chapter 3
Which of the following orbits shows the planet at aphelion?
Aphelion is the point in a planet's orbit that is farthest from the Sun.
Jupiter orbits the Sun at an average distance of 5.203 AU and takes 11.86years to complete each orbit. Based on these facts, which statement is true? Jupiter orbits the Sun at an average distance of and takes to complete each orbit. Based on these facts, which statement is true? Jupiter's orbital period is 5.2033 times Earth's orbital period. Jupiter's orbital period is 5.2032 times Earth's orbital period. 5.2032=11.863 11.862=5.2033
11.862=5.2033
Which of the following statements about scientific theories is false? Which of the following statements about scientific theories is false? A theory can never be proved beyond all doubt; we can only hope to collect more and more evidence that might support it. A theory must make predictions that can be checked by observation or experiment. Theories are not taken seriously if they contradict older, more developed, theories. If even a single new fact is discovered that contradicts what we expect according to a particular theory, then the theory must be revised or discarded. A theory is a model designed to explain a number of observed facts.
Theories are not taken seriously if they contradict older, more developed, theories.
What do the structures of Stonehenge, the Templo Mayor, and the Sun Dagger all have in common? What do the structures of Stonehenge, the Templo Mayor, and the Sun Dagger all have in common? They were all built on the orders of ancient Mediterranean kings. They were all places used for religious sacrifice. They all can be used as lunar calendars. They were all used by ancient peoples for astronomical observations. all of the above
They were all used by ancient peoples for astronomical observations.
He was the first to prove that comets lie beyond Earth's atmosphere. He was the first to prove that comets lie beyond Earth's atmosphere. Copernicus Galileo Kepler Tycho Brahe Aristotle
Tycho Brahe
The ancient Greeks get a lot of attention for their contributions to science because _________. the books of every other culture were lost in the destruction of the library of Alexandria they were the first people known to try to explain nature with models based on reason and mathematics, without resort to the supernatural they were the only ancient culture that kept written records of their astronomical observations they were the first people to realize that Earth is a planet orbiting the Sun
they were the first people known to try to explain nature with models based on reason and mathematics, without resort to the supernatural
Why did Ptolemy have the planets orbiting Earth on "circles upon circles" in his model of the universe? to properly account for the varying distances of the planets from Earth to explain why the Greeks were unable to detect stellar parallax to explain the fact that planets sometimes appear to move westward, rather than eastward, relative to the stars in our sky to explain why more distant planets take longer to make a circuit through the constellations of the zodiac to explain why Venus goes through phases as seen from Earth
to explain the fact that planets sometimes appear to move westward, rather than eastward, relative to the stars in our sky
A scientific model must make a testable prediction. A scientific model must make a testable prediction. True False
true
Galileo found "imperfections" on the Sun in the form of sunspots and "imperfections" on the Moon in the form of mountains and valleys. Galileo found "imperfections" on the Sun in the form of sunspots and "imperfections" on the Moon in the form of mountains and valleys. True False
true
Process of Science: If any single test of a scientific hypothesis contradicts it, the hypothesis must be revised. (Assume that you've ruled out errors in the testing process; that is, the test result really does contradict the hypothesis.) True False
true
The names of the seven days of the week are derived from the names of the bodies of the solar system that are visible to the naked eye. The names of the seven days of the week are derived from the names of the bodies of the solar system that are visible to the naked eye. True False
true
Which of the following is not one of, nor follows directly from, Kepler's laws? Which of the following is not one of, nor follows directly from, Kepler's laws? The force of attraction between any two objects decreases with the square of the distance between their centers. As a planet moves around its orbit, it sweeps out equal areas in equal times. The orbit of each planet about the Sun is an ellipse with the Sun at one focus. More distant planets move at slower speeds. A planet travels faster when it is nearer to the Sun and slower when it is farther from the Sun.
The force of attraction between any two objects decreases with the square of the distance between their centers.
Process of Science: What is Occam's razor? Process of Science: What is Occam's razor? A long, steep cliff on Mercury that may have been produced as the planet contracted as it formed. The principle that everyone should agree on a theory before it is considered correct. An unusual implement that Professor Occam uses to remove facial hair. The principal that any theory can be verified by others. The idea that scientists should prefer the simpler of two models that agree equally well with observations.
