Stars and Galaxies 9th Edition by Seeds - Test Bank

Stars and Galaxies 9th Edition by Seeds – Test Bank

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Chapter_05_Gravity
1 Newton’s first law of motion is essentially a restatement of Galileo’s law of
inertia.
True
False
2 Aristotle believed that objects falling to the ground fall at a constant rate of
speed.
True
False
3 Galileo believed that motion stops in the absence of a force.
True
False
4 Newtonian gravity is often called universal mutual gravitation because
every particle with mass in the Universe must attract every other particle.
True
False
5 Changing the direction of a moving body does not impact its velocity.
True
False
6 The escape velocity at a given distance from a planet is less than the
circular velocity of an orbit around that planet at the same distance.
True
False
7 The Moon pulls more strongly on Earth’s near and far side than on its
center.
True
False
8 The apparent positions of stars around the sun during an eclipse have been
used to prove the general theory of relativity.
True
False
9 The neap tides occur at the new moon and full moon.
True
False
10 Spring tides occur during the new and full lunar phases.
True
False
11 Two objects in orbit around each other orbit their common center of mass.
True
False
12 Newton’s third law states that forces occur in pairs acting in the same
direction.
True
False
13 If an object’s velocity equals or exceeds the escape velocity, it will follow a
closed parabolic or hyperbolic orbit.
True
False
14 The second postulate of special relativity states that the speed of light,
when measured in a vacuum, is constant for all observers.
True
False
15 Special relativity states the relationship between energy and mass as
.
True
False
16 According to Aristotle, an object with no forces acting on it will ____.
move faster and faster
eventually stop moving
move at a constant speed forever
first increase and then decrease in speed
first decrease and then increase in speed
17 In contradiction to the teachings of Aristotle, Galileo found that an object
with no forces (and no friction) acting on it will ____.
move faster and faster
eventually stop moving
move at a constant speed forever
first increase and then decrease in speed
first decrease and then increase in speed
18 According to Galileo, the acceleration of a freely falling object due to
gravity is ____.
larger if the object is dropped from a greater height
smaller if the object is dropped from a greater
height
larger if the mass of the object is larger
smaller if the mass of the object is larger
the same regardless of the mass and the height
from which it is dropped
19 According to Aristotle, which scenario illustrates violent motion?
An apple falling from a tree
A mass of warm air rising above hot pavement
An arrow moving through the air after leaving the
bow
A person pushing a car along the street
A barrel rolling down a ramp
20 Galileo determined that ____.
heavy objects accelerate at a slower speed than
lighter objects
lighter objects accelerate at a slower speed than
heavier objects
an object’s acceleration is due to the height from
which it is dropped
all objects fall at a constant speed
all objects fall at a constant acceleration
21 Mutual gravitation is ____.
a type of force that acts on an object moving at
constant speed
the acceleration of an object in the absence of a
force
a property of all matter in the universe
the limit of gravitational force from one object to
another
a type of force that repels surrounding particles
22 Newton concluded that some force must act on the Moon because ____.
a force is needed to pull the Moon away from
straight line motion
a force is needed to pull the Moon outward
a force is needed to keep the Moon in motion
the Moon has at a constant velocity
the Moon has a constant acceleration
23 When two objects of unequal mass orbit each other, the center of mass is
____.
at the center of the more massive object
at the center of the least massive object
half way between the centers of each object
always closer to the less massive of the two objects
always closer to the more massive of the two
objects
24 The ____ of an object is a measure of the amount of matter it contains. The
____ is a measure of the gravitational force on an object.
weight; mass
mass; weight
energy; force
force; energy
momentum; energy
25 Gravity obeys the inverse square law, which implies that the gravitational
force of one body on another will be ____ times stronger at two meters than
at six meters apart.
