Question 1

What two properties of the universe are determined by the values of  $\Omega$mass and  $\Omega$$\wedge$ ?

Accepted Answer

A)  size and temperature 
B)  expansion rate and size 
C)  size and age 
D)  age and expansion rate 
E)  age and temperature 
A)  size and temperature 
B)  expansion rate and size 
C)  size and age 
D)  age and expansion rate 
E)  age and temperature

Question 2

To verify whether or not some grand unified theories are correct, physicists are searching for:

Accepted Answer

A)  the Big Rip 
B)  mini-black holes 
C)  antimatter 
D)  protons that decay 
E)  dark matter that decays 
A)  the Big Rip 
B)  mini-black holes 
C)  antimatter 
D)  protons that decay 
E)  dark matter that decays

Question 3

The ratio of the density of luminous matter in our universe to the critical density is 0.3.

Accepted Answer

A) True 
 B)False

Question 4

Explain why inflation could be lead to an infinite number of multiverses inside our own universe. Are they likely to be similar or different than our own universe?

Accepted Answer

Because inflation made the universe trem

Question 5

Which of the following is a FALSE statement about inflation?

Accepted Answer

A)  Inflation occurred when the universe was $\lt$10-33 seconds old. 
B)  Inflation occurred when the universe expanded by a factor of approximately 1030. 
C)  Inflation solves the horizon problem. 
D)  Inflation is currently driving the expansion of the universe. 
E)  Inflation solves the flatness problem. 
A)  Inflation occurred when the universe was $\lt$10-33 seconds old. 
B)  Inflation occurred when the universe expanded by a factor of approximately 1030. 
C)  Inflation solves the horizon problem. 
D)  Inflation is currently driving the expansion of the universe. 
E)  Inflation solves the flatness problem.

Question 6

The theory of inflation assumes that at some point in the future dark energy will decay and the universe will expand rapidly by a factor of 1030.

Accepted Answer

A) True 
 B)False

Question 7

In a closed (spherical) universe, the sum of the angles in a triangle is:

Accepted Answer

A)  "180 degrees" 
B)  "$\lt$ 180 degrees" 
C)  "120 degrees" 
D)  "$\gt$180 degrees" 
E)  "240 degrees" 
A)  "180 degrees" 
B)  "$\lt$ 180 degrees" 
C)  "120 degrees" 
D)  "$\gt$180 degrees" 
E)  "240 degrees"

Question 8

In the early universe, which type of particle and anti-particle first stopped being spontaneously formed out of photons in the CMB?

Accepted Answer

A)  Protons and neutrons, because their formation requires a larger number of photons 
B)  Electrons and positrons, because their formation requires a smaller number of photons 
C)  Protons and antiprotons, because their formation requires higher energy photons 
D)  Electrons and neutrinos, because their formation requires lower energy photons 
E)  Protons, antiprotons, electrons, and neutrinos stopped forming at the same time. 
A)  Protons and neutrons, because their formation requires a larger number of photons 
B)  Electrons and positrons, because their formation requires a smaller number of photons 
C)  Protons and antiprotons, because their formation requires higher energy photons 
D)  Electrons and neutrinos, because their formation requires lower energy photons 
E)  Protons, antiprotons, electrons, and neutrinos stopped forming at the same time.

Question 9

What can simultaneously solve both the flatness and horizon problems in cosmology?

Accepted Answer

A)  GUT 
B)  quantum mechanics 
C)  TOE 
D)  inflation 
E)  dark energy 
A)  GUT 
B)  quantum mechanics 
C)  TOE 
D)  inflation 
E)  dark energy

Question 10

Figure 1
-Figure 1 shows five graphs of the scale factor of the universe as a function of time. Which of these graphs would occur for a universe with  $\Omega$mass $\lt$ 1 and  $\Omega$$\wedge$$\gt$ 0?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 11

In quantum electrodynamics (QED), what mediates the electromagnetic force between particles?

Accepted Answer

In QED, the electromagnetic fo

Question 12

According to the theory of inflation. when the universe was approximately 1 second old, its size grew by a factor of 1030.

Accepted Answer

A) True 
 B)False

Question 13

Gravity acts to __________ the expansion of the universe, and dark energy acts to __________ the expansion.

Accepted Answer

A)  slow; slow 
B)  slow; speed up 
C)  speed up; slow 
D)  speed up; speed up 
A)  slow; slow 
B)  slow; speed up 
C)  speed up; slow 
D)  speed up; speed up

Question 14

The three fundamental forces of nature are gravity, electromagnetism, and the strong force.

Accepted Answer

A) True 
 B)False

Question 15

Observations of Type I supernovae in distant galaxies have shown that:

Accepted Answer

A)  the star formation rate in galaxies decreases with increasing redshift 
B)  the expansion rate of the universe is increasing 
C)  the cosmological constant is zero 
D)  dark energy is negligible at the present time 
E)  there were more stars in the past than at the present time 
A)  the star formation rate in galaxies decreases with increasing redshift 
B)  the expansion rate of the universe is increasing 
C)  the cosmological constant is zero 
D)  dark energy is negligible at the present time 
E)  there were more stars in the past than at the present time

Question 16

Why does a unified force split to become two separate forces?

