The Essential Cosmic Perspective, 8e (Bennett et al.)
Chapter 3 The Science of Astronomy
3.1 Multiple Choice Questions
1) People of central Africa predicted the peak of their rainy season by
A) recording the seasonal changes in average temperature.
B) observing the path of the planets across the sky.
C) observing the length of the lunar cycle.
D) observing the orientation of the crescent moon relative to the horizon.
E) observing the location of the Moon relative to the Sun in the sky.
2) Historians trace the origins of a 24-hour day to
A) the druids of Stonehenge.
B) the ancient Egyptians.
C) the Mayans.
D) the Aztecs.
E) the Babylonian astronomer, Meton.
3) At the Sun Dagger in New Mexico, a dagger-shaped beam of sunlight pierces a spiral
A) every day at noon.
B) at noon on the summer solstice.
C) at sunset on the spring equinox.
D) at noon on the day of the full moon each month.
E) during the totality of a total solar eclipse.
4) The Muslim fast of Ramadan occurs
A) on the December solstice, coincident with the Saturnalia.
B) during the ninth month of the lunar calendar, between new moons.
C) on the 15th day of Nisan, the first month of the lunar calendar.
D) at the beginning of each Metonic Cycle.
5) Which of the following statements expresses what we mean by a scientific theory?
A) a simple model that explains a wide variety of phenomena and that has survived repeated tests
B) an explanation for a physical phenomenon, an explanation that hasn’t been tested yet
C) an educated guess
D) an hypothesis
6) The Jewish calendar is kept roughly synchronized with a solar calendar by
A) adding a thirteenth lunar month to 7 out of every 19 years.
B) having a thirteenth month with 5 days each year.
C) skipping a month every 7 out of 19 years.
D) having the first lunar month begin on the spring equinox.
E) having the first lunar month begin on the June solstice.
7) The path that led to modern science emerged from ancient civilizations in which part of the
world?
A) Central and South America
B) the Mediterranean and the Middle East
C) North America
D) China
E) Southern Asia
8) When and where did the Library of Alexandria exist?
A) from A.D. 600 to A.D. 1800 in Greece
B) from A.D. 600 to A.D. 1800 in Egypt
C) from 300 B.C. to A.D. 400 in Rome
D) from 300 B.C. to A.D. 400 in Greece
E) from 300 B.C. to A.D. 400 in Egypt
9) How did Eratosthenes estimate the size of Earth in 240 B.C.?
A) by observing the duration of a solar eclipse
B) by measuring the size of Earth’s shadow on the Moon in a lunar eclipse
C) by comparing Sun angles of two locations at noon on the equinox
D) by sending fleets of ships around Earth
E) by walking south and measuring the extent of the southern celestial sphere revealed
10) Which of the following statements about scientific models is true?
A) A model tries to represent all aspects of nature.
B) A model tries to represent only one aspect of nature.
C) A model can be used to explain and predict real phenomena.
D) All models that explain nature well are correct.
E) All current models are correct.
11) When did Ptolemy live?
A) about 5000 years ago
B) about 2000 years ago
C) about 1000 years ago
D) about 500 years ago
E) about 100 years ago
12) Why did Ptolemy have the planets orbiting Earth on “circles upon circles” in his model of the
universe?
A) to explain why more distant planets take longer to make a circuit through the constellations of
the zodiac
B) to explain the fact that planets sometimes appear to move westward, rather than eastward,
relative to the stars in our sky
C) to explain why the Greeks were unable to detect stellar parallax
D) to properly account for the varying distances of the planets from Earth
E) to explain why Venus goes through phases as seen from Earth
13) During the Dark Ages in Europe, the scientific work of the ancient Greeks was preserved and
further developed primarily by scholars in
A) Baghdad, Iraq.
B) Athens, Greece.
C) Rome, Italy.
D) Dublin, Ireland.
E) Beijing, China.
