 On December 26 th 2004 there was a great earth quake that happened in Sumatra
Andaman. Actually scientists didn ’ t predict the event would occur because, due to the theory, the area was believed to be immune to such giant earth quakes and hence, this made scientists rethink the theory of plate tectonics.
(http://www.sciencedaily.com/releases/2007/01/070109142217.htm)

 The theory says that giant earth quakes occur in fast, young subduction zones.
However, this particular incident happened in a middle aged and slowly moving subduction zone.

 To what extent does prediction test the validity of a scientific theory?

 A scientific theory is a well supported body of interconnected statements that explains observations and can be used to make testable predictions.
( en.wikipedia.org/wiki/Scientific_theory )

 Prediction
 Explanatory powers

What are the bases for prediction
 Analysis of patterns
 Patterns are recurring events

 Natural Sciences
 Human Sciences

Theories to be considered in this presentation
 Plate Tectonics
 Evolution by Natural Selection
 Valance shell Electron Pair Repulsion
Theory
 Phillips Curve

 Pattern
 Prediction from pattern

 Normally able to predict places where the giant earthquakes and volcanic eruptions likely to happen.
 Able to predict the magnitude of earthquake, volcano or tsunami.
 Provides a mechanism to explain continental drift theory

Possible areas of weakness of theories in general
 Sometimes Impossible to experiment
 Danger overgeneralization (problem of induction)
 Obtaining precise prior knowledge
(measurement difficulties)
 Influence observer effect (uncertainty principle)
 Complexity and interacting variable

Implication of the event on the theory
 Scientists are rethinking their theory, based on data collected after the earthquake
 Re-examining some of the pre-December
2004 assumptions scientists made about such rare events.
 Some of this assumptions were, giant earth quakes occur only in fast, young subduction zones

Evolution
The future course of evolution
Can the theory of evolution make predictions?

It has explanatory power
Use of evidence for example fossil records, homologous anatomical structures and artificial selection

Possible areas of weakness of theories in general
 Sometimes Impossible to experiment
 Danger overgeneralization (problem of induction)
 Obtaining precise prior knowledge
(measurement difficulties)
 Influence observer effect (uncertainty principle)
 Complexity and interacting variable

 Evolution is more sensitive to initial conditions, so specific predictions about what mutations will occur and what traits will survive are impractical. (Abel,145)

Initial condition
Gene Mutation
Environmental Effect
Food availability
Predator effect
Weather condition
Gene combinations

 But not all scientific theories are able to make testable predictions?
 No scientific theory can ever be used to make predictions unless the initial conditions are specified: and all theories require elimination of irrelevant factor ”
( Reuben Abel)
This is a difficulty for both the human scientists and
Evolutionary Biologists.

 Periodicity - refers to the repeating pattern of physical and chemical properties that is seen at regular interval in the periodic table.

Valance Shell Electron Pair
Repulsion Theory (VSEPR)

Valance shell electron pair repulsion theory (VSEPR)
 mainly involves predicting the layout of electron pairs surrounding one or more central atoms in a molecule, which are bonded to two or more other atoms. The geometry of these central atoms in turn determines the geometry of the larger whole. It is also a model in chemistry used to predict the shape of individual molecules based upon the extent of electron-pair electrostatic repulsion

 It plays a great role in predicting the structure of a compound by looking at the geometrical structure of the central atom and using the valance shell electrons.
 To determine the melting and the boiling of a compound.
 For Example H
2
O is V-shaped molecule

Possible areas of weakness of theories in general
 Sometimes Impossible to experiment
 Danger overgeneralization (problem of induction)
 Obtaining precise prior knowledge
(measurement difficulties)
 Influence observer effect (uncertainty principle)
 Complexity and interacting variable

 It is Qualitative and hence, we can not talk about the quantitative properties of the compounds for instance we can not determine the exact degree of repulsion between each bonds.
 This theory can not apply to all compounds for instance Benzene is exceptional to the rule
(Overgeneralization)

