Theory of Plate Tectonics An explanation of science and prediction

1. Theory of Plate TectonicsAn explanation of science and prediction

2. Real life situation • On December 26th 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)

3. Continued … • 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.

5. Knowledge issue • To what extent does prediction test the validity of a scientific theory?

6. 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 )

7. Roles of Scientific Theory • Prediction • Explanatory powers

8. What are the bases for prediction • Analysis of patterns • Patterns are recurring events

9. Where do we observe patterns? • Natural Sciences • Human Sciences

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

11. NATURAL SCIENCES

12. Theory of plate tectonics

13. Plate Tectonic Theory • Pattern • Prediction from pattern

15. Strength of the theory • 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

16. 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

17. 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

18. EVOLUTION

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

20. Strength of the theory It has explanatory power Use of evidence for example fossil records, homologous anatomical structures and artificial selection

21. 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

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

23. Initial Conditions

24. 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.

25. Periodicity

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

27. Mendeleev Periodic Table

28. Valance Shell Electron Pair Repulsion Theory (VSEPR)

29. 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

30. Strength of the theory • 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 H2O is V-shaped molecule

31. 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

32. Weakness of the theory • 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)

33. Scientific method • Hypothesis • Experimentation • Observation • Data collection • Conclusion

34. 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)

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

36. Why can’t we measure • The problem of observer effect – The physicist measuring devices interact with what he is measuring on subatomic level.

37. Prediction in Human sciences

38. 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.

39. Why Human scientists find it difficult to Predict

40. Problems of applying the scientific method in the Human sciences • 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-are-always-wrong/ ) • Sometimes the predictions are based on extrapolating well beyond what is reasonable.

41. The Phillips curve theory?

42. Example The Phillips curve

43. The butterfly Effect • 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

44. The Cassandra paradox • 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?

45. 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

46. 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.

47. Conclusion • 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.

48. Bibliography • “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> • “Scientific Theory". Wikipedia- the 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-are- always-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