Question 1

The only chemical elements that formed as the universe cooled down after the Big Bang were hydrogen,deuterium,and helium.

Accepted Answer

A) True 
 B)False

Question 2

Assuming the Hubble constant is equal to 22 km/s/Mly,estimate the age of the universe (or Hubble time).Note that 1 Mly = 9.5 × 1018 km and 1 year = 3.17 × 107 s.

Accepted Answer

t = 1/H₀ = 1/[22 km/(s Mly)] =

Question 3

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 4

After the Big Bang,as the universe cooled and protons and electrons combined so that the universe became neutral,what important consequence happened?

Accepted Answer

A)  Photons began to travel freely through the universe. 
B)  Neutrinos ceased to interact with normal matter. 
C)  Dark matter ceased to interact with normal matter. 
D)  Protons and neutrons combined to form nuclei such as deuterium and helium. 
A)  Photons began to travel freely through the universe. 
B)  Neutrinos ceased to interact with normal matter. 
C)  Dark matter ceased to interact with normal matter. 
D)  Protons and neutrons combined to form nuclei such as deuterium and helium.

Question 5

Examine the figure below.Describe why the distance ladder is so important to the field of cosmology.

Accepted Answer

The distance ladder provides m

Question 6

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 z $\approx$ 20. 
B)  From redshifts of z = 0 to 100,photons are gravitationally lensed by the dark matter in the universe. 
C)  At redshifts of z > 1,000,most of the photons are blocked by large amounts of cold gas and dust. 
D)  For redshifts of z > 1,000,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 z $\approx$ 20. 
B)  From redshifts of z = 0 to 100,photons are gravitationally lensed by the dark matter in the universe. 
C)  At redshifts of z > 1,000,most of the photons are blocked by large amounts of cold gas and dust. 
D)  For redshifts of z > 1,000,photons are heavily altered because they easily react with individual protons and electrons in the universe.

Question 7

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 8

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

Accepted Answer

A) True 
 B)False

Question 9

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 10

Which of the following is NOT a prediction of the standard Big Bang theory that has been successfully verified by observations?

Accepted Answer

A)  The universe is expanding. 
B)  The faintest galaxies look redder because their stars are younger. 
C)  Helium,lithium,and beryllium were made as the universe cooled after the initial Big Bang. 
D)  The early universe was very hot and dense. 
A)  The universe is expanding. 
B)  The faintest galaxies look redder because their stars are younger. 
C)  Helium,lithium,and beryllium were made as the universe cooled after the initial Big Bang. 
D)  The early universe was very hot and dense.

Question 11

If the density of normal matter,such as protons and electrons,were higher in the early universe,would there have been more or less 4He made in the Big Bang?

Accepted Answer

If there were more protons and

Question 12

To be a standard candle an object must have a constant:

Accepted Answer

A)  lifetime 
B)  brightness 
C)  luminosity 
D)  distance 
A)  lifetime 
B)  brightness 
C)  luminosity 
D)  distance

Question 13

If the spectrum of a distant galaxy is observed to have a calcium K absorption line that occurs at a wavelength of 500.4 nm,what is this galaxy's distance if the rest wavelength of this absorption line is 393.4 nm?

Accepted Answer

A)  950 Mly 
B)  1,800 Mly 
C)  2,300 Mly 
D)  3,700 Mly 
A)  950 Mly 
B)  1,800 Mly 
C)  2,300 Mly 
D)  3,700 Mly

Question 14

Why are some galaxies' spectra blueshifted rather than redshifted?

Accepted Answer

A)  Some distant galaxies are gravitationally lensed. 
B)  Some nearby galaxies are attracted to us because of the mass of the Milky Way. 
C)  Some nearby galaxies have vigorous star formation and are much bluer than others. 
D)  Some distant galaxies have AGN at their centers. 
A)  Some distant galaxies are gravitationally lensed. 
B)  Some nearby galaxies are attracted to us because of the mass of the Milky Way. 
C)  Some nearby galaxies have vigorous star formation and are much bluer than others. 
D)  Some distant galaxies have AGN at their centers.

Question 15

The cosmic microwave background radiation contains photons left over from the epoch in the universe's history when electrons recombined with nuclei.

Accepted Answer

A) True 
 B)False

Question 16

Describe the two assumptions regarding the universe that the cosmological principle makes.

Accepted Answer

The universe is homogeneous (t

Question 17

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 18

The spectrum of a galaxy is observed to have a hydrogen emission line,normally found at 656.3 nm,with a measured wavelength of 928.7 nm.What is its redshift?

