Question 1

Does the initial rate of star formation have any effect on the type of galaxy that is formed from a pre-galactic gas cloud?

Accepted Answer

A)  No, the initial rate of star formation determines the size of the galaxy. A high initial rate of star formation means that many stars have formed a large galaxy before the remaining gas and dust dissipate and star formation ceases. But a galaxy of any type is equally likely to form. 
B)  Yes, a high initial rate of star formation uses up the gas and dust before it has a chance to settle into a disk. So this results in an elliptical galaxy. 
C)  Yes, a high initial rate of star formation produces an early generation of stars that evolve and send out more gas and dust to form a disk and to perpetuate star formation. So this results in a spiral galaxy. 
D)  Yes, an initially high rate of star formation produces many high-mass stars that explode and send out shock waves to trigger the formation of other stars. This chaotic situation results in an irregular galaxy. 
A)  No, the initial rate of star formation determines the size of the galaxy. A high initial rate of star formation means that many stars have formed a large galaxy before the remaining gas and dust dissipate and star formation ceases. But a galaxy of any type is equally likely to form. 
B)  Yes, a high initial rate of star formation uses up the gas and dust before it has a chance to settle into a disk. So this results in an elliptical galaxy. 
C)  Yes, a high initial rate of star formation produces an early generation of stars that evolve and send out more gas and dust to form a disk and to perpetuate star formation. So this results in a spiral galaxy. 
D)  Yes, an initially high rate of star formation produces many high-mass stars that explode and send out shock waves to trigger the formation of other stars. This chaotic situation results in an irregular galaxy.

Question 2

Which description is NOT consistent with the universe as envisioned by Isaac Newton?

Accepted Answer

A)  infinite 
B)  static 
C)  having existed forever 
D)  expanding slowly 
A)  infinite 
B)  static 
C)  having existed forever 
D)  expanding slowly

Question 3

If we could have turned a receiver toward the heavens in hopes of observing the cosmic microwave radiation 4.5 billion years ago,at the time the solar nebula was forming,what would we have found?

Accepted Answer

A)  We would have seen nothing since the CMB had not yet been created. 
B)  We would have seen the same blackbody curve we see now, with a peak intensity at a wavelength of about 1 mm. 
C)  We would have seen a blackbody curve of the same shape we see now but with a peak intensity at a wavelength shorter than 1 mm. 
D)  We would have seen a blackbody curve of the same shape we see now but with a peak intensity at a wavelength longer than 1 mm. 
A)  We would have seen nothing since the CMB had not yet been created. 
B)  We would have seen the same blackbody curve we see now, with a peak intensity at a wavelength of about 1 mm. 
C)  We would have seen a blackbody curve of the same shape we see now but with a peak intensity at a wavelength shorter than 1 mm. 
D)  We would have seen a blackbody curve of the same shape we see now but with a peak intensity at a wavelength longer than 1 mm.

Question 4

Which of the four fundamental forces holds the electrons in the atom?

Accepted Answer

A)  strong nuclear force 
B)  gravitational force 
C)  weak nuclear force 
D)  electromagnetic force 
A)  strong nuclear force 
B)  gravitational force 
C)  weak nuclear force 
D)  electromagnetic force

Question 5

At what time did the universe cool to a temperature of about 3 K?

Accepted Answer

A)  the end of the inflationary era 
B)  the end of the Planck time 
C)  very recently 
D)  the era of recombination 
A)  the end of the inflationary era 
B)  the end of the Planck time 
C)  very recently 
D)  the era of recombination

Question 6

If the early universe had been perfectly uniform,galaxies could not have formed.As it is,we believe the variations in density which were sufficient to produce the galaxies and other structure we now see were only about one part in:

Accepted Answer

A)  10. 
B)  1000. 
C)  100,000. 
D)  10 million. 
A)  10. 
B)  1000. 
C)  100,000. 
D)  10 million.

Question 7

In a state of thermal equilibrium,particles and radiation are all at the same temperature as they interact with one another.In this environment,are the pair-production and annihilation reactions that can occur limited by the particular temperature of the environment?

