Question 1

Is the actual size of the universe larger than 14 billion light years?

Accepted Answer

A)  The observable universe is 14 billion light years in each direction,so the actual universe is greater than 14 billion light years across.
B)  We do not have enough information to know this.
C)  The universe must be exactly equal in size to its age,so it must not be larger than 14 billion light years across in size.
D)  It is only 14 billion light years across to us;to an observer 10 billion light years away,it is smaller.E) C) and D)
F) A) and D)

Question 2

A television advertisement claiming that a product is light-years ahead of its time does not make sense because

Accepted Answer

A)  it doesn't specify the number of light-years.
B)  it uses "light-years" to talk about time,but a light-year is a unit of distance.
C)  a light-year is an astronomically large unit,so a product could not possibly be so advanced.
D)  light-years can only be used to talk about light.E) A) and D)
F) B) and C)

Question 3

The age of the universe is

Accepted Answer

A)  between 10 million and 16 million years.
B)  between 100 million and 160 million years.
C)  between 1 billion and 1.6 billion years.
D)  between 10 billion and 16 billion years.
E)  between 100 billion and 160 billion years.F) All of the above
G) C) and D)

Question 4

Imagine that you could drive your car in space.Assume that you can drive at a constant speed of 100 kilometers per hour.Suppose you started driving from the Sun.How long would it take,in years,to reach Earth?

Accepted Answer

t = <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30"> = 1.5 million h...

Question 5

Explain why it is so difficult to see planets around other stars.

Accepted Answer

Planets are very faint compared to the s...

Question 6

From the fact that virtually every galaxy is moving away from us and more distant galaxies are moving away from us at a faster rate than closer ones,we conclude that

Accepted Answer

A)  the Milky Way Galaxy is expanding.
B)  we are located at the center of the universe.
C)  the farthest galaxies will eventually be moving faster than the speed of light.
D)  the universe is expanding.
E)  the universe is shrinking.F) C) and D)
G) A) and B)

Question 7

On the scale of the cosmic calendar,in which the history of the universe is compressed to 1 year,how long has human civilization (i.e. ,since ancient Egypt) existed?

Accepted Answer

A)  about half the year
B)  about a month
C)  a few hours
D)  a few seconds
E)  less than a millionth of a secondF) B) and D)
G) C) and E)

Question 8

How many galaxies are there in the observable universe?

Accepted Answer

A)  roughly (within a factor of 10) the same as the number of stars in our galaxy
B)  roughly a thousand times more than the number of stars in our galaxy
C)  about as many as the number of stars we see in the sky with our naked eyes
D)  about as many as the number of grains of sand on all the beaches on Earth
E)  an infinite numberF) A) and B)
G) A) and C)

Question 9

Process of Science: Think of some ways in which you can demonstrate the following by simply looking at the sky:
a)the Sun and stars lie beyond the Earth's atmosphere
b)the stars are further away than the Moon

Accepted Answer

a)The Sun and stars disappear behind clo...

Question 10

The solar system contains about 100 billion stars.

Accepted Answer

A) True 
 B)False

Question 11

The observable universe is the same size today as it was a few billion years ago.

Accepted Answer

A) True 
 B)False

Question 12

Consider the following statement,and explain whether or not it is sensible: It will take me light-years to complete this homework assignment.

Accepted Answer

This statement does not make s...

Question 13

What do we mean by the observable universe?

Accepted Answer

A)  the part of the universe that we can see with the naked eye
B)  the part of the universe that we can see through telescopes
C)  the part of the universe that could be observed in principle,including things that may require future technologies
D)  the compendium of all objects that we have observed to date
E)  the entire universe,since it is inconceivable that there could be parts of the universe that we cannot observeF) None of the above
G) B) and E)

Question 14

How big is Earth on the 1-to-10 billion scale described in Section 1.2?

Accepted Answer

Scaled radius of Earth = actual radius /...

Question 15

The number of stars in the Milky Way Galaxy is approximately

Accepted Answer

A)  a few hundred.
B)  a few hundred thousand.
C)  a few hundred billion.
D)  a few hundred million.E) A) and B)
F) All of the above

Question 16

Suppose we imagine the Sun to be about the size of a grapefruit.Which of the following describes the size and distance of Earth on the same scale?