The idea that scientists should prefer the simpler of two models that agree equally well with observations.
Which of the following orbits has the largest semimajor axis?
The semimajor axis is half of the distance across the ellipse in its longest direction (which means half of the major axis), which is also the planet's average distance from the Sun. Therefore, the ellipse that measures the longest across is the one with the largest semimajor axis.
He discovered that Jupiter has moons. He discovered that Jupiter has moons. Kepler Galileo Aristotle Tycho Brahe Ptolemy
Galileo
He discovered what we now call Newton's first law of motion. He discovered what we now call Newton's first law of motion. Tycho Brahe Kepler Ptolemy Galileo Copernicus
Galileo
Process of Science: I am doing science when I already know the answer to my scientific question and I am searching for evidence in the natural world strictly to support what I know. True False
false
Kepler's third law, p2 = a3, means that all orbits with the same semimajor axis have the same period. the period of a planet does not depend on its mass. a planet's period does not depend on the eccentricity of its orbit. planets that are farther from the Sun move at slower average speeds than nearer planets. All of the above are correct.
All of the above are correct.
During the Dark Ages in Europe, the scientific work of the ancient Greeks was preserved and further developed primarily by scholars in During the Dark Ages in Europe, the scientific work of the ancient Greeks was preserved and further developed primarily by scholars in China. India. Rome. Greece. Baghdad.
Baghdad.
Earth is slightly closer to the Sun in January than in July. How does the area swept out by Earth's orbit around the Sun during the 31 days of January compare to the area swept out during the 31 days of July? Earth is slightly closer to the Sun in January than in July. How does the area swept out by Earth's orbit around the Sun during the 31 days of January compare to the area swept out during the 31 days of July? The area swept out in July is larger. The area swept out in January is larger. Both areas are the same.
Both areas are the same. Kepler's second law tells us that a planet always sweeps out equal areas in equal times. Therefore, Earth sweeps out the same area in any 31-day period, no matter what month it is.
One of the "nails in the coffin" for Earth-centered universe was One of the "nails in the coffin" for Earth-centered universe was eclipses of the Sun. the retrograde motion of the planets. the phases of the Moon. Galileo's observation of stars in the Milky Way. Galileo's observations of the moons of Jupiter
Galileo's observations of the moons of Jupiter.
he chemical content of the universe is mostly hydrogen and helium, earth is at the center of the solar system, the observable universe contains approximately 100 billion galaxies, the sun is at the center of the solar system/the laws of nature are magnificent and beautiful, we are all playthings in a computer program created by advanced aliens, the universe was created by god
Classify each claim according to whether or not it is falsifiable. (list the falsifiable statements first then separate the non-falsifiable statements with a /) -We are all playthings in a computer program created by advanced aliens. -The universe was created by God. -The chemical content of the universe is mostly hydrogen and helium. -Earth is at the center of the solar system. -The observable universe contains approximately 100 billion galaxies. -The Sun is at the center of the solar system. -The laws of nature are magnificent and beautiful.
The controversial book of this famous person, published in 1543 (the year of his death), suggested that Earth and other planets orbit the Sun. Copernicus Tycho Brahe Kepler Galileo Ptolemy
Copernicus
Which of the following orbits is the most eccentric?
Eccentricity is a measure of how "stretched out" an ellipse is. A perfect circle has zero eccentricity, and the most stretched out ellipse has the largest eccentricity.
Copernicus was the first person to suggest a Sun-centered solar system. Copernicus was the first person to suggest a Sun-centered solar system. True False
False
How did the Ptolemaic model explain the apparent retrograde motion of the planets? How did the Ptolemaic model explain the apparent retrograde motion of the planets? It held that the planets moved along small circles that moved on larger circles, also known as epicycles, around Earth. It held that sometimes the planets moved backward along their circular orbits. It held that the planets moved along small circles that moved on larger circles around the Sun. It varied the motion of the celestial sphere so that it sometimes moved backward. It placed the Sun at the center so that the planets' apparent retrograde motion was seen as Earth passed each one in its orbit.