Accepted Answer

A)  Yes. Both pair production and annihilation reactions are limited by the temperature. 
B)  Pair production reactions are limited by the temperature but annihilation reactions are not. 
C)  Annihilation reactions are limited by the temperature but pair production reactions are not. 
D)  Neither pair production reactions nor annihilation reactions are limited by the temperature. 
A)  Yes. Both pair production and annihilation reactions are limited by the temperature. 
B)  Pair production reactions are limited by the temperature but annihilation reactions are not. 
C)  Annihilation reactions are limited by the temperature but pair production reactions are not. 
D)  Neither pair production reactions nor annihilation reactions are limited by the temperature.

Question 8

At an age of 500,000 years,the temperature of the universe had fallen to 3000 K,and electrons could then combine with protons to produce neutral hydrogen gas.What major transition took place in the universe at this time?

Accepted Answer

A)  The present laws of physics began to apply for the first time. 
B)  The universe suddenly lost its electrical charge and become neutral. 
C)  Nuclear fusion no longer occurred below this temperature. 
D)  The universe became transparent to light for the first time. 
A)  The present laws of physics began to apply for the first time. 
B)  The universe suddenly lost its electrical charge and become neutral. 
C)  Nuclear fusion no longer occurred below this temperature. 
D)  The universe became transparent to light for the first time.

Question 9

Suppose the expansion of the universe has been slowing since the Big Bang,and the value H₀ is the Hubble constant that is appropriate to the universe today.What would this say about the age of the universe?

Accepted Answer

A)  The age should still be 1/H₀ = 13.7 billion years. 
B)  The age would be less than 13.7 billion years. 
C)  The age would be greater than 13.7 billion years. 
D)  It is not possible to answer the question based only on this information. 
A)  The age should still be 1/H₀ = 13.7 billion years. 
B)  The age would be less than 13.7 billion years. 
C)  The age would be greater than 13.7 billion years. 
D)  It is not possible to answer the question based only on this information.

Question 10

The cosmic microwave background is found to be extremely uniform throughout space,with only very small fluctuations in intensity.The event that produced this remarkable smoothness in the early universe was:

Accepted Answer

A)  the occurrence of the Big Bang everywhere in space at the same time. 
B)  the start of the production of matter in the universe, which smoothed out the irregularities in space. 
C)  an exemplar of Heisenberg's uncertainty principle that prevented the concentration of radiant energy in localized volumes of space. 
D)  a sudden but brief period of rapid expansion (cosmic inflation) of the universe during the general expansion of the early universe. 
A)  the occurrence of the Big Bang everywhere in space at the same time. 
B)  the start of the production of matter in the universe, which smoothed out the irregularities in space. 
C)  an exemplar of Heisenberg's uncertainty principle that prevented the concentration of radiant energy in localized volumes of space. 
D)  a sudden but brief period of rapid expansion (cosmic inflation) of the universe during the general expansion of the early universe.

Question 11

Grand unified theories,or GUTs,predict that at temperatures above 10²⁷ K,the:

Accepted Answer

A)  strong and weak forces are indistinguishable from each other, but the other forces are different. 
B)  strong, weak, electromagnetic, and gravitational forces are indistinguishable from each other. 
C)  weak and electromagnetic forces are indistinguishable from each other, but the other forces are different. 
D)  strong, weak, and electromagnetic forces are indistinguishable from each other, but gravity is different. 
A)  strong and weak forces are indistinguishable from each other, but the other forces are different. 
B)  strong, weak, electromagnetic, and gravitational forces are indistinguishable from each other. 
C)  weak and electromagnetic forces are indistinguishable from each other, but the other forces are different. 
D)  strong, weak, and electromagnetic forces are indistinguishable from each other, but gravity is different.

Question 12

In the universe,we can consider four different regimes of space in which distances between objects might be changing as a result of the general expansion of the universe: (1)distances between different parts of Earth; (2)distance between planets in the solar system; (3)distances between stars in the Milky Way; (4)distances between clusters of galaxies.In which of these regimes are the distances changing because of this expansion?

Accepted Answer

A)  4, 3, 2, 1 
B)  4 
C)  4, 3, 2 
D)  4, 3 
A)  4, 3, 2, 1 
B)  4 
C)  4, 3, 2 
D)  4, 3

Question 13

How many fundamental forces are known in science at the present time under normal conditions?

Accepted Answer

A)  four 
B)  five 
C)  three 
D)  six 
A)  four 
B)  five 
C)  three 
D)  six

Question 14

Why did Newton view the universe as infinite in extent?