Accepted Answer

A)  Earth is the size of a tip of a ballpoint pen about 1 meter away from the Sun.
B)  Earth is the size of a golf ball about 1 meter away from the Sun.
C)  Earth is the size of a tip of a ballpoint pen about 15 meters away from the Sun.
D)  Earth is the size of a golf ball about 15 meters away from the Sun.
E)  Earth is the size of a marble about 25 miles away from the Sun.F) A) and E)
G) B) and E)

Question 17

Why do the patterns of the stars in our sky look the same from year to year?

Accepted Answer

A)  because the stars in the constellations are so far away
B)  because the stars in the constellations are not moving
C)  because the stars in the constellations all move at the same speeds and in the same directions,so they don't change their relative positions
D)  because the stars in the constellations move so slowly-typically about the speed of a snail-that their motions are not noticeableE) All of the above
F) A) and B)

Question 18

What is the Sun mainly made of?

Accepted Answer

A)  hydrogen and oxygen
B)  hydrogen and helium
C)  carbon and nitrogen
D)  oxygen and carbon
E)  nearly equal portions of all the elementsF) A) and D)
G) B) and D)

Question 19

On the 1-to-10-billion scale,about how far is it to the nearest stars besides the Sun?

Accepted Answer

A)  4 kilometers
B)  400 kilometers
C)  1,000 kilometers
D)  4,400 kilometers
E)  10,000 kilometersF) C) and E)
G) A) and E)

Question 20

Briefly explain what we mean by the statement "The farther away we look in distance,the further back we look in time."

Accepted Answer

It means that when we look at ...

Exam 1: A Modern View of the Universe

Imagine that you could drive your car in space.Assume that you can drive at a constant speed of 100 kilometers per hour.Suppose you started driving from the Sun.How long would it take,in years,to reach Earth?

Correct Answerverifiedt = = 1.5 million h...View AnswerShow Answer

Briefly explain what we mean by the statement "The farther away we look in distance,the further back we look in time."

Correct AnswerverifiedIt means that when we look at ...View AnswerShow Answer

Is the actual size of the universe larger than 14 billion light years?

Correct AnswerverifiedShow Answer

Consider the following statement,and explain whether or not it is sensible: It will take me light-years to complete this homework assignment.

Correct AnswerverifiedThis statement does not make s...View AnswerShow Answer

The solar system contains about 100 billion stars.

Correct AnswerverifiedShow Answer

On the 1-to-10-billion scale,about how far is it to the nearest stars besides the Sun?

Correct AnswerverifiedShow Answer

How many galaxies are there in the observable universe?

Correct AnswerverifiedShow Answer

The age of the universe is

Correct AnswerverifiedShow Answer

Process of Science: Think of some ways in which you can demonstrate the following by simply looking at the sky: a)the Sun and stars lie beyond the Earth's atmosphere b)the stars are further away than the Moon

Correct Answerverifieda)The Sun and stars disappear behind clo...View AnswerShow Answer

How big is Earth on the 1-to-10 billion scale described in Section 1.2?

Correct AnswerverifiedScaled radius of Earth = actual radius /...View AnswerShow Answer

Why do the patterns of the stars in our sky look the same from year to year?

Correct AnswerverifiedShow Answer

Explain why it is so difficult to see planets around other stars.

Correct AnswerverifiedPlanets are very faint compared to the s...View AnswerShow Answer

Suppose we imagine the Sun to be about the size of a grapefruit.Which of the following describes the size and distance of Earth on the same scale?

Correct AnswerverifiedShow Answer

What is the Sun mainly made of?

Correct AnswerverifiedShow Answer

A television advertisement claiming that a product is light-years ahead of its time does not make sense because

Correct AnswerverifiedShow Answer

The number of stars in the Milky Way Galaxy is approximately

Correct AnswerverifiedShow Answer

What do we mean by the observable universe?

Correct AnswerverifiedShow Answer

From the fact that virtually every galaxy is moving away from us and more distant galaxies are moving away from us at a faster rate than closer ones,we conclude that

Correct AnswerverifiedShow Answer

On the scale of the cosmic calendar,in which the history of the universe is compressed to 1 year,how long has human civilization (i.e. ,since ancient Egypt) existed?

Correct AnswerverifiedShow Answer

The observable universe is the same size today as it was a few billion years ago.

Correct AnswerverifiedShow Answer

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t = = 1.5 million h...
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It means that when we look at ...
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This statement does not make s...
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a)The Sun and stars disappear behind clo...
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Scaled radius of Earth = actual radius /...
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Planets are very faint compared to the s...
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