Question 1

The fact that the cosmic microwave background radiation has almost exactly the same temperature in every direction is referred to as the _______________ problem.

Accepted Answer

horizon

Question 2

Why did the big bang only create hydrogen, helium, and trace amounts of lithium?

Accepted Answer

Atoms with an atomic weight of 5 or 8 are unstable. Lithium can have weights of 6 or 7. Nuclei with atomic weights of 5 and 8 are radioactive and decay almost instantly back into smaller nuclei.   Therefore, it is hard to jump from helium (4 to Lithium (6 without having a stable atom with a weight of 5. It is virtually impossible to jump from lithium-7 to higher elements without a stable element at 8.

Question 3

Dark energy accounts for about 70% of the critical density of the Universe.

Accepted Answer

A) True 
 B)False  True

Question 4

Einstein's theory of mass-energy equivalence shows that high-energy photons can convert into matter and _______________.

Accepted Answer

antimatter

Question 5

What are the four fundamental forces in the Universe and how did they affect the first steps of the big bang and the inflation of the Universe?

Accepted Answer

The four fundamental forces in the Unive

Question 6

The recombination era of the big bang was very important in several ways. Explain what happened during this time and what observable effects of the era existed.

Accepted Answer

Originally, the Universe was so hot that

Question 7

Which statement about the behavior of Universe geometries is correct?

Accepted Answer

A)  Closed and open universes expand forever. 
B)  Closed universes expand and then contract. 
C)  Only flat universes expand forever. 
D)  Flat and open universes expand and then contract. 
E)  Only flat universes expand and then contract. 
A)  Closed and open universes expand forever. 
B)  Closed universes expand and then contract. 
C)  Only flat universes expand forever. 
D)  Flat and open universes expand and then contract. 
E)  Only flat universes expand and then contract.

Question 8

Einstein's mass-energy equivalence () is important to the first phases of the big bang in explaining how____.

Accepted Answer

A)  gamma ray photons create matter and antimatter 
B)  stable protons and neutrons can exist below a certain temperature 
C)  antimatter can exist 
D)  matter became more prevalent than antimatter 
E)  the Universe expanded rapidly 
A)  gamma ray photons create matter and antimatter 
B)  stable protons and neutrons can exist below a certain temperature 
C)  antimatter can exist 
D)  matter became more prevalent than antimatter 
E)  the Universe expanded rapidly

Question 9

Dark energy is the term used to describe ____.

Accepted Answer

A)  the pressure inflating "voids" in the distribution of galaxies 
B)  radiation from antimatter and non-baryonic matter 
C)  a component of the cosmic microwave background radiation 
D)  an effect that works with gravity to decelerate the expansion of the Universe 
E)  an effect that works against gravity to accelerate the expansion of the Universe 
A)  the pressure inflating "voids" in the distribution of galaxies 
B)  radiation from antimatter and non-baryonic matter 
C)  a component of the cosmic microwave background radiation 
D)  an effect that works with gravity to decelerate the expansion of the Universe 
E)  an effect that works against gravity to accelerate the expansion of the Universe

Question 10

The "big bang" was an explosion of material that created galaxies flying away from the center of the explosion.

Accepted Answer

A) True 
 B)False

Question 11

The _______________ universe hypothesis predicts a sudden, temporary episode of rapid, enormous expansion of the early Universe.

Accepted Answer

The answer of The _______________ universe hypothesis predicts a sudden,...

Question 12

Briefly describe the steps in the big bang that provided the protons, neutrons, and electrons necessary for nucleosynthesis - the building of complex atoms.

Accepted Answer

In the first phase of the big bang, the

Question 13

All dark matter in our Universe falls into the category of "hot dark matter".

Accepted Answer

A) True 
 B)False

Question 14

Figure 18-12 (for the following questions)
The re-ionization of the Universe occurredclosest to ____ degrees Kelvin.

Accepted Answer

A)  tens of thousands of 
B)  thousands of 
C)  hundreds of 
D)  tens of 
E)  less than ten 
A)  tens of thousands of 
B)  thousands of 
C)  hundreds of 
D)  tens of 
E)  less than ten

Question 15

The main criterion for deciding between Universe geometries is ____.