14) The controversial book On the Revolutions of the Celestial Spheres of this famous person,
published in 1543 (the year of his death), suggested that Earth and other planets orbit the Sun.
A) Tycho Brahe
B) Copernicus
C) Kepler
D) Galileo
E) Ptolemy
15) Galileo observed all of the following. Which observation offered direct proof of a planet
orbiting the Sun?
A) phases of Venus
B) the Milky Way is composed of many individual stars
C) patterns of shadow and sunlight near the dividing line between the light and dark portions of
the Moon’s face
D) four moons orbiting Jupiter
16) According to Kepler’s third law (p2 = a3), how does a planet’s mass affect its orbit around the
Sun?
A) A planet’s mass has no effect on its orbit around the Sun.
B) A more massive planet must have a larger semimajor axis.
C) More massive planets orbit the Sun at higher average speed.
D) More massive planets must have more circular orbits.
17) He discovered that the orbits of planets are ellipses.
A) Tycho Brahe
B) Copernicus
C) Kepler
D) Galileo
E) Ptolemy
18) He discovered that Jupiter has moons.
A) Tycho Brahe
B) Aristotle
C) Kepler
D) Galileo
E) Ptolemy
19) How did the Ptolemaic model explain the apparent retrograde motion of the planets?
A) It held that the planets resided on giant spheres that sometimes turned clockwise and
sometimes turned counterclockwise.
B) It held that this motion occurs as Earth passes by another planet in its orbit of the Sun.
C) It held that sometimes the planets moved backwards along their circular orbits.
D) It held that the planets moved along small circles that moved on larger circles around Earth,
and that the combined motion sometimes resulted in backward motion.
20) Which of the following is not necessary of a good scientific theory?
A) A scientific theory cannot be accepted until it has been proven true beyond all doubt.
B) A scientific theory should be based on natural processes and should not invoke the
supernatural or divine.
C) A scientific theory must explain a wide variety of phenomena observed in the natural world.
D) A scientific theory must make testable predictions that, if found to be incorrect, could lead to
its own modification or demise.
21) Which of the following statements about Copernican model for the solar system is false?
A) It used combinations of perfect circles to describe the orbits of the planets.
B) It was not widely accepted or even read when it was published.
C) It made better predictions than the Ptolemaic geocentric model.
D) It assumed the Sun is in the center of the solar system.
22) When we see Venus in its full phase, what phase would Earth be in as seen by a hypothetical
Venetian?
A) full
B) new
C) first quarter
D) third quarter
E) waning crescent
23) Kepler’s third law, p2 = a3, means that
A) a planet’s period does not depend on the eccentricity of its orbit.
B) all orbits with the same semimajor axis have the same period.
C) the period of a planet does not depend on its mass.
D) planets that are farther from the Sun move at slower average speeds than nearer planets.
E) All of the above are correct.
24) From Kepler’s third law, a hypothetical planet that is twice as far from the Sun as Earth
should have a period of
A) 1/2 Earth year.
B) 1 Earth year.
C) 2 Earth years.
D) more than 2 Earth years.
E) It depends on the planet’s mass.
25) From Kepler’s third law, an asteroid with an orbital period of 8 years lies at an average
distance from the Sun equal to
A) 2 astronomical units.
B) 4 astronomical units.
C) 8 astronomical units.
D) 16 astronomical units.
E) It depends on the asteroid’s mass.
26) 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) a planet travels faster when it is nearer to the Sun and slower when it is farther from the Sun.
B) a planet’s period does not depend on the eccentricity of its orbit.
C) planets that are farther from the Sun move at slower average speeds than nearer planets.
D) the period of a planet does not depend on its mass.
E) planets have circular orbits.
27) The Earth is instantly replaced in its orbit by a speck of dust. Which statement best describes
the subsequent orbital motion of that piece of dust?
A) The dust particle will spiral into the Sun.
B) The dust particle will be ejected from the solar system.
C) The dust particle will continue in the same orbit as the Earth did, orbiting the Sun in 1 year.
