Question 1

A photon is produced 300,000 years after the Big Bang,eventually reaching a telescope on Earth.How did it travel to get there?

Accepted Answer

A)  It traveled in a straight line. 
B)  It scattered off matter until it hit the telescope. 
C)  It traveled in a straight line for 100,000 years and then scattered off matter until it hit the telescope. 
D)  It scattered off matter for 100,000 years and then traveled in a straight line. 
A)  It traveled in a straight line. 
B)  It scattered off matter until it hit the telescope. 
C)  It traveled in a straight line for 100,000 years and then scattered off matter until it hit the telescope. 
D)  It scattered off matter for 100,000 years and then traveled in a straight line.

Question 2

In the early history of the Universe,an unstable quantum field decayed to its ground state.How did this affect the Universe?

Accepted Answer

It caused

Question 3

Which curve on the figure below corresponds to the Universe undergoing the most deceleration?

Accepted Answer

A)  the middle (light gray) curve 
B)  the lower (medium gray) curve 
C)  the upper (black) curve 
D)  It is impossible to determine. 
A)  the middle (light gray) curve 
B)  the lower (medium gray) curve 
C)  the upper (black) curve 
D)  It is impossible to determine.

Question 4

By approximately what factor did the Universe expand between 10⁻⁴³ and 10⁻³³ seconds after the Big Bang,according to present models?

Accepted Answer

A)  10 
B)  1010 
C)  1050 
D)  The Universe did not expand during that interval. 
A)  10 
B)  1010 
C)  1050 
D)  The Universe did not expand during that interval.

Question 5

An astronomer wishes to test the Big Bang model by studying helium-4.In which environment should he or she look in order to test the Big Bang model?

Accepted Answer

A region uncontamina

Question 6

In the context of the classic Big Bang model,why is the uniformity of the cosmic microwave background's temperature puzzling?

Accepted Answer

Different parts of the univers

Question 7

How do scientists characterize the Universe before the Big Bang?

Accepted Answer

They cannot,as our u

Question 8

The figure below shows a portion of the Universe's expansion history.What problem with the classic Big Bang model is solved by the highlighted portion?

Accepted Answer

A)  the observed geometry of the Universe 
B)  the observed acceleration of the Universe's expansion 
C)  the observed size of the Universe 
D)  the observed dominance of dark energy at the present day 
A)  the observed geometry of the Universe 
B)  the observed acceleration of the Universe's expansion 
C)  the observed size of the Universe 
D)  the observed dominance of dark energy at the present day

Question 9

What process is thought by most astronomers to be responsible for making the Universe flat?

Accepted Answer

The answer of What process is thought by most astronomers...

Question 10

Which of the following pieces of evidence favor the Big Bang model over the steady-state model?

Accepted Answer

A)  the cosmological constant does not change with time 
B)  the quasar population changes with redshift 
C)  the ongoing creation of matter in the spaces between galaxies 
D)  the average density of dark matter in the Universe 
A)  the cosmological constant does not change with time 
B)  the quasar population changes with redshift 
C)  the ongoing creation of matter in the spaces between galaxies 
D)  the average density of dark matter in the Universe

Question 11

Consider two universes with identical Hubble constants.Universe A has a higher density than universe B.If neither universe has dark energy,this implies that:

Accepted Answer

A)  universe A is older than universe B. 
B)  universe A is the same age as universe B. 
C)  universe A is younger than universe B. 
D)  This situation is not possible according to the Big Bang model. 
A)  universe A is older than universe B. 
B)  universe A is the same age as universe B. 
C)  universe A is younger than universe B. 
D)  This situation is not possible according to the Big Bang model.

Question 12

How does cosmological recombination affect the interaction of photons and matter?

Accepted Answer

It causes

Question 13

The Universe's geometry is determined by its:

Accepted Answer

A)  size. 
B)  age. 
C)  density of matter-energy. 
D)  homogeneity. 
A)  size. 
B)  age. 
C)  density of matter-energy. 
D)  homogeneity.

Question 14

Which of the following is NOT an example of a cosmological investigation?

Accepted Answer

A)  using supernovas to understand the stellar population 
B)  using Cepheid variables to measure the Hubble constant 
C)  using the cosmic microwave background to measure the geometry of the Universe 
D)  characterizing the average abundance of different elements in the Universe 
A)  using supernovas to understand the stellar population 
B)  using Cepheid variables to measure the Hubble constant 
C)  using the cosmic microwave background to measure the geometry of the Universe 
D)  characterizing the average abundance of different elements in the Universe

Question 15

Which of the following were necessary for Einstein to formulate equations describing the Universe as a whole?

Accepted Answer

A)  homogeneity 
B)  isotropy 
C)  general relativity 
D)  all of the above 
A)  homogeneity 
B)  isotropy 
C)  general relativity 
D)  all of the above

Question 16

A particular region in space has a galaxy cluster today.How would the density and temperature of that same region have compared to an average region of the Universe at the time of cosmological recombination?

Accepted Answer

It would h

Question 17

An astronomer discovers that all galaxies with a particular characteristic have a radius precisely equal to 10 kpc.He or she measures the angular sizes of a large set of these galaxies.How can he or she use his or her measurements to deduce the overall density of the Universe?

Accepted Answer

He or she can measure the geom

Question 18

Why is baryogenesis NOT a key observational pillar of the classic Big Bang model?

