Scientific Method

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Scientific Method

• What is Science?

What sciences have we, as a group, studied?
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What is Science?
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Scientific Method The Process of Science
General
Specific
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The Story of Semmelweiss

• The Problem 2 maternity wards at Vienna General
  Hospital (mid 1800s)
• Medical school ward 11-13 mortality rate from
  puerperal fever
• Second ward (mid-wives) 2-3 mortality rate

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Hypotheses Tested

• Overcrowding
• Diet
• General care
• Psychological factors
• Delivery position

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A Clue

• A doctor was cut doing an autopsy and died from a
  fever very similar to childbed fever
• New hypothesis
• Doctors might be carrying cadaveric matter from
  autopsy room directly to maternity ward

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The rest of the story

• Obstetricians virtually declared war on
  Semmelweiss
• He died without ever knowing that his discovery
  caused puerperal fever to nearly disappear
• Statements of opponents

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Scientific Method
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Limitations of Science

• Certainties
• Specialized focus
• Empirical Epistemology
• Objectivity
• Non-subjectivity
• Repeatability

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Limitations of Science

• Uncertainties
• Methodological
• Error
• Problem of Induction
• Confirmation Paradox
• Presupposition (faith)
• Intrinsic
• Statistical uncertainty
• Heisenberg uncertainty

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Revolutions In Science

• Astronomy a science that developed about the
  same time as accounting in ancient cultures

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Aristotle (384-322 BC)

• Geo-centric
• Perfect circular motion of stars around the earth
  (on 45-55 crystal spheres)
• Problem could not explain retrogression of
  planets

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Ptolemy (127-151 AD)

• Retained perfect circular motion
• Added 4 theoretical devices
• Deferent
• Epicycle
• Eccentric
• Equant
• These devices used in about 80places to account
  for the astronomical observations of the time

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Copernicus (1473-1543)

• Theoretical objections to Ptolemy
• To make his system work, he put sun in middle
  which simplified computations
• With new system, only 34-48 devices needed to
  explain apparent movements
• The system was more elegant
• Its predictions were no better than Ptolemys
  system

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Crisis Arises Due to Technology

• Better instruments seemed to support Copernicus
  rather than Ptolemy
• Galileo (1564-1642) proposed that the earth
  really did move around the sun
• Had to recant his ideas in 1633 to avoid
  excommunication

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Kepler (1571-1630)

• Assignment map the orbit of Mars
• 6 years of work, 9,000 pages of calculations
• Observed position differed from predicted
  position by 8 minutes of arc
• 1/4 apparent diameter of full moon

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Morals of the Story

• New facts alone do not necessarily make a new
  theory
• New facts alone do not destroy an outlived theory
• Consensus is important
• The role of beauty (art?)