Question 1

Which of the following statements cannot be tested by science today?

Accepted Answer

A) The universe is 14 billion years old. 
B) The expansion of the universe is now accelerating. 
C) Our universe is flat. 
D) Prior to the Planck time, our universe sprouted from another universe. 
A) The universe is 14 billion years old. 
B) The expansion of the universe is now accelerating. 
C) Our universe is flat. 
D) Prior to the Planck time, our universe sprouted from another universe.

Question 2

The Cosmic Microwave Background Radiation: The CMB is one of the true observational bonanzas of 20th- and 21st- century astronomy. Make as complete a list as possible of the various observations of the cosmic
microwave background that have been used to confirm, challenge, and extend the Big Bang theory for the origin and evolution of the universe.

Accepted Answer

1. Penzias and Wilson's discovery in 196

Question 3

Which forces have physicists shown to be the same force under conditions of very high temperature, as confirmed by experiments in particle accelerators?

Accepted Answer

A) the electromagnetic and weak forces 
B) the strong and electromagnetic forces 
C) the strong and weak forces 
D) gravity and the strong force 
E) gravity and the weak force 
A) the electromagnetic and weak forces 
B) the strong and electromagnetic forces 
C) the strong and weak forces 
D) gravity and the strong force 
E) gravity and the weak force

Question 4

From what cosmic epoch do the photons in the cosmic background radiation originate?

Accepted Answer

A) the end of the Planck era 
B) during the era of nucleosynthesis 
C) during the era of galaxy formation 
D) the end of the era of nuclei 
E) the moment of the Big Bang 
A) the end of the Planck era 
B) during the era of nucleosynthesis 
C) during the era of galaxy formation 
D) the end of the era of nuclei 
E) the moment of the Big Bang

Question 5

The cosmic microwave background gives us a view of the universe when it was

Accepted Answer

A) 14 billion years old. 
B) about 1 million years old. 
C) 380,000 years old. 
D) 3- 5 minutes old. 
A) 14 billion years old. 
B) about 1 million years old. 
C) 380,000 years old. 
D) 3- 5 minutes old.

Question 6

Evidence that the cosmic background radiation is the remnant of a Big Bang comes from predicting characteristics of remnant radiation from the Big Bang theory and comparing these predictions with observations. Four of the five statements below are real. Which one is fictitious?

Accepted Answer

A) The cosmic background radiation is expected to have a perfect thermal spectrum, and observations from the COBE spacecraft verify this prediction. 
B) The cosmic background radiation is expected to have a temperature just a few degrees above absolute zero, and its actual temperature turns out to be 2.73 K. 
C) The cosmic background radiation is expected to look essentially the same in all directions, and it does. 
D) The cosmic background radiation is expected to contain redshifted emission lines from hydrogen and helium, and it does. 
E) The cosmic background radiation is expected to have tiny temperature fluctuations at the level of about 1 part in 100,000. Such fluctuations were found in the COBE data. 
A) The cosmic background radiation is expected to have a perfect thermal spectrum, and observations from the COBE spacecraft verify this prediction. 
B) The cosmic background radiation is expected to have a temperature just a few degrees above absolute zero, and its actual temperature turns out to be 2.73 K. 
C) The cosmic background radiation is expected to look essentially the same in all directions, and it does. 
D) The cosmic background radiation is expected to contain redshifted emission lines from hydrogen and helium, and it does. 
E) The cosmic background radiation is expected to have tiny temperature fluctuations at the level of about 1 part in 100,000. Such fluctuations were found in the COBE data.

Question 7

According to the Big Bang theory, why do we live in a universe that is made of almost entirely of matter rather than antimatter?

Accepted Answer

A) The fact that we live in a universe made of matter is not surprising, because antimatter has never been shown to exist for real. 
B) GUT theories predict that under the conditions that prevailed in the early universe, the normal laws of physics would have been suspended so that only matter particles were created, and no particles of antimatter. 
C) During the first 0.001 second after the Big Bang, particles and antiparticles were made in almost but not perfectly equal numbers. Everything annihilated except the very slight excess of matter particles. 
D) Einstein's famous equation E = mc2 tells us that energy can turn into matter, but does not tell us that it can turn into antimatter. 
A) The fact that we live in a universe made of matter is not surprising, because antimatter has never been shown to exist for real. 
B) GUT theories predict that under the conditions that prevailed in the early universe, the normal laws of physics would have been suspended so that only matter particles were created, and no particles of antimatter. 
C) During the first 0.001 second after the Big Bang, particles and antiparticles were made in almost but not perfectly equal numbers. Everything annihilated except the very slight excess of matter particles. 
D) Einstein's famous equation E = mc2 tells us that energy can turn into matter, but does not tell us that it can turn into antimatter.