Accepted Answer

A)  It was based on purely religious/philosophical grounds. 
B)  Newton had some idea of the scale of the universe because of the lack of observable parallax for even the closest stars. So, he reasoned, with the huge number of faint stars he could see through his telescope, the universe must go on infinitely in all directions. 
C)  Newton believed the universe was expanding outward. If it were finite in extent, it would long ago have stopped and would have begun to collapse. 
D)  If the universe had an edge, there would be an imbalance of forces on objects near the edge and they would not be in equilibrium. 
A)  It was based on purely religious/philosophical grounds. 
B)  Newton had some idea of the scale of the universe because of the lack of observable parallax for even the closest stars. So, he reasoned, with the huge number of faint stars he could see through his telescope, the universe must go on infinitely in all directions. 
C)  Newton believed the universe was expanding outward. If it were finite in extent, it would long ago have stopped and would have begun to collapse. 
D)  If the universe had an edge, there would be an imbalance of forces on objects near the edge and they would not be in equilibrium.

Question 15

Why is the universe expanding?

Accepted Answer

A)  The energy from all the stars is heating the universe, making it expand like a gas that is heated. 
B)  Spacetime itself is expanding, carrying the galaxies (or superclusters of galaxies) with it. 
C)  The universe is not expanding-it is we who are getting smaller, making the universe seem bigger and bigger. 
D)  An infinitely dense clump of matter exploded, sending the galaxies (or superclusters of galaxies) hurtling out through space. 
A)  The energy from all the stars is heating the universe, making it expand like a gas that is heated. 
B)  Spacetime itself is expanding, carrying the galaxies (or superclusters of galaxies) with it. 
C)  The universe is not expanding-it is we who are getting smaller, making the universe seem bigger and bigger. 
D)  An infinitely dense clump of matter exploded, sending the galaxies (or superclusters of galaxies) hurtling out through space.

Question 16

The first 10-⁴³ seconds of the universe's existence are called the Planck era.The kind of physics needed to describe that era is:

Accepted Answer

A)  Newtonian physics. 
B)  general relativity. 
C)  quantum physics. 
D)  presently unknown. 
A)  Newtonian physics. 
B)  general relativity. 
C)  quantum physics. 
D)  presently unknown.

Question 17

When is the weak nuclear force encountered?

Accepted Answer

A)  when a neutron is transformed into a proton with the ejection of an electron and a neutrino 
B)  when a positively charged nucleus repels another positively charged nucleus in the core of a star like the Sun 
C)  when two quarks interact inside a proton or neutron 
D)  when an atom absorbs a photon and one of the electrons in the atom is sent into a higher energy level 
A)  when a neutron is transformed into a proton with the ejection of an electron and a neutrino 
B)  when a positively charged nucleus repels another positively charged nucleus in the core of a star like the Sun 
C)  when two quarks interact inside a proton or neutron 
D)  when an atom absorbs a photon and one of the electrons in the atom is sent into a higher energy level

Question 18

Measurement of structure in the cosmic microwave background radiation has recently indicated that we live in a flat universe between a closed and an open universe,and yet the measured density of detected matter and radiation is only 20-40% of the critical density required for a flat universe.In what form is the other 60-80% of the "matter" thought to be?

Accepted Answer

A)  myriads of small primordial black holes whose gravitational effects are spread throughout the universe and that emit no radiation 
B)  dark energy emitting no visible radiation 
C)  antimatter, which generates a negative gravitational effect and emits radiation only if it meets matter and is annihilated 
D)  neutrinos, which have very little rest mass and are very difficult to detect, but are very abundant 
A)  myriads of small primordial black holes whose gravitational effects are spread throughout the universe and that emit no radiation 
B)  dark energy emitting no visible radiation 
C)  antimatter, which generates a negative gravitational effect and emits radiation only if it meets matter and is annihilated 
D)  neutrinos, which have very little rest mass and are very difficult to detect, but are very abundant

Question 19

When the isotropy of the cosmic microwave radiation was first realized,what effect did this discovery have on the contemporary theories of cosmology?

Accepted Answer

A)  The discovery was a great support for the Big Bang cosmology that predicts this isotropy. 
B)  The discovery was a great support for the Steady state cosmology that predicts this isotropy. 
C)  The discovery was a great problem because it was prohibited by all the main cosmologies. 
D)  The discovery was a puzzle because the Big Bang cosmology does not predict this isotropy, although it is not prohibit it, either. 
A)  The discovery was a great support for the Big Bang cosmology that predicts this isotropy. 
B)  The discovery was a great support for the Steady state cosmology that predicts this isotropy. 
C)  The discovery was a great problem because it was prohibited by all the main cosmologies. 
D)  The discovery was a puzzle because the Big Bang cosmology does not predict this isotropy, although it is not prohibit it, either.

