Question 1

The effect that makes the cosmic microwave background appear slightly warmer in one direction and cooler in the opposite direction is:

Accepted Answer

A)  a basic asymmetry in the background radiation, related to its origin. 
B)  the Doppler shift caused by motion of the Milky Way Galaxy through space toward the constellation Leo. 
C)  microwave emission from cool, primordial (pre-galactic) clouds of gas and dust in that direction. 
D)  the presence of large clusters of galaxies in only one direction. 
A)  a basic asymmetry in the background radiation, related to its origin. 
B)  the Doppler shift caused by motion of the Milky Way Galaxy through space toward the constellation Leo. 
C)  microwave emission from cool, primordial (pre-galactic) clouds of gas and dust in that direction. 
D)  the presence of large clusters of galaxies in only one direction.

Question 2

What is the isotropy (or horizon)problem?

Accepted Answer

A)  The universe is not as uniform as the standard cosmological model predicts it should be. 
B)  If the universe expanded at the rate originally predicted, then the parts we see in opposite directions would never have been in equilibrium with each other and should not exhibit the degree of isotropy we observe. 
C)  Without modification, the standard theory suggests that an observer on a distant galaxy would not be able to see our Galaxy because of the intense cosmological redshift. 
D)  As we observe galaxies on the "horizon," the farthest distance obtainable, the standard theory predicts that the recessional velocity should approach the speed of light. 
A)  The universe is not as uniform as the standard cosmological model predicts it should be. 
B)  If the universe expanded at the rate originally predicted, then the parts we see in opposite directions would never have been in equilibrium with each other and should not exhibit the degree of isotropy we observe. 
C)  Without modification, the standard theory suggests that an observer on a distant galaxy would not be able to see our Galaxy because of the intense cosmological redshift. 
D)  As we observe galaxies on the "horizon," the farthest distance obtainable, the standard theory predicts that the recessional velocity should approach the speed of light.

Question 3

The isotropy of the cosmic microwave background radiation (same temperature in all directions)indicates that:

Accepted Answer

A)  the universe had an early period of inflation in which regions initially in contact were carried out of contact with one another. 
B)  the universe did not begin to expand significantly until after the era of recombination. 
C)  regions that appear to us to be on opposite sides of the visible universe are in fact in close contact with one another. 
D)  the universe has always been dominated by matter. 
A)  the universe had an early period of inflation in which regions initially in contact were carried out of contact with one another. 
B)  the universe did not begin to expand significantly until after the era of recombination. 
C)  regions that appear to us to be on opposite sides of the visible universe are in fact in close contact with one another. 
D)  the universe has always been dominated by matter.

Question 4

In cosmology,the constant that is intimately related to the present "age" of the universe is:

Accepted Answer

A)  the constant in Wien's law of radiation. 
B)  1/G, the inverse of the universal gravitational constant. 
C)  the Planck time, 10-⁴³ s, in which space and time came into existence. 
D)  1/H₀, the inverse of the Hubble constant of expansion. 
A)  the constant in Wien's law of radiation. 
B)  1/G, the inverse of the universal gravitational constant. 
C)  the Planck time, 10-⁴³ s, in which space and time came into existence. 
D)  1/H₀, the inverse of the Hubble constant of expansion.

Question 5

The electromagnetic and weak nuclear forces are predicted to have been indistinguishable at some stage in the early universe.What conditions were required at this stage?

Accepted Answer

A)  extremely high temperatures, producing very energetic collisions between components of matter 
B)  very low density of matter, such that the weak force became as strong as the electromagnetic force in this region of space 
C)  very high density of matter, such as the interior of the nucleus of an atom or a neutron star, where particles are so close that weak forces become equivalent to electromagnetic forces 
D)  extremely low temperatures, where collisions of particles were of low energy and extremely infrequent, such that electromagnetic and weak forces were equivalent 
A)  extremely high temperatures, producing very energetic collisions between components of matter 
B)  very low density of matter, such that the weak force became as strong as the electromagnetic force in this region of space 
C)  very high density of matter, such as the interior of the nucleus of an atom or a neutron star, where particles are so close that weak forces become equivalent to electromagnetic forces 
D)  extremely low temperatures, where collisions of particles were of low energy and extremely infrequent, such that electromagnetic and weak forces were equivalent

Question 6

If space has a hyperbolic geometry (open universe),what will happen to two initially parallel laser beams as they traverse billions of light years of space?