2
3
4
9
10
26 Perigee is the point in ____.
the Moon’s orbit when the Moon is farthest from
Earth
an object’s orbit around Earth when the object is
closest to Earth
an object’s orbit around Earth when the object is
closest to the Sun
a planet’s orbit when the planet is closest to its sun
a planet’s orbit when the planet is farthest from its
sun
27 A comet near the Sun whose orbit is ____ would never be near the Sun
again.
apogee
circular
elliptical
hyperbolic
radial
Incentives are costs and benefits that induce changes
in human behavior. When aligned with the social
interest, incentives can be powerful forces for good but
misaligned incentives can be equally powerful forces for
bad. One of the goals of economics is to understand
which institutions generate good incentives. Getting the
incentives right is an important goal of managers who
want to motivate employees, stockholders who want to
motivate managers, parents who want to motivate
children, and consumers who want to motivate real
estate agents, physicians, or lawyers, among many
others.
28 Newtonian physics tells us that Kepler’s second law is a result of the
conservation of ____.
angular momentum
linear acceleration
energy
mass
velocity
If public schools are paid for higher test scores, they
will get higher test scores. But test scores are an
imperfect measure of the purposes of the pay, which
are more productive teachers and more knowledgeable
students. Similarly, what corporations pay for is higher
stock prices, but what they really want is a more
profitable firm.
29 A(n) ____ orbit is one where the orbiting object is always above the same
location on Earth’s surface.
closed
elliptical
geosynchronous
hyperbolic
parabolic
It means that sometimes an incentive scheme, if badly
designed, will cause the agents involved in the scheme
to engineer their activities to appear to yield good
results, even if those results are not actually true.
30 Tides occur at ____.
first quarter moon and third quarter moon
new moon and first quarter moon
new moon and third quarter moon
new moon and full moon
third quarter moon and full moon
Advertisements in different countries have to be
translated into the local language. Hurriedly translating
the advertisements into local languages may cause
some incorrect translations. For example, look up the
famous international blunders made by Pepsi and KFC
when translating their slogans into Chinese. Thus a
pitfall of this incentive scheme is that advertising
managers will seek to maximize output without enough
regard for quality.
31
The circular velocity of a satellite orbiting Earth is given by .
In this equation, M represents the ____.
mass of the satellite, and r its radius
mass of the satellite, and r the distance from Earth
to the satellite
mass of the satellite, and r the distance from Earth’s
surface to the satellite
mass of Earth, and r the radius of Earth
mass of Earth, and r the distance from Earth to the
satellite
HSV assume that cutting quality is the way to cut cost.
But sometimes higher quality is also a path to lower
costs. When quality and cost cutting go together, a
private firm has a strong incentive to increase quality.
Though weak incentives reduce the incentive for public
prisons to cut costs, they don’t increase the incentive to
produce high quality.
32 The apogee of a(n) ____ orbit does not exist.
closed
elliptical
geosynchronous
hyperbolic
parabolic
A piece rate system attracts more productive workers
because piece rates give productive workers a chance
to earn more money. The hourly wage plan will attract
workers who are relatively less productive. When some
workers are more productive than other workers, piece
rates will tend to increase inequality in earnings.
33 The radius of Earth is 6,378 km. The force of gravity on a 1 kg ball at
Earth’s surface is 9.8 kg m/s2. What is the force of gravity on this same
ball when the ball is located 12,756 km from Earth’s center? Hint: G = 6.67
10 11 m3/s2/kg
2.45 kg m/s2
4.9 kg m/s2
9.8 kg m/s2
19.6 kg m/s2
39.2 kg m/s2
Piece rate systems reward worker effort directly by
compensating the worker for the number of pieces of
output produced. This payment system gives an
incentive for productive workers to increase their effort
and produce more output for the firm. Firms that offer
piece rates will attract more productive workers than
those firms offering hourly wage rates. Piece rates may
cause workers to overemphasize the quantity of output
at the expense of quality, since more output means
more pay. Firms may need to monitor or set standards
for quality. Another problem is that workers may fear
the ratchet effect: a situation in which the firm reduces
the piece rate, thereby causing the worker to produce
even more output to maintain the same level of pay.
Piece rates are difficult to implement in team
production settings, since it is hard to determine any
one worker’s contribution to output.
34 If the orbital velocity of the Moon is 1.0 km/s, what is the orbital velocity of
a satellite that is 1/16th as far from Earth as the Moon?
