Question 1

In cosmology,what is the inflationary period?

Accepted Answer

A)  the period when the cost of living rose faster than astronomers' salaries 
B)  the first 500,000 years of the life of the universe, when matter and radiation interacted vigorously 
C)  the period of universal expansion from the Big Bang to the present 
D)  the short period of extremely rapid expansion when the universe was very young 
A)  the period when the cost of living rose faster than astronomers' salaries 
B)  the first 500,000 years of the life of the universe, when matter and radiation interacted vigorously 
C)  the period of universal expansion from the Big Bang to the present 
D)  the short period of extremely rapid expansion when the universe was very young

Question 2

Helium nuclei began permanent formation in the early universe,when the temperature dropped to the point where the gamma radiation no longer had enough energy to break nuclei apart as soon as they formed.Did this helium production cease? If so,why?

Accepted Answer

A)  Helium production at the site of the Big Bang has continued, although the rate has decreased. 
B)  Helium production did not cease until millions of years later, when the density of the primordial universe became too low to support nuclear fusion. 
C)  The production of helium in the early universe ceased after a few minutes, but only because the available energy and particles were being used up in the production of heavier nuclei like carbon, oxygen, and silicon. 
D)  After a few minutes, the early universe cooled to the point where protons no longer had enough energy to overcome the repulsion of the electromagnetic force and come close enough to each other to undergo nuclear fusion. 
A)  Helium production at the site of the Big Bang has continued, although the rate has decreased. 
B)  Helium production did not cease until millions of years later, when the density of the primordial universe became too low to support nuclear fusion. 
C)  The production of helium in the early universe ceased after a few minutes, but only because the available energy and particles were being used up in the production of heavier nuclei like carbon, oxygen, and silicon. 
D)  After a few minutes, the early universe cooled to the point where protons no longer had enough energy to overcome the repulsion of the electromagnetic force and come close enough to each other to undergo nuclear fusion.

Question 3

According to our current understanding of cosmology,what is the origin of the foamy structure of the universe,with clusters of galaxies distributed on the perimeters of voids?

Accepted Answer

A)  The early epoch of star formation caused the clusters of galaxies to repel one another, and the present distribution was the result. 
B)  The matter in the universe is now believed to be very smoothly distributed, just as it was after the Big Bang. What we see as voids is really dark matter. 
C)  Quantum fluctuations in the early universe were greatly exaggerated during the epoch of inflation to become the uneven distribution we now observe. 
D)  The universe was formed "clumpy" in the Big Bang, and the clumpiness persists to the present day. 
A)  The early epoch of star formation caused the clusters of galaxies to repel one another, and the present distribution was the result. 
B)  The matter in the universe is now believed to be very smoothly distributed, just as it was after the Big Bang. What we see as voids is really dark matter. 
C)  Quantum fluctuations in the early universe were greatly exaggerated during the epoch of inflation to become the uneven distribution we now observe. 
D)  The universe was formed "clumpy" in the Big Bang, and the clumpiness persists to the present day.

Question 4

If we compare an elliptical galaxy and a spiral galaxy of the same mass a billion years after both began formation:

Accepted Answer

A)  they should each have about the same number of stars. 
B)  the elliptical galaxy will have formed more stars than the spiral. 
C)  the spiral galaxy will have formed more stars than the elliptical. 
D)  neither galaxy will have formed any stars during the first billion years. 
A)  they should each have about the same number of stars. 
B)  the elliptical galaxy will have formed more stars than the spiral. 
C)  the spiral galaxy will have formed more stars than the elliptical. 
D)  neither galaxy will have formed any stars during the first billion years.

Question 5

What do cosmologists study?

Accepted Answer

A)  the formation, structure, and evolution of stars 
B)  the origin, structure, and evolution of the solar system 
C)  the formation, structure, and evolution of galaxies 
D)  the origin, structure, and evolution of the universe 
A)  the formation, structure, and evolution of stars 
B)  the origin, structure, and evolution of the solar system 
C)  the formation, structure, and evolution of galaxies 
D)  the origin, structure, and evolution of the universe

Question 6

The Milky Way Galaxy is moving at about 600 km/s relative to the cosmic microwave background.How does this compare with Earth's speed in its orbit and with the speed of the solar system in its orbit around the galactic center?

Accepted Answer

A)  This speed is less than both the speed of the solar system and Earth's orbital speed. 
B)  This speed is greater than Earth's orbital speed but less than the solar system's speed. 
C)  This speed is greater than the solar system's speed but less than Earth's speed in its orbit. 
D)  This speed is greater than both Earth's speed in its orbit and the solar system's speed. 
A)  This speed is less than both the speed of the solar system and Earth's orbital speed. 
B)  This speed is greater than Earth's orbital speed but less than the solar system's speed. 
C)  This speed is greater than the solar system's speed but less than Earth's speed in its orbit. 
D)  This speed is greater than both Earth's speed in its orbit and the solar system's speed.