Accepted Answer

A)  Baryogenesis occurred too early to be directly observable. 
B)  Baryogenesis would have occurred in the same way in a steady-state universe. 
C)  Baryogenesis occurs too rapidly to depend upon the expansion of the Universe. 
D)  Cosmologists do not fully understand baryogenesis. 
A)  Baryogenesis occurred too early to be directly observable. 
B)  Baryogenesis would have occurred in the same way in a steady-state universe. 
C)  Baryogenesis occurs too rapidly to depend upon the expansion of the Universe. 
D)  Cosmologists do not fully understand baryogenesis.

Question 19

Which of the following provides the best test of inflation?

Accepted Answer

A)  the geometry of the Universe 
B)  the temperature fluctuations in the cosmic microwave background 
C)  nucleosynthesis 
D)  the size of the observable Universe 
A)  the geometry of the Universe 
B)  the temperature fluctuations in the cosmic microwave background 
C)  nucleosynthesis 
D)  the size of the observable Universe

Question 20

Which of the following statements is true in both the steady-state and Big Bang models of cosmology?

Accepted Answer

A)  The cosmic microwave background was only generated at a particular time period in the past. 
B)  The curvature of the Universe evolves over time as matter spreads out due to expansion. 
C)  The Universe is homogeneous and isotropic. 
D)  The density of galaxies never changes. 
A)  The cosmic microwave background was only generated at a particular time period in the past. 
B)  The curvature of the Universe evolves over time as matter spreads out due to expansion. 
C)  The Universe is homogeneous and isotropic. 
D)  The density of galaxies never changes.

A photon is produced 300,000 years after the Big Bang,eventually reaching a telescope on Earth.How did it travel to get there?

In the early history of the Universe,an unstable quantum field decayed to its ground state.How did this affect the Universe?

Which curve on the figure below corresponds to the Universe undergoing the most deceleration?

By approximately what factor did the Universe expand between 10⁻⁴³ and 10⁻³³ seconds after the Big Bang,according to present models?

An astronomer wishes to test the Big Bang model by studying helium-4.In which environment should he or she look in order to test the Big Bang model?

In the context of the classic Big Bang model,why is the uniformity of the cosmic microwave background's temperature puzzling?

How do scientists characterize the Universe before the Big Bang?

The figure below shows a portion of the Universe's expansion history.What problem with the classic Big Bang model is solved by the highlighted portion?

What process is thought by most astronomers to be responsible for making the Universe flat?

Which of the following pieces of evidence favor the Big Bang model over the steady-state model?

Consider two universes with identical Hubble constants.Universe A has a higher density than universe B.If neither universe has dark energy,this implies that:

How does cosmological recombination affect the interaction of photons and matter?

The Universe's geometry is determined by its:

Which of the following is NOT an example of a cosmological investigation?

Which of the following were necessary for Einstein to formulate equations describing the Universe as a whole?

A particular region in space has a galaxy cluster today.How would the density and temperature of that same region have compared to an average region of the Universe at the time of cosmological recombination?

An astronomer discovers that all galaxies with a particular characteristic have a radius precisely equal to 10 kpc.He or she measures the angular sizes of a large set of these galaxies.How can he or she use his or her measurements to deduce the overall density of the Universe?

Why is baryogenesis NOT a key observational pillar of the classic Big Bang model?

Which of the following provides the best test of inflation?

Which of the following statements is true in both the steady-state and Big Bang models of cosmology?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Filters

Exam 18: Cosmology

A photon is produced 300,000 years after the Big Bang,eventually reaching a telescope on Earth.How did it travel to get there?

In the early history of the Universe,an unstable quantum field decayed to its ground state.How did this affect the Universe?

Which curve on the figure below corresponds to the Universe undergoing the most deceleration?

By approximately what factor did the Universe expand between 10⁻⁴³ and 10⁻³³ seconds after the Big Bang,according to present models?

An astronomer wishes to test the Big Bang model by studying helium-4.In which environment should he or she look in order to test the Big Bang model?

In the context of the classic Big Bang model,why is the uniformity of the cosmic microwave background's temperature puzzling?

How do scientists characterize the Universe before the Big Bang?

The figure below shows a portion of the Universe's expansion history.What problem with the classic Big Bang model is solved by the highlighted portion?

What process is thought by most astronomers to be responsible for making the Universe flat?

Which of the following pieces of evidence favor the Big Bang model over the steady-state model?

Consider two universes with identical Hubble constants.Universe A has a higher density than universe B.If neither universe has dark energy,this implies that:

How does cosmological recombination affect the interaction of photons and matter?

The Universe's geometry is determined by its:

Which of the following is NOT an example of a cosmological investigation?

Which of the following were necessary for Einstein to formulate equations describing the Universe as a whole?

A particular region in space has a galaxy cluster today.How would the density and temperature of that same region have compared to an average region of the Universe at the time of cosmological recombination?

An astronomer discovers that all galaxies with a particular characteristic have a radius precisely equal to 10 kpc.He or she measures the angular sizes of a large set of these galaxies.How can he or she use his or her measurements to deduce the overall density of the Universe?

Why is baryogenesis NOT a key observational pillar of the classic Big Bang model?

Which of the following provides the best test of inflation?

Which of the following statements is true in both the steady-state and Big Bang models of cosmology?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Filters