Deck 17: The Beginning of Time

Question 1

How long after the Big Bang was the Planck time, the time at which our current theories become completely unable to describe conditions any earlier in the universe?

A) 10⁻¹⁰ seconds
B) 10⁻³⁵ seconds
C) 10⁻⁴³ seconds
D) 3 minutes
E) 380,000 years

Answer 1

C

Question 2

Why did the era of nuclei end when the universe was about 380,000 years old?

A) All the free particles had combined to form the nuclei of atoms.
B) The universe had expanded and cooled enough for stable, neutral atoms to form.
C) Atomic nuclei were finally able to escape the plasma of the early universe.
D) Photons were finally able to escape the plasma of the early universe and were no longer available to produce hydrogen and helium nuclei.
E) The nucleosynthesis era that produced the nuclei heavier than helium ended.

Answer 2

B

Question 3

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

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

Answer 3

D

Question 4

(From a science quiz that appeared in the weekly magazine The Economist.) Economic history is easier to write than the history of the universe. Nevertheless, most cosmologists now think that when the universe was formed,

A) first there was a Big Bang and then inflation (of space) which caused recession (of all matter, away from the Big Bang).
B) first there was inflation, which caused the Big Bang, then recession.
C) first there was a Big Bang. There has not been any inflation yet, but if it comes it will cause recession.

Question 5

Why does the Big Bang theory predict that the cosmic background radiation should have a perfect thermal radiation spectrum?

A) The background radiation came from the heat of the universe, with a peak corresponding to the temperature of the universe.
B) The spectrum of pure hydrogen gas must be a perfect thermal radiation spectrum.
C) The spectrum of 75 percent hydrogen and 25 percent helium must be a perfect thermal radiation spectrum.
D) The light from all the stars and gas in the sky averaged over the entire universe will be a perfect thermal radiation spectrum.
E) It doesn't predict that the cosmic background radiation should have a perfect thermal radiation spectrum.

Question 6

What kinds of atomic nuclei formed during the nucleosynthesis era?

A) only hydrogen
B) only helium
C) hydrogen, helium and trace amounts of lithium, beryllium, and boron
D) roughly equal amounts of hydrogen, helium, lithium, beryllium, and boron
E) essentially all of the chemical elements, except for those heavier than uranium

Question 7

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

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

Question 8

What direct evidence do we have that the weak and electromagnetic forces were once unified as a single force?

A) The most advanced telescopes are able to see back to the GUT era in the universe.
B) Detectors on Earth have received photons and high-energy particles from the GUT era.
C) Temperatures in the center of the Sun can reproduce the conditions during the Electroweak era.
D) Particle accelerators on Earth can reach energies equivalent to the high temperatures of the Electroweak era and have produced particles predicted by the unified theory.
E) We have no direct evidence of such a unified force.

Question 9

A GUT (grand unified theory) refers to theories that

A) unify all four forces.
B) unify gravity and the electromagnetic and weak forces.
C) unify gravity and the strong and weak forces.
D) unify the strong force and the electromagnetic and weak forces.
E) unify the electromagnetic and weak forces.

Question 10

Why can't current theories describe what happened during the Planck era?

A) We do not yet have a theory that links quantum mechanics and general relativity.
B) We do not understand the properties of the antimatter that would have been produced at this time.
C) We do not yet have a theory that links the weak and electromagnetic forces.
D) We do not yet have a theory that explains how the universe underwent a rapid period of inflationary expansion.
E) The Planck era was the time before the Big Bang, and we cannot describe what happened before the beginning of the universe.

Question 11

How many forces operated in the universe during the GUT era?

A) One: a single, symmetric "super force"
B) Two: gravity and the GUT force
C) Two: gravity and the electroweak force
D) Three: gravity, the strong force, and the electroweak force
E) All four of the known forces

Question 12

Which of the following statements about the cosmic background radiation is not true?

A) It has a temperature of about 3 degrees K above absolute zero.
B) It is the result of a mixture of radiation from many independent sources, such as stars and galaxies that formed within the first billion years of the Big Bang.
C) It had a much higher temperature in the past.
D) It was discovered by Penzias and Wilson in the mid 1960s.
E) It appears essentially the same in all directions (it is isotropic).

