Changing Planet: Past, Present, Future

Lecture 2 – Building Scientific Knowledge: The Story of Plate Tectonics

by Naomi Oreskes, PhD
  1.  1.  Start of Lecture Two
  2.  2.  Profile of Dr. Naomi Oreskes
  3.  3.  Science as a process, not a body of knowledge
  4.  4.  Building scientific knowledge is a community effort
  5.  5.  Scientific methods come in many forms
  6.  6.  Scientific knowledge requires consensus building
  7.  7.  Plate tectonics: The unifying theory of modern earth science
  8.  8.  Historically, continents were thought to be fixed in position
  9.  9.  Demo: Principle of Isostasy
  10. 10.  Wegener's evidence for continental drift
  11. 11.  Animation: Continental Movement Over the Last 200 Million Years
  12. 12.  Demo: Isostasy Is Key to Understanding Continental Drift
  13. 13.  Despite evidence, continental drift was initially rejected
  14. 14.  Q&A: Why was all of early Earth's land in one place?
  15. 15.  Q&A: Why do the continents change shape as they move?
  16. 16.  Q&A: Is the mantle solid or liquid?
  17. 17.  Q&A: Can we predict the future locations of the continents?
  18. 18.  Subduction: a possible mechanism for continental drift
  19. 19.  Animation: Daly's Model of Subduction
  20. 20.  Another model for continental drift based on convection
  21. 21.  Animation: Holmes's Model of Convection
  22. 22.  Why was the theory of continental drift rejected?
  23. 23.  Inductive versus deductive approaches to science
  24. 24.  Rejection of continental drift: Politics and science
  25. 25.  Hess's work on gravity anomalies supports continental drift
  26. 26.  Data from geomagnetism and seismology also supported continental drift
  27. 27.  Plate tectonics and continental drift accepted
  28. 28.  The nature of scientific consensus
  29. 29.  Science is not about "proof"
  30. 30.  Q&A: Why do magnetic reversals occur?
  31. 31.  Q&A: Has there been a time when the continents did not move?
  32. 32.  Q&A: Can we predict the next magnetic reversal?
  33. 33.  Q&A: What are gravity anomalies?
  34. 34.  Q&A: What does "negative gravity" mean?
  35. 35.  Q&A: Does magnetic pole reversal occur gradually?
  36. 36.  Q&A: What caused the Virginia earthquake in 2011?
  37. 37.  Q&A: Is inductive or deductive science more accepted?
  38. 38.  Q&A: Is the process of inductive science still used?
  39. 39.  Q&A How does inductive science work?
  40. 40.  Credits


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