Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.

Scientist 1

The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.

Scientist 2

The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.

If research concluded that the Moon's composition was the same as the Earth's composition, which viewpoint would this support?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at fifteen different locations around each city. Measurements were taken at each location three times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week, and the results were compiled into Table 1.

Experiment 2

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation, and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward-facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in Table 3.

In which experiment was the greatest number of measurements taken?

According to the Big Bang theory, which proposes that the universe is roughly 13.7 billion years old, all matter and energy were at one time compressed into a single microscopic point. This point then exploded outward in all directions in a rapid expansion. The expansion has continued to the present day, which has allowed matter to cool to a state at which stable atomic components can form. The Big Bang theory proposes that our universe is finite in age, and since nothing can travel faster than the speed of light, there exists a cosmological horizon, which is the maximum distance light or energy could have travelled since the occurrence of the Big Bang. Since the universe is still expanding, however, regions of space that are visible from our vantage point are not within each other's cosmological horizons. For example, if galaxy A is 10 billion light years away from us, and galaxy B is 10 billion light years away from us in the opposite direction, there is a total distance of 20 billion light years between them. The universe has only existed long enough for light, energy, or information to travel 13.7 billion light years between them; thus, it is not possible for any contact to have been made between the two galaxies. Yet, even these vastly separated regions of space have been observed to be extremely homogeneous—they have remarkably similar features and properties despite being so far away from each other. The question, therefore, is what caused this apparent homogeneity observed in the universe. If matter rapidly expanded outward, why does the universe have such a uniform appearance in every direction? If the Big Bang theory is correct, some explanation for this horizon problem is needed.

Scientist 1

In the current state of the universe there exist regions that lie beyond the cosmological horizons of others, and therefore cannot possibly be influenced by them. This was not always the case. At a point in time mere microseconds after the Big Bang, all of the matter in the universe experienced a period of exponential expansion, known as inflation, before the rate of expansion fell to a more stable level. This inflation led to all regions of the universe having homogeneous features, even though they are not capable of affecting one another in any way in their current state.

Scientist 2

Although there is ample evidence that a Big Bang occurred, the horizon problem, as well as the flatness problem, suggest that the Big Bang is not the full story of the inception of the universe. The horizon problem can be solved if, instead of viewing the Big Bang as the "beginning of everything," we stipulate that the expansion seen after the Big Bang was already occurring for some time before the Big Bang occurred. This marks the Big Bang as a sort of "causal horizon," which disallows us from directly observing evidence from any period beforehand. If we assume the universe is cyclic, the homogeneity of the universe is explained as the result of a continuous cycle of expansion and compression, which would naturally lead to a universe having uniform features.

From the context of the passage, "light year" most nearly means __________.

Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.

Scientist 1

The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.

Scientist 2

The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.

Which of the following best states the basis for the belief of Scientist 1?

Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.

Scientist 1

The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.

Scientist 2

The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.

Which of the following best states the basis for the belief of Scientist 1?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at fifteen different locations around each city. Measurements were taken at each location three times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week, and the results were compiled into Table 1.

Experiment 2

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation, and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward-facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in Table 3.

In which experiment was the greatest number of measurements taken?

According to the Big Bang theory, which proposes that the universe is roughly 13.7 billion years old, all matter and energy were at one time compressed into a single microscopic point. This point then exploded outward in all directions in a rapid expansion. The expansion has continued to the present day, which has allowed matter to cool to a state at which stable atomic components can form. The Big Bang theory proposes that our universe is finite in age, and since nothing can travel faster than the speed of light, there exists a cosmological horizon, which is the maximum distance light or energy could have travelled since the occurrence of the Big Bang. Since the universe is still expanding, however, regions of space that are visible from our vantage point are not within each other's cosmological horizons. For example, if galaxy A is 10 billion light years away from us, and galaxy B is 10 billion light years away from us in the opposite direction, there is a total distance of 20 billion light years between them. The universe has only existed long enough for light, energy, or information to travel 13.7 billion light years between them; thus, it is not possible for any contact to have been made between the two galaxies. Yet, even these vastly separated regions of space have been observed to be extremely homogeneous—they have remarkably similar features and properties despite being so far away from each other. The question, therefore, is what caused this apparent homogeneity observed in the universe. If matter rapidly expanded outward, why does the universe have such a uniform appearance in every direction? If the Big Bang theory is correct, some explanation for this horizon problem is needed.