D) The dust particle will move to a smaller orbit and orbit the Sun in less than 1 year.
E) The dust particle will move to a larger orbit and orbit the Sun in more than 1 year.
28) The point along a planet’s orbit where it is closest to the Sun is called the orbit’s
A) perihelion.
B) aphelion.
C) eccentricity.
D) semi-major axis.
E) period.
29) What is meant by a scientific paradigm?
A) a paradox: two theories, each believed to be true, that contradict each other
B) a radical change in scientific thought
C) a generally well-established scientific theory or set of theories
D) a model that tells a story in the form of a parable
E) a historical theory that has been proved inaccurate
30) The principle of Occam’s Razor states that
A) in explaining natural phenomena, the simplest explanation consistent with the observations is
to be preferred.
B) no scientific theory, no matter how well tested, can ever be proved absolutely true.
C) a disciplined approach is required for separating false hypotheses from true hypotheses.
D) while personal biases may influence individual scientists, the process of science itself can
uncover these biases.
E) only a model that has survived repeated observational tests deserves to be called a scientific
theory.
31) Which of the following statements best describes the accomplishments of these men?
A) Newton collected the data, Tycho provided the model in the form of laws, Kepler explained
the model in terms of gravity.
B) Tycho collected the data, Kepler provided the model in the form of laws, Newton explained
the model in terms of gravity.
C) Kepler collected the data, Tycho provided the model in the form of laws, Newton explained
the model in terms of gravity.
D) Tycho collected the data, Newton provided the model in the form of laws, Kepler explained
the model in terms of gravity.
32) The ancient goal of astrology was to
A) connect to the gods for which the planets were named.
B) make a more accurate model of the geocentric universe.
C) predict the occurrence of eclipses and the passage of the seasons.
D) predict future events affecting nature and people.
33) When did humans first learn that Earth is not the center of the universe?
A) within the past 500 years
B) about 2000 years ago
C) around the time that early humans acquired language
D) We haven’t; there is still considerable scientific debate about whether Earth is the center of
the universe.
34) His model put the Sun in the center, but was not very accurate because the orbits were
perfect circles.
A) Galileo
B) Newton
C) Copernicus
D) Kepler
E) Tycho
35) In the Ptolemaic model of the solar system, Venus should exhibit which of the following
phases?
A) new
B) crescent
C) full
D) both A and B
E) both B and C
36) Galileo observed which of the following phases of Venus?
A) new
B) crescent
C) gibbous
D) full
E) all of the above
37) Which of the following statements about Kepler’s laws is false?
A) Kepler’s laws provide mathematical descriptions of the motion of the planets.
B) Kepler’s laws explain why planets with larger semi-major axes have much longer orbital
periods.
C) Kepler’s second law implies that when planets are closer to the sun, they move faster.
D) Kepler’s first law states that planetary orbits are shaped as ellipses.
38) Falsifiability. Which of the statements can be falsified by scientific experiment?
A) War is morally justified.
B) Picasso was the best artist of his generation.
C) A supernatural being created the world.
D) The stars at your birth predict your personality and health.
39) What discoveries or further ideas were most critical for Copernicus’ hypothesis that the
planets orbit the sun to be promoted to a theory?
A) observation of Venus’ phases
B) observation of sunspots
C) observation of the moons of Jupiter
D) both A and B
E) both A and C
40) He angered the Pope with his assertions that the Earth moved around the Sun.
A) Galileo
B) Copernicus
C) Kepler
D) Tycho
41) What led Kepler to discover that planetary orbits are ellipses?
A) Tycho’s calculations that the distance between the Earth and Sun changes yearly
B) his recalculation of the eccentric orbit of a comet
C) his inability to compute a circular orbit for Mars
D) He read the ancient writings of Aristarchus, who had hinted at this possibility.
3.2 True/False Questions
1) The names of the seven days of the week are derived from the names of the members of the
solar system that are visible to the naked eye.
