The Scientific Revolution in the 17th Century

1
The Scientific Revolution in the 17th Century

• From Aristotle to Newton

2
Aristotle (384 - 322 B.C.)

• known as "the Philosopher" by later thinkers,
  created a huge body of work that was virtually
  synonymous with philosophy for over 2000 years.
• "perplexed with obscure terms and useless
  questions" John Lock (16321704)
• "a naive and childlike animistic view of the
  world." Jean Piaget (1896-1980)
• The greatest philosopher of all times
• Modern attitude to Aristotle

3
Aristotle's cosmology

• Geocentric
• Crystal spheres
• Dualist
• Sublunary world is imperfect
• Beyond the moon the world is perfect,
  unchangeable and eternal

4
Aristotle's cosmology I

• Sun and planets were attached to crystal spheres
  revolving around the Earth.
• All motions beyond the moon were perfectly
  circular.
• Gravitation was a phenomenon applying to the
  Earth only, as an expression for things seeking
  their natural place

5
Aristotle's cosmology II.

• A organized and classified an immense amount of
  knowledge, much of it scientific theories
  developed with only the crudest observational
  tools.
• All knowledge is organized into the theoretical
  disciplines (physics, "first philosophy"
  metaphysics, and math) practical disciplines
  (ethics and politics) and productive disciplines
  (engineering, medicine, etc.).

6
Aristotle's cosmology III.

• He classified four types of change (generation /
  corruption, increase / decrease, alteration, and
  locomotion)
• and four types of causation (the material, the
  formal, the initiating force, and the goal).

7
Aristotle's cosmology IV.

• Aristotle formed a metaphysical theory of what is
  real ("substance"), and described the idea that
  all things have "potential" and "actual"
  characteristics.
• He created logic to distinguish correct from
  incorrect reasoning and
• he reasoned that all motion ultimately is caused
  by an immutable perfection, an unmoved "primer
  mover" - which Aristotle called "God."

8
Claudius Ptolemy

• Egyptian living in Alexandria, at about 150 A.D.,
  gathered and organized the thoughts of the
  earlier thinkers - Almagest
• Created a geocentric cosmology based on
  mathematics and observation
• A perfect circle was the only possibility for
  movement in the sky
• No physics in his model

9
Eccentric, epicycle, equant
eccentric
equant
Combined Equant and epicycle
epicycle
10
(No Transcript)
11
Nicolas Copernicus (1473-1543)

• Could not accept the complexity of Ptolemys
  theory nor that could exist two different
  theories.
• 1543 De Revolutionibus Orbium Caelestium (On
  the Revolution of the Heavenly Orbs).
• Heliocentric world view!

12
Copernicus cosmology

• Mostly the Aristotelian model where Copernicus
  places the sun in the middle instead of the earth

13
The Problems of Copernicus

• If the earth is moving, why do things not fly
  away?
• The parallax
• The orbits of his theory did not fit with
  observations
• He still had to use epicycles...
• Why did the moon circle around the earth?

14
The parallax
15
Tycho Brahe (1546-1601)

• Denmark's hottest stargazer
• Refined the tools and equipment for the
  observation of the heavenly bodies
• 1572-73 Crab Nebula
• 1577 new comet
• Crashed the crystal spheres
• Alternative cosmology

16
Brahes astronomy
17
(No Transcript)
18
Johannes Kepler (1571-1630)

• Three Laws of Planetary Motion
• Solved many of the problems of Copernicus

19
Kepler's Laws of Planetary Motion

• The First Law
• Planets move in ellipses with the Sun at one
  focus.
• The Second Law
• The radius vector describes equal areas in equal
  times
• The Third Law
• The squares of the periodic times are to each
  other as the cubes of the mean distances

20
Circular and Elliptical Orbits Having the Same
Period and Focus
21
Galileo Galilei (1564-1642)

• 1600 Giordano Bruno burnt
• 1601-1610 The Telescope
• 1615 Letter to Grand Duchess of Tuscany
• 1632 Dialogue on Two World Systems
• 1633 Galileo banned by the Church
• 1638 Discourse on Two New Sciences

22
Galileos contributions

• Heliocentric cosmology of Copernicus
• Critics of Aristotle's theory of motion
• Pendulum
• Through the telescope Galileo saw
• The mountains of the moon, discovered the four
  satellites of Jupiter, observed a supernova,
  verified the phases of Venus, and discovered
  sunspots.
• His discoveries proved the Copernican system
  which states that the earth and other planets
  revolve around the sun.