Hints: There is a long way and a short way to do this calculation.
; G = 6.67 10 11 m3/s2/kg
1/16 km/s
1/8 km/s
4 km/s
8 km/s
16 km/s
By tying output quality to their incomes, and
compensating them relative to the profit outcome for
the firm. If workers earn more when the firm is more
profitable, they have an incentive to better their own
company.
35 What is the escape velocity from the Moon for a lunar landing module
sitting on the Moon’s surface?
Hints: ;
The mass of the Moon is 7.2 × 1022 kg; its radius is 1738 km; G = 6.67 10
11 m3/s2/kg
2.3 m/s
23 m/s
2.3 km/s
11 km/s
23 km/s
By asking the borrowers to self select themselves into
groups of five. The women thus have an incentive to
select only those who they know are reliable and apt to
pay back the loans, since the loans are given in
sequential order in the groups.
36 What is the circular velocity of an object orbiting Earth at a distance of
100,000 km from Earth’s center?
Hint: ; G = 6.67 10 11 m3/s2/kg
0.2 m/s
2 m/s
20 m/s
200 m/s
2,000 m/s
When CEOs are paid in stock options that become more
profitable to exercise when stock prices rise
significantly.
37 Spring tides occur at ____.
new moon and first quarter moon
new moon and full moon
first quarter moon and third quarter moon
first quarter moon and full moon
third quarter moon and full moon
A tournament is a compensation scheme in which pay
is based on relative performance. When they are used
effectively, tournaments can tie rewards more closely
to actions that an agent controls, thereby improving
productivity and pay.
[Answers here will vary; this example is from the text.]
Imagine a golf game in which players are paid based on
the total number of strokes to finish the course (by the
nature of golf, fewer strokes mean better play and thus
higher payments). If the weather is bad, scores will be
high and agents won’t earn very much even if they
work hard. If the weather is good (clear day, no wind)
scores will be low and agents will earn a lot even if they
don’t work very hard. Either way, when players are
paid based on their absolute scores, random forces—
such as the weather—will influence how much the
players earn. By ranking the golfers relative to each
other, the external random forces do not matter, since
all golfers are affected by the random factors.
38 The equivalence principle can be best illustrated by ____.
a person riding in an elevator
a rocket coasting through space at a constant
velocity
the change in mass of a moving body
the formation of energy by nuclear fusion
a car ride on a highway with the windows open
Tournament theory could be used to improve CEO
performance. The winner of a tournament is based on
relative performance, not absolute performance. For
example, if CEOs are paid according to stock prices
there are a number of things besides CEO ability that
can cause stock prices to rise and fall. If tournaments
were used it would require CEOs performance to be
evaluated on the basis of relative achievement rather
than something that may not be under their control.
39 According to the theory of general relativity, gravity is caused by the ____.
linear motion of stars
change in mass of a moving body
curvature of space time
constant speed of light
inertia of a moving body
Intrinsic motivation has to do with morale boosting and
status, while extrinsic motivation involves primarily
monetary rewards.
40 One of the first tests of the general theory of relativity was the ____.
description of the orbit of the moon
determination of the speed of light as a constant
change in mass of a particle moving at a high speed
demonstration of a hammer and a feather falling at
the same rate on the moon
determination of the rate of advance of the
perihelion of Mercury’s orbit
The system of values and norms that people use to
interact with each other within an organization or firm.
41 The second postulate of special relativity states that ____.
observers cannot detect their uniform motion except
relative to other objects
observers cannot distinguish locally between inertial
forces and uniform gravitational forces due to
acceleration and the presence of a massive body
the laws of physics are the same for all observers
regardless of their motion as long as their speed is
constant
the speed of light is constant and will be the same
for all observers independent of their motion relative to
the light source
the acceleration of an object is proportional to the
applied force and inversely proportional to its mass
You get what you pay for, but what you pay for is not
always what you get. Tie pay to performance to reduce
risk. Money is not everything.
42 Special relativity predicts that the observed mass of a moving particle
depends on its ____.
inertia
curvature
velocity
force
true position
a. Money isn’t everything.
b. You get what you pay for.
c. Tie pay to performance to reduce risk.