Question 20

During what time interval was helium created in the Big Bang?

Accepted Answer

A)  during the first 10-⁴³ s 
B)  during the first 10-⁶ s 
C)  during the first 500,000 years 
D)  during the first 3 minutes 
A)  during the first 10-⁴³ s 
B)  during the first 10-⁶ s 
C)  during the first 500,000 years 
D)  during the first 3 minutes

Does the initial rate of star formation have any effect on the type of galaxy that is formed from a pre-galactic gas cloud?

Which description is NOT consistent with the universe as envisioned by Isaac Newton?

If we could have turned a receiver toward the heavens in hopes of observing the cosmic microwave radiation 4.5 billion years ago,at the time the solar nebula was forming,what would we have found?

Which of the four fundamental forces holds the electrons in the atom?

At what time did the universe cool to a temperature of about 3 K?

If the early universe had been perfectly uniform,galaxies could not have formed.As it is,we believe the variations in density which were sufficient to produce the galaxies and other structure we now see were only about one part in:

In a state of thermal equilibrium,particles and radiation are all at the same temperature as they interact with one another.In this environment,are the pair-production and annihilation reactions that can occur limited by the particular temperature of the environment?

At an age of 500,000 years,the temperature of the universe had fallen to 3000 K,and electrons could then combine with protons to produce neutral hydrogen gas.What major transition took place in the universe at this time?

Suppose the expansion of the universe has been slowing since the Big Bang,and the value H₀ is the Hubble constant that is appropriate to the universe today.What would this say about the age of the universe?

The cosmic microwave background is found to be extremely uniform throughout space,with only very small fluctuations in intensity.The event that produced this remarkable smoothness in the early universe was:

Grand unified theories,or GUTs,predict that at temperatures above 10²⁷ K,the:

How many fundamental forces are known in science at the present time under normal conditions?

Why did Newton view the universe as infinite in extent?

Why is the universe expanding?

The first 10-⁴³ seconds of the universe's existence are called the Planck era.The kind of physics needed to describe that era is:

When is the weak nuclear force encountered?

When the isotropy of the cosmic microwave radiation was first realized,what effect did this discovery have on the contemporary theories of cosmology?

During what time interval was helium created in the Big Bang?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Astrobiology

Filters

Exam 14: Cosmology

Does the initial rate of star formation have any effect on the type of galaxy that is formed from a pre-galactic gas cloud?

Which description is NOT consistent with the universe as envisioned by Isaac Newton?

If we could have turned a receiver toward the heavens in hopes of observing the cosmic microwave radiation 4.5 billion years ago,at the time the solar nebula was forming,what would we have found?

Which of the four fundamental forces holds the electrons in the atom?

At what time did the universe cool to a temperature of about 3 K?

If the early universe had been perfectly uniform,galaxies could not have formed.As it is,we believe the variations in density which were sufficient to produce the galaxies and other structure we now see were only about one part in:

In a state of thermal equilibrium,particles and radiation are all at the same temperature as they interact with one another.In this environment,are the pair-production and annihilation reactions that can occur limited by the particular temperature of the environment?

At an age of 500,000 years,the temperature of the universe had fallen to 3000 K,and electrons could then combine with protons to produce neutral hydrogen gas.What major transition took place in the universe at this time?

Suppose the expansion of the universe has been slowing since the Big Bang,and the value H₀ is the Hubble constant that is appropriate to the universe today.What would this say about the age of the universe?

The cosmic microwave background is found to be extremely uniform throughout space,with only very small fluctuations in intensity.The event that produced this remarkable smoothness in the early universe was:

Grand unified theories,or GUTs,predict that at temperatures above 10²⁷ K,the:

How many fundamental forces are known in science at the present time under normal conditions?

Why did Newton view the universe as infinite in extent?

Why is the universe expanding?

The first 10-⁴³ seconds of the universe's existence are called the Planck era.The kind of physics needed to describe that era is:

When is the weak nuclear force encountered?

When the isotropy of the cosmic microwave radiation was first realized,what effect did this discovery have on the contemporary theories of cosmology?

During what time interval was helium created in the Big Bang?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Astrobiology

Filters