Deck 2: Gravitation and the Motion of the Planets

Question 1

The groundwork for modern science was laid by the first investigators who used mathematics to describe natural phenomena. These were

A) the Babylonians, about 1800 B.C.
B) the Ionians, about 600 B.C.
C) the Pythagoreans, about 550 B.C.
D) Ptolemy and his associates, about 150 A.D.

Answer 1

the Pythagoreans, about 550 B.C.

Question 2

Which one of these is NOT part of the scientific method?

A) propose a new experiment
B) take a formal vote at a recognized international scientific conference
C) modify existing theory
D) make predictions

Answer 2

take a formal vote at a recognized international scientific conference

Question 3

A major theme of ancient Greek philosophy was that stars and planets in the sky

A) followed patterns that could be described logically.
B) could be controlled by the thoughts and actions of humans.
C) were at the mercy of gods and spirits, and the behavior of these objects depended on their whims.
D) behaved chaotically, and their future behavior was totally unpredictable.

Answer 3

followed patterns that could be described logically.

Question 4

Which one of these is NOT part of the scientific method?

A) make an observation or do an experiment
B) analyze results
C) determine consistence with recognized authorities
D) choose the simplest existing theory

Question 5

As far as is known, the first person who claimed that natural phenomena could be described by mathematics was

A) Copernicus.
B) Pythagoras.
C) Aristotle.
D) Ptolemy.

Question 6

According to the scientific method, a hypothesis that is proposed to explain a particular physical phenomenon is considered to be wrong if

A) leading scientists in the world believe that it is wrong.
B) it disagrees with the accepted theory at the time of the proposal.
C) it appears to defy logic and logical reasoning.
D) it is in conflict with the results of just one reliable and repeatable observation.

Question 7

Which of these is a critical component of the scientific method?

A) belief that a theory accepted by leading scientists is correct
B) rejection of new scientific results when they disagree with the presently accepted theory
C) automatic rejection of a theory when new results disagree with its predictions
D) testing of predictions from a scientific theory or theoretical model

Question 8

In science, if new and reliable observations disagree with a particular theory, then the

A) observations must be discarded.
B) theory must be modified.
C) the observations and the theory should both be retained.
D) theory must be discarded.

Question 9

What distinguished the Pythagoreans from the natural philosophy of the investigators who came before them?

A) They uncovered the scientific writings of the Babylonians.
B) They invented a crude telescope.
C) They attempted to make mathematical models of physical phenomena.
D) Through trade routes, they had been exposed to the philosophy of the ancient orient.

Question 10

In following the principles of the scientific method, a theory proposed to explain a given phenomenon must

A) agree with and build on previous theories but need not explain all observations because some of the observations may be erroneous.
B) predict new and different experiments that will extend the scope of the theoretical understanding but need not explain all the previous observations because no theory is expected to explain everything completely.
C) explain all previous reliable observations in a consistent manner but need not suggest new tests for the theory because a theory should be complete in itself.
D) explain all known reliable observations and predict new experiments and observations.

Question 11

The intellectual foundation of science is

A) observation, faith, and acceptance.
B) rejection of all observations that disagree with theory.
C) logical derivation entirely from fundamental principles.
D) observation, logic, and skepticism.

Question 12

In applying the scientific method to the study of natural surroundings, scientists are

A) discovering by observation the absolute truth about limited areas of science and are therefore slowly building up the correct view of the universe.
B) slowly amassing a vast bank of observations of nature that at some time in the future will be assembled into the correct description of the universe.
C) formulating hypotheses or models that describe the present observations of nature and that predict possible further tests for these models.
D) developing a theoretical view of the universe that incorporates all previous ideas and beliefs as part of an overall philosophy.

Question 13

In science, if new and reliable observations disagree with a well-established theory, then the

A) observations should be classified for future reference and the theory retained as the best explanation of the phenomenon.
B) observations must be discarded.
C) theory must be discarded.
D) theory must be modified to account for the observations, and if this is not possible, then the theory must be discarded.

Question 14

The scientific method is a major force in science, and theories describing physical phenomena have been developed with the aim of ensuring that

A) they agree with what we find in experiments and observations.
B) results from experiments can be adjusted to agree with carefully constructed theoretical ideals.
C) they agree with the wisdom of the ancients.
D) they are so good and our faith in them is so strong that we never need to test them against observations.

Question 15

A vital part of a scientific hypothesis is that

A) it is possible, in principle, to disprove it by observation.
B) it is possible, in principle, to disprove it by logical argument.
C) it must be mathematically simple.
D) it must be mathematically complex.