43 According to the inverse square law, the force due to gravity between two
masses will ____.
increase as the distance between the two masses
increases
decrease as the square of the distance between the
two masses increases
cause the two masses to move away from each
other
cause the two masses to move in a straight line
cause the two masses to orbit each other
44 Newton’s law of gravitational force states that ____.
an object with no force on acting on it continues at
rest or moves in uniform motion in a straight line with
constant velocity
an object with no force on it moves in a straight line
with constant acceleration
for every action, there is an equal and opposite
reaction
the force between two objects is directly
proportional to the product of their masses and
inversely proportional to the distance between them
squared
an object with a force on it is accelerated in the
direction of the force an amount inversely proportional
to its mass and directly proportional to the size of the
force
45 Which statement expresses Newton’s first law of motion?
An object with no force on acting on it continues at
rest or moves in uniform motion in a straight line with
constant velocity.
An object with a force on it is accelerated in the
direction of the force an amount inversely proportional
to its mass and directly proportional to the size of the
force.
For every action, there is an equal and opposite
reaction.
The force between two objects is directly
proportional to the product of their masses and
inversely proportional to the distance between them
squared.
The force between two objects is inversely
proportional to the product of their masses and directly
proportional to the distance between them squared.
46 An object’s momentum is equal to its ____.
acceleration multiplied by its mass
acceleration divided by its weight
velocity multiplied by the gravitational constant
velocity multiplied by its mass
velocity divided by its weight
47 The first postulate of special relativity states that ____.
observers can always detect their uniform motion
relative to other objects
observers can never detect their uniform motion
except relative to other objects
the speed of light is constant regardless of location
the speed of light in a vacuum is constant
energy equals mass multiplied by the speed of light,
squared
48 The importance of the general theory of relativity lies in its description of
____.
acceleration
gravity
mass
space time
velocity
49 Einstein revolutionized modern physics by ____.
documenting the existence of gravity through
experiments on objects in motion
proving that Galileo and Newton were fundamentally
incorrect about gravity
explaining how specific gravity impacts the
geometry of curved space time
providing an explanation of gravity based on the
geometry of curved space time
defining the difference between violent motion and
natural motion
50 The force due to the gravity between two objects depends on the ____,
combined mass and velocity of both objects
mass of each object and the distance between them
distance of each object from Earth and distance
between them
speed of light and the distance of each object from
Earth
mass of each object and the speed of light
51 As described by Kepler’s second law, an object in an elliptical orbit reaches
its highest velocity when it is as at ____.
lowest; pedigree
highest; apogee
highest; pedigree
lowest; apogee
escape velocity; pedigree
52
Figure 5 15
Consider the accompanying figure. Due to the curvature of space time by
the sun, light from stars that pass near the edge of the sun will ____.
be bent so that the stars appear further from the
edge of the sun
be bent so that the stars appear closer to the edge
of the sun
be bent so that the stars are no longer visible
be bent so that the stars will appear intermittently
not be affected by the curvature of space time
53 What is an example of the conservation of angular momentum?
A volleyball player serves a ball and it follows a
parabolic path.
A baseball player strikes the ball with the bat
A cross country skier accelerates as she moves in a
straight line
A skateboarder maintains the same velocity in the
same direction
A diver brings his arms and legs closer to his body
54 Newton’s second law of motion is represented by ____.
55 Kinetic energy refers to the energy of a(n)____.
stationary body
moving body
moon
gravitational field
object due to its position
56 A ball is dropped from the top of a science building. After falling for three
seconds, the speed of the ball would be _______________ m/sec.
Answer:
29.4
57 Newton’s first law of motion was very similar to descriptions of motion
proposed by _______________.
Answer:
Galileo
58 The ______________ of the Moon’s orbit is the location at which it is
farthest from Earth.
Answer:
apogee
59 _______________ occur when tides caused by the Sun and Moon partially
cancel out.
Answer:
Neap tides
60 The _______________ states that an observer cannot distinguish locally the
difference between inertial forces due to acceleration and uniform
gravitational forces due to the presence of a massive object.