Accepted Answer

A)  density 
B)  mass 
C)  temperature 
D)  age 
E)  inflation 
A)  density 
B)  mass 
C)  temperature 
D)  age 
E)  inflation

Question 16

The radiation detected by Penzias and Wilson is sometime referred to as CMBR, which stands for   _______________ radiation.

Accepted Answer

cosmic mic

Question 17

During one phase of the big bang, gamma ray photons were creating electrons and positrons (anti-electrons). At this time, the Universe also contained ____.

Accepted Answer

A)  protons and antiprotons 
B)  protons and neutrons 
C)  neutrons only 
D)  no other matter or antimatter 
E)  neutral atoms 
A)  protons and antiprotons 
B)  protons and neutrons 
C)  neutrons only 
D)  no other matter or antimatter 
E)  neutral atoms

Question 18

The acceleration of the Universe depends on the effect of ____.

Accepted Answer

A)  baryonic matter being greater than the effects of dark matter and dark energy 
B)  baryonic matter and dark energy being greater than the effect of dark matter. 
C)  dark matter and dark energy being greater than the effect of baryonic matter. 
D)  baryonic matter and dark matter being greater than the effect of dark energy. 
E)  dark matter being greater than the effect of dark energy. 
A)  baryonic matter being greater than the effects of dark matter and dark energy 
B)  baryonic matter and dark energy being greater than the effect of dark matter. 
C)  dark matter and dark energy being greater than the effect of baryonic matter. 
D)  baryonic matter and dark matter being greater than the effect of dark energy. 
E)  dark matter being greater than the effect of dark energy.

Question 19

The gas created by the big bang was so hot that it was completely _______________ until the Universe was no longer radiation-dominated.

Accepted Answer

The answer of The gas created by the big bang...

Question 20

The big bang only created hydrogen and helium (with miniscule amounts of lithium) because____.

Accepted Answer

A)  gamma ray photons disrupt large nuclei more easily 
B)  antimatter is attracted to large nuclei, leaving only light nuclei 
C)  heavier elements can only be formed through fusion 
D)  elements with an atomic weight of 5 or 8 are unstable 
E)  temperatures were high enough to fuse hydrogen, but not helium 
A)  gamma ray photons disrupt large nuclei more easily 
B)  antimatter is attracted to large nuclei, leaving only light nuclei 
C)  heavier elements can only be formed through fusion 
D)  elements with an atomic weight of 5 or 8 are unstable 
E)  temperatures were high enough to fuse hydrogen, but not helium

Exam 18: Modern Cosmology

The fact that the cosmic microwave background radiation has almost exactly the same temperature in every direction is referred to as the _______________ problem.

Why did the big bang only create hydrogen, helium, and trace amounts of lithium?

Dark energy accounts for about 70% of the critical density of the Universe.

Einstein's theory of mass-energy equivalence shows that high-energy photons can convert into matter and _______________.

What are the four fundamental forces in the Universe and how did they affect the first steps of the big bang and the inflation of the Universe?

The recombination era of the big bang was very important in several ways. Explain what happened during this time and what observable effects of the era existed.

Which statement about the behavior of Universe geometries is correct?

Einstein's mass-energy equivalence () is important to the first phases of the big bang in explaining how____.

Dark energy is the term used to describe ____.

The "big bang" was an explosion of material that created galaxies flying away from the center of the explosion.

The _______________ universe hypothesis predicts a sudden, temporary episode of rapid, enormous expansion of the early Universe.

Briefly describe the steps in the big bang that provided the protons, neutrons, and electrons necessary for nucleosynthesis - the building of complex atoms.

All dark matter in our Universe falls into the category of "hot dark matter".

Figure 18-12 (for the following questions) The re-ionization of the Universe occurredclosest to ____ degrees Kelvin.

The main criterion for deciding between Universe geometries is ____.

The radiation detected by Penzias and Wilson is sometime referred to as CMBR, which stands for _______________ radiation.

During one phase of the big bang, gamma ray photons were creating electrons and positrons (anti-electrons). At this time, the Universe also contained ____.

The acceleration of the Universe depends on the effect of ____.

The gas created by the big bang was so hot that it was completely _______________ until the Universe was no longer radiation-dominated.

The big bang only created hydrogen and helium (with miniscule amounts of lithium) because____.

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