 Hypothesis
 Experimentation
 Observation
 Data collection
 Conclusion

Uncertainty principle: Heisenberg
 This principle states that it is impossible to know the exact position and momentum of an electron.
As momentum is related to time, what this implies is that it is impossible to know the exact location of an electron at an exact momentum in time. The more precisely the location is known, the less precisely the time known and vice versa. Heisenberg ’ s principle applies to any particle with mass, but the more massive the less the uncertainty of the particle. (Neuss,35)

Uncertainty principle: Heisenberg
 Scientists are using as base where there is a high probability that electrons are located in order to make prediction
 This applies to the whole of the physical universe for example in describing the three dimensional shapes of atomic orbital where there is a high probability that electrons are located

 The problem of observer effect – The physicist measuring devices interact with what he is measuring on subatomic level.

What enables Human Scientists to predict?
 The law of large numbers
 Reasoning enables us to establish a relationship between particular experience and more broadly general ones with in the world we perceive.
 Once we have explained the last event satisfactorily we can predict the up coming
 Through evidence, we can associate cause and effect, make correlations and predict.
 Understanding of pattern allows us to predict.

Why Human scientists find it difficult to Predict

Problems of applying the scientific method in the Human sciences
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Impossible to carry out controlled experiment
Too many variables
Some observation biased
Individual behavior is unpredictable
The weakness of baseline assumptions limit the predictive ability of human sciences
“ It doesn ’ t matter if the assumptions are wrong as long as one can extract general rules from which one can make predictions ” ( perbylund.com/.../why-economists-predictions-arealways-wrong/
)
Sometimes the predictions are based on extrapolating well beyond what is reasonable .

Example
The Phillips curve

 The prediction of the behavior of any large system is virtually impossible unless one could account for all tiny factors
 A small change in some tiny variable may cause larger variation in a dynamic system

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Example of interaction between a social investigator and what is been investigated
Unlike in natural science there is unavoidable interaction between the predictor and the people for whom the prediction is made
Human tend to try to falsify the predictions made about them
“ A prediction to you about you may motivate you to defy the prediction ” (Abel,116)
What about our measurements from thermometer?

Possible areas of weakness of theories in general
 Sometimes Impossible to experiment
 Danger overgeneralization (problem of induction)
 Obtaining precise prior knowledge
(measurement difficulties)
 Influence observer effect (uncertainty principle)
 Complexity and interacting variable

Implication on theory of plate tectonics
 There are things scientists can ’ t really measure but this variable may cause unpredicted effects. For instance exact measurement of the speed and age of plate is difficult.

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In our presentation we have talked about the role of prediction in validating a scientific theory.
As we have seen from the 2004 tsunami incident our theories fail sometimes to predict.
Mismatch between theory of plate tectonics and
2004 tsunami
Uncertainty principle and observer effect
Historical approach versus experimental approach
But there are other qualities to validate scientific theory such as explanatory powers.


“ Sumatra Earthquake: New Data Overturn Common View That Great
Earthquakes Only Occur In Fast, Young Subduction Zones ” . sciencedialy. Jan. 10, 2007
.
Oct. 1, 2009.
< http://www.sciencedaily.com/releases/2007/01/070109142217.htm
>
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“ Scientific Theory". Wikipediathe Free Encyclopedia . 2009.Nov. 3, 2009.
< en.wikipedia.org/wiki/Scientific_theory >
Bylund, Per. “ Why Economists ’ Predictions are Always Wrong ” .2009.
Nov. 3, 2009 . http://perbylund.com/blog/2009/05/why-economists-predictions-arealways-wrong/
Neuss, Geoffrey. Chemistry course companion. Oxford, USA: Oxford university press 2007. Nov. 3, 2009.
• Abel, Reuben. Man Is The Measure. New York: THE FREE PRESS 1976. 1
Oct 2009