Answer:
equivalence principle
61 The term _______________ refers to a change in velocity.
Answer:
acceleration
62 The velocity required to escape an astronomical body is known as the
_______________.
Answer:
escape velocity
63 According to __________, _______________ motion occurs when natural
motion has to be sustained by a force.
Answer:
Aristotle; violent
64 The resistance of matter to changes in motion is known as
_______________.
Answer:
inertia
65 An object in a closed orbit under the influence of an attractive force that
follows the inverse square law must behave a(n) _______________ path.
Answer:
elliptical
66 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
States that a gravitational field is a curvature of space time caused by the
presence of mass
Answer:
j
67 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
A measure of an object’s amount of motion
Answer:
d
68 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
A measure of an object’s mass along with its speed of rotation
Answer:
h
69 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
The resistance of matter to changes in motion
Answer:
b
70 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
Follows an elliptical path
Answer:
f
71 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
Occurs without force
Answer:
a
72 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
The amount of matter in a body
Answer:
c
73 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
The velocity required to break free of an astronomical body
Answer:
g
74 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
States that observers cannot detect their uniform motion through space
through internal tests
Answer:
i
75 Match the terms below with the appropriate description or definition.
a. Natural motion f. Closed orbit
b. Inertia g. Escape velocity
c. Mass h. Angular momentum
d. Momentum i. Special theory of relativity
e. Inverse square law j. General theory of relativity
States that the force of gravity is inversely proportional to the square of the
distance between two masses
Answer:
e
76 How did Aristotle describe gravity and in what context?
Answer:
Aristotle believed that objects fall downward because they are moving
toward their proper place. That is one reason why Aristotle’s universe had
to be geocentric. His explanation of gravity why things fall down only
works if the center of Earth is also the center of the Universe.
77 Define and distinguish among the terms speed, velocity, and acceleration.
Answer:
Speed is the pace at which an object moves through a distance (regardless
of direction).Velocity is the pace at which an object moves through a
distance, including a specific direction. Acceleration is the rate at which
an object’s velocity changes. The distinguishing feature between speed and
velocity is that speed does not include a direction, whereas velocity
specifies a direction.
78 How did Newton clarify prior laws of planetary motion?
Answer:
Newton’s understanding of gravity allowed him to explain why the planets
obey Kepler’s laws of planetary motion. His work finished the
transformation of what were once considered the mysterious wanderings of
the planets into understandable motions that follow simple rules. In fact, his
discovery of gravity explained something else that had mystified
philosophers for millennia the ebb and flow of ocean tides.
79 Why does the circular velocity of an Earth satellite depend on the distance
from Earth’s center?
Answer:
The equation for circular velocity is as follows:
The constant G is the gravitational constant that connects units of mass to
units of gravitational force, M is the mass of the central body and r is the
radius of the orbit in metes. Thus, the distance between the satellite and
Earth’s center impacts circular velocity.
80 How can tidal forces affect the rotation of celestial bodies and their orbital
motion?
Answer:
Earth rotates eastward, and friction with the ocean beds drags the tidal
bulges slightly eastward out of a direct Earth Moon line. These tidal bulges
are massive, and their gravitational field pulls the Moon forward in its orbit.
As a result, the Moon’s orbit is growing larger by about 3.8 cm a year, an
effect that astronomers can measure by bouncing laser beams off reflectors
left on the lunar surface by the Apollo astronauts.
81 Describe two experiments that provide evidence of space time curvature by
the presence of a mass.
Answer:
Two key experiments confirmed that space time can be curved the presence
of a mass: the advance of perihelion of Mercury’s orbit and the motion of
light near the Sun.
Each time Mercury returns to perihelion, its closest point to the Sun, it is
about 29 km (18 mi) past the position predicted by Newton’s laws. This is
such a small distance compared with the planet’s diameter of 4880 km that
it could never have been detected had it not been cumulative. Each orbit,
Mercury gains only 29 km, but in a century it’s ahead by over 12,000 km
more than twice its own diameter. To remedy this difference, he first
calculated how much the Sun’s mass curves space time in the region of
Mercury’s orbit and then he calculated how Mercury moves through the
space time. The theory predicted that the curved space time should cause
Mercury’s orbit to advance by 43.03 arc seconds per century, well within
the range of uncertainty in the observed excess. His theory matched
Newton’s observations.