Question 13

Why is the nucleosynthesis era so important in determining the chemical composition of the universe?

A) All the elements except hydrogen were produced in the nucleosynthesis era.
B) We can observe spectra from this era to determine what the primordial mix of the elements was at the beginning of the universe.
C) Except for a small amount of elements heavier than helium produced later by stars, the chemical composition of the universe is the same now as at the end of the nucleosynthesis era.
D) We can study the processes that occurred during the nucleosynthesis era to determine how most of the elements in the universe were created.
E) By knowing how much matter was created during the nucleosynthesis era, we can determine whether the universe is open or closed.

Question 14

Approximately how long did the nucleosynthesis era last?

A) 10⁻¹⁰ seconds
B) 0.001 seconds
C) 5 seconds
D) 5 minutes
E) 5 years

Question 15

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?

A) 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.
B) The cosmic background radiation is expected to have a perfect thermal spectrum, and observations from the COBE spacecraft verify this prediction.
C) The cosmic background radiation is expected to contain redshifted emission lines from hydrogen and helium, and it does.
D) The cosmic background radiation is expected to look essentially the same in all directions, 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 16

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

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

Question 17

What do we mean by inflation?

A) The expansion of universe starting with the instant after the Big Bang
B) A sudden expansion of the universe driven by the energy released when the strong and electroweak forces froze out from the GUT force
C) The rapid expansion of the universe, driven by white dwarf supernova, that we still observe today
D) The sudden release of photons when particles and antiparticles annihilate each other
E) The photons released when electrons and protons first combined, forming the Cosmic Microwave Background Radiation

Question 18

Why might inflation have occurred at the end of the GUT era?

A) Gravity was an extremely weak force at this period in time.
B) Large amounts of matter and antimatter annihilated at this time.
C) There wasn't enough matter present to slow down the expansion at that time.
D) The universe was too small and needed to grow quickly.
E) An enormous amount of energy was released when the strong and electroweak forces froze out from the GUT force.

Question 19

What happened to all of the quarks that existed freely during the particle era?

A) They combined in groups to make protons, neutrons, and their antiparticles.
B) They froze out of the soup of particles at the end of the era.
C) They evaporated.
D) They combined in groups to make electrons and neutrinos.

Question 20

The Planck era refers to the time period

A) before the Big Bang.
B) before the Planck time.
C) after the Planck time.
D) after inflation.
E) after the GUT era.

Question 21

Based on the observed amount of deuterium in the universe, we can conclude that

A) ordinary (baryonic) matter makes 75 percent of the mass of the universe.
B) neutrons outnumber protons 7 to 1 in the universe.
C) most of the deuterium that was created during the era of nucleosynthesis has since been destroyed.
D) the density of ordinary (baryonic) matter is about 4 percent of the critical density.
E) we live in a critical-density universe.

Question 22

The observed composition of ordinary matter in the universe-roughly 75 percent hydrogen and 25 percent helium-closely matches theoretical predictions based on the Big Bang model.

Question 23

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

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

Question 24

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
You are in a place that is extremely hot and dense. You can't see far because your surroundings are opaque to light. Around you, nuclear fusion is converting carbon into oxygen and other elements. Where are you?

A) You are in the center of a star very much like our Sun.
B) You are in the early universe during the era of nucleosynthesis.
C) You are inside a nuclear power plant on Earth.
D) You are in the center of a massive star near the end of its life.
E) You are in the center of a white dwarf.

Question 25

Helium originates from

A) stellar nucleosynthesis only.
B) the Big Bang only.
C) mostly from stellar nucleosynthesis with a small contribution from the Big Bang.
D) mostly from the Big Bang with a small contribution from stellar nucleosynthesis.
E) radioactive decay of elements heavier than carbon.

Question 26

Why do we expect the cosmic background radiation to be almost, but not quite, the same in all directions?

A) The overall structure of the universe is very uniform, but the universe must have contained some regions of higher density in order for galaxies to form.
B) The temperature of the universe can be found by taking an average over the entire sky, but individual stars will create peaks in the temperature over small angles.
C) Dark matter will smooth out the spectrum, but the small patches of "light" matter create fluctuations in the temperature.
D) The overall structure of the universe is very uniform, but the synthesis of different elements produces varying signatures within the background radiation.
E) The overall structure of the universe is very uniform, but intervening gas between us and the era of nuclei absorbs wavelengths depending on the composition and redshift of the gas.

Question 27

In the cosmic timeline for the universe starting at the Big Bang, we live in the Planck era.

Question 28

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
It is bright everywhere. You have been able to travel around, and it's clear that you are not inside a star. Yet your surroundings seem as bright as looking directly at the Sun. As you travel around, you notice that you cannot find a single neutral atom anywhere, nor can you find any nucleus besides those of hydrogen and helium. While it is hot (a few thousand degrees Kelvin), it is nowhere near the temperature needed for nuclear fusion. Where are you?

A) You are in the universe during its first 380,000 years.
B) You are in the universe more than 10¹⁰⁰ years in the future.
C) You are in an accretion disk around a supermassive black hole.
D) You are in the central regions of a quasar.
E) You are in the planetary nebula that the Sun will form about 5 billion years from now.

Question 29

A postulated inflationary era in which the early universe expanded in size by a factor of 10³⁰ in approximately 10⁻³⁶ seconds is incompatible with the theory of relativity because the universe would have expanded faster than the speed of light.

Question 30

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
You are on the surface of an object, and you have a fairly clear view out into space. Unfortunately, you are also very squashed. The light you observe from distant objects is slightly blueshifted. The surface of the object is composed primarily of carbon and oxygen, and the distance to the horizon seems about the same as that on Earth. By observing the sky for a few weeks, you realize that there are several planets orbiting your object. Where are you?

A) You are on the surface of the Earth.
B) You are on the surface of a planet that is somewhat more massive than the Earth.
C) You are on the surface of a white dwarf.
D) You are "on" an accretion disk around a black hole.
E) You are on the surface of a neutron star.

Question 31

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
You are in a hot, dense place. You are surrounded by nuclear reactions that are rapidly fusing hydrogen into helium. You notice that your surroundings are cooling and rapidly dropping in density. Within about 5 minutes, the fusion reactions stop. Where are you?

A) You are in the center of a star very much like our Sun.
B) You are in the early universe during the era of nucleosynthesis.
C) You are inside a nuclear power plant on Earth.
D) You are in the center of a star much smaller than the Sun.
E) You are in the center of a massive star near the end of its life.

Question 32

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
As far as you look, there seems to be nothing at all. Even the nearest electron is light-years away. No matter how far you travel, you can find no solid matter, not even a single proton. It's as if all of the matter in the universe has disintegrated. You do, however, detect a few strong gravitational fields-probably due to supermassive black holes-at enormous distances from you. Where are you?

A) You are in the Planck Era of the early universe.
B) You are in the universe when it is 10⁴⁰ years old.
C) You are in the universe when it is 10¹⁰⁰ years old.
D) You are in the central regions of a quasar.
E) You are in the GUT era of the early universe during the period of inflation.

Question 33

What are the two key observational facts that led to widespread acceptance of the Big Bang model?

A) the cosmic background radiation and the helium content of the universe
B) the cosmic background radiation and the expansion of the universe
C) the cosmic background radiation and the near-critical density of the universe
D) the predominance of matter over antimatter and the near-critical density of the universe
E) the predominance of matter over antimatter and the large scale structure of the universe

Question 34

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
You find yourself in a very low-density gas that is extremely hot. In fact, the temperature of the gas is so high that it is emitting lots of X-rays. There are no stars anywhere within about 10,000 light-years of you, but at slightly greater distances, your sky is brightened by hundreds (perhaps thousands) of beautiful, star-filled structures, some with majestic spiral shapes. Where are you?

A) You are in the universe when it was about 500 million years old, just before galaxies began to form.
B) You are in the center of the Milky Way Galaxy, looking outward into the Local Group.
C) You are in the universe about 380,000 years after the Big Bang when the cosmic microwave background radiation was formed.
D) You are in intergalactic space within a rich cluster of thousands of galaxies.
E) You are in the outskirts of a galaxy whose nucleus is a powerful quasar.

Question 35

Measuring the amount of deuterium in the universe allows us to set a limit on

A) the temperature of the universe at the end of the era of nuclei.
B) the total amount of mass in the universe.
C) the density of ordinary (baryonic) matter in the universe.
D) the expansion rate of the universe.
E) the current age of the universe.

Question 36

Olbers' paradox is an apparently simple question, but its resolution suggests that the universe is finite in age. What is the simple question posed by Olbers' paradox?

A) What would it be like to ride on a beam of light?
B) Can we measure the position and momentum of an electron at the same time?
C) How does the Sun produce energy?
D) Why is the sky dark at night?
E) How many stars are in the universe?

Question 37

What is postulated to have caused a sudden inflation of the early universe?

A) The energy released from the annihilation of matter and antimatter
B) The energy absorbed by the separation of the electromagnetic and weak forces
C) The energy released from the "freezing out" of the strong force from the GUT force
D) The energy released in the fusion of protons and neutrons to produce helium
E) The energy absorbed by giant quantum fluctuations

Question 38

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
You find yourself in a place that is unimaginably hot and dense. A rapidly changing gravitational field randomly warps space and time. Gripped by these huge fluctuations, you notice that there is but a single, unified force governing the universe. Where are you?

A) You are in the center of a young star.
B) You are in the early universe before the Planck time.
C) You are floating somewhere in the universe near its end, 10¹⁰⁰ years from now.
D) You are inside the nucleus of an atom.
E) You are in the universe shortly after inflation.

Question 39

Refer to this scenario for the following questions:
A multi-dimensional being reaches down to Earth and pulls you out of the universe. You are then thrown back into the universe at a place and time of the being's choosing, and you are permitted to leave only after you have identified your surroundings. This process is repeated several times. Through a scientifically unexplainable miracle, you are able to survive in every one of the places that you find yourself. In each scenario below, identify your surroundings (and potentially your cosmic era) from among the choices given.
A moment before, you were enveloped in a bright plasma. You could not see very far as free electrons zipped around your head, scattering photons. But now, the universe has suddenly become transparent and you can see clearly. There seem to be no planets or stars, only a gas filled with mostly neutral hydrogen atoms. Where are you?

A) You are in the universe when it was about 500 million years old, just before galaxies began to form.
B) You are in the universe about 380,000 year after the Big Bang during the formation of the cosmic background radiation.
C) You are in the universe about 5 minutes after the Big Bang just as the nucleosynthesis era is ending.
D) You are in a closed universe just as it begins to re-collapse.
E) You are in intergalactic space within a rich cluster of galaxies.

Question 40

GUT theories predict that protons will eventually decay, causing all solid objects in the universe to fall apart if the universe keeps expanding forever.

Question 41

Recent measurements of temperature fluctuations in the cosmic microwave background radiation indicate that 72 percent of the mass-energy in the universe must be in the form of dark energy.

Question 42

Briefly describe the two key pieces of evidence that support the Big Bang theory.

Question 43

What do we mean by inflation, and why might it have occurred at the end of the GUT era?

Question 44

Briefly explain how Hubble's discovery of a relationship between galactic distance and redshift led to the idea of the Big Bang.

Question 45

New Perspectives? Chapter 17 ends the discussion of the origin and evolution of the universe. Galaxy and star formation, as well as the origin of planetary systems, were discussed in earlier chapters. It is perhaps time to reflect upon what has been learned. There is an oft-quoted line in T.S. Eliot's poem Little Gidding (1942): "And the end of all our exploring will be to arrive where we started and know the place for the first time." Have you gained any new perspectives on the position of the Earth (and human beings) within the universe through your study of the science of astronomy? If so, what are they?

Question 46

Briefly explain why radiation was trapped for 380,000 years during the era of nuclei, and why the cosmic background radiation was formed at the end of this era.

Question 47

If inflation really occurred, then our observable universe is only a tiny portion of the entire universe born in the Big Bang.

Question 48

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?

Question 49

Recent measurements of the temperature fluctuations in the cosmic microwave background radiation support the prediction of inflation that the overall geometry of the universe is flat.

Question 50

The Cosmic Microwave Background Radiation: The CMBR 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.

Question 51

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

Question 52

What is Olbers' paradox, and what is its resolution?

Question 53

What did COBE satellite find regarding the smoothness of the cosmic background radiation?

Question 54

What happens when matter collides with anti-matter?

A) The two particles attract each other, and form a neutral atom.
B) The two particles destroy each other, and create photons.
C) The two particles repel each other, and they fly apart.

Question 55

Which of the following histories are in the correct order of occurrence?

A) The Big Bang, then the expansion starts, then stars make the first elements heavier than helium, then the Sun forms.
B) The Big Bang happens simultaneously with the start of the expansion of the universe, then stars make the first elements heavier than helium, then the Sun forms.
C) The Big Bang happens simultaneously with the start of the expansion of the universe, then the Sun and stars make the first elements heavier than helium.
D) The Big Bang, then the expansion starts, then the Sun and stars make the first elements heavier than helium.

Question 56

Current measurements of the matter density of the universe (including dark matter) support the prediction of the theory of inflation that the universe should be flat.

Question 57

Why is the era of nucleosynthesis so important in determining the chemical composition of the universe?

Question 58

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.

Question 59

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

Question 60

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

Question 61

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

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

Question 62

The four fundamental forces that operate in the universe today are ________.

A) strong force, weak force, electromagnetic force, gravity
B) strong force, weak force, electric force, magnetic force
C) nuclear force, electromagnetic force, gravity, tidal force
D) nuclear force, gravity, electric force, magnetic force

Question 63

Which of the following statements correctly summarizes the events in the early universe according to the Big Bang theory?

A) The universe began with the forces unified. During the first fraction of a second, the forces separated and there was a brief but important episode of inflation. Subatomic particles of both matter and antimatter then began to appear from the energy present in the universe. Most of the particles annihilated to make photons, but some became protons, neutrons, electrons, and neutrinos. The protons and neutrons underwent some fusion during the first three minutes, thereby determining the basic chemical composition of the universe.
B) An episode of what we call inflation initiated the event of the Big Bang. Once the Big Bang got underway, particles and forces began to appear one by one. The forces produced protons, which fused to make hydrogen and helium until the universe was about 380,000 years old. Then gravity began to act, turning the hydrogen and helium into galaxies.
C) Forces and various subatomic particles began to appear during the first second after the Big Bang. For reasons not understood, the particles were all made of ordinary matter and none were made of antimatter, thus explaining why we live in a universe made of matter. The particles underwent some fusion for the first 380,000 years after the Big Bang, at which time the first stars were born.
D) The Big Bang began with the initiation of what we call inflation, which gradually slowed to the current expansion rate of the universe. Forces came to exist for a different reason, having to do with quantum fluctuations in the space-time continuum. Particles came to exist as a result of cracks made when forces froze. Once there were particles, gravity brought them together to make stars, and the stars then turned the particles into hydrogen, helium, and other elements.

Question 64

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.)

A) Today, 1 million years after the Big Bang, 100 million years after the Big Bang
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) 100 million years after the Big Bang, 1 million years after the Big Bang, today

Question 65

Which of the following claims cannot be proved or disproved by science?

A) The universe is about 14 billion years old.
B) The universe is about 2000 years old.
C) The universe was created by God.
D) The universe started out very hot.

Question 66

Which of the following hypothetical observations, if true, would disprove a prediction of the Big Bang theory? The discovery of

A) a galaxy with 30% helium abundance.
B) the temperature of the universe is only 2.73 K.
C) a galaxy with 10% helium abundance.
D) a galaxy moving toward us.
E) two galaxies, at the same distance, moving away with slightly different speeds.

Question 67

Early in the history of the universe, the universe was

A) hotter.
B) the same temperature it is now.
C) colder.