Question 16

The ancient Greek thinker Pythagoras held the view that

A) triangles do not exist.
B) natural phenomena are wonderful to watch but cannot be described by mathematics.
C) the Sun is at the center of the planetary system.
D) natural phenomena can be described mathematically.

Question 17

The first person to realize that the force holding us onto Earth is the same force that holds the solar system together was apparently

A) Plato.
B) Aristotle.
C) Newton.
D) Einstein.

Question 18

A scientific theory is accepted as the best description of a certain phenomenon if it

A) can be independently and repeatedly checked by observation.
B) has been developed by a scientist with a solid reputation, such as Albert Einstein or Sir Isaac Newton.
C) has obtained the stamp of approval of an internationally renowned scientific body, such as the Royal Society of London or the International Astronomical Union.
D) accounts for a full range of historical observations, even though recent observations cast doubt on it.

Question 19

In ancient Greece, the philosopher Aristotle put forth the idea that

A) the universe is governed by regular laws.
B) the Sun is the center of the solar system.
C) Earth is only one of hundreds of planets scattered throughout the galaxy.
D) gravitation keeps the planets in their orbits.

Question 20

A scientist observes a new phenomenon that disagrees with his explanation or hypothesis. Following the scientific method, he should

A) discard the observation as erroneous.
B) modify his hypothesis.
C) wait until someone develops an adequate explanation before announcing his observation.
D) reject those observations that do not agree with the theory.

Question 21

The development of the scientific theory related to the Higgs boson was unusual in that

A) it began with observations made over a century ago.
B) it began with theoretical calculations rather than observations.
C) the observations that began the investigation completely disproved the currently accepted model, thus leaving the theorists with no structure to build on.
D) the original theory was an outgrowth of an entirely unrelated area of philosophy.

Question 22

The planets that were known before the telescope was invented were

A) Mercury, Venus, Mars, Jupiter, and Neptune.
B) Saturn, Venus, Mars, Mercury, and Jupiter.
C) Jupiter, Mercury, Mars, Uranus, and Venus.
D) Venus, Jupiter, Saturn, Mars, and Pluto.

Question 23

What is the name for a theory that describes the overall structure and evolution of the universe?

A) field theory
B) astrology
C) cosmology
D) astronomy

Question 24

When observing planetary motions from Earth, the phrase "retrograde motion" refers to the

A) apparent westward motion of the planet (and the Sun, the Moon, and stars) across the sky due to the rotation of Earth.
B) motion of the planet away from Earth during part of its orbit.
C) slow eastward motion of the planet from night to night compared to the background stars.
D) slow westward motion of the planet from night to night compared to the background stars.

Question 25

An apparent westward motion of a planet from night to night compared to the background stars (as viewed from Earth) is referred to as

A) retrograde motion.
B) precession.
C) rising (if in the east) or setting (if in the west).
D) direct motion.

Question 26

Planets move past the background stars as seen by someone on Earth. What is the normal direction of this motion?

A) east to west because of the rotation of Earth
B) east to west because of the motion of the planet along its orbit
C) west to east because of the motion of Earth along its orbit
D) west to east because of the motion of the planet along its orbit

Question 27

Which of these statements MOST closely expresses the principle of "Occam's razor" as it applies to theoretical explanations of physical phenomena?

A) The theory with the longest history is the most likely explanation.
B) The theory requiring the least number of unproven assumptions is the most likely explanation.
C) The newest theory is most likely to be the correct one.
D) The theory requiring the largest number of assumptions is the most likely explanation.

Question 28

The discovery of gravitational radiation is an unusual example of the scientific method because

A) it began with observations made over a century ago.
B) it began with theoretical calculations rather than observations.
C) the observations that began the investigation completely disproved the currently accepted model, thus leaving the theorists with no structure to build on.
D) the original theory was an outgrowth of an entirely unrelated area of philosophy.

Question 29

The concept called "Occam's razor" states that:

A) the theory that is applicable to the greatest range of phenomena is more likely to be correct.
B) when two theories describe the same phenomena equally accurately, the theory with the greater complexity is more likely to be correct.
C) when two theories describe the same phenomena equally accurately, the simpler theory is more likely to be correct.
D) the theory that describes phenomena more accurately is more likely to be correct.