A second test of general relativity was related to the motion of light through
the curved space time near the Sun. Because light has a limited speed,
Newton’s laws predict that the gravity of an object should slightly bend the
paths of light beams passing nearby. The equations of general relativity
indicated that light should have an extra deflection caused by traveling
through curved space time, just as a rolling golf ball is deflected by
undulations in a putting green. Einstein predicted that starlight grazing the
Sun’s surface would be deflected by 1.75 arc seconds, twice the deflection
that Newton’s law of gravity would predict. Starlight passing near the Sun is
normally lost in the Sun’s glare, but during a total solar eclipse, stars beyond
the Sun can be seen. During the next solar eclipse, measurements were
taken and they matched his predictions.
82 Explain why the term acceleration is important to the first postulate of
special relativity.
Answer:
The first postulate states that the laws of physics are the same for all
observers, no matter what their motion, so long as they are not accelerated.
The word accelerated is important. If either spaceship were to fire its
rockets, then its velocity would change. The crew of that ship would know
it because they would feel the acceleration pressing them into their
couches. Accelerated motion, therefore, is different the pilots of the
spaceships can always tell which ship is accelerating and which is not. The
postulates of relativity discussed here apply only to the special case of
observers in uniform motion, which means unaccelerated motion. That is
why the theory is called the special theory of relativity.
83 How does gravity explain the presence of the tides we experience on Earth?
Answer:
Tides are caused by small differences in gravitational forces. For example,
Earth’s gravity attracts your body downward with a force equal to your
weight. The Moon is less massive and more distant, so it attracts your body
with a force that is a tiny percent of your weight. You don’t notice that little
force, but Earth’s oceans respond visibly.
84 Explain why the spring and neap tides occur periodically.
Answer:
Gravity is universal, so the Sun also produces tides on Earth. The Sun is 27
million times more massive than the Moon, but it lies almost 400 times
farther from Earth. Tides on Earth caused by the Sun are less than half as
high as those caused by the Moon. Twice a month, at new moon and at full
moon, the Moon and Sun produce tidal bulges that add together and produce
extreme tidal changes: At those moon phases, high tides are exceptionally
high, and low tides are exceptionally low. Such tides are called spring tides.
Here the word spring does not refer to the season of the year but to the
rapid rising up of water. At first and third quarter moons, the Sun and
Moon pull at right angles to each other, and the tides caused by the Sun
partly cancel out the tides caused by the Moon. These less extreme tides
are called neap tides, and they do not rise very high or fall very low.
85 How did Newton’s Principia impact science?
Answer:
After the Principia was published, physicists and astronomers understood
that the motions of celestial bodies are governed by simple, universal rules
that describe the motions of everything from orbiting planets to falling
apples. Suddenly the Universe was understandable in simple terms, and
astronomers could accurately predict future planetary motions.
The Principia also changed science in general. The works of Copernicus
and Kepler had been mathematical, but no book before the Principia had so
clearly demonstrated the power of mathematics as a language of precision.
Newton’s arguments in his book were such powerful illustrations of the
quantitative study of nature that scientists around the world adopted
mathematics as their most powerful tool.
Finally, the Principia changed the way people thought about nature. Newton
showed that the rules that govern the Universe are simple. Particles move
according to just three laws of motion, and attract each other with a force
called gravity. These motions are predictable, and that makes the Universe
seem like a vast machine, but one whose operations are based on a few
simple rules. The Universe is complex only in that it contains a vast number
of particles. In Newton’s view, if he knew the location and motion of every
particle in the Universe, he could, in principle, derive the past and future of
the Universe in every detail. This idea of mechanical determinism has been
modified by modern quantum mechanics (laws that govern behavior of
particles inside atoms), but it dominated science for more than two
centuries. During those years, scientists thought of nature primarily as a
beautiful clockwork that would be perfectly predictable if they knew how
all the gears meshed.