Accepted Answer

z = (@#LAT-DLM&_obs - @#LAT-DLM&_rest)/@#LAT-DLM&_rest = (928.7

Question 19

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 20

If you found a galaxy with a hydrogen emission line,normally found at 656.3 nm,with a measured wavelength of 756.3 nm,what would the galaxy's recessional velocity be if the Hubble constant is 22 km/s/Mly?

Accepted Answer

A)  1,120 km/s 
B)  2,080 km/s 
C)  6,070 km/s 
D)  8,500 km/s 
A)  1,120 km/s 
B)  2,080 km/s 
C)  6,070 km/s 
D)  8,500 km/s

The only chemical elements that formed as the universe cooled down after the Big Bang were hydrogen,deuterium,and helium.

Assuming the Hubble constant is equal to 22 km/s/Mly,estimate the age of the universe (or Hubble time).Note that 1 Mly = 9.5 × 10¹⁸ km and 1 year = 3.17 × 10⁷ s.

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

After the Big Bang,as the universe cooled and protons and electrons combined so that the universe became neutral,what important consequence happened?

Examine the figure below.Describe why the distance ladder is so important to the field of cosmology.

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

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

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

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.

Which of the following is NOT a prediction of the standard Big Bang theory that has been successfully verified by observations?

If the density of normal matter,such as protons and electrons,were higher in the early universe,would there have been more or less ⁴He made in the Big Bang?

To be a standard candle an object must have a constant:

If the spectrum of a distant galaxy is observed to have a calcium K absorption line that occurs at a wavelength of 500.4 nm,what is this galaxy's distance if the rest wavelength of this absorption line is 393.4 nm?

Why are some galaxies' spectra blueshifted rather than redshifted?

The cosmic microwave background radiation contains photons left over from the epoch in the universe's history when electrons recombined with nuclei.

Describe the two assumptions regarding the universe that the cosmological principle makes.

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

The spectrum of a galaxy is observed to have a hydrogen emission line,normally found at 656.3 nm,with a measured wavelength of 928.7 nm.What is its redshift?

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.

If you found a galaxy with a hydrogen emission line,normally found at 656.3 nm,with a measured wavelength of 756.3 nm,what would the galaxy's recessional velocity be if the Hubble constant is 22 km/s/Mly?

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: The Sun

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

Filters

Exam 14: The Expansion of Space

The only chemical elements that formed as the universe cooled down after the Big Bang were hydrogen,deuterium,and helium.

Assuming the Hubble constant is equal to 22 km/s/Mly,estimate the age of the universe (or Hubble time).Note that 1 Mly = 9.5 × 1018 km and 1 year = 3.17 × 107 s.

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

After the Big Bang,as the universe cooled and protons and electrons combined so that the universe became neutral,what important consequence happened?

Examine the figure below.Describe why the distance ladder is so important to the field of cosmology.

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

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

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

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.

Which of the following is NOT a prediction of the standard Big Bang theory that has been successfully verified by observations?

If the density of normal matter,such as protons and electrons,were higher in the early universe,would there have been more or less 4He made in the Big Bang?

To be a standard candle an object must have a constant:

If the spectrum of a distant galaxy is observed to have a calcium K absorption line that occurs at a wavelength of 500.4 nm,what is this galaxy's distance if the rest wavelength of this absorption line is 393.4 nm?

Why are some galaxies' spectra blueshifted rather than redshifted?

The cosmic microwave background radiation contains photons left over from the epoch in the universe's history when electrons recombined with nuclei.

Describe the two assumptions regarding the universe that the cosmological principle makes.

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

The spectrum of a galaxy is observed to have a hydrogen emission line,normally found at 656.3 nm,with a measured wavelength of 928.7 nm.What is its redshift?

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.

If you found a galaxy with a hydrogen emission line,normally found at 656.3 nm,with a measured wavelength of 756.3 nm,what would the galaxy's recessional velocity be if the Hubble constant is 22 km/s/Mly?

Our Place in the Universe

Patterns in the Skymotions of Earth

Laws of Motion

Light and Telescopes

The Formation of Stars and Planets

Terrestrial Worlds in the Inner Solar System

Atmospheres of Venus, Earth, and Mars

The Giant Planets

Small Bodies of the Solar System

Measuring the Stars

Our Star: The Sun

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

The Realm of the Galaxies

Our Galaxy: The Milky Way

Modern Cosmology and the Origin of Structure

Life in the Universe

Filters

Assuming the Hubble constant is equal to 22 km/s/Mly,estimate the age of the universe (or Hubble time).Note that 1 Mly = 9.5 × 10¹⁸ km and 1 year = 3.17 × 10⁷ s.

If the density of normal matter,such as protons and electrons,were higher in the early universe,would there have been more or less ⁴He made in the Big Bang?