae 
B)  Parallax,main-sequence fitting,Cepheids,Type I supernovae 
C)  Parallax,main-sequence fitting,Type I supernovae,Cepheids 
D)  Main-sequence fitting,parallax,Cepheids,Type I supernovae

Question 17

As the universe expands,the sizes of galaxies expand a measurable amount as well.

Accepted Answer

A) True 
 B)False

Question 18

How did Edwin Hubble definitively prove that "spiral nebulae" were individual galaxies that were separate from the Milky Way?

Accepted Answer

Hubble identified Cepheid variable stars

Question 19

Why can Type I supernovae be used to determine a galaxy's distance?

Accepted Answer

A)  Type I supernovae occur only in very luminous galaxies. 
B)  Type I supernova have approximately the same luminosity. 
C)  Type I supernovae have approximately the same size. 
D)  A Type I supernova occurs in a typical galaxy about once every 100 years. 
A)  Type I supernovae occur only in very luminous galaxies. 
B)  Type I supernova have approximately the same luminosity. 
C)  Type I supernovae have approximately the same size. 
D)  A Type I supernova occurs in a typical galaxy about once every 100 years.

Question 20

Why is it NOT possible to look all the way back to the Big Bang itself?

Accepted Answer

A)  Photons are not produced until the stars begin to shine at a redshift of   . 
B)  From redshifts of   to 100,photons are gravitationally lensed by the dark matter in the universe. 
C)  At redshifts of   ,most of the photons are blocked by large amounts of cold gas and dust. 
D)  For redshifts of   ,photons are heavily altered because they easily react with individual protons and electrons in the universe. 
A)  Photons are not produced until the stars begin to shine at a redshift of   . 
B)  From redshifts of   to 100,photons are gravitationally lensed by the dark matter in the universe. 
C)  At redshifts of   ,most of the photons are blocked by large amounts of cold gas and dust. 
D)  For redshifts of   ,photons are heavily altered because they easily react with individual protons and electrons in the universe.

Exam 18: Our Expanding Universe

The Cosmological Principle says that physical laws that are true in one part of the universe must be true in every part of the universe.

In the Great Debate of 1920,Curtis argued that spiral nebulae were individual galaxies,while Shapley argued spiral nebulae must be part of the Milky Way because the Milky Way was very large in size.

Charles Messier published the first galaxy catalog containing over 2,000 nearby galaxies.

The standard Big Bang theory successfully predicts that the fraction of helium by mass in the primordial universe was 2 percent.

The CBR is a snapshot of the radiation in the universe at a redshift of when the universe was

If suddenly we find that the distance between Earth and the Sun is now 10 percent larger than we thought it was before,what else will change?

There is no special center to the expansion of the universe.

The inverse of the value of is a

If we lived on a galaxy one billion light-years from our own,what would we see?

We can measure the value of directly with no intermediate steps.

Name three "rungs" in the distance ladder that let us estimate the value of .

What important event in the universe's history marked the creation of the cosmic background radiation?

What did Edwin Hubble study in the Andromeda Galaxy that proved it was an individual galaxy and not part of our own Milky Way?

The current temperature of the cosmic microwave background radiation is 17 K.

When we measure distances to very faint galaxies with Type I supernovae,the accuracy of the measurement is only as good as that of the calibration of the Cepheids.

Which of the following lists distance indicators that are used to measure distances ranging from the very nearest to the very farthest?

As the universe expands,the sizes of galaxies expand a measurable amount as well.

How did Edwin Hubble definitively prove that "spiral nebulae" were individual galaxies that were separate from the Milky Way?

Why can Type I supernovae be used to determine a galaxy's distance?

Why is it NOT possible to look all the way back to the Big Bang itself?

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

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

The Origin of Structure

Life

Filters