2) The Polynesian navigators of the South Pacific found their way primarily by observing the
position of Polaris in the night sky.
3) The Ptolemaic model of the solar system was useless for predicting planetary positions.
4) Copernicus was the first person to suggest a Sun-centered solar system.
5) Copernicus’s model of the solar system gave much better predictions than the model of
Ptolemy.
6) The “margin of error” specifies the inaccuracy of a measurement.
7) Galileo found “imperfections” on the Sun in the form of sunspots and “imperfections” on the
Moon in the form of mountains and valleys.
8) “Observational bias” is the term for tendency of an observer to see what (s)he wants to see, as
opposed to what is actually there.
9) Scientific thinking developed only in the past few decades.
10) Scientific theories can never be proved true beyond all doubt.
11) A scientific model must make observational predictions.
12) Astronomy and astrology were often practiced together in ancient cultures, and astrology
played an important role in the historical development of astronomy.
13) Science can say nothing about the validity of nonscientific practices that do not make
testable predictions.
14) Columbus was the first person to discover that Earth is round.
15) Tycho used his high accuracy observations to conclude that the Earth revolves around the
sun.
16) Kepler developed his model of elliptical orbits because of an 8-arcminute discrepancy
between observations and a model of planetary motion with circular orbits.
17) Einstein’s General Theory of Relativity showed that Newton’s theory of gravity was
fundamentally wrong.
18) The science of astrology (studying effects of the planets on our lives) exists as an alternative
scientific methodology to astronomy.
19) Tycho failed to understand planetary motion because his data, taken before there were any
telescopes, was simply too inaccurate.
20) The Polynesians traversed thousands of miles of open ocean to settle new islands navigating
only by the stars.
3.3 Process of Science Questions
1) The Scientific Method: The pseudoscience astrology predicts that your personality is based on
the date of your birth. Consider this hypothesis: your personality might in fact correlate to your
birth date for scientific reasons. Babies born in a northern winter, in their early months of
outdoor exposure, will experience a slow seasonal thaw and the general warming of their
environment. As their world became warmer and more hospitable, they might develop optimistic
personalities. Summer-born children might develop pessimistic personalities while encountering
the unexpected harshness of winter in their first months.
If you wanted to test this hypothesis, how would you do it? (Recall that the seasons are reversed
in the North and South latitudes).
2) An end to science? Will there ever be an “end to science?” While we can be fairly sure that
new art and literature will be created so long as humanity persists, do you think scientific
research, at some point, will settle into some final, absolute truths about the physics of nature?
We might understand the reason for art to continue to flourish is the limitlessness of human
imagination. But, is there an equivalent limitless depth to the physics of the natural world? Is
there an out-of-reach understanding we can never attain, or will there come a day when a
complete set of theories will be confirmed that correctly and fully describe the natural world?
3) The flow of science: Consider two different approaches, each utilizing the scientific method:
(1) using new instruments to carefully observe the patterns in nature (as Galileo did when he
pointed his telescope at the sky) and then making hypotheses to explain the new things seen, or
(2) identifying two or more competing hypotheses (e.g., a round Earth vs. a flat Earth) and
designing focused experiments that collect data to deduce which hypothesis is correct by finding
one that has predictive ability.
Which type of scientific approach do you think it is better for our nation to invest our resources
toward?
4) Observational tests: Observations are the ultimate test of physical models and their
predictions. Both Tycho Brahe and Galileo Galilei made decisive observations that helped
distinguish between the geocentric and heliocentric models for the solar system. Compare and
contrast the types of observations that Tycho and Galileo gathered. Which do you think were
more persuasive?
5) An historical science: Scientists in many fields can test their hypotheses by proposing and
carrying out experiments in which they can change variables in a controlled fashion.
Astronomers, however, cannot adjust the properties of the objects they study. In what sense,
then, can astronomers still conduct experiments?