Accepted Answer

A)  The beams will gradually diverge (move apart). 
B)  The beams will remain parallel. 
C)  The beams will gradually diverge (move apart) to a maximum separation, then gradually approach and cross. 
D)  The beams will gradually approach each other and eventually cross. 
A)  The beams will gradually diverge (move apart). 
B)  The beams will remain parallel. 
C)  The beams will gradually diverge (move apart) to a maximum separation, then gradually approach and cross. 
D)  The beams will gradually approach each other and eventually cross.

Question 7

Suppose new experimental evidence were to point to a Hubble constant value of H₀ = 50 km/s/Mpc.A calculation of the age of the universe using this value would give:

Accepted Answer

A)  the same value we now calculate, namely 13.7 billion years. 
B)  an age younger than 13.7 billion years. 
C)  an age older than 13.7 billion years. 
D)  a different value of the age, but more information is needed to estimate what it would be. 
A)  the same value we now calculate, namely 13.7 billion years. 
B)  an age younger than 13.7 billion years. 
C)  an age older than 13.7 billion years. 
D)  a different value of the age, but more information is needed to estimate what it would be.

Question 8

What is the cosmic microwave background radiation?

Accepted Answer

A)  uniform background of radiation from electrons spiraling in weak intergalactic magnetic fields 
B)  radiation left over from the Big Bang after the universe expanded and cooled 
C)  almost uniform background of radiation from distant, unresolved, overlapping galaxies 
D)  radiation from a very tenuous, ionized gas that fills the universe equally in all directions 
A)  uniform background of radiation from electrons spiraling in weak intergalactic magnetic fields 
B)  radiation left over from the Big Bang after the universe expanded and cooled 
C)  almost uniform background of radiation from distant, unresolved, overlapping galaxies 
D)  radiation from a very tenuous, ionized gas that fills the universe equally in all directions

Question 9

On the basis of recent results from very bright and very distant Type Ia supernovae,what seems to be our situation in the universe regarding the past and present motion of clusters of galaxies?

Accepted Answer

A)  We live in a "flat" universe with a decelerating rate of expansion. 
B)  We live in an open universe with a constant rate of expansion given by the Hubble law. 
C)  We live in a closed universe with a decelerating rate of expansion. 
D)  We live in a "flat" universe with an accelerating rate of expansion. 
A)  We live in a "flat" universe with a decelerating rate of expansion. 
B)  We live in an open universe with a constant rate of expansion given by the Hubble law. 
C)  We live in a closed universe with a decelerating rate of expansion. 
D)  We live in a "flat" universe with an accelerating rate of expansion.

Question 10

What order of events do we predict in the early universe,from earlier to later?

Accepted Answer

A)  Planck time, Big Bang, inflation, formation of elementary particles 
B)  Big Bang, Planck time, formation of elementary particles, inflation 
C)  Big Bang, inflation, Planck time, formation of elementary particles 
D)  Big Bang, Planck time, inflation, formation of elementary particles 
A)  Planck time, Big Bang, inflation, formation of elementary particles 
B)  Big Bang, Planck time, formation of elementary particles, inflation 
C)  Big Bang, inflation, Planck time, formation of elementary particles 
D)  Big Bang, Planck time, inflation, formation of elementary particles

Question 11

Who predicted the existence of the cosmic microwave background radiation,the radiation left over from the Big Bang,and began making preparations to detect it?

Accepted Answer

A)  Ralph Alpher and George Gamow 
B)  Arno Penzias and Robert Wilson 
C)  Anthony Hewish and Jocelyn Bell 
D)  Robert Dicke and P. J. E. Peebles 
A)  Ralph Alpher and George Gamow 
B)  Arno Penzias and Robert Wilson 
C)  Anthony Hewish and Jocelyn Bell 
D)  Robert Dicke and P. J. E. Peebles

Question 12

When did Einstein originally introduce his theory of general relativity,including the cosmological constant?

Accepted Answer

A)  in 1896, before the modern stellar spectral classification scheme was devised 
B)  in 1915, before the question of the nature of the Milky Way Galaxy had been resolved 
C)  in 1930, after Hubble had discovered evidence for the expanding universe 
D)  in 1968, after the discovery of the cosmic microwave background gave evidence of the Big Bang 
A)  in 1896, before the modern stellar spectral classification scheme was devised 
B)  in 1915, before the question of the nature of the Milky Way Galaxy had been resolved 
C)  in 1930, after Hubble had discovered evidence for the expanding universe 
D)  in 1968, after the discovery of the cosmic microwave background gave evidence of the Big Bang

Question 13

The cosmological redshift in the light from distant galaxies is explained by which effect?