Question 7

The Planck era refers to the:

Accepted Answer

A)  time at which the expanding universe became transparent to radiation. 
B)  time of extremely rapid inflation that started 10-³⁵ s after the universe began. 
C)  first 10-⁴³ s of time, when all four fundamental forces were united. 
D)  present age of the universe as given by Hubble's law. 
A)  time at which the expanding universe became transparent to radiation. 
B)  time of extremely rapid inflation that started 10-³⁵ s after the universe began. 
C)  first 10-⁴³ s of time, when all four fundamental forces were united. 
D)  present age of the universe as given by Hubble's law.

Question 8

What is the difference between a proton and a neutron in terms of their constituent quarks?

Accepted Answer

A)  A proton is made of two "up" quarks and a "down" quark, and a neutron is made of two "down" quarks and an "up" quark. 
B)  A proton is made of two "down" quarks and an "up" quark, and a neutron is made of two "up" quarks and a "down" quark. 
C)  A proton is made of three "up" quarks, and a neutron is made of three "down" quarks. 
D)  A proton is made of three "down" quarks, and a neutron is made of three "up" quarks. 
A)  A proton is made of two "up" quarks and a "down" quark, and a neutron is made of two "down" quarks and an "up" quark. 
B)  A proton is made of two "down" quarks and an "up" quark, and a neutron is made of two "up" quarks and a "down" quark. 
C)  A proton is made of three "up" quarks, and a neutron is made of three "down" quarks. 
D)  A proton is made of three "down" quarks, and a neutron is made of three "up" quarks.

Question 9

How does the universe behave according to the steady-state theory?

Accepted Answer

A)  As the universe expands, new matter is created from which new galaxies form, thus maintaining a "steady state." 
B)  New matter is being continuously created, which adds to the absorption of light in the universe and makes distant galaxies seem farther and farther away. 
C)  The universe is static, not expanding or contracting, but new matter is being created so that as old galaxies die, new galaxies form to take their place. 
D)  The universe is static, neither expanding nor contracting, thus maintaining a "steady state" in which no change takes place. 
A)  As the universe expands, new matter is created from which new galaxies form, thus maintaining a "steady state." 
B)  New matter is being continuously created, which adds to the absorption of light in the universe and makes distant galaxies seem farther and farther away. 
C)  The universe is static, not expanding or contracting, but new matter is being created so that as old galaxies die, new galaxies form to take their place. 
D)  The universe is static, neither expanding nor contracting, thus maintaining a "steady state" in which no change takes place.

Question 10

The Milky Way Galaxy is moving at about 600 km/s relative to the cosmic microwave background radiation.Why?

Accepted Answer

A)  The Milky Way is being attracted by several nearby superclusters of galaxies. 
B)  This speed is the orbital speed of the Local Group of galaxies around the Virgo cluster. 
C)  There is no particular reason. All galaxies have "small" random speeds in addition to the universal expansion, and 600 km/s is the speed of the Milky Way. 
D)  This speed is the orbital speed of the Milky Way Galaxy around the Andromeda Galaxy. 
A)  The Milky Way is being attracted by several nearby superclusters of galaxies. 
B)  This speed is the orbital speed of the Local Group of galaxies around the Virgo cluster. 
C)  There is no particular reason. All galaxies have "small" random speeds in addition to the universal expansion, and 600 km/s is the speed of the Milky Way. 
D)  This speed is the orbital speed of the Milky Way Galaxy around the Andromeda Galaxy.

Question 11

The fate of a pre-galactic cloud of gas and dust as to what type of galaxy it will ultimately become appears to depend on all of the following EXCEPT ONE.Which is the exception?

Accepted Answer

A)  the initial rate of star formation 
B)  collisions 
C)  how close the formation site is to the Great Attractor 
D)  the density of dark matter at the formation site 
A)  the initial rate of star formation 
B)  collisions 
C)  how close the formation site is to the Great Attractor 
D)  the density of dark matter at the formation site

Question 12

What condition is necessary for the universe to be closed?

Accepted Answer

A)  The universe must have no mass in it. 
B)  The density of the universe must be large. 
C)  The density of the universe must be small. 
D)  The cosmological constant must be large. 
A)  The universe must have no mass in it. 
B)  The density of the universe must be large. 
C)  The density of the universe must be small. 
D)  The cosmological constant must be large.

Question 13

What was the temperature of the universe at the time the universe became transparent to radiation?

Accepted Answer

A)  300,000 K 
B)  30 billion K 
C)  3 K 
D)  3000 K 
A)  300,000 K 
B)  30 billion K 
C)  3 K 
D)  3000 K

Question 14

The forces of gravity and electromagnetism are long-range forces,extending in principle from their source (mass and electric charge,respectively)to infinity.Why is it that,in the universe,only gravity extends to infinity,whereas electromagnetic forces are much more limited in extent?

Accepted Answer

A)  Gravity and electromagnetism are one and the same force, with electromagnetic effects extending over limited spatial ranges and transforming into gravitational forces at large distances from matter. 
B)  Electromagnetic forces from charged particles will move other charged particles around to produce a uniform charge distribution and therefore zero electromagnetic forces, whereas gravity concentrates mass and enhances the overall gravity force. 
C)  Electromagnetic forces from positive charges are canceled by negative charges, whereas there are no negative "masses" to cancel the gravitational force. 
D)  All atoms are electrically neutral, so in reality the electromagnetic force never reaches beyond the size of an atomic nucleus. 
A)  Gravity and electromagnetism are one and the same force, with electromagnetic effects extending over limited spatial ranges and transforming into gravitational forces at large distances from matter. 
B)  Electromagnetic forces from charged particles will move other charged particles around to produce a uniform charge distribution and therefore zero electromagnetic forces, whereas gravity concentrates mass and enhances the overall gravity force. 
C)  Electromagnetic forces from positive charges are canceled by negative charges, whereas there are no negative "masses" to cancel the gravitational force. 
D)  All atoms are electrically neutral, so in reality the electromagnetic force never reaches beyond the size of an atomic nucleus.

Question 15

Our view of the universe is limited because of what fundamental fact?

Accepted Answer

A)  The cosmological redshift has moved the light from very distant objects out of our detectable range, making these objects invisible to us. 
B)  The matter expanding into space from the Big Bang extends only so far since matter can travel only at or below the speed of light. 
C)  Light from objects farther away than a certain distance, defined by the travel time of light in the lifetime of the universe, has not yet reached us. 
D)  Intergalactic space contains absorbing material that blocks our view of more distant objects. 
A)  The cosmological redshift has moved the light from very distant objects out of our detectable range, making these objects invisible to us. 
B)  The matter expanding into space from the Big Bang extends only so far since matter can travel only at or below the speed of light. 
C)  Light from objects farther away than a certain distance, defined by the travel time of light in the lifetime of the universe, has not yet reached us. 
D)  Intergalactic space contains absorbing material that blocks our view of more distant objects.

Question 16

Who first proposed that the observed motion of galaxies away from Earth originated with a colossal,high-temperature explosion at the beginning of the universe?

Accepted Answer

A)  Robert Dicke 
B)  George Gamow 
C)  Fred Hoyle 
D)  Edwin Hubble 
A)  Robert Dicke 
B)  George Gamow 
C)  Fred Hoyle 
D)  Edwin Hubble

Question 17

Even though cosmic microwave background photons outnumber hydrogen atoms by about 1 billion to 1 in the universe,the universe is still considered to be matter-dominated because the:

Accepted Answer

A)  photon energies are extremely small. 
B)  nature of the photons is such that they interact with nothing as they pass through the universe. 
C)  photons, while collectively carrying a large amount of energy, do not carry an equivalent amount of momentum and hence play little role in collisions with matter. 
D)  photons have no rest mass and hence can generate no gravity. 
A)  photon energies are extremely small. 
B)  nature of the photons is such that they interact with nothing as they pass through the universe. 
C)  photons, while collectively carrying a large amount of energy, do not carry an equivalent amount of momentum and hence play little role in collisions with matter. 
D)  photons have no rest mass and hence can generate no gravity.

Question 18

During the first millionth of a second in the history of the universe,hydrogen atom could not exist.Why not?

Accepted Answer

A)  During this time, quarks existed in isolation and so protons did not exist. 
B)  The electromagnetic force did not exist during this era. 
C)  Cosmic inflation had pushed protons and electrons too far apart to interact with each other. 
D)  Protons and anti-protons were continually annihilating each other, and there were no protons to form hydrogen atoms. 
A)  During this time, quarks existed in isolation and so protons did not exist. 
B)  The electromagnetic force did not exist during this era. 
C)  Cosmic inflation had pushed protons and electrons too far apart to interact with each other. 
D)  Protons and anti-protons were continually annihilating each other, and there were no protons to form hydrogen atoms.

Question 19

Which statement CORRECTLY describes our current state of knowledge about the future expansion of the universe?