Accepted Answer

A)  The universe expands so much that carrier particles become too dense. 
B)  The average energy of photons in the universe becomes less than the mass of the unified force's carrier particles. 
C)  Dark energy becomes significant at later times and forces the two to split. 
D)  The spatial dimensions split and so must the forces. 
E)  Too many particles are created for the unified force to manage. 
A)  The universe expands so much that carrier particles become too dense. 
B)  The average energy of photons in the universe becomes less than the mass of the unified force's carrier particles. 
C)  Dark energy becomes significant at later times and forces the two to split. 
D)  The spatial dimensions split and so must the forces. 
E)  Too many particles are created for the unified force to manage.

Question 17

The observations that show that the expansion of the universe is speeding up tell us the universe must contain:

Accepted Answer

A)  gravity 
B)  dark matter 
C)  a force opposing gravity 
D)  black holes 
E)  cosmic microwave background radiation 
A)  gravity 
B)  dark matter 
C)  a force opposing gravity 
D)  black holes 
E)  cosmic microwave background radiation

Question 18

If gravity were slowing down the expansion of the universe, how would very distant galaxies differ from nearby galaxies?

Accepted Answer

A)  Distant galaxies would have a larger value for H0 than nearby galaxies. 
B)  Distant galaxies would have a smaller value for H0 than nearby galaxies. 
C)  Distant galaxies would contain more dark energy than nearby galaxies. 
D)  Distant galaxies would contain less dark energy than nearby galaxies. 
E)  Distant and nearby galaxies would be the same. 
A)  Distant galaxies would have a larger value for H0 than nearby galaxies. 
B)  Distant galaxies would have a smaller value for H0 than nearby galaxies. 
C)  Distant galaxies would contain more dark energy than nearby galaxies. 
D)  Distant galaxies would contain less dark energy than nearby galaxies. 
E)  Distant and nearby galaxies would be the same.

Question 19

How would astronomers describe the antiparticle of an electron?

Accepted Answer

A)  It would have the same charge but opposite spin. 
B)  It would have the same mass but opposite charge. 
C)  It would have the opposite charge and higher mass. 
D)  It would have the opposite spin and higher mass. 
E)  It would have the opposite charge but same spin. 
A)  It would have the same charge but opposite spin. 
B)  It would have the same mass but opposite charge. 
C)  It would have the opposite charge and higher mass. 
D)  It would have the opposite spin and higher mass. 
E)  It would have the opposite charge but same spin.

Question 20

Explain what the uncertainty principle means, and how it relates to the horizon problem.

Accepted Answer

The uncertainty principle says that, as

Exam 22: Modern Cosmology

What two properties of the universe are determined by the values of Ω\OmegaΩ mass and Ω\OmegaΩ ∧\wedge∧ ?

To verify whether or not some grand unified theories are correct, physicists are searching for:

The ratio of the density of luminous matter in our universe to the critical density is 0.3.

Explain why inflation could be lead to an infinite number of multiverses inside our own universe. Are they likely to be similar or different than our own universe?

Which of the following is a FALSE statement about inflation?

The theory of inflation assumes that at some point in the future dark energy will decay and the universe will expand rapidly by a factor of 1030.

In a closed (spherical) universe, the sum of the angles in a triangle is:

In the early universe, which type of particle and anti-particle first stopped being spontaneously formed out of photons in the CMB?

What can simultaneously solve both the flatness and horizon problems in cosmology?

Figure 1 -Figure 1 shows five graphs of the scale factor of the universe as a function of time. Which of these graphs would occur for a universe with Ω\OmegaΩ mass <\lt< 1 and Ω\OmegaΩ ∧\wedge∧ >\gt> 0?

In quantum electrodynamics (QED), what mediates the electromagnetic force between particles?

According to the theory of inflation. when the universe was approximately 1 second old, its size grew by a factor of 1030.

Gravity acts to __________ the expansion of the universe, and dark energy acts to __________ the expansion.

The three fundamental forces of nature are gravity, electromagnetism, and the strong force.

Observations of Type I supernovae in distant galaxies have shown that:

Why does a unified force split to become two separate forces?

The observations that show that the expansion of the universe is speeding up tell us the universe must contain:

If gravity were slowing down the expansion of the universe, how would very distant galaxies differ from nearby galaxies?

How would astronomers describe the antiparticle of an electron?

Explain what the uncertainty principle means, and how it relates to the horizon problem.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Large-Scale Structure in the Universe

Life

Filters

What two properties of the universe are determined by the values of $\Omega$ _mass and $\Omega$ _$\wedge$ ?

The theory of inflation assumes that at some point in the future dark energy will decay and the universe will expand rapidly by a factor of 10³⁰.

According to the theory of inflation. when the universe was approximately 1 second old, its size grew by a factor of 10³⁰.

Gravity acts to the expansion of the universe, and dark energy acts to the expansion.