Scientist 1

In the current state of the universe there exist regions that lie beyond the cosmological horizons of others, and therefore cannot possibly be influenced by them. This was not always the case. At a point in time mere microseconds after the Big Bang, all of the matter in the universe experienced a period of exponential expansion, known as inflation, before the rate of expansion fell to a more stable level. This inflation led to all regions of the universe having homogeneous features, even though they are not capable of affecting one another in any way in their current state.

Scientist 2

Although there is ample evidence that a Big Bang occurred, the horizon problem, as well as the flatness problem, suggest that the Big Bang is not the full story of the inception of the universe. The horizon problem can be solved if, instead of viewing the Big Bang as the "beginning of everything," we stipulate that the expansion seen after the Big Bang was already occurring for some time before the Big Bang occurred. This marks the Big Bang as a sort of "causal horizon," which disallows us from directly observing evidence from any period beforehand. If we assume the universe is cyclic, the homogeneity of the universe is explained as the result of a continuous cycle of expansion and compression, which would naturally lead to a universe having uniform features.

From the context of the passage, "light year" most nearly means __________.

Earth’s moon rotates like a satellite around Earth. It is the fifth largest moon in the Solar System and is best seen at night. The Earth’s moon is about 384,400 km from Earth and has an orbital period of twenty-seven days. Most scientists agree that the Moon formed about 4.5 billion years ago; however, there are several conflicting theories on the moon’s origin. Below two scientists discuss what they believe to be true.

Scientist 1

The Fission Theory states that the Moon and Earth were once the same formation. A part of the formation separated from Earth and became the moon. The formation that broke off to form the moon most likely came from the Pacific Ocean Basin. The rock densities of the moon are similar to the rock densities of the Earth’s mantle. This is because the part that broke off from the Earth to form the moon broke off from the outer part of the Earth’s mantle. The theory that the Moon and Earth formed separately is highly unlikely. For this theory to be true, Earth’s gravitational field would have had to pull the moon into orbit. This is unlikely because it would have required a very particular set up. Most objects that come into the Earth’s gravitational field have elliptical orbits. If the Moon was pulled into orbit with the Earth, it would have a comet-like elliptical orbit—which it does not.

Scientist 2

The Impactor Theory states that a small planet collided with the Earth just after the solar system was formed. This caused large amounts of materials from the outer shell of both planets to break off. This debris started orbiting the Earth and forming one collective body of material. That collective piece is what we now call the moon. The lunar rocks studied are burnt, implying they were heated at one time. This would make sense because when the small planet and Earth collide, the material became heated due to impact. In addition, the Moon does not have a magnetic field like Earth, but some of the rocks on the surface of the Moon hint the Moon could have had some sort of magnetic qualities at one time. This is because the Moon was partially made up of Earth’s outer rocks.

If research concluded that the Moon's composition was the same as the Earth's composition, which viewpoint would this support?

A group of scientists wanted to investigate weather patterns in four cities across the United States. They conducted a series of experiments to look for similarities and differences among the four cities. The scientists measured wind speed and direction, amount of precipitation, and percentage of cloud cover for one week. Further explanation can be found below.

Experiment 1

Scientists measured wind speed using an anemometer at 15 different locations around each city. Measurements were taken at each location 3 times a day and then averaged to get a daily wind speed for each city. This was repeated every day for one week and the results were compiled into table 1.

Experiment 2

Scientists set up barometers at five locations in each city. At the end of each day, the precipitation levels in the five barometers were averaged to find the average daily precipitation and the results are compiled in Table 2.

Experiment 3

For the final experiment, scientists placed upward facing cameras atop the ten tallest buildings in each city. The cameras took one picture per hour. The scientists then used computer software to stitch together the images from all the cameras. The resulting meta-image was then analyzed with another computer program to find the percent of the sky covered by clouds. The results can be found in table 3.

Which of the following is supported by the data in Experiment 3?

Scientists studying historical trends in climate change have a number of tools at their disposal. One method of analyzing paleoclimate data involves the use of fossilized pollen spores embedded in sediment. Pollen spores are specific to the plant that produced them. Because the spores are resilient and are widely-distributed by wind, they provide a snapshot of the vegetation that was widespread at a particular point in time. By identifying the age of a sample and the composition of the various spores, scientists can identify the prominent vegetation and use this information to gain insight into the climate at the time the spores were deposited.

Scientists took sediment samples from various depths of a lakebed. They found that five types of pollen spores make up the majority of spore deposits in each sample. In Table 1, plants are listed along with the respective temperature ranges and levels of precipitation for the areas in which they are commonly found. Table 2 shows the composition of the assortment of spores in each of the four samples taken by the scientists.

A fifth sample is taken at a different depth. If it contains few spores from any of the 5 plants, which is the most likely explanation for their absence?