Transcript Feynman ch2 - Baylor University

• “The great difficulty is in trying to imagine
something that you have never seen,
• that is consistent in every detail with what you
have seen,
• and that is different from what has been thought
of;
• furthermore it must be definite and not a vague
proposition.” Feynman page 23
Thinking About Health & Disease:
The Power of Epidemiology
• Example: causes of disease
• Florence Nightingale: a pushy rich dame
who could count and knew the power of
metaphor and men
• John Snow: an anesthesiologist who could
imagine what he could not see and who
could put pins in a map
Florence Nightingale
• Used a powerful metaphor to inspire people
to do the right thing for the wrong reason
• Metaphor: disease as response to lack of
harmony, organization, and cleanliness
• Common terms of early 19th century:
miasma, contagion, fermentation
• Lack of doubt -- would have meant no role
for the nurse
Definition of Disease
• “... the thing which strikes the experienced
observer most forcibly... the symptoms or
the sufferings generally considered to be
inevitable and incident to the disease are not
symptoms of the disease at all, ...
• of the want of fresh air, or of light, or of
warmth, or of quiet, or of cleanliness, or of
punctuality and care...”
What is Infection:
• I was brought up, both by scientific men
and ignorant women... to believe that smallpox was a thing of which there was once a
first specimen in the world which when on
propagating itself...just as there was a first
dog (or a first pair of dogs)
• With a little overcrowding, continued fever
grow up, a little more typhoid fever.. typhus
19th Century Reasoning Revolution
• Formalistic
philosophical
assumptions
• Abstract reasoning
• Belief in miasma,
damp, filth, lack of
moral purity, or
harmony as general
causes of all disease
• Statistics
• Disciplined
observations
• Belief in specific
environmental causes
for specific diseases
• Cause could reproduce
indefinitely -- has to
be living thing
John Snow & Broad Street Pump
(1864)
• Observed both changes in human body with
“Cholera” and changes across person, place,
and time in cases of Cholera
• Epidemiological reasoning: clusters of cases
around one pump, but also most cases got
water from Southwark& Vauxhall
• Imagined an explanation
Signs of Cholera
• diarrhea, vomiting, and muscle cramps;
possible coma and death
• 19th century scientists found increased
amount of serum to solids and more acidity
(gave unsterile saline injections)
• Snow observed intestine and saw changes
that convinced him gut was source, not
blood
Geographical Variation of Cases
• Map of London to show where two major
water companies were located
• Snow walked around London and marked
where cases occurred on a map
• Asked each household where they got their
water
• Predecessor of the Odds Ratio
Odds of Getting Cholera
• Lambeth served 26,000 houses; 14 died
• Southwark & Vauxhall served 40,000
houses; 286 died
– 14/26000=.000538
– 286/40000=.00715
– Odds ratio= .00715/.000538=13.3
Scientific Progress
• Koch discovered the Cholera Vibrio in 1883
• We have antibiotics and a vaccine
• We also have epidemics of Cholera that
have swept accross most of Latin America
infecting over 1,000,000 and killing 10,000
• Does the Cholera Vibrio kill?
• How can we interrupt transmission?
Transmission Mechanisms
• Waterborne
– municipal water
– putting hand in water vessel
• Food borne
– street vendors’ foods & beverages & ices
– leftover rice
– fruits/vegetables
• Seafood -- uncooked and cooked
another quote
• “You have to permit the possibility that you
do not have it exactly right.”
• “If you have made up your mind already,
you might not solve it.” Feynman page 27
Feynman ch2
Religion: the way people believe
about their religious beliefs
Most (natural) scientists do not
believe in God
• they were taught?
– No
• they know it all?
– No
• they do not understand science correctly?
Belief in science and religion is
consistent, but difficult
• It is valuable and necessary to doubt in
science
• Conflict between partial facts of science and
beliefs
• Science does not impact on moral conduct
and ethical views
Religion is
• Metaphysical
–
–
–
–
–
what things are
where they came from
what man is
what God is
properties of God
• Ethical: how to behave
• Inspirational:
motivates to act well,
and inspire arts
– science sometimes
conflicts with 1 and 2
(should not 2?)
Moral values (ethics) lie outside
the realm of science
• conflicts (earth as center of universe) led to
change in metaphysics, but no change in ethics
• Some practice Christian ethics without being
Christian
• No external scientific evidence that the Golden
Rule is good
• "Should I" has two parts
– scientific: what will happen? (positive)
– ethical: do I want that outcome? (normative)
illustrations:
the importance of individuals
vs the importance of the group(s)
• the Golden rule: individuals suffer
voluntarily
– uberimae fideii
– public education
• First, do no harm
– innovation in pharmaceuticals
– genetic research
illustrations continued
• Star Trek: The needs of the many vs, the
needs of the few.
– welfare/redistribution
– salary caps
– life insurance premia
•
•
•
•
smoking
sex
race
religion
– discriminate on basis of things under your
control
illustrations continued
• Pareto improvement:
Everyone at least as
well off, and one party
better
– the notion of
externalities: safety,
pollution
– theory of comparative
advantage
Elverum
Mordor
Trucks
5
4
Computers
10
2
• Max production if all
resources allocated to one
good
• in Elverum, 1C = .5T
• in Mordor, 1C = 2 T
– these ratios are from a
production frontier, not
shown
Elverum
Mordor
4
2
Computers 2
1
Trucks
• Let Elverum produce
more computers
– = 4 computers, 3 trucks
• Let Mordor produce
trucks
– = 4 trucks, 0 computer
Elverum
Mordor
4
3
Computers 3
1
Trucks
• Let Morder send 1
truck for 1 computer
– M has 3 trucks, 1 C
– E has 4 trucks, 3 Cs
What happened?
• Because the relative costs of production
were different, total (world) production rose
through specialization and trade
– more computers, and more trucks
• Called the “theory of comparative
advantage.
illustrations continued
• Jesus improvement: Everyone better off,
but one incredibly worse off
–
–
–
–
break up IBM
break up ATT
Microsoft???
deregulation?
Virtue as a basis for ethics
•
•
•
•
•
•
•
Honor
honesty
integrity
temperance
fidelity
humility
patience
•
•
•
•
•
Persistence
modesty
reliability
Loyalty
Recall Smith
–
–
–
–
Prudence
Benevolence
Justice
Self-command
Value: The role of government
• Laissez Faire
– Smith and the “invisible hand”
• Fiscal policy
– John Maynard Keynes
• Monetary Policy
– Milton Friedman
Western Civilization is built on
two heritages
• humility of the intellect: "scientific spirit of
adventure”
• humility of the spirit: Christian ethics
Russia v. US
• Suppression of ideas v. free ideas,