Transcript Oct 13

Lecture 4 (re-ordered)
1.
2.
3.
4.
5.
Film continued
Discussion
(Yet) more leftovers
A.J. Ayer on “verifiability”
Discussion
Part I
The Elegant Universe
continued
The Elegant Universe
Note the title! The universe is “elegant”!
 String Theory: everything there is is made of
tiny vibrating strings of energy… (not some
one or more particles!)
 Goals: a grand theory of everything!
 Unifying physics

 Resolving
the contradictions between the 2 pillars
of contemporary physics:
 Quantum theory
 Relativity
The Elegant Universe

Relationships to course issues
 More
positing of unobservable objects (strings, 6
or 7 more dimensions, parallel universes, multiple
“Big Bangs”, etc.)
 Quest for simplicity/unity; One and the Many;
Reality vs. Appearances
 The Demarcation Problem:
 Is
String Theory testable?
 If not, is it science?
The Elegant Universe
Issues that once faced (or continue to face) String
Theory
 Testable? (If not, is it scientific?)
 Anomalies:

 Contradictions
 Empirical
of 1 and/or 2 sorts:
inconsistency (the apparently retrograde motion
of Mars for the Aristotelian theory of the (then known)
universe)
 Mathematical and/or logical inconsistency (internal to a
theory and allowing any and all consequences to follow
“validly”)
Part II
Discussion
The Elegant Universe

What do particle physicists (such as Democritus
and Lederman) and String Theorists have in
common in terms of assumptions?
 Metaphysical/ontological?
 Methodological?
 Epistemological?
 Technological?
 Aesthetic?

Is there some (general) argument Lederman and
Greene both offer to justify their theories and
reasoning?
Part III
(Yet) more leftovers
Leftovers
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For a great episode on the discovery of and
years of work to put Ardi together:
www.pbs.org/newshour/videos
For a great read every Tuesday:
www.nytimes.com: “Science Times”
How did Lucy get her name?
Ardi on the Discovery channel
Leftovers
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The evidence for subatomic particles – and for
evolutionary processes and events – is indirect
We draw inferences from what we can observe to
what we cannot
In evolutionary theorizing (as well as other
historical sciences such as geology, cosmology,
paleontology, and archaeology), scientists often
reason along the lines of “reverse engineering”:
Start with some trait and attempt to explain it by
reference to variations in an ancestral population
and selection pressures.
This assumes that traits that proliferate are the
product of R&D/evolutionary forces
The Panda’s Thumb
O: the panda’s “thumb” (TPT) and what it actually
is (an enlarged wrist bone)
H1: TPT came about through natural selection: the
(blind) tinkering with available parts that gave
those ancestors with it an advantage and, thus,
the trait spread.
H2: TPT was designed by perfect engineer.
Gould:
P(O/H1) >> P(O/H2)
An example of inference to the best explanation
Paley’s reasoning updated…
 Not
random?
 After
all, mutations are often random… and
they underlie
phenotypic/morphological/behavioral
change…
 True, but NS is not itself a random process.
 Consider it to be an algorithm…
 Like long division?
 No.
 More like an elimination tournament in tennis.
The algorithm of natural selection
Round Result
1
A v. B B
Round Result
2
C v. D
C
B v. G
G
E v. F
F
G v. H
G
C v. F
C
Final
round
Result
C v. G
G
The algorithm of natural selection
Waves of competition among con-specifics who
vary
2. Selection pressures such that some variation or
variations provide an advantage (however
small)
Results:
3. Winners (survive and reproduce better) and
losers
4. Winners tend to pass on the relevant traits to
their offspring
1.
Darwin’s orchids
Non-sexual reproduction is cheaper, but sexual
reproduction insures that an organism’s progeny
are varied (and thus will have a better chance of
survival if conditions change).
 From the same relatively primitive petal of its
ancestor, varieties of orchids have different
“contraptions” for insuring cross-pollination

QWERTY PHENOMENA
Like the arrangements of the keys on a keyboard,
QWERTY phenomena are phenomena that show
signs of history: a history of R&D (research and
development) using what’s available, and limited
or directed by contingencies and constraints…
Francis Crick called them “frozen accidents”
QWERTY phenomena abound in the organic
world.
QWERTY PHENOMENA
In our case:
Wisdom teeth, the blank spot in the center of each of our
eyes, the possibility of retinal detachment, our “tail
bone”, our back problems, (perhaps) our appendix,
relatively short gestational period, male nipples….
Other cases:
blind fish in dark caves, with eyes that don’t function,
but whose ancestors had functioning eyes
blind fish in dark caves, without eyes, whose ancestors
did have eyes
“toothless” species of whales in which embryos have
teeth and lose them during natal development
Part IV
Verifiability as the criterion that
distinguishes science from “pseudo”
science
What distinguishes science from pseudo-science?

Logical Positivism:
 Science
should and must be a positive force for
human wellbeing

Logical Empiricism (same movement):
 Working
to identify the role of logic and that of
experience in the workings of genuine science.

Both emphases underlie the work to identify the
criterion (or criteria) that demarcate science (i.e.,
distinguish it from) “pseudo-science” and “nonscience”.
What distinguishes science from pseudo-science?
Logical Positivism/ Logical Empiricism
 What motivated (and still does…) the question?
 Then:
 The rise of Nazism and fascism

 Science
as an antidote to ideologies
 Nazism claims “scientific status” for its claims

The “semi-eclipse” of Newtonian mechanics by
Relativity
What distinguishes science from pseudo-science?
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A.J. Ayer
A Logical Positivist
His target as “pseudo-science” (“nonsense” or
without meaning): statements that cannot be verified
by experience.
His criterion for literal/factual significance:
verifiability
A sentence is verifiable if and only if there are
observations that could verify it (demonstrate it is
true).
Verifiability comes to be accepted as that which
marks genuinely scientific claims, hypotheses,
theories
What distinguishes science from pseudo-science?


1.
2.
3.
If there are no such observations, it is not
literally or factually significant … but
“nonsense”
Compare:
“The Absolute … does not enter into
change.”
“There are mountains on the far side of the
moon.”
“The universe began with The Big Bang.”
Part V
Discussion
Discussion of Ayer
 Does
“the demarcation problem” matter
today?
 How does Ayer’s criterion of verifiability
help, if it does, in today’s context?
 How does it not? And, if not, why not?