Question 30

The term "retrograde motion" for a planet refers to the

A) temporary reversal of the planet's normal east-to-west motion past the background stars as seen from Earth.
B) apparent motion of a planet's moon in the opposite direction to the motion of the planet itself during half of each orbit of the moon around the planet.
C) temporary reversal of a planet's direction of spin about its axis of rotation.
D) temporary reversal of the planet's normal west-to-east motion past the background stars as seen from Earth.

Question 31

In the ancient Greek era, it was almost universally believed that the

A) pole star represented the center of the universe about which Earth and all other objects revolved.
B) Milky Way represented the observable universe, and its center was the center of the universe.
C) Sun was at the center of the universe.
D) Earth was at the center of the universe.

Question 32

When observing planetary motions from Earth, the phrase "direct motion" refers to the

A) slow westward motion of the planet from night to night compared to the background stars.
B) apparent westward motion of the planet (and the Sun, the Moon, and stars) across the sky due to the rotation of Earth.
C) motion of the planet directly toward or away from Earth in certain parts of the planet's orbit.
D) slow eastward motion of the planet from night to night compared to the background stars.

Question 33

The center, or fixed point, of the Greek model of the universe was

A) the center of the galaxy.
B) a point midway between Earth and the Sun.
C) the Sun's center.
D) close to Earth's center.

Question 34

An apparent eastward motion of a planet from night to night compared to the background stars (as viewed from Earth) is referred to as

A) rising (if in the east) or setting (if in the west).
B) direct motion.
C) precession.
D) retrograde motion.

Question 35

Not counting Earth, the number of planets known to the ancients was

A) 4.
B) 5.
C) 7.
D) 8.

Question 36

What is the ultimate test for a scientific theory or idea?

A) A world body such as the United Nations must decree that the theory is correct.
B) The theory must be accepted by the vast majority of the population of Earth.
C) The theory must make predictions that are verifiable by observation or measurement.
D) The theory must be accepted by the vast majority of the scientific community.

Question 37

The word "planet" is derived from a Greek term meaning

A) bright nighttime object.
B) astrological sign.
C) wanderer.
D) nontwinkling star.

Question 38

The direction of retrograde motion for a planet as seen by an observer on Earth is

A) west to east relative to the background stars.
B) east to west relative to the background stars.
C) east to west relative to objects on the person's horizon.
D) west to east relative to objects on the person's horizon.

Question 39

The ancient Greek thinker whose model of the universe came to dominate the medieval world was

A) Archimedes.
B) Alexander.
C) Ptolemy.
D) Zorba.

Question 40

The motions of the planets against the background stars in the sky can BEST be described as

A) regular patterns with general eastward motion interrupted by periods of westward motion.
B) regular and uniform eastward motion.
C) general eastward motion but with occasional stationary periods with no motion at all.
D) regular patterns with general westward motion interrupted by periods of eastward motion.

Question 41

Ptolemy's model for the solar system was

A) Earth-centered, with the Sun, the Moon, and the planets moving in ellipses in the sky.
B) Sun-centered, with elliptical planetary orbits.
C) Sun-centered, with the planets moving in circles around it.
D) Earth-centered, with planetary orbits composed of deferents and epicycles.

Question 42

Which of these objects does NOT experience retrograde motion when viewed from Earth?

A) Mercury
B) Mars
C) the Moon
D) Jupiter

Question 43

Retrograde motion of a planet against the background stars is always

A) apparent motion of the planet away from Earth.
B) movement northward away from the ecliptic plane.
C) movement from west to east.
D) movement from east to west.

Question 44

Retrograde motion causes the planets to

A) rise in the west and set in the east.
B) move westward with respect to the stars.
C) move at the same rate as the stars.
D) move eastward with respect to the stars.

Question 45

Retrograde motion of a planet when viewed from Earth is caused by the fact that the

A) planet's orbit is inclined at an angle to Earth's orbit.
B) planet's orbit is elliptical.
C) Sun is moving.
D) Earth is moving.

Question 46

Observers on Earth see occasional retrograde motion in the motion of

A) only the inner planets: Mercury and Venus.
B) only the outer planets: Mars and beyond.
C) all the planets.
D) all the planets and the Moon.

Question 47

The epicycle, in the Greek planetary model, is the

A) circle centered on Earth about which the center of the smaller circular motion moves.
B) off-center point in the planetary system occupied by Earth.
C) focus of the ellipse that is the orbit of the planet around Earth.
D) small circle through which the planet moves as the center of this circle orbits Earth.

Question 48

Retrograde motion of a planet is

A) westward motion against the star background.
B) westward motion with respect to the foreground on Earth.
C) eastward motion with respect to the Moon.
D) eastward motion against the star background.

Question 49

Viewed from Earth, Mars is

A) always above the ecliptic.
B) always below the ecliptic.
C) sometimes above and sometimes below the ecliptic.
D) always on the ecliptic.

Question 50

When the planet Mars is moving in a retrograde direction, its motion against the background stars is seen to be

A) stationary, with no motion against the stars.
B) exactly perpendicular to the equator.
C) eastward.
D) westward.

Question 51

The Greek mathematician Ptolemy devised a

A) sundial.
B) geocentric model for the solar system.
C) heliocentric model for the solar system.
D) method to measure Earth's radius.

Question 52

If an observer were observing Earth's motion from another planet, would they observe occasional retrograde motion?

A) no
B) yes, but only from the inner planets: Mercury and Venus
C) yes, but only from the outer planets: Mars and beyond
D) yes, from any of the planets

Question 53

In the geocentric model of the solar system developed by Ptolemy, the planets move

A) with varying speeds in elliptical orbits around Earth.
B) at constant speeds in circular orbits around Earth.
C) in circular epicycles around the Sun, while the Sun moves in a circular orbit around Earth.
D) in circular epicycles, while the centers of the epicycles move in circular orbits around Earth.

Question 54

Which of these objects does NOT experience retrograde motion when viewed from Earth?

A) Mars
B) Venus
C) the Sun
D) Pluto

Question 55

In the path of Mars against the background stars shown in Figure 2-2, the planet appears from Earth to move in a loop, moving westward for a period of time. In the 2012 loop, what is the angle between the Earth-Sun line and Earth-Mars line when the planet is halfway through the retrograde motion, in late February?

A) 180°
B) It can be any angle.
C) 0°
D) 90°

Question 56

When viewed from Earth, the celestial sphere (the background of stars) moves east to west on a daily basis. This motion is caused by the

A) rotation of Earth on its axis.
B) revolution of Earth around the Sun.
C) motion of the Sun through the Galaxy.
D) motion of the stars around the galactic center.

Question 57

Ptolemy's nationality was

A) Polish.
B) Greek.
C) Italian.
D) Egyptian.

Question 58

A major contribution of Ptolemy to the development of astronomy was

A) origination of the idea of a geocentric (Earth-centered) cosmology, which was later developed by Aristarchus.
B) derivation of a model for the solar system in which the planets move around the Sun in circular orbits.
C) derivation of the model for the solar system in which the planets move around Earth in elliptical orbits, moving fastest when closest to Earth.
D) derivation of a model for the solar system in which the planets moved in epicycles and the epicycles orbited Earth.

Question 59

Ptolemy's system of the heavens put Earth at or near the center. The motivation for this choice was primarily

A) religious, placing mankind at the center of creation.
B) religious, relegating Earth to an inferior position outside the perfect celestial realm.
C) based on observations.
D) based on the mathematics of the Pythagoreans.

Question 60

Retrograde motion of a planet refers to which motion, when viewed from Earth?

A) setting of the planet in the west to any observer, caused by Earth rotation
B) eastward apparent motion with respect to the stars
C) southward motion of the planet as it moves away from the northern sky
D) westward apparent motion with respect to the stars

Question 61

Which one of these bodies would NOT exhibit retrograde motion if observed from Mercury?

A) Venus
B) Earth
C) the Sun
D) Mars

Question 62

In Ptolemy's geocentric theory of the solar system, what name is given to the large circle (orbit) that carries the planet around Earth?

A) deferent
B) celestial equator
C) ecliptic
D) epicycle

Question 63

Ptolemy's system of planetary motions, as described in the Almagest, was based on

A) magnetism.
B) gravitation.
C) electrical forces.
D) no underlying physical theory.

Question 64

If one were an astronomer in the closing days of the Roman Empire, say, around 400 A.D., his or her main reference book would have been

A) Ptolemy's Almagest.
B) Plato's Republic.
C) Aristotle's Metaphysics.
D) Galileo's Dialogue Concerning the Two Chief World Systems.

Question 65

The MOST serious flaw in the solar system model of Copernicus was

A) Earth was at the center of the system.
B) the orbits were circular rather than elliptical.
C) it failed to take precession into account.
D) it failed to take retrograde motion into account.

Question 66

The retrograde portion of a planet's motion has what duration?

A) a few days to a few weeks
B) a few weeks to a few months
C) a few days to a few months
D) a few weeks to a few years

Question 67

In Ptolemy's geocentric theory of the solar system, what name is given to the small circle around which the planet moves while the center of this circle orbits Earth?

