Question 1

How does the addition of a nonzero cosmological constant affect the expansion of the universe?

Accepted Answer

A)  It is possible for the mass density of the universe to be below the critical density and still collapse. 
B)  It is possible for the density of the universe to be below the critical density and still expand forever. 
C)  It is impossible to have a collapsing universe,regardless of its density. 
D)  It is impossible to have an expanding universe,regardless of its density. 
A)  It is possible for the mass density of the universe to be below the critical density and still collapse. 
B)  It is possible for the density of the universe to be below the critical density and still expand forever. 
C)  It is impossible to have a collapsing universe,regardless of its density. 
D)  It is impossible to have an expanding universe,regardless of its density.

Question 2

A grand unified theory unites which forces?

Accepted Answer

A)  Only electromagnetism,weak nuclear,and strong nuclear 
B)  Only gravity and strong nuclear 
C)  Only electromagnetism,gravity,and weak nuclear 
D)  All four known forces 
A)  Only electromagnetism,weak nuclear,and strong nuclear 
B)  Only gravity and strong nuclear 
C)  Only electromagnetism,gravity,and weak nuclear 
D)  All four known forces

Question 3

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

Accepted Answer

A)  GUTs 
B)  Quantum mechanics 
C)  Inflation 
D)  Dark energy 
A)  GUTs 
B)  Quantum mechanics 
C)  Inflation 
D)  Dark energy

Question 4

Soon after the Big Bang,we believe the four fundamental forces of nature were united into one superforce,and __________ was the first to split off from the others.

Accepted Answer

A)  the strong force 
B)  electromagnetism 
C)  gravity 
D)  nucleosynthesis 
A)  the strong force 
B)  electromagnetism 
C)  gravity 
D)  nucleosynthesis

Question 5

The critical density of the universe is approximately equal to

Accepted Answer

A)    . 
B)    . 
C)    . 
D)    . 
A)    . 
B)    . 
C)    . 
D)    .

Question 6

At what stage in the universe's history do we think the asymmetry between matter and antimatter was created?

Accepted Answer

A)  At the very moment the Big Bang occurred 
B)  Around the time gravity separated out of the theory of everything 
C)  Around the time the strong force separated out of the grand unified theory 
D)  Around the time the weak force and electromagnetism separated 
A)  At the very moment the Big Bang occurred 
B)  Around the time gravity separated out of the theory of everything 
C)  Around the time the strong force separated out of the grand unified theory 
D)  Around the time the weak force and electromagnetism separated

Question 7

What was the temperature of the universe when a typical CBR photon was no longer able to spontaneously create a proton and antiproton pair? Note that a photon has an energy equal to   ,the CBR at any point in time has a blackbody spectrum that peaks at   ,and the mass of a single proton is   .

Accepted Answer

In order to create a proton an

Question 8

What is the difference between a grand unified theory and a theory of everything?

Accepted Answer

A TOE can link all four fundam

Question 9

Why does the sum of   and   determine the shape of our universe?

Accepted Answer

The mass and energy density af

Question 10

What will happen to the expansion of the universe in the future if:     ,and   ?

Accepted Answer

For each case,
(a)The universe's expansi

How does the addition of a nonzero cosmological constant affect the expansion of the universe?

A grand unified theory unites which forces?

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

Soon after the Big Bang,we believe the four fundamental forces of nature were united into one superforce,and __________ was the first to split off from the others.

The critical density of the universe is approximately equal to

At what stage in the universe's history do we think the asymmetry between matter and antimatter was created?

What was the temperature of the universe when a typical CBR photon was no longer able to spontaneously create a proton and antiproton pair? Note that a photon has an energy equal to ,the CBR at any point in time has a blackbody spectrum that peaks at ,and the mass of a single proton is .

What is the difference between a grand unified theory and a theory of everything?

Why does the sum of and determine the shape of our universe?

What will happen to the expansion of the universe in the future if: ,and ?

Why Learn Astronomy

Patterns in the Skymotions of Earth

Gravity and Orbitsa Celestial Ballet

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 Liquidthe Giant Planets

Gravity Is More Than Keplers Laws

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

A Run-Of-The-Mill G-Type Starour Sun

Star Formation and the Interstellar Medium

Stars in the Slow Lanelow-Mass Stellar Evolution

Live Fast,die Younghigh-Mass Stellar Evolution

Our Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

The Origin of Structure

Life

Filters

Exam 21: Modern Cosmology

How does the addition of a nonzero cosmological constant affect the expansion of the universe?

A grand unified theory unites which forces?

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

Soon after the Big Bang,we believe the four fundamental forces of nature were united into one superforce,and __________ was the first to split off from the others.

The critical density of the universe is approximately equal to

At what stage in the universe's history do we think the asymmetry between matter and antimatter was created?

What was the temperature of the universe when a typical CBR photon was no longer able to spontaneously create a proton and antiproton pair? Note that a photon has an energy equal to ,the CBR at any point in time has a blackbody spectrum that peaks at ,and the mass of a single proton is .

What is the difference between a grand unified theory and a theory of everything?

Why does the sum of and determine the shape of our universe?

What will happen to the expansion of the universe in the future if: ,and ?

Why Learn Astronomy

Patterns in the Skymotions of Earth

Gravity and Orbitsa Celestial Ballet

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 Liquidthe Giant Planets

Gravity Is More Than Keplers Laws

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

A Run-Of-The-Mill G-Type Starour Sun

Star Formation and the Interstellar Medium

Stars in the Slow Lanelow-Mass Stellar Evolution

Live Fast,die Younghigh-Mass Stellar Evolution

Our Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

The Origin of Structure

Life

Filters