23
(No Transcript)
24
(No Transcript)
25
Galileo's telescope (1601)
26
(No Transcript)
27
(No Transcript)
28
Galileo and the Inquisition
29
Francis Bacon (1561-1625)

• 1620 Novum Organum (New Tools)
• Theory of Induction
• Empiricist
• The gunpowder and the compass have 'changed the
  whole face and state of things throughout the
  world, there will be more of such things in the
  future.
• Through science we will master nature.

30
Bacon/Novum Organum
31
Descartes/
32
Rene Descartes (1596-1650)

• 1637 Discourse on Method
• Theory of Deduction
• Abandoned the Copernican theory
• In its place he devised a theory of vortices in
  which space was entirely filled with matter, in
  various states, whirling about the sun.

33
Descartes...

• Pure mechanistic cosmology
• Vacuum does not exist
• Optics
• Discovered of the fundamental law of reflection
  that the angle of incidence is equal to the angle
  of reflection
• Descartes' treatment of light as a type of
  pressure in a solid medium paved the way for the
  undulatory theory of light

34
Isaac Newton (1642-1727)
35
Isaac Newton two main contributions

• 1687 Philosophiae Naturalis Principia Mathematica
  (Mathematical Principles of Natural Philosophy)
• Opticks - 1704

36
Newton's Three Laws of Motion

• 1. A body moves in a straight line unless
  impeded. (Inertia).
• 2. Every action has equal and opposite reaction.
  
• 3. Every body attracts every other body with a
  force proportional to the distance between.

37
Newton's theory of gravitation

• Newton proposed his law of gravitation in 1687
  and stated that every particle in the universe
  attracts every other particle in the universe
  with a force that depends on the product of the
  two particles' masses divided by the square of
  the distance between them
• Universal law - same physics in heaven as on earth

38
Newton and the apple

• Dealing with the apple and the satellite solve
  the problem of gravity and connect heaven and
  earth in the same physics!

39
Anatomy and Medicine

• Hippocrates (ca. 460-377 B.C.) He also gave the
  world the Hippocratic Oath, a code of ethics for
  physicians which is still taken by graduates at
  many modern medical schools. The Hippocratic Oath

40
Hippocrates

• Perhaps history's most famous physician.
• By rejecting superstition in favor of scientific
  observation,
• By classifying diseases,
• By creating a set of moral and professional
  standards for physicians,
• He earned the title of 'Father of Medicine.'

41
The Hippocratic biophysics

• The elaborate general doctrine of the Four Humors
  endured through many centuries and is central to
  the tenets of the Hippocratic Corpus
• The elaborate general doctrine of the Four Humors
  endured through many centuries and is central to
  the tenets of the Hippocratic Corpus. It was
  grounded on the Empedoclean principle of the four
  supposed elements earth, air, fire and water.
• The four constituent elements, or humors, in man
  were identified analogously as phlegm, blood,
  yellow bile and black bile, all of which had to
  be in correct proportion to one another.

42
Erasistratus of Ceos (c.250 BC)

• Greek physician, born in Ceos.
• He founded a school of anatomy at Alexandria
• Considered one of the pioneers of modern
  medicine.
• He is said to have been the first to trace
  arteries and veins to the heart, and to have
  named the tricuspid valve in the heart.

43
Galenos (131-201 a.d.)

• Greek physician.
• He studied medicine at Pergamum, Smyrna, Corinth,
  and Alexandria, and later lived in Rome.
• He was a voluminous writer on medical and
  philosophical subjects, and gathered up all the
  medical knowledge of his time, thus becoming the
  authority used by subsequent Greek and Roman
  medical writers.
• The authority for 1500 years.

44
Vesalius (151464)

• Advanced dissection of the human body
• De humani corporis fabrica libri septem (1543,
  Seven Books on the Structure of the Human Body)

45
William Harvey (15781657)

• De motu cordis et sanguinis in animalibus (On the
  Motion of the Heart and Blood in Animals), in
  which the circulation of the blood was first
  described, was published in 1628.

46
Malpighi(162894) Pisa

• The founder of microscopic anatomy, he described
  the major types of plant and animal structures
• Capillaries 1661