Question 8

Based on our current understanding of physics, we can understand the conditions that prevailed in the early universe as far back in time as about .

Accepted Answer

A) 10 billion years ago 
B) one ten- billionth of a second after the Big Bang 
C) 380,000 years after the Big Bang 
D) 10- 45 seconds after the Big Bang 
A) 10 billion years ago 
B) one ten- billionth of a second after the Big Bang 
C) 380,000 years after the Big Bang 
D) 10- 45 seconds after the Big Bang

Question 9

Rank these times based on the wavelength of the peak intensity of the cosmic background radiation at those times, from shortest to longest. (Hint: consider how the temperature of the universe or the cosmic background radiation changed with time.)

Accepted Answer

A) 100 million years after the Big Bang, 1 million years after the Big Bang, today 
B) today, 100 million years after the Big Bang, 1 million years after the Big Bang 
C) 1 million years after the Big Bang, 100 million years after the Big Bang, today 
D) today, 1 million years after the Big Bang, 100 million years after the Big Bang 
A) 100 million years after the Big Bang, 1 million years after the Big Bang, today 
B) today, 100 million years after the Big Bang, 1 million years after the Big Bang 
C) 1 million years after the Big Bang, 100 million years after the Big Bang, today 
D) today, 1 million years after the Big Bang, 100 million years after the Big Bang

Question 10

Evidence for Inflation: What is the observational evidence the universe underwent a brief but very rapid period of inflation at the end of the GUT era, early in the history of the universe. Does any of this evidence count as direct observational evidence? Does the validity of the Big Bang depend on inflation being correct?

Accepted Answer

The concept of inflation refers to a the

Question 11

We have direct experimental evidence (from large particle accelerators)for the physical conditions in the universe back to about after the Big Bang.

Accepted Answer

A) 380,000 years 
B) 300 years 
C) 3 minutes 
D) 10- 10 seconds 
E) 1 million years 
A) 380,000 years 
B) 300 years 
C) 3 minutes 
D) 10- 10 seconds 
E) 1 million years

Question 12

Briefly describe one of the three questions left unanswered by the standard Big Bang theory which are solved by inflation. That is, describe either the structure problem, the uniformity (or smoothness)problem, or the density (or flatness)problem.

Accepted Answer

Structure problem: The fact that there a

Question 13

The Big Bang predicts that the universe should be 25 percent hydrogen and 75 percent helium.

Accepted Answer

A) True 
 B)False

Question 14

This figure shows the temperature of the universe over time, according to models of the Big Bang. At what age did the universe cool to 1 million degrees?

Accepted Answer

A) about 1 second after the Big Bang 
B) about 1015 seconds after the Big Bang 
C) about 10- 3 seconds after the Big Bang 
D) about 107 seconds after the Big Bang 
A) about 1 second after the Big Bang 
B) about 1015 seconds after the Big Bang 
C) about 10- 3 seconds after the Big Bang 
D) about 107 seconds after the Big Bang

Question 15

Observations of the cosmic background radiation from the COBE satellite revealed tiny variations in its temperature by about 1 part in 100,000.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following is not consistent with observations of the cosmic microwave background?

Accepted Answer

A) The universe is at least 20 billion years old. 
B) The universe is geometrically "flat" (in the four dimensions of spacetime). 
C) The matter density (both luminous and dark matter combined)in the universe is only about one- fourth of the critical density. 
D) Dark energy, whatever it is, represents the majority of the energy content of the universe. 
A) The universe is at least 20 billion years old. 
B) The universe is geometrically "flat" (in the four dimensions of spacetime). 
C) The matter density (both luminous and dark matter combined)in the universe is only about one- fourth of the critical density. 
D) Dark energy, whatever it is, represents the majority of the energy content of the universe.

Question 17

Why do we think tiny quantum ripples should have been present in the very early universe?

Accepted Answer

A) The energy released when the strong force froze out of the GUT force caused shock waves that produced ripples in the universe. 
B) The shock wave of the Big Bang caused ripples that expanded outward with time. 
C) The principles of quantum mechanics require that the energy fields at any point in space be continually fluctuating. 
D) The annihilation of matter and antimatter particles caused tiny explosions that produced ripples in the radiation field. 
E) The principles of quantum mechanics require that matter and antimatter particles formed from high- energy photons continuously eject energy into the universe causing the ripples. 
A) The energy released when the strong force froze out of the GUT force caused shock waves that produced ripples in the universe. 
B) The shock wave of the Big Bang caused ripples that expanded outward with time. 
C) The principles of quantum mechanics require that the energy fields at any point in space be continually fluctuating. 
D) The annihilation of matter and antimatter particles caused tiny explosions that produced ripples in the radiation field. 
E) The principles of quantum mechanics require that matter and antimatter particles formed from high- energy photons continuously eject energy into the universe causing the ripples.