Accepted Answer

A)  The amount of matter (both visible and dark) is only 1/3 of the amount needed to halt expansion, so the expansion will continue to slow down but will never stop. 
B)  The amount of matter (both visible and dark) is only 1/3 of the amount needed to halt expansion, and there is mounting evidence of a previously unknown form of energy that acts to accelerate the expansion. 
C)  The amount of matter (both visible and dark) is exactly the right amount needed to halt expansion after an infinite amount of time has gone by. 
D)  The amount of matter (both visible and dark) is three times the amount needed to halt expansion, so the expansion will eventually stop and the universe will begin to collapse. 
A)  The amount of matter (both visible and dark) is only 1/3 of the amount needed to halt expansion, so the expansion will continue to slow down but will never stop. 
B)  The amount of matter (both visible and dark) is only 1/3 of the amount needed to halt expansion, and there is mounting evidence of a previously unknown form of energy that acts to accelerate the expansion. 
C)  The amount of matter (both visible and dark) is exactly the right amount needed to halt expansion after an infinite amount of time has gone by. 
D)  The amount of matter (both visible and dark) is three times the amount needed to halt expansion, so the expansion will eventually stop and the universe will begin to collapse.

Question 20

The one physical force that extends farthest in our universe and is NOT canceled out by other effects is the _____ force.

Accepted Answer

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

In cosmology,what is the inflationary period?

Helium nuclei began permanent formation in the early universe,when the temperature dropped to the point where the gamma radiation no longer had enough energy to break nuclei apart as soon as they formed.Did this helium production cease? If so,why?

According to our current understanding of cosmology,what is the origin of the foamy structure of the universe,with clusters of galaxies distributed on the perimeters of voids?

If we compare an elliptical galaxy and a spiral galaxy of the same mass a billion years after both began formation:

What do cosmologists study?

The Milky Way Galaxy is moving at about 600 km/s relative to the cosmic microwave background.How does this compare with Earth's speed in its orbit and with the speed of the solar system in its orbit around the galactic center?

The Planck era refers to the:

What is the difference between a proton and a neutron in terms of their constituent quarks?

How does the universe behave according to the steady-state theory?

The Milky Way Galaxy is moving at about 600 km/s relative to the cosmic microwave background radiation.Why?

The fate of a pre-galactic cloud of gas and dust as to what type of galaxy it will ultimately become appears to depend on all of the following EXCEPT ONE.Which is the exception?

What condition is necessary for the universe to be closed?

What was the temperature of the universe at the time the universe became transparent to radiation?

The forces of gravity and electromagnetism are long-range forces,extending in principle from their source (mass and electric charge,respectively)to infinity.Why is it that,in the universe,only gravity extends to infinity,whereas electromagnetic forces are much more limited in extent?

Our view of the universe is limited because of what fundamental fact?

Who first proposed that the observed motion of galaxies away from Earth originated with a colossal,high-temperature explosion at the beginning of the universe?

Even though cosmic microwave background photons outnumber hydrogen atoms by about 1 billion to 1 in the universe,the universe is still considered to be matter-dominated because the:

During the first millionth of a second in the history of the universe,hydrogen atom could not exist.Why not?

Which statement CORRECTLY describes our current state of knowledge about the future expansion of the universe?

The one physical force that extends farthest in our universe and is NOT canceled out by other effects is the _____ force.

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

In cosmology,what is the inflationary period?

Helium nuclei began permanent formation in the early universe,when the temperature dropped to the point where the gamma radiation no longer had enough energy to break nuclei apart as soon as they formed.Did this helium production cease? If so,why?

According to our current understanding of cosmology,what is the origin of the foamy structure of the universe,with clusters of galaxies distributed on the perimeters of voids?

If we compare an elliptical galaxy and a spiral galaxy of the same mass a billion years after both began formation:

What do cosmologists study?

The Milky Way Galaxy is moving at about 600 km/s relative to the cosmic microwave background.How does this compare with Earth's speed in its orbit and with the speed of the solar system in its orbit around the galactic center?

The Planck era refers to the:

What is the difference between a proton and a neutron in terms of their constituent quarks?

How does the universe behave according to the steady-state theory?

The Milky Way Galaxy is moving at about 600 km/s relative to the cosmic microwave background radiation.Why?

The fate of a pre-galactic cloud of gas and dust as to what type of galaxy it will ultimately become appears to depend on all of the following EXCEPT ONE.Which is the exception?

What condition is necessary for the universe to be closed?

What was the temperature of the universe at the time the universe became transparent to radiation?

The forces of gravity and electromagnetism are long-range forces,extending in principle from their source (mass and electric charge,respectively)to infinity.Why is it that,in the universe,only gravity extends to infinity,whereas electromagnetic forces are much more limited in extent?

Our view of the universe is limited because of what fundamental fact?

Who first proposed that the observed motion of galaxies away from Earth originated with a colossal,high-temperature explosion at the beginning of the universe?

Even though cosmic microwave background photons outnumber hydrogen atoms by about 1 billion to 1 in the universe,the universe is still considered to be matter-dominated because the:

During the first millionth of a second in the history of the universe,hydrogen atom could not exist.Why not?

Which statement CORRECTLY describes our current state of knowledge about the future expansion of the universe?

The one physical force that extends farthest in our universe and is NOT canceled out by other effects is the _____ force.

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