It held that the planets moved along small circles that moved on larger circles, also known as epicycles, around Earth.
He discovered that the orbits of planets are ellipses. He discovered that the orbits of planets are ellipses. Kepler Galileo Tycho Brahe Copernicus Ptolemy
Kepler
Which of the following paths could not be a real orbit for a planet around the Sun?
Kepler's first law tells us that the orbit of a planet must be an ellipse with the Sun at one focus. Therefore, the path that shows the Sun in the center of the ellipse, rather than at a focus, cannot be the real orbital path of a planet. (Note that the circular path is allowed because a circle is an ellipse in which both foci are at the center.)
All of the following statements are true. Which one can be explained by Kepler's second law? All of the following statements are true. Which one can be explained by Kepler's second law? All the planets orbit the Sun in nearly the same plane. Earth is slightly closer to the Sun in January than in July. The Sun is not in the precise center of Saturn's orbit. Venus orbits the Sun at a faster orbital speed than Earth. Mars moves faster in its orbit when it is closer to the Sun than when it is farther from the Sun.
Mars moves faster in its orbit when it is closer to the Sun than when it is farther from the Sun. Kepler's second law tells us that a planet moves faster in its orbit when it is closer to the Sun (near perihelion) than when it is farther (near aphelion). This law applies to all planets and therefore explains the statement about Mars.
Which of the following are the three key hallmarks of science? Select exactly three statements. Select exactly three statements. Modern science seeks explanations for observed phenomena that rely solely on natural causes. Scientific models must be structured so that they can be proved true by a single good observation or experiment. Science progresses through careful application of what is called the scientific method. Models must make testable predictions that will force us to revise or abandon the model if they do not agree with observations. Scientific models are miniature representations of reality. Science progresses through the creation and testing of models of nature that explain the observations as simply as possible.
Modern science seeks explanations for observed phenomena that rely solely on natural causes. Models must make testable predictions that will force us to revise or abandon the model if they do not agree with observations. Science progresses through the creation and testing of models of nature that explain the observations as simply as possible.
Let's start with an example from history. Listed below are a series of claims regarding United States President John F. Kennedy (1917-1963). Classify each statement according to whether or not it is falsifiable.
Note that both of the falsifiable claims in this example happen to be true. The claim about Kennedy being the 35th President is falsifiable because it can be checked against historical records. The claim that Kennedy died from a bullet in his brain is falsifiable because it could have been shown false by the medical examiner. The remaining claims are not falsifiable: Statements that call on any type of supernatural being are by definition out of the realm of science. Similarly, a claim of something being "undetectable" could not be falsified, and a claim about what Kennedy would have done if he had lived is a conjecture that cannot be disproven.
As you learned in the video, Galileo's observations of Venus in gibbous (nearly full) phase showed conclusively that Venus orbits the Sun, not Earth. Which figure shows Venus's position when Galileo saw it in gibbous phase? The figure shows Earth orbiting the Sun at a position directly infront of the Sun with Venus in an orbit between them. Venus is positioned at angle approximately 45 degrees clockwise from a line joining the Sun and Earth. The figure shows Earth orbiting the Sun at a position directly infront of the Sun with Venus in an orbit between them. Venus is positioned at angle approximately 270 degrees clockwise from a line joining the Sun and Earth The figure shows Earth orbiting the Sun at a position directly infront of the Sun with Venus in an orbit between them. Venus is positioned directly between the Sun and Earth. The figure shows Earth orbiting the Sun at a position directly infront of the Sun with Venus in an orbit between them. Venus is positioned at angle approximately 135 degrees clockwise from a line joining the Sun and Earth.
Notice that the gibbous phase occurs when Venus is farther from Earth than the Sun, and this could never happen in Ptolemy's system. That is how Galileo concluded that Venus must orbit the Sun.