Question 18

What are the two possible explanations for not seeing something glowing brightly along every line- of- sight? I)The universe is infinite in size and infinitely old, but dust absorbs starlight from far away stars.
II)The universe has a finite number of stars.
III)The universe is changing in some way as to prevent us from seeing an infinite number of stars.

Accepted Answer

A) I and II 
B) II and III 
C) I and III 
A) I and II 
B) II and III 
C) I and III

Question 19

Why did the era of nucleosynthesis end?

Accepted Answer

A) Too many heavy elements were produced. 
B) The temperature of the universe became too low. 
C) Neutrinos carried off too much energy. 
D) The density of the universe became too low. 
A) Too many heavy elements were produced. 
B) The temperature of the universe became too low. 
C) Neutrinos carried off too much energy. 
D) The density of the universe became too low.

Question 20

Why weren't many elements heavier than helium produced during the nucleosynthesis era?

Accepted Answer

By the time helium nuclei could exist in

Which of the following statements cannot be tested by science today?

Which forces have physicists shown to be the same force under conditions of very high temperature, as confirmed by experiments in particle accelerators?

From what cosmic epoch do the photons in the cosmic background radiation originate?

The cosmic microwave background gives us a view of the universe when it was

Evidence that the cosmic background radiation is the remnant of a Big Bang comes from predicting characteristics of remnant radiation from the Big Bang theory and comparing these predictions with observations. Four of the five statements below are real. Which one is fictitious?

According to the Big Bang theory, why do we live in a universe that is made of almost entirely of matter rather than antimatter?

Based on our current understanding of physics, we can understand the conditions that prevailed in the early universe as far back in time as about .

Rank these times based on the wavelength of the peak intensity of the cosmic background radiation at those times, from shortest to longest. (Hint: consider how the temperature of the universe or the cosmic background radiation changed with time.)

We have direct experimental evidence (from large particle accelerators)for the physical conditions in the universe back to about after the Big Bang.

Briefly describe one of the three questions left unanswered by the standard Big Bang theory which are solved by inflation. That is, describe either the structure problem, the uniformity (or smoothness)problem, or the density (or flatness)problem.

The Big Bang predicts that the universe should be 25 percent hydrogen and 75 percent helium.

This figure shows the temperature of the universe over time, according to models of the Big Bang. At what age did the universe cool to 1 million degrees?

Observations of the cosmic background radiation from the COBE satellite revealed tiny variations in its temperature by about 1 part in 100,000.

Which of the following is not consistent with observations of the cosmic microwave background?

Why do we think tiny quantum ripples should have been present in the very early universe?

Why did the era of nucleosynthesis end?

Why weren't many elements heavier than helium produced during the nucleosynthesis era?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters

Exam 17: The Birth of the Universe

Which of the following statements cannot be tested by science today?

Which forces have physicists shown to be the same force under conditions of very high temperature, as confirmed by experiments in particle accelerators?

From what cosmic epoch do the photons in the cosmic background radiation originate?

The cosmic microwave background gives us a view of the universe when it was

Evidence that the cosmic background radiation is the remnant of a Big Bang comes from predicting characteristics of remnant radiation from the Big Bang theory and comparing these predictions with observations. Four of the five statements below are real. Which one is fictitious?

According to the Big Bang theory, why do we live in a universe that is made of almost entirely of matter rather than antimatter?

Based on our current understanding of physics, we can understand the conditions that prevailed in the early universe as far back in time as about .

Rank these times based on the wavelength of the peak intensity of the cosmic background radiation at those times, from shortest to longest. (Hint: consider how the temperature of the universe or the cosmic background radiation changed with time.)

We have direct experimental evidence (from large particle accelerators)for the physical conditions in the universe back to about after the Big Bang.

Briefly describe one of the three questions left unanswered by the standard Big Bang theory which are solved by inflation. That is, describe either the structure problem, the uniformity (or smoothness)problem, or the density (or flatness)problem.

The Big Bang predicts that the universe should be 25 percent hydrogen and 75 percent helium.

This figure shows the temperature of the universe over time, according to models of the Big Bang. At what age did the universe cool to 1 million degrees?

Observations of the cosmic background radiation from the COBE satellite revealed tiny variations in its temperature by about 1 part in 100,000.

Which of the following is not consistent with observations of the cosmic microwave background?

Why do we think tiny quantum ripples should have been present in the very early universe?

Why did the era of nucleosynthesis end?

Why weren't many elements heavier than helium produced during the nucleosynthesis era?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters