ASTR 1401 Chapter 1

On a cosmic calendar, in which the history of the universe is compressed into one year, how long is the average human life span? - 0.2 second - 2 hours - 0.2 millisecond - 2 minutes - 2 seconds

0.2 second

Approximately how fast are you moving with the rotation of the earth? - 13,000 km/hr - 1,300 km/hr - 130 km/hr - 13 km/hr - not moving at all

1,300 km/hr

One light-hour is the distance that light travels in an hour. How far is this, in kilometers? (Recall that the speed of light is 300,000 km/s.) - 300,000 km - 1.08 billion km - 18 million km - 100 million km - 9.46 trillion km

1.08 billion km

Modern telescopes are capable of seeing bright galaxies up to about - 1 billion light years away. -1 million light years away. -10 million light years away. -10 billion light years away. -1 trillion light years away.

10 billion light years away.

Roughly how many stars are in the Milky Way Galaxy? - 10 billion -100 billion -100 trillion -100 million -1 billion

100 billion

If we use 1 millimeter to represent 1 light-year, how large in diameter is the Milky Way Galaxy? - 100 meters - 1 million millimeters - 100 kilometers - 1 kilometer - 100 millimeters

100 meters

Suppose we imagine the Sun to be about the size of a grapefruit. How far away are the nearest stars (the three stars of Alpha Centauri)? - the length of a football field - 2.5 miles - 250 miles - 2,500 miles - 25,000 miles

2,500 miles

What do we mean when we say that the universe is expanding? - Average distances are increasing between star systems within galaxies. -Everything in the universe is gradually growing in size. -Average distances are increasing between galaxies. -The statement is not meant to be literal; rather, it means that our knowledge of the universe is growing. -Individual galaxies are gradually growing in size.

Average distances are increasing between galaxies.

Which scientists played a major role in overturning the ancient idea of an Earth-centered universe, and about when? - Copernicus, Kepler, and Galileo; about 400 years ago - Aristotle and Copernicus; about 400 years ago - Huygens and Newton; about 300 years ago - Aristotle and Plato; about 2,000 years ago - Newton and Einstein; about 100 years ago

Copernicus, Kepler, and Galileo; about 400 years ago

Which of the following correctly lists speeds from slowest to fastest? - the speeds of very distant galaxies relative to us, typical speeds of stars in the local solar neighborhood relative to us, Earth's speed of rotation on its axis, Earth's speed of revolution about the Sun, the speed of our solar system orbiting the center of the Milky Way Galaxy - Earth's speed of rotation on its axis, Earth's speed of revolution about the Sun, typical speeds of stars in the local solar neighborhood relative to us, the speed of our solar system orbiting the center of the Milky Way Galaxy, the speeds of very distant galaxies relative to us - Earth's speed of revolution about the Sun, typical speeds of stars in the local solar neighborhood relative to us, Earth's speed of rotation on its axis, the speed of our solar system orbiting the center of the Milky Way Galaxy, the speeds of very distant galaxies relative to us - the speed of our solar system orbiting the center of the Milky Way Galaxy, Earth's speed of revolution about the Sun, Earth's speed of rotation on its axis, the speeds of very distant galaxies relative to us, typical speeds of stars in the local solar neighborhood relative to us - Earth's speed of revolution about the Sun, Earth's speed of rotation on its axis, the speed of our solar system orbiting the center of the Milky Way Galaxy, typical speeds of stars in the local solar neighborhood relative to us, the speeds of very distant galaxies relative to us

Earth's speed of rotation on its axis, Earth's speed of revolution about the Sun, typical speeds of stars in the local solar neighborhood relative to us, the speed of our solar system orbiting the center of the Milky Way Galaxy, the speeds of very distant galaxies relative to us

Which of the following statements about the ecliptic plane is not true? - The nodes of the Moon's orbit lie in the ecliptic plane. - During a lunar eclipse, the Moon lies in the ecliptic plane. - During a solar eclipse, the Moon lies in the ecliptic plane. - It is the plane of the Moon's orbit around the earth. - It is the plane of the earth's orbit around the Sun.

It is the plane of the Moon's orbit around the earth.

The earth is made mostly of metals and rocks. Where did this material come from? - It was produced in the Big Bang. - It was created by chemical reactions in interstellar space. - It was made by nuclear fission of uranium and other radioactive materials. - It was made by our Sun. - It was produced by nuclear fusion in stars.

It was produced by nuclear fusion in stars.

Which of the following statements does not use the term light-year in an appropriate way? - The Milky Way Galaxy is about 100,000 light-years in diameter. -It's about 4 light-years from here to Alpha Centauri. -A light-year is about 10 trillion kilometers. -It will take the Voyager spacecraft about 20,000 years to travel just 1 light-year. -It will take me light-years to complete this homework assignment.

It will take me light-years to complete this homework assignment.

Imagine that we put a raisin cake into the oven, with each raisin separated from the others by 1 cm. An hour later, we take it out and the distances between raisins are 3 cm. If you lived in one of the raisins and watched the other raisins as the cake expanded, which of the following would you conclude? - All raisins would be moving away from you at the same speed. - More distant raisins would be moving away from you faster. - More distant raisins would be moving away from you more slowly. - It depends: If you lived in a raisin near the left side of the cake, you'd see other raisins moving away from you, but they'd be coming toward you if you lived in a raisin near the right side of the cake.

More distant raisins would be moving away from you faster.

Which of the following statements about the Milky Way Galaxy is not true? - The galaxy is about 100,000 light-years in diameter. - One rotation of the galaxy takes about 200 million years. - Our view of distant objects is obscured by gas and dust when we look into the galactic plane. - It contains between 100 billion and 1 trillion stars. - Our solar system is located very close to the center of the Milky Way Galaxy.

Our solar system is located very close to the center of the Milky Way Galaxy.

Suppose we imagine the Sun to be about the size of a grapefruit. Which of the following describes the size and distance of the earth on the same scale? - The earth is the size of a point about 15 meters away from the Sun. - The earth is the size of a golf ball about 1 meter away from the Sun. - The earth is the size of a marble about 25 miles away from the Sun. - The earth is the size of a golf ball about 15 meters away from the Sun. - The earth is the size of a point about 1 meter away from the Sun.

The earth is the size of a point about 15 meters away from the Sun.

Patterns of stars in constellations hardly change in appearance over times of even a few thousand years. Why? - Stars are fixed and never move. - The stars in our sky actually move rapidly relative to us — thousands of kilometers per hour — but are so far away that it takes a long time for this motion to make a noticeable change in the patterns in the sky. - Although most stars move through the sky, the brightest stars do not, and these are the ones that trace the patterns we see in the constellations. - Stars move, but they move very slowly — only a few kilometers in a thousand years. - Stars within a constellation move together as a group, which tends to hide their actual motion and prevent the pattern from changing.

The stars in our sky actually move rapidly relative to us — thousands of kilometers per hour — but are so far away that it takes a long time for this motion to make a noticeable change in the patterns in the sky.

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? - about half the year - a few hours - a few seconds - about a month - less than a millionth of a second

a few seconds

The age of the universe is - between 100 billion and 160 billion years. - between 100 million and 160 million years. - between 10 billion and 16 billion years. - between 1 billion and 1.6 billion years. - between 10 million and 16 million years.

between 10 billion and 16 billion years.

On a cosmic calendar, in which the history of the universe is compressed into 1 year, when did the dinosaurs become extinct? - in late November - in late September - in late December - in late October - in late August

in late December

How many galaxies are there in the observable universe? - roughly (within a factor of 10) the same as the number of stars in our galaxy - roughly a thousand times more than the number of stars in our galaxy - about as many as the number of stars we see in the sky with our naked eyes - about as many as the number of grains of sand on all the beaches on Earth - infinity

roughly (within a factor of 10) the same as the number of stars in our galaxy

How long would it take to count all the stars in the Milky Way Galaxy at a rate of one star per second? - several days - several weeks - several years - several thousand years - hundreds of thousands of years

several thousand years

Which of the following is largest? - size of a typical galaxy - 1 light-year - distance to the nearest star (other than our Sun) - size of Pluto's orbit

size of a typical galaxy

Which of the following is smallest? - size of a typical planet - 1 AU - 1 light-second - size of a typical star

size of a typical planet

The distribution of the mass of the Milky Way Galaxy is determined by - studying the rotation of the galaxy. - determining the amount of gas and dust. studying how stars are distributed in the Milky Way. - weighing various parts of the Milky Way. - counting the number of stars.

studying the rotation of the galaxy.

What do we mean by the observable universe? - the compendium of all objects that we have observed to date - the part of the universe that we can see through telescopes - the part of the universe that we can see with the naked eye - the entire universe, since it is inconceivable that there could be parts of the universe that we cannot observe -the part of the universe that could be observed in principle, including things that may require future technologies

the part of the universe that could be observed in principle, including things that may require future technologies

What is nuclear fusion? an explosion caused by putting together two volatile chemicals the process of splitting nuclei to produce energy a process that only occurs in bombs the process of turning matter into pure energy - the process of combining lightweight nuclei to make heavier nuclei

the process of combining lightweight nuclei to make heavier nuclei

What is the meaning of the word cosmos? -the dark sky -the sum total of all matter and energy, that is, everything within and between all galaxies -the Milky Way -the light from a distant astronomical object -the origin of the earth and life upon it

the sum total of all matter and energy, that is, everything within and between all galaxies

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 - the Milky Way Galaxy is expanding. - the universe is shrinking. - we are located at the center of the universe. - the farthest galaxies will eventually be moving faster than the speed of light. - the universe is expanding.

the universe is expanding.

Which of the following has your "address" in the correct order? -you, Earth, solar system, Milky Way, Local Supercluster, Local Group -you, Earth, solar system, Milky Way, Local Group, Local Supercluster -you, Earth, solar system, Local Group, Local Supercluster, Milky Way -you, Earth, solar system, Local Group, Milky Way, Local Supercluster -you, Earth, Local Group, Local Supercluster, solar system, Milky Way

you, Earth, solar system, Milky Way, Local Group, Local Supercluster