Based on the video, which Venus phase would be impossible to see (from Earth) if Venus orbited Earth as described in Ptolemy's Earth-centered model? Based on the video, which Venus phase would be impossible to see (from Earth) if Venus orbited Earth as described in Ptolemy's Earth-centered model? crescent on the left side crescent on the right side gibbous (nearly full) new
Phases that show more than a crescent are not possible in Ptolemy's Earth-centered model, so a gibbous or full Venus could never occur if Venus orbited Earth. gibbous (nearly full)
He developed a system for predicting planetary positions that remained in use for some 1,500 years. He developed a system for predicting planetary positions that remained in use for some 1,500 years. Ptolemy Tycho Brahe Copernicus Kepler Galileo
Ptolemy
You discover an asteroid that orbits the Sun with the same 1-year orbital period as Earth. Which of the following statements must be true? You discover an asteroid that orbits the Sun with the same 1-year orbital period as Earth. Which of the following statements must be true? The asteroid shares the same orbit around the Sun as Earth. The asteroid has a more eccentric orbit than Earth. The asteroid will eventually collide with Earth. The asteroid has the same perihelion distance as Earth. The asteroid's average (semimajor axis) distance from the Sun is 1AU.
The asteroid's average (semimajor axis) distance from the Sun is 1AU. Kepler's third law tells us that an object's average orbital distance can be calculated from its orbital period using the formula p2=a3 (where p is the planet's orbital period in years and a is its average orbital distance in AU). Therefore, all objects that share Earth's orbital period of 1 year must also share Earth's average orbital distance of 1AU.
Which of the following statements about an ellipse is NOT true? View Available Hint(s) Which of the following statements about an ellipse is NOT true? The semimajor axis of an ellipse is half the length of the longest line that you can draw across an ellipse. An ellipse with a large eccentricity looks much more elongated (stretched out) than an ellipse with a small eccentricity. The focus of an ellipse is always located precisely at the center of the ellipse. A circle is considered to be a special type of ellipse.
The focus of an ellipse is always located precisely at the center of the ellipse.
All the following statements are true. Which one follows directly from Kepler's third law? All the following statements are true. Which one follows directly from Kepler's third law? Venus is larger than Mercury. Venus orbits the Sun at a slower average speed than Mercury. Venus has a thicker atmosphere than Mercury. Venus is more massive than Mercury.
Venus orbits the Sun at a slower average speed than Mercury.
Which of the following can you observe about Venus with the naked eye? Select all that apply. Which of the following can you observe about Venus with the naked eye? Select all that apply. Venus sometimes shines brightly in the western sky shortly after sunset Venus sometimes shines brightly in the eastern sky shortly before dawn When Venus is brightest, it is visible all night long Venus is visible at midnight when it is in its full phase
Venus sometimes shines brightly in the western sky shortly after sunset Venus sometimes shines brightly in the eastern sky shortly before dawn. Venus always remains close to the Sun in our sky. Therefore, when it is visible, it is either in the evening sky for up to a few hours after sunset or in the morning sky for up to a few hours before dawn.
In Ptolemy's Earth-centered model for the solar system, Venus always stays close to the Sun in the sky and, because it always stays between Earth and the Sun, its phases range only between new and crescent. The following statements are all true and were all observed by Galileo. Which one provides evidence that Venus orbits the Sun and not Earth? In Ptolemy's Earth-centered model for the solar system, Venus always stays close to the Sun in the sky and, because it always stays between Earth and the Sun, its phases range only between new and crescent. The following statements are all true and were all observed by Galileo. Which one provides evidence that Venus orbits the Sun and not Earth? We never see Venus at midnight. We sometimes see a crescent Venus. We sometimes see gibbous (nearly but not quite full) Venus. We need a telescope to observe the phases of Venus.
