1. Revolution & Change

9. Revolution
The action or fact, on the part of celestial
bodies, of moving round in an orbit (1390)
The return or recurrence of a point or
period of time; the lapse of a certain time
(1430)

10. Revolution
An instance of great change or alteration in
affairs or in some particular thing. (1450)
A complete overthrow of the established
government in any country or state by those
who were previously subject to it; a forcible
substitution of a new ruler or form of
government. (1600)

11. Political
The “Glorious Revolution” (1688)
American Revolution (1776)
French Revolution (1789)
Russian Revolution (1917)
Chinese Revolution (1949)

12. Revolution
Political revolutions involve major
transformations in political structures.
Social revolutions involve major
transformations in social structure.
Scientific revolutions involve major
transformations in conceptual structures.

13. The Scientific Revolution
1543 (Copernicus) to 1687 (Newton) to ...
“The most profound revolution achieved or
suffered by the human mind” since Greek antiquity
(Alexander Koyré, 1943)
It “outshines everything since the rise of
Christianity and reduces the Renaissance and
Reformation to the rank of mere episodes … [it is]
the real origin both of the modern world and of
the modern mentality.” (Herbert Butterfield, 1949)

14. Individual Revolutions
Copernicus’ On The Revolutions (1543)
Galileo’s Dialogue Concerning the Two Chief World
Systems (1632)
Newton’s Principia (1687)
Lavoisier’s theory of combustion (1783)
Darwin’s Origin of Species(1859)
Einstein’s theories of relativity (1905 / ‘15)
Wegener’s theory of continental drift (1915)

15. A systematic method for understanding facts
about the natural world with reference to
natural law.

16. Naturalism
Methodological: Science can
only study nature using
natural laws. Supernatural
entities, while they may
exist, are not allowed as
scientific explanations of
phenomena.
Philosophical: The
supernatural does not exist.

17. Popular Hierarchy
Fact
Hypothesis
Theory

18. Philosophical Hierarchy
Hypothesis
Fact

19. Theory
“A well-substantiated explanation of some
aspect of the natural world that can
incorporate facts, laws, inferences, and tested
hypotheses.” (NAS, 1998)
“Science not only generates facts but seeks to
explain them, and the interlocking and well-
supported explanations for those facts are
known as theories.” (T. Ryan Gregory, 2008)

20. Theory
Theories are the ultimate goal of science.
They explain facts and are tested by
generating hypotheses. These three things are
distinct aspects of science.

21. Hypothesis
“A tentative statement about the natural
world leading to deductions that can be
tested.” (NAS 2008)
“The rejection of an hypothesis does not
automatically imply the refutation of an
entire theory because hypotheses are usually
sufficiently focussed to test only one aspect
of complex theories.” (Gregory, 2008)

22. Law
A “generalization about how some aspect of
the natural world behaves under stated
circumstances.” (NAS, 1998)
Descriptive not prescriptive

23. Universal Gravitation

24. Gravity
We have facts that we need to explain.
There are laws that describe the behavior of
objects under the influence of gravity
We currently do not have a mechanism for
gravitational attraction

25. General Relativity
Gravity as a consequence
of the warping of space-
time
An incomplete theory -
how does it reconcile with
sub-atomic quantum
effects? Why is gravity
relatively weak?
Does this incompleteness
make gravity “just a
theory”?

27. Theories
• Big Bang Theory • Theory of Plate
Tectonics
• Cell Theory
• Acoustic Theory
• Evolutionary Theory
• Electromagnetic Theory
• Germ Theory of Disease
• Quantum Field Theory
• Atomic Theory
• Kinetic Theory of Gases

28. String “Theory”

30. A General Pathway
Observe world (collect observations / facts)
Ask “why” questions
Make explanatory hypothesis
Make predictions or retrodictions
Test predictions or retrodictions by experiment or
further observation - Assume uniform cause and
effect (actualism)
Eventually form a theory

32. How Does Conceptual
Change Happen?

33. I.B. Cohen’s Stages
1. The “intellectual revolution” or “revolution-
in-itself” (private)
2. Written commitment to the new method,
concept or theory (private)
3. Dissemination of the ideas (public)
4. Adoption by a critical mass of individuals or
groups (public)

34. Thomas Kuhn
(1922 - 1996)

35. Pre-science
Normal Science
Crisis
Revolution
New Science

36. Key Concepts
A paradigm organizes scientific inquiry.
Normal science is “puzzle-solving” and does not
question the reigning paradigm.
A state of crisis eventually emerges when unsolved
puzzles and anomalies accumulate.
Revolutionary science is methodologically
unconstrained and often irrational forces are at work
(idiosyncrasies and accidents of history).
Successive paradigms are incommensurable

37. Paradigm
Kuhn himself had 21 different usages, but two
“levels” emerge
Narrow sense: A standard exemplar of
“good” science - the right kind of problem to
solve and the right way to solve it.
Broad sense: A framework of shared
methods, standards, modes of explanation,
theories

38. Paradigm
Metaphysical views about the nature of the
world and the things in it
Methodological rules about correct scientific
practice and of what constitutes a legitimate
scientific question or a scientific fact

39. Resulting Claims
The conflict among paradigms can’t be
settled on any rational methodological
grounds, because each paradigm contains its
own view of rational scientific methodology
and of what counts as a “fact.”

40. Resulting Claim
Different paradigms are in thus
incommensurable, i.e. not comparable by any
neutral standard.
Adherents of different paradigms “live in
different worlds,” and speak different
technical languages.

41. Resulting Claim
Scientists with different theoretical viewpoints
will generally fail to understand one another
and the arguments made in favor of one
theory will not be fully understood by, or
persuasive for, adherents of the other.
New paradigms will introduce new theoretical
terms, or change the meanings of old ones, in
ways that will be incomprehensible to anyone
who doesn’t already accept the new theory.

43. Resulting Claim
A scientific revolution has to be regarded as
a social and psychological phenomenon
rather than as a purely intellectual one. For
an individual scientist, the change in point of
view is more like a religious conversion than
a rational process of comparing theories
against the facts.

44. Karl Popper
(1902 - 1994)
All science is “normal” and it
proceeds by “conjecture and
refutation”
No accumulation of confirming
instances is sufficient to verify a
universal generalization, but only
one disconfirming instance suffices
to refute a universal generalization
Scientific theories are distinguished
by the fact that they are falsifiable

45. Imre Lakatos
(1922 - 1974)
Scientific theories are “research
programmes” that consist of: a “hard
core” of fundamental principles, and a
“protective belt” of “auxiliary
hypotheses” that explain how the
fundamental principles apply to
particular cases, and how to deal with
apparent discrepancies.
The fundamental difference is
between progressive and
degenerating programmes.

46. Paul Feyerabend
(1924 - 1994)
Epistemological
Anarchism
There are no rules to
science - anything goes
to get one’s theory
accepted

47. Descriptive
versus
Prescriptive?
Science and
Philosophy