Accepted Answer

A)  A photon's wavelength is a distance and is therefore lengthened by the general expansion of the universe, making the light appear reddened. 
B)  The light we on Earth see was Doppler-shifted to longer wavelengths by the motion of the objects (e.g., galaxies) away from Earth. 
C)  The light spreads out over larger areas as distance increases according to 1/(distance)², which causes the wavelength to increase in proportion to distance. 
D)  The light from more distant galaxies has traveled through the gravitational fields of more galaxies in getting to us and is therefore more gravitationally redshifted. 
A)  A photon's wavelength is a distance and is therefore lengthened by the general expansion of the universe, making the light appear reddened. 
B)  The light we on Earth see was Doppler-shifted to longer wavelengths by the motion of the objects (e.g., galaxies) away from Earth. 
C)  The light spreads out over larger areas as distance increases according to 1/(distance)², which causes the wavelength to increase in proportion to distance. 
D)  The light from more distant galaxies has traveled through the gravitational fields of more galaxies in getting to us and is therefore more gravitationally redshifted.

Question 14

In the present theory of the Big Bang,what significant event occurred at about 500,000 years after the universe started expanding?

Accepted Answer

A)  The primordial helium in the universe was produced. 
B)  The universe became transparent to neutrinos. 
C)  The temperature of the cosmic background radiation had cooled to its present level of about 3 K. 
D)  The universe became transparent to photons of radiation. 
A)  The primordial helium in the universe was produced. 
B)  The universe became transparent to neutrinos. 
C)  The temperature of the cosmic background radiation had cooled to its present level of about 3 K. 
D)  The universe became transparent to photons of radiation.

Question 15

The greatest support for the Big Bang theory of cosmology came from the discovery of:

Accepted Answer

A)  the cosmic microwave background. 
B)  the cosmic neutrino background. 
C)  isotropy in the universe. 
D)  homogeneity in the universe. 
A)  the cosmic microwave background. 
B)  the cosmic neutrino background. 
C)  isotropy in the universe. 
D)  homogeneity in the universe.

Question 16

Good evidence for an original Big Bang that "created" our universe comes from:

Accepted Answer

A)  the rapid motions of some nearby stars, such as Barnard's star. 
B)  a background "glow" of microwaves, with blackbody temperature of about 3 K. 
C)  the measurement of the rotation of the Milky Way Galaxy. 
D)  the amount of gas and dust in the solar neighborhood. 
A)  the rapid motions of some nearby stars, such as Barnard's star. 
B)  a background "glow" of microwaves, with blackbody temperature of about 3 K. 
C)  the measurement of the rotation of the Milky Way Galaxy. 
D)  the amount of gas and dust in the solar neighborhood.

Question 17

Who discovered the cosmic microwave background radiation,the radiation left over from the Big Bang?

Accepted Answer

A)  Ralph Alpher and George Gamow 
B)  Arno Penzias and Robert Wilson 
C)  Anthony Hewish and Jocelyn Bell 
D)  Robert Dicke and P. J. E. Peebles 
A)  Ralph Alpher and George Gamow 
B)  Arno Penzias and Robert Wilson 
C)  Anthony Hewish and Jocelyn Bell 
D)  Robert Dicke and P. J. E. Peebles

Question 18

The cosmological redshift of the light from very distant galaxies is caused by the:

Accepted Answer

A)  rotation of the universe around its center (faster at greater distances from Earth). 
B)  expansion of space, stretching the photon's wavelength while the photon is traveling toward Earth. 
C)  absorption of blue light by interstellar dust between Earth and the galaxy so that only the red wavelengths reach Earth. 
D)  Doppler shift, in which the photon's wavelength is stretched by the galaxy's motion through space, away from Earth, while the photon is being emitted. 
A)  rotation of the universe around its center (faster at greater distances from Earth). 
B)  expansion of space, stretching the photon's wavelength while the photon is traveling toward Earth. 
C)  absorption of blue light by interstellar dust between Earth and the galaxy so that only the red wavelengths reach Earth. 
D)  Doppler shift, in which the photon's wavelength is stretched by the galaxy's motion through space, away from Earth, while the photon is being emitted.

Question 19

What experimental evidence do we have for the direct transformation of energy into matter?

Accepted Answer

A)  an increase in the force upon a body when it is accelerated upward (e.g., in an elevator) 
B)  the conversion of gamma-ray photons into electrons and antielectrons (i.e., positrons) 
C)  the blueshift of light because of the motion of its source 
D)  the relativistic increase in mass of an object when it is moving very rapidly 
A)  an increase in the force upon a body when it is accelerated upward (e.g., in an elevator) 
B)  the conversion of gamma-ray photons into electrons and antielectrons (i.e., positrons) 
C)  the blueshift of light because of the motion of its source 
D)  the relativistic increase in mass of an object when it is moving very rapidly

Question 20

How do we detect the relative amounts of dark matter and luminous matter in the early universe?

