Galileo and the Origins of the Modern World

1
Galileo and the Origins of the Modern World

• David Banach
• Department of Philosophy

2
Galileo and the Origins of the Modern WorldDavid
Banach
3
Discoverer of new worlds
4
Proponent of New Theories
5
Saint for Science
6
Galileo at Arcetri
7
Galileo and Milton at Arcetri
8
Galileo and Milton at Arcetri
9
Galileo at Arcetri
10
Galileo at Arcetri
11
Galileo Discourse on the Two New Sciences (1638)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
Galileo and Scientific Method

• 1602-Pendulum experiments.
• 1604- Inclined plane experiments of natural
  acceleration.
• 1607-Systematic manipulation of shapes and
  weights of wax balls to study flotation.
• Investigation of projectile motion. Discovery of
  parabolic character of projectile motion.

20
Science and the Modern World

• Scientific Method as a model for Reason The new
  method of knowledge introduced by Galileo and the
  Scientific Revolution increased the confidence in
  the power of human reason and its ability to
  transform civilization. The hundred or so years
  following the Scientific Revolution (the 1700s,
  the Enlightenment) saw an unprecedented revision
  of the forms of human government and culture on
  the basis of the application of this new method.
  The Post-Modern world will ask whether Science
  can deliver on the promise of objectivity and
  whether a society can be ordered on the basis of
  reason.
• The Mechanistic world view The Scientific
  revolution introduced a radically new view of the
  world as a mechanism composed of inert parts,
  whose configuration and mechanical relations
  determine all of its properties. The Post-Modern
  world will ask whether human values and the human
  soul can find a place in this mechanistic world.
  This is the real conflict between science and
  religion.

21
The Scientific Method

• Science does not trust the senses. It mistrusts
  and re-interprets them.
• Science does not aim at understanding the
  particular, but at isolating how nature acts
  under ideal conditions
• Scientific discovery involves more than merely
  looking in the right place. It requires
  uncovering the hidden order within appearances.

22
The Scientific Method

• Purifying the Appearances
• Separating the Relative from the Absolute

23
Separating Relative and AbsoluteThe Copernican
Revolution

• The senses tell us that the sun is moving. Using
  our minds we can see that the motion of the sun
  in the sky is really our motion, merely relative
  to us.

24
Copernicuss Revolution The Motion we see
outside us in the Sun
25
Is not in the sun but in us Is not real but
merely relative
26
The Laws of Terrestrial Motion

• 1. Free fall Aristotle believed heavy objects
  fell faster than light objects, since they had
  more earth than air or fire or water in them.
  Galileo saw that all objects fall at the same
  rate. The senses supported Aristotle. Galileos
  experiments aimed at purifying the senses and
  isolating only the effects of weight from all the
  other causes involved such as air resistance,
  friction, and buoyancy.
• 2. Inertia Aristotle thought that an object in
  natural motion moved to its natural place and
  stopped and that to keep it moving in violent
  motion required energy. Galileo formulated the
  law of inertia that an object in motion tends to
  stay in motion. The senses supported Aristotle.
  Only Galileos purification of the senses in
  experiments proved him to be correct.

27
Aristotle on Terrestrial MotionNatural Place
28
Purifying the appearances
Simple unified motions often arise from an impure
conglomeration of forces such as friction and air
resistance. The scientific method systematically
manipulates properties to isolate the real source
of phenomena.
29
Only in a vacuum do objects fall at the same rate
30
The Law of Inertia

• The senses tell us that objects require force to
  keep them moving and eventually slow down.
• Only under ideal conditions does an object in
  motion tend to stay in motion

31
Three Experiments

• 1. The Pendulum Used to demonstrate the law of
  inertia and that heavy and light bodies fall at
  the same rate. Galileo also discovered the
  mathematical laws governing the length of the
  string, the period of the motion, and the
  amplitude of the swing.2. The Inclined Plane and
  the Rate of Acceleration Galileo used the
  inclined plane to slow the motion of falling
  objects enough to accurately measure how their
  speed increased.
• 3. Projectile Motion Galileo also used the
  inclined plane to control the speeds and heights
  of projectiles in order to discover the
  mathematical properties of their paths.

32
1. Pendulum
33
Pendulum

• "...repeat many times the fall through a small
  height in such away that I might accumulate all
  those intervals of time that elapse between the
  arrival of the heavy and light bodies
  respectively at their common terminus, so that
  this sum makes an interval of time which is not
  only observable, but easily observable."  
• "...two balls, one of lead and one of cork, the
  former more than a hundred times heavier than the
  latter, and suspended them by means of two equal
  fine threads, each four or five cubits
  long. "This free vibration repeated a hundred
  times showed clearly that the heavy body
  maintained so nearly the period of the light body
  that neither in a hundred swings nor even in a
  thousand will the former anticipate the latter by
  as much as a single moment, so perfectly do they
  keep step."         Galileo  

34
Pendulum

• Momentum is conserved

35
Pendulum

• 1. Robust Regular motion remains independent of
  impurities in environment.
• 2. Demonstrates regular fall of bodies and law of
  inertia.
• 3. Allows mathematical study of dependence of
  motion on string length and mass of pendulum.