6) The practice of science: In what ways does the modern practice of science establish positive
feedback to encourage further discoveries? Can you identify elements within the historical
accounts of Copernicus, Tycho, Kepler, and Galileo that provide an example of positive
feedback? Currently, papers reporting discoveries are reviewed by peers in the field who stay
anonymous. Do you think this is fair?
1) How did ancient peoples of central Africa predict the weather?
2) Why was a knowledge of the stars so important to Polynesians?
3) Describe how Eratosthenes first measured the size of Earth over 2000 years ago.
4) Describe the Ptolemaic model of the solar system. How did Ptolemy account for the apparent
retrograde motion of the planets?
5) Describe one major accomplishment for each of the following people: Copernicus, Tycho
Brahe, Kepler, and Galileo.
6) State Kepler’s three laws of planetary motion.
7) You are using a piece of string and two tacks to draw ellipses on a piece of paper. How can
you draw two ellipses with the same semi-major axes but different eccentricities?
8) Describe what a scientific test of astrology would involve.
9) Suppose that an ancient civilization had built a stone structure 6000 years ago to point towards
a bright star as it rose. Would that structure still point at that star today? If not, why not, and
what information would archaeoastronomers need to figure out which star the structure pointed
at?
10) What reasons can you think of as for why astrology might not be a useful predictor of future
events?
11) What ancient beliefs did Galileo debunk?
12) Name some practical benefits of astronomy in the history of civilization.
13) Why did the incorrect geocentric model of the universe persist for nearly 2000 years?
3.5 Mastering Astronomy Reading Quiz
1) Why did the Greeks conclude that the Earth was stationary, and that the Sun and the planets
orbited around the Earth?
A) They did not understand the concept of stellar parallax.
B) They felt that the Sun was really the god Apollo.
C) They knew that everything in the heavens had to be a perfect circle.
D) They did not observe any change in the separation of stars during Earth’s orbit.
2) Scientific thinking is ________.
A) based on everyday ideas of observation and trial-and-error experiments
B) completely different from any other type of thinking
C) a difficult process that only a handful of people can do well
D) an ancient mode of thinking first invented in Egypt
3) The names of the seven days of the week are based on ________.
A) the names of the seven planets closest to the Sun
B) the seven most prominent constellations in the summer sky
C) the names of prophets in the Bible
D) the seven naked-eye objects that appear to move among the constellations
4) The Metonic cycle is
A) used to keep lunar calendars approximately synchronized with solar calendars.
B) used to predict the future orientation of the Earth’s axis in space.
C) the ancient Greek name for the cycle of lunar phases that repeats every 29-1/2 days.
D) the 18-year, 11-day period over which the pattern of eclipses repeats.
5) Ptolemy was important in the history of astronomy because he ________.
A) developed a model of the solar system that made sufficiently accurate predictions of planetary
positions to remain in use for many centuries
B) developed the first scientific model of the universe
C) was the first to create a model of the solar system that placed the Sun rather than the Earth at
the center
D) was the first to believe that all orbits are perfect circles
6) The ancient Greeks get a lot of attention for their contributions to science because ________.
A) they were the first people known to try to explain nature with models based on reason and
mathematics, without resort to the supernatural
B) the books of every other culture were lost in the destruction of the library of Alexandria
C) they were the first people to realize that Earth is a planet orbiting the Sun
D) they were the only ancient culture that kept written records of their astronomical observations
7) Why do we distinguish the Greeks from earlier civilizations?
A) They were the first to offer natural explanations for what they observed.
B) They were the first to record observations.
C) They were the first to make predictions based on observations.
D) They wrote books in the form of scrolls.
8) He realized that Tycho’s data, with 1 arcminute uncertainties, could not fit the predictions of
circular orbits, which missed the actual star positions by 8 arcminutes. So his model was the first
to consider elliptical orbits.
A) Galileo
B) Newton
C) Copernicus
D) Kepler
9) The great contribution of Nicholas Copernicus was to ________.