Accepted Answer

A)  the same way we do in the present universe: rotation curves, gravitational lensing, etc. 
B)  by measuring the sizes of the peaks created by acoustic waves in the cosmic microwave background. 
C)  by measuring the relative amplitudes in the acoustic overtone waves in the cosmic microwave background. 
D)  by measuring the relative frequencies in the acoustic overtone waves in the cosmic microwave background. 
A)  the same way we do in the present universe: rotation curves, gravitational lensing, etc. 
B)  by measuring the sizes of the peaks created by acoustic waves in the cosmic microwave background. 
C)  by measuring the relative amplitudes in the acoustic overtone waves in the cosmic microwave background. 
D)  by measuring the relative frequencies in the acoustic overtone waves in the cosmic microwave background.

The effect that makes the cosmic microwave background appear slightly warmer in one direction and cooler in the opposite direction is:

What is the isotropy (or horizon)problem?

The isotropy of the cosmic microwave background radiation (same temperature in all directions)indicates that:

In cosmology,the constant that is intimately related to the present "age" of the universe is:

The electromagnetic and weak nuclear forces are predicted to have been indistinguishable at some stage in the early universe.What conditions were required at this stage?

If space has a hyperbolic geometry (open universe),what will happen to two initially parallel laser beams as they traverse billions of light years of space?

Suppose new experimental evidence were to point to a Hubble constant value of H₀ = 50 km/s/Mpc.A calculation of the age of the universe using this value would give:

What is the cosmic microwave background radiation?

On the basis of recent results from very bright and very distant Type Ia supernovae,what seems to be our situation in the universe regarding the past and present motion of clusters of galaxies?

What order of events do we predict in the early universe,from earlier to later?

Who predicted the existence of the cosmic microwave background radiation,the radiation left over from the Big Bang,and began making preparations to detect it?

When did Einstein originally introduce his theory of general relativity,including the cosmological constant?

The cosmological redshift in the light from distant galaxies is explained by which effect?

In the present theory of the Big Bang,what significant event occurred at about 500,000 years after the universe started expanding?

The greatest support for the Big Bang theory of cosmology came from the discovery of:

Good evidence for an original Big Bang that "created" our universe comes from:

Who discovered the cosmic microwave background radiation,the radiation left over from the Big Bang?

The cosmological redshift of the light from very distant galaxies is caused by the:

What experimental evidence do we have for the direct transformation of energy into matter?

How do we detect the relative amounts of dark matter and luminous matter in the early universe?

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

The effect that makes the cosmic microwave background appear slightly warmer in one direction and cooler in the opposite direction is:

What is the isotropy (or horizon)problem?

The isotropy of the cosmic microwave background radiation (same temperature in all directions)indicates that:

In cosmology,the constant that is intimately related to the present "age" of the universe is:

The electromagnetic and weak nuclear forces are predicted to have been indistinguishable at some stage in the early universe.What conditions were required at this stage?

If space has a hyperbolic geometry (open universe),what will happen to two initially parallel laser beams as they traverse billions of light years of space?

Suppose new experimental evidence were to point to a Hubble constant value of H₀ = 50 km/s/Mpc.A calculation of the age of the universe using this value would give:

What is the cosmic microwave background radiation?

On the basis of recent results from very bright and very distant Type Ia supernovae,what seems to be our situation in the universe regarding the past and present motion of clusters of galaxies?

What order of events do we predict in the early universe,from earlier to later?

Who predicted the existence of the cosmic microwave background radiation,the radiation left over from the Big Bang,and began making preparations to detect it?

When did Einstein originally introduce his theory of general relativity,including the cosmological constant?

The cosmological redshift in the light from distant galaxies is explained by which effect?

In the present theory of the Big Bang,what significant event occurred at about 500,000 years after the universe started expanding?

The greatest support for the Big Bang theory of cosmology came from the discovery of:

Good evidence for an original Big Bang that "created" our universe comes from:

Who discovered the cosmic microwave background radiation,the radiation left over from the Big Bang?

The cosmological redshift of the light from very distant galaxies is caused by the:

What experimental evidence do we have for the direct transformation of energy into matter?

How do we detect the relative amounts of dark matter and luminous matter in the early universe?

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