Lecture 6: 25th September

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Lecture 6 25th September
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Whats expected

• Details of scientific episodes not required.
• This course is about skills, not facts.
• The exercises in the book give you the idea.

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The Revolution in Geology

• The Contractionist Hypothesis
• The Earth was formed as a molten sphere that
  gradually contracted as it cooled.
• Stabilism The hypothesis that oceans and land
  masses do not move around.

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Mobilism

• Alfred Wegener (1915) proposed that the original
  cooling produced one land mass - Pangea that
  has since broken up.

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1920s Evidence for Mobilism

• 1. The matching coastlines of Africa and South
  America

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• 2. There are mountain ranges on the western edges
  of North and South America, but not on the
  eastern edges
• 3. The similarities among plants and animals in
  places like Africa and South America

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Analysis 1920s Evidence

• 1. Real World. The structure and history of
  oceans and land masses on Earth.
• 2. Model. Wegeners model of a planet with
  drifting continents.
• 3. Prediction. The model predicts the matching
  coastlines of Africa and S America, the mountain
  ranges along the western edges of North and South
  America, and the similarities of plants and
  animals in places like Africa and S America.
• 4. Dat. The data match the prediction
• 5. Negative evidence? No.
• 6. Positive evidence? Could the contractionist
  model account for the evidence? The similarities
  in plants and animals could be explained by land
  bridges that have sunk. The matching coastlines
  and mountain ranges could be due to chance.

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Evidence for Mobilism

• Radioactivity. If there were radioactive decay in
  the Earth, it would be hot enough to produce
  convection currents of molten rock.

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Geomagnetism

• The core of the Earth is magnetic, and switches
  poles over millions of years.

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• Molten material rising to the surface is free to
  orient itself with the Earths magnetic field.
• When it gets to surface and spreads out, it cools
  and the magnetized material is locked in place.
• Researchers in the 1960s found such alternating
  magnetic strips.

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Analysis 1960s Evidence

• 1. Real World. The structure and history of
  oceans and land masses on Earth.
• 2. Model. Wegeners model of a planet with
  drifting continents.
• 3. Prediction. The prediction is that alternating
  strips of magnetic material will be found
  parallel to oceanic ridges.
• 4. Data. The data match the prediction
• 5. Negative evidence? No. The prediction and data
  agree.
• 6. Positive evidence? Could the contractionist
  model account for the evidence? No.

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Pseudoscience and Marginal Science

• Philosophers have tried to find criteria to
  demarcate science from pseudoscience. But the
  search, as ever, has been unsuccessful.
• So it is better to classify some area as marginal
  science inquiries in which the data is
  consistently inconclusive.

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Dodgy science Tricks to look for

• 1. No predictions just accommodate the data.
• 2. Vague predictions make any possible facts
  look like they were predicted.
• 3. Cherry-picking the data.
• 4. Argue by elimination there are no contenders
  other than my theory.
• 5. Shift the burden of proof. Theres no
  evidence against my theory.

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Freudian Psychology

• Conscious Everything of which
• we are aware
• Preconscious Everything we
• can remember. Thoughts of
• which we can become aware.
• Unconscious Drives and impulses of which we are
  not aware.

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Freudian Psychology

• Superego The moral component of the psyche.
• Id The impulsive, child-like component of the
  psyche.
• Ego The rational component that attempts to
  strike a balance between the superego and the id.

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Superego
Conscious
Ego
Preconscious
Id
Unconscious
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Defence mechanisms

• The ego has to balance the conflicting desires of
  the id and superego.
• It has various mechanisms for coping with the
  stress
• Denial, repression, and displacement.
• But repressed desires can surface from the
  unconscious.
• Bringing the desires into consciousness through
  psychotherapy would resolve the conflict.

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Case study Little Hans

• Problem Little Hans irrational fear of horses.
• Background story The previous summer Hans had
  spent lots of time with just his mother. Now they
  were living with his father, and Hans was
  spending less time with his mother as a result.

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• Freuds Hypothesis
• Hans was afraid of his father (Id). The superego
  had been taught that one should love ones
  parents.
• So Hans ego repressed his fear of his father and
  projected it onto horses.

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• Bringing this conflict into the conscious mind
  should resolve it.
• The father also re-assured Hans that he was not
  angry with him for wanting to spend time with his
  mother.
• The symptoms did lessen somewhat over the next
  few days.
• The symptoms disappeared over the next few
  months.

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Analysis

• 1. Real World. The object of study is Little Hans
  and his fear of horses.
• 2. Model. Freuds model of psychological
  development and structure.
• 3. Prediction. Freuds model predicts that
  bringing the conflict into consciousness will
  eliminate the abnormal behaviour.
• 4. Data. After treatment, Hans fear of horses
  lessened and eventually disappeared
• 5. Negative evidence? No. The data and prediction
  agree. (Time span?)
• 6. Positive evidence? Would the abnormal
  behaviour have gone away even if Freuds model
  didnt fit the case? Probably. Young children are
  very changeable.

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Verdict Mixed

• Freud Set psychiatry back one hundred years
  H. J. Eysenck
• Freud knew from the very start thathispatients
  were not cured, and yet he did not hesitate to
  build grand theories on these non-existent
  foundations...he disguised fragments of his
  self-analysis as objective cases, that he
  concealed his sources, that he conveniently
  antedated some of his analyses, that he sometimes
  attributed to his patients free associations
  that he himself made up, that he inflated his
  therapeutic successes, that he slandered his
  opponents - Mikkel Borch-Jacobsen

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Extra-terrestrial visitation

• Percentage of children aged 6 and 7 interviewed
  by a British researcher who say they believe in
  Santa Claus
• 31
• Percentage of Canadians in an Angus Reid /
  Southam News poll who say Earth has been visited
  by aliens
• 55
• From Spectrum Statistical lore for everyday
  living by Warren Clements.

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• Number of stars in our galaxy 10 11
• Suppose 10 have planets 10 10
• Planet not too far or too close to star
• 10 8
• Planet not too big or small 10 7
• Life evolved 10 6
• Our galaxy has a volume of 10 14 cubic light
  years.
• On average, each life-supporting planet occupies
  a volume of 10 14 / 10 6 10 8 light years.
• Estimated distance to next life-supporting
  planet 8th root of 10 8 500 light years.
• The nearest star is 4.3 light years away.

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Von Daniken Evidence

• Many different cultures have myths about gods who
  came from the heavens and performed great feats.
• The huge temples and pyramids in Egypt and Peru.
• The carved stones of Easter Island.

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• Positive evidence for alien visitation would
  require that no alternative hypothesis can
  reasonably explain the data.
• But ancient methods for constructing such objects
  is well documented even by the anthropologist
  von Daniken cites.

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• 1. No predictions just accommodate the data.
• 2. Vague predictions make any possible facts
  look like they were predicted.
• 3. Cherry-picking the data.
• 4. Argue by elimination there are no contenders
  other than my theory.
• 5. Shift the burden of proof. Theres no
  evidence against my theory.