We sometimes see gibbous (nearly but not quite full) Venus. In the Ptolemaic system, we should never see more than a crescent for Venus. Because we do in fact see more, the Ptolemaic model must be wrong. The full range of phases that we see for Venus is consistent only with the idea that Venus orbits the Sun. Galileo was the first to observe the phases of Venus — and hence to find this evidence in support of the Sun-centered system — because he was the first to observe Venus through a telescope. Without a telescope, we cannot tell that Venus goes through phases
What do we mean by a geocentric model of the universe? a model of the Milky Way Galaxy that has our solar system located at its center a model designed to explain what we see in the sky while having Earth located in the center of the universe the name given to sphere-shaped models that show all the constellations as they appear in our sky on the celestial sphere a model designed to explain what we see in the sky while having Earth orbit the Sun
a model designed to explain what we see in the sky while having Earth located in the center of the universe
In the Ptolemaic system, Venus should not show phases. True False
false
Kepler's second law, which states that as a planet moves around its orbit it sweeps out equal areas in equal times, means that Kepler's second law, which states that as a planet moves around its orbit it sweeps out equal areas in equal times, means that a planet's period does not depend on the eccentricity of its orbit. a planet travels faster when it is nearer to the Sun and slower when it is farther from the Sun. the period of a planet does not depend on its mass. planets that are farther from the Sun move at slower average speeds than nearer planets. planets have circular orbits.
a planet travels faster when it is nearer to the Sun and slower when it is farther from the Sun.
When did Ptolemy live? about 2000 years ago about 100 years ago about 1000 years ago about 5000 years ago about 500 years ago
about 2000 years ago
When did Copernicus live? When did Copernicus live? about 1000 years ago about 2000 years ago about 5000 years ago about 500 years ago about 100 years ago
about 500 years ago
At the Sun Dagger in New Mexico, a dagger-shaped beam of sunlight pierces a spiral At the Sun Dagger in New Mexico, a dagger-shaped beam of sunlight pierces a spiral every day at noon. during the totality of a total solar eclipse. at noon on the day of full Moon each month. at sunset on the spring equinox. at noon on the summer solstice.
at noon on the summer solstice.
When would a new Venus be highest in the sky? View Available Hint(s) When would a new Venus be highest in the sky? just after sunset midnight just before dawn at noon
at noon. A new Venus occurs when Venus is directly between the Sun and Earth, which means a new Venus will be highest in the sky at the same time that the Sun is highest in the sky, which is around noon (local time).
Imagine that Venus is in its full phase today. If we could see it, at what time would the full Venus be highest in the sky? View Available Hint(s) Imagine that Venus is in its full phase today. If we could see it, at what time would the full Venus be highest in the sky? just after sunset midnight at noon just before dawn
at noon. Because Venus is full when it is on the opposite side of the Sun from Earth, the Sun and Venus both appear to move through the sky together at that time. Venus, therefore, rises with the Sun, reaches its highest point at noon, and sets with the Sun.
Scientific thinking is _________. Scientific thinking is _________. an ancient mode of thinking first invented in Egypt based on everyday ideas of observation and trial-and-error experiments a difficult process that only a handful of people can do well completely different from any other type of thinking
based on everyday ideas of observation and trial-and-error experiments
Where was the Sun in Ptolemy's model of the universe? Where was the Sun in Ptolemy's model of the universe? between the orbits of Venus and Mars at the center between Earth and the Moon's orbit at the outer edge, beyond Saturn's orbit slightly offset from the center
between the orbits of Venus and Mars
How did Eratosthenes estimate the size of Earth in 240 B.C.? by observing the duration of a solar eclipse by sending fleets of ships around Earth by comparing the maximum altitude of the Sun in two cities at different latitudes on the summer solstice by measuring the size of Earth's shadow on the Moon in a lunar eclipse We don't know how he did it since all his writings were destroyed.
by comparing the maximum altitude of the Sun in two cities at different latitudes on the summer solstice
Ptolemy was important in the history of astronomy because he was the first to create a model of the solar system that placed the Sun rather than Earth at the center. developed a scientifically accurate model of the universe. was the first to believe that all orbits are perfect circles. was the first to believe in an Earth-centered universe. developed a model of the solar system that made sufficiently accurate predictions of planetary positions to remain in use for many centuries.
developed a model of the solar system that made sufficiently accurate predictions of planetary positions to remain in use for many centuries.