A) epicycle
B) ecliptic
C) deferent
D) celestial equator

Question 68

Retrograde motion was a major source of difficulty in designing a theoretical model of the solar system. What is the explanation for retrograde motion?

A) The planets actually stop and reverse direction in their orbits.
B) The planets move not in uniform circular motion about the Sun but rather in circular orbits (epicycles) about points which themselves move about the Sun in circular orbits.
C) Retrograde motion is an apparent motion of other planets, which we observe only because we are viewing their motion from Earth, itself in motion around the Sun.
D) Retrograde motion is an apparent motion caused by the precession of Earth's rotation axis.

Question 69

Nicolaus Copernicus was the first person to

A) develop a comprehensive model for a Sun-centered solar system.
B) use a telescope to observe the sky at night.
C) use ellipses to describe the orbits of the planets.
D) describe planetary orbits using the force of gravity.

Question 70

In the geocentric universe, when is the planet closest to Earth?

A) There is no specific time in the orbit when the planet is closest to Earth.
B) during retrograde motion, westward
C) during direct motion, eastward
D) when the planet is crossing the deferent

Question 71

According to the Ptolemaic model of the solar system, during retrograde motion a planet would be

A) at varying distances from Earth, sometimes closer and sometimes farther away than the average distance.
B) farther away from Earth than average.
C) closer to Earth than average.
D) always at the same distance from Earth because the planet orbits Earth in a circle in this model.

Question 72

The Almagest, a collection of earlier data and description of calculations, was written by

A) Kepler.
B) Copernicus.
C) Erathosthenes.
D) Ptolemy.

Question 73

Before the invention of the telescope, the known planets were

A) Mercury, Venus, Mars, Jupiter, and Saturn.
B) Mercury, Venus, Mars, Jupiter, and Uranus.
C) Jupiter, Venus, Neptune, Mars, and Saturn.
D) Mars, Neptune, Jupiter, Mercury, and Venus.

Question 74

In the geocentric model for the solar system developed by Ptolemy, to what does the word "deferent" refer?

A) distance of the center of the epicycle from the center of Earth
B) small circle about which a planet moves while the center of the circle moves around Earth
C) distance of offset between the center of Earth and the center of a planet's orbit
D) large circle (orbit) that carries the planet around Earth while the planet itself is moving in a smaller circle

Question 75

The initial reason that the geocentric model for the solar system began to be discarded after the fifteenth century A.D. was that

A) observations by spacecraft proved that all planets orbit the Sun.
B) the invention of the telescope provided observations that were in better agreement with a heliocentric model.
C) Isaac Newton was able to derive all planetary motion from one universal law of gravity.
D) the heliocentric model is conceptually simpler.

Question 76

The purpose of describing planetary orbits in terms of epicycles and deferents was to account for the

A) fact that a planet's speed in its orbit is fastest when it is closest to the Sun.
B) pattern of alternating conjunctions and oppositions.
C) pattern of alternating direct and retrograde motion.
D) general motion of all objects toward the west in the sky each day.

Question 77

The Almagest is a(n)

A) detailed multivolume account of a heliocentric cosmology produced by ancient Greek astronomers.
B) collection of ancient data and predictions of positions of the Sun, the Moon, and the planets, compiled by Ptolemy.
C) Renaissance book describing in detail the development of a heliocentric universe, with elliptical orbits, the law of equal areas, and the harmonic law.
D) ancient book describing the construction of Stonehenge.

Question 78

In the geocentric model for the solar system developed by Ptolemy, to what does the word "epicycle" refer?

A) small circle about which a planet moves while the center of this circle moves around Earth
B) large circle (orbit) that carries the planet around Earth while the planet itself is moving in a smaller circle
C) complete cycle of planetary motions after which the motions repeat themselves (almost) exactly
D) length of time from when the planet is farthest from Earth to the next time it is farthest from Earth

Question 79

In Ptolemy's description of the solar system, the deferent is a(n)

A) elliptical path along which a planet moves around the Sun.
B) circular path (around the Sun) along which the center of a planet's epicycle moves.
C) circular path (around Earth) along which the center of a planet's epicycle moves.
D) circular path along which a planet moves while the center of the path moves in a circle around Earth.

Question 80

In the Greek planetary model, the deferent is the

A) part of the planet's orbit when it appears to move "backward" (i.e., westward) in the sky.
B) off-center point in the planetary system occupied by Earth.
C) small circle about which the planet moves as the center of the circle orbits Earth.
D) circle about which each planet's epicycle center moves.