Question 68

Which event in the history of the universe happened last?

A) The electroweak force separated into electromagnetic and weak nuclear forces.
B) Stable helium nuclei formed.
C) Neutral atoms formed.
D) The GUT force separated into the electroweak force and strong force.

Question 69

Consider the data points together with the models in the graph of expansion models. Which model is most strongly supported by the data?

A) Critical
B) Accelerating
C) Recollapsing
D) Coasting

Question 70

The more baryons there are in the universe (a higher density of baryonic matter), the lower the ratio of deuterium to hydrogen is. Therefore, if Harry measures a higher ratio of deuterium to hydrogen than Sally, Harry infers

A) the same density of baryons as Sally.
B) a lower density of baryons than Sally.
C) a higher density of baryons than Sally.

Question 71

Creation science claims that scientific evidence can and does prove God made the universe. Select the statement which does NOT identify a legitimate objection to this claim. (Recall the hallmarks of science.)

A) Scientists are not allowed to believe in God.
B) If "God did it" is the explanation for everything, then final exams in astronomy would be very simple (all answers would be the same!), and science experiments would be very easy to explain: but we wouldn't learn much about the natural world.
C) Science cannot prove (or disprove) the existence of a superpowerful, supernatural deity.
D) The statement that "God did it" cannot be falsified by science, and therefore it is not a statement that science can test.

Question 72

Comparing the following 4 models, which model predicts that galaxies had the largest separations in the past? (Use the graph of expansion models as a guide.)

A) Accelerating
B) Coasting
C) Critical
D) Recollapsing

Question 73

What is the significance of the Planck time?

A) Before it, conditions were so extreme that our current understanding of physics is insufficient to predict what might have occurred.
B) It is the time at which inflation is thought to have occurred.
C) It is the time when the cosmic microwave background was released.
D) It is the amount of time required for two protons to fuse to make deuterium.

Question 74

A "GUT" (grand unified theory) refers to theories that ________.

A) unify the strong force with the electromagnetic and weak forces
B) unify gravity with the strong and weak forces
C) unify the electromagnetic and weak forces
D) unify all four forces together

Question 75

Why is the night sky is dark?

A) The universe has a physical edge, beyond which there is nothing.
B) The dust clouds in interstellar space block the light.
C) Dark matter obscures light from distant objects.
D) The universe is finite in age.

Question 76

The graph above shows 4 models for how the average distance between galaxies could change with time, from the past (left) to now (middle) to the future (right hand side). The graph also shows real data, based on studies of supernovae. Each black dot on the graph is for one supernova explosion. The data are plotted with dots and black lines that indicate the range of uncertainty of each individual measurement. Use this graph to answer the following questions about cosmological models for the expansion of the universe. (Note that the models are in the same order, from top to bottom, whether on the right hand side of the graph or the left hand side. For example the accelerating model is the top line on both sides of the graph. You should also have a handout with a better version of this graph.) Which model(s) predict that galaxies are getting farther apart NOW?

A) Accelerating
B) Coasting
C) Critical
D) Recollapsing
E) All of them. F) None of them.

Question 77

Consider the graph of expansion models. Which model(s) predicts that galaxies will eventually get closer together?

A) Accelerating
B) Coasting
C) Critical
D) Recollapsing
E) All of them. F) None of them.

Question 78

What happens when a particle of matter meets its corresponding antiparticle of antimatter?

A) The combined mass of the two particles is completely transformed into energy (photons).
B) They can form a complete atom.
C) They fuse to make a heavier particle.
D) The question makes no sense, since antimatter does not really exist.

Question 79

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 ________.

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

Question 80

What do we mean by inflation?

A) A sudden and extremely rapid expansion of the universe that occurred in a tiny fraction of a second during the universe's first second of existence
B) The expansion of the universe that we still observe today
C) The sudden release of photons when a particle and antiparticle annihilate one another
D) Quantum fluctuations by high speed, relativistic particles in a state of false vacuum that caused disturbances in the space-time continuum leading to the process described in the question to which this answer refers