In Ptolemy's Earth-centered model for the solar system, Venus's phase is never full as viewed from Earth because it always lies between Earth and the Sun. In reality, as Galileo first recognized, Venus is __________. View Available Hint(s) In Ptolemy's Earth-centered model for the solar system, Venus's phase is never full as viewed from Earth because it always lies between Earth and the Sun. In reality, as Galileo first recognized, Venus is __________. never full because the sunlit side of Venus never faces directly toward Earth full whenever it lies directly between Earth and the Sun never full because Earth's shadow falls on Venus at the time when it would otherwise be full full whenever it is on the opposite side of the Sun from Earth
full whenever it is on the opposite side of the Sun from Earth. A full Venus always occurs when it is on the opposite side of the Sun as viewed from Earth. Galileo used this fact as evidence for the Sun-centered view of the solar system: The fact that Venus goes through all the phases must mean it goes all the way around the Sun. In contrast, in the Ptolemaic model, Venus only varies between new and crescent phases.
Why wasn't the Sun-centered model of Copernicus immediately adopted after he proposed it? Why wasn't the Sun-centered model of Copernicus immediately adopted after he proposed it? it was not noticeably more accurate than the old Ptolemaic model it featured the Earth at the center, which had already been ruled out by observations Aristarchus had already formulated a Sun-centered model some 1500 years earlier. observations made with telescopes ruled it out
it was not noticeably more accurate than the old Ptolemaic model. Even though it featured more elegant explanations for phenomena like retrograde motion, it was no more accurate than the older model, so there was no compelling reason to think it was a better description of nature.
When would you expect to see Venus high in the sky at midnight? View Available Hint(s) When would you expect to see Venus high in the sky at midnight? in its waning crescent phase in its waxing crescent phase in its waxing gibbous phase in its full phase never
never. For Venus to be high in the sky at midnight, it would have to be on the opposite side of our sky from the Sun. But that never occurs because Venus is closer than Earth to the Sun.
In Ptolemy's Earth-centered model, when would Venus appear directly behind the Sun as viewed from Earth? In Ptolemy's Earth-centered model, when would Venus appear directly behind the Sun as viewed from Earth? when it is in farthest from Earth when it is in a crescent phase never when it is in closest to Earth
never. In the Earth-centered model, Venus always remains somewhere between Earth and the Sun, and never appears behind the Sun in our sky.
The great contribution of Tycho Brahe was to _________. discover four moons orbiting Jupiter, thereby lending strong support to the idea that Earth is not the center of the universe observe planetary positions with sufficient accuracy so that Kepler could later use the data to discover the laws of planetary motion discover that planets orbit the Sun in elliptical orbits with varying speed offer the first detailed model of a Sun-centered solar system, thereby beginning the process of overturning the Earth-centered model of the Greeks
observe planetary positions with sufficient accuracy so that Kepler could later use the data to discover the laws of planetary motion
The names of the seven days of the week are based on the seven naked-eye objects that appear to move among the constellations. seven largest constellations of the ancient world. seven planets closest to the Sun. seven brightest stars in the prominent constellation Orion. most popular Norse gods.
seven naked-eye objects that appear to move among the constellation
Which of the following was NOT observed by Galileo? Which of the following was NOT observed by Galileo? four moons orbiting Jupiter mountains and valleys on the Moon stellar parallax phases of Venus
stellar parallax
The shadow cast by a simple stick or obelisk allowed ancient people to The shadow cast by a simple stick or obelisk allowed ancient people to tell the time of day record accurate measurements of the motions of the stars show that the solar system is really Sun-centered observe retrograde motion of the planets
tell the time of day. A stick or obelisk acts as a simple sundial, which allows you to estimate the local time because the position of the shadow changes as the Sun moves across the sky during the day.
The path that led to modern science emerged from ancient civilizations in which part of the world? The path that led to modern science emerged from ancient civilizations in which part of the world? Central and South America Southern Asia the Mediterranean and the Middle East China North America
the Mediterranean and the Middle East
An original observation of Galileo's that helped to overturn the ancient Earth-centered model was An original observation of Galileo's that helped to overturn the ancient Earth-centered model was the phases of Venus stellar parallax that planets move in elliptical orbits retrograde motion of planets in our sky
the phases of Venus. Galileo's observations of the phases of Venus directly contradicted the predictions of the Earth-centered model but agreed with what we expect in a Sun-centered model.