36
2. Inclined Plane
37
Inclined Plane"...in such a plane, just as well
as in a vertical plane, one may discover how
bodies of different weight behave..."  Galileo
38
Inclined Plane"...in such a plane, just as well
as in a vertical plane, one may discover how
bodies of different weight behave..."  Galileo
39
Inclined Plane"...in such a plane, just as well
as in a vertical plane, one may discover how
bodies of different weight behave..."  Galileo
Total distance traveled is proportional to the
square of time.
40
Inclined Plane
Slows down motion to enable the measurement of
mathematical relationships. Corrects for the
effects of air resistance. Simplifying and
purifying the appearancesallows discovery of
first mathematical law of motion.
41
3. Projectile Motion
42
Projectile Motion

• Purifying the appearances Separating and
  Analyzing the Components of motion.

43
All Projectile paths are Parabolas
44
(No Transcript)
45
Parabola is a Conic Section
46
Vertical motion can be separated from the
horizontal motion
47
Projectile Motion
48
The apparent single motion is actually composed
of two different motions
49
Which function independently even when united
50
(No Transcript)
51
Separating the Relative and the Absolute
52
(No Transcript)
53
Projectile Motion

• Purifying the appearances allows the different
  components of motion to be separated and describe
  mathematically.
• The Scientific method is reductionistic. It
  breaks down complex things into their simple
  parts.

54
Primary and Secondary Properties The Assayer 1623

• Separating the relative from the absolute

55
All our sense perceptions are relative to the
five senses
56
Sensible properties are relative

• Once we separate the relative from the absolute
  within our perceptions, we find that most of the
  properties we found to be indicative of unities
  that required a single nature as their source are
  really not in the external world at all, but are
  the effects that the primary qualities of objects
  have on our constitutions.

57
Sensible properties are relative

• 1. Primary properties are the properties really
  in the object such as the size, shape, number, or
  speed of the atoms or particles of matter.2.
  Secondary properties are the effects that the
  object has on us and exist only in us, not in
  the object itself. (E.g. the tickle of the
  feather.) Galileo saw that all sensible qualities
  such as color, sound, warmth, taste, and smell
  were really only in the mind.

58
The world is made of numbers

• Galileo in The Assayer
• Philosophy is written in this grand book, the
  Universe, which stands continually open to our
  gaze. . . . It is written in the language of
  mathematics, and its characters are triangles,
  circles, and other geometric figures without
  which it is humanely impossible to understand a
  single word of it.

59
(No Transcript)
60
May God us keep/ From single vision, and Newton's
sleep! (William Blake)
61
Galileo and the Modern World

• 1. Science is a model for how impartial human
  reason works. Science is objective. It forms the
  basis for our hopes of a rationally organized
  society. (Jefferson)
• 2. We are no longer at home in the world revealed
  by science. Science unweaves the rainbow. There
  is no room for the human spirit in the purified
  appearances. (Beethoven)

62
1. Science as a model for human reason

• Science is objective. Purifying the appearances
  and separating the relative from the absolute
  means that science eliminates us, our biases, our
  prejudices, our point of view, from the
  appearances.

63
The Scientist separates the relative from the
absolute
64
The Scientist separates the relative from the
absolute
65
Does the Scientist separate themselves from
their humanity?
66
The Mad Scientist
67
2. Mechanistic Reductionism and the Human Soul

• Mechanism The World is a Machine. The world
  consists of matter in motion and the mathematical
  laws that govern its motion.
• Reductionism The qualities of complex objects,
  such as squirrels, persons, or countries, can be
  explained completely by an examination of the
  basic forms of the components that make them up
  and the scientific laws that govern them.

68
Mechanism
69
Reductionism
70
May God us keep/ From single vision, and Newton's
sleep! (William Blake)
71
Do not all charms fly/ At the mere touch of cold
philosophy?/ There was an awful rainbow once in
heavenWe know her woof, her texture she is
given/ In the dull catalogue of common things./
Philosophy will clip an Angels wings,Conquer
all mysteries by rule and line,/ Empty the
haunted air, and gnomed mine / Unweave a
rainbow (John Keats)
72
Two Questions

• Is Science objective? Do Science and Reason
  really give us absolute and complete knowledge of
  the world? Can all questions be solved
  scientifically through the application of the
  scientific method? Are humans capable of being
  completely objective?
• Does Science leave room for the human spirit?
  Does Science oversimplify and rob the world of
  its beauty and grandeur? Are human beings more
  than machines, and are there limitations to the
  applicability of the views and methods of
  science? Is science a savior of mankind, or are
  the pervasive applications of Galileos methods
  an enemy to human values.

73
(No Transcript)