A) create a detailed model of our solar system with the Sun rather than Earth at the center
B) prove that the Earth is not the center of the universe
C) discover the laws of planetary motion
D) discover the law of gravity
10) The great contribution of Tycho Brahe was to ________.
A) observe planetary positions with sufficient accuracy so that Kepler could later use the data to
discover the laws of planetary motion
B) discover four moons orbiting Jupiter, thereby lending strong support to the idea that the Earth
is not the center of the universe
C) offer the first detailed model of a Sun-centered solar system, thereby beginning the process of
overturning the Earth-centered model of the Greeks
D) discover that planets orbit the Sun in elliptical orbits with varying speed
11) Which of the following was not observed by Galileo?
A) stellar parallax
B) mountains and valleys on the Moon
C) four moons orbiting Jupiter
D) phases of Venus
12) Which of the following statements about an ellipse is not true?
A) The focus of an ellipse is always located precisely at the center of the ellipse.
B) A circle is considered to be a special type of ellipse.
C) The semimajor axis of an ellipse is half the length of the longest line that you can draw across
an ellipse.
D) An ellipse with a large eccentricity looks much more elongated (stretched out) than an ellipse
with a small eccentricity.
13) Which of the following is not one of, nor a direct consequence of, Kepler’s Laws?
A) The force of attraction between any two objects decreases with the square of the distance
between their centers.
B) As a planet moves around its orbit, it sweeps out equal areas in equal times.
C) The orbit of each planet about the Sun is an ellipse with the Sun at one focus.
D) More distant planets orbit the Sun at slower speeds.
14) Scientific models are used to ________.
A) present the scale of the solar system to the general public
B) make specific predictions that can be tested through observations or experiments
C) make miniature representations of the universe
D) prove that past paradigms no longer hold true
15) In science, a broad idea that has been repeatedly verified so as to give scientists great
confidence that it represents reality is called ________.
A) a paradigm
B) a hypothesis
C) a Ptolemaic model
D) a theory
16) Kepler’s Third Law relates a planet’s orbital period (p) and its average distance (a) from the
Sun (p2 = a3). If a planet were discovered with an average distance from the Sun of 100 AU, its
period would be
A) 10,000 years.
B) 1000 years.
C) Not enough information to say.
D) 1 million years.
17) Consider the elliptical orbit of a comet around the Sun. Where in its orbit is the comet
moving the fastest?
A) It is always moving at the same speed.
B) When it is farthest from the Sun.
C) When it is closest to the Sun.
18) Toddlers learn by
A) following instruction designed for their level of development.
B) testing hypotheses, just like scientists.
C) slowly tapping into their innate knowledge, which is present from birth.
D) following the example of adults.
19) The root of modern science began with
A) ancient man’s ascription of natural causes to physical events.
B) the accumulation of written records (scrolls) kept for scholars in libraries.
C) the blossoming of a period of open thinking during the Renaissance in Europe.
D) the Copernican Revolution, placing the Sun at the center of the solar system.
20) When the perhaps hundreds of thousands of scrolls of the ancient scholars were lost in the
burning of the Ancient Library of Alexandria, Egypt, some translated copies were preserved by
the scholars of
A) the Vatican, in Rome, Italy.
B) Athens, in Greece.
C) Taxila, in India.
D) Baghdad, in Iraq.
21) What ancient evidence was found for a spherical Earth?
A) the different angles of equinox shadows measured at cities in Egypt by Eratosthenes
B) the curved shape of Earth’s lunar eclipse shadow
C) the subtle curvature of the horizon sighted by the Greek astronomer, Metaxa
D) A and B
E) A, B and C
22) From Kepler’s Second Law: Planetary orbits, when drawn with a line connecting the planet
to the Sun, show that this line sweeps out equal areas in equal times, no matter where the planet
is in its orbit, we may conclude that
A) planets move slower when they are closer to the Sun.
B) planets move faster when they are closer to the Sun.
C) planets have circular orbits.
D) planets have elliptical orbits.
3.6 Mastering Astronomy Concept Quiz
1) Galileo refuted the idea that
A) objects require an external force to keep moving.
B) the Sun orbits Venus.
C) heavenly bodies are perfect.
D) all of the above
2) How does a 12-month lunar calendar differ from our 12-month solar calendar?
A) It has about 11 fewer days.
B) It does not have seasons.
C) Its new year always occurs in February instead of on January 1.
D) It uses a 23-hour rather than a 24-hour day.
3) Eratosthenes measured the circumference of Earth to within 4% of the correct value
A) using the detailed reports of far-sailing mariners.
B) looking at stick shadows on the equinox.
C) sighting the stars from within the deepest well in Egypt on the day of the solstice.
D) noting how much more of the celestial sphere came into view when walking south.
4) Failing to predict this planet’s orbit so frustrated Kepler that it led him to consider an ellipse,
rather than a circle, as the shape of a planet’s orbit.
A) Venus
B) Mars
C) Jupiter
D) Saturn
5) When Copernicus first created his Sun-centered model of the universe, it did not lead to
substantially better predictions of planetary positions than the Ptolemaic model. Why not?
A) Copernicus used perfect circles for the orbits of the planets.
B) Copernicus placed the planets in the wrong order going outward from the Sun.
C) Copernicus misjudged the distances between the planets.
D) Copernicus placed the Sun at the center, but did not realize that the Moon orbits the Earth.
6) Earth is farthest from the Sun in July and closest to the Sun in January. During which
Northern Hemisphere season is Earth moving fastest in its orbit?
A) spring
B) summer
C) fall
D) winter
7) Which planet hosts the Galilean moons?
A) Venus
B) Mars
C) Jupiter
D) Saturn
8) All the following statements are true. Which one follows directly from Kepler’s third law
?
A) Venus orbits the Sun at a slower average speed than Mercury.
B) Venus is more massive than Mercury.
C) Venus takes longer to rotate than it does to orbit the Sun.
D) Venus has a thicker atmosphere than Mercury.
9) Suppose a comet orbits the Sun on a highly eccentric orbit with an average (semimajor axis)
distance of 1 AU. How long does it take to complete each orbit, and how do we know?
A) Each orbit takes about 1 year, which we know from Kepler’s third law.
B) It depends on the eccentricity of the orbit, as described by Kepler’s second law.
C) It depends on the eccentricity of the orbit, as described by Kepler’s first law.
D) Each orbit should take about 2 years, because the eccentricity is so large.
10) Galileo challenged the idea that objects in the heavens were perfect by ________.
A) showing that heavy objects fall at the same rate as lighter objects
B) observing sunspots on the Sun and mountains on the Moon
C) proving Kepler’s laws were correct
D) inventing the telescope
11) Which is an essential quality of an accepted scientific result?
A) mathematical elegance
B) agreement with previous models
C) testability
D) support by many scientists
12) Which of the following is not consistent with the major hallmarks of science?
A) Science consists of proven theories that are understood to be true explanations of reality.
B) Scientific explanations should be based solely on natural causes.
C) Science progresses through the creation and testing of models that explain observation as
simply as possible.
D) A scientific model must make testable predictions.
13) The use of epicycles to explain planetary motion
A) was a triumph of the Ptolemaic system. It explains retrograde motion and is still in use today.
B) demonstrates how non-intuitive the laws governing planetary motion truly are.
C) was a causality of Occam’s razor.
D) proved the Sun-centered model of the solar system to be correct.
14) Only one of the statements below uses the term theory in its correct, scientific sense. Which
one?
A) Einstein’s theory of relativity has been tested and verified thousands of times.
B) Evolution is only a theory, so there’s no reason to think it really happened.
C) I have a new theory about the cause of earthquakes, and I plan to start testing it soon.
D) I wrote a theory that is 152 pages long.