1. Iberian peninsula, 1
  2. IBM, 1, 2 n. 3
  3. ice, 1, 2, 3 n. 3
  4. ice, fresh-water, 1
  5. ice ages, 1, 2, 3, 4, 5, 6, 7 n. 22, 8 n. 8;
    1. see also Snowball Earths
  6. ice caps, 1
  7. ice skating, 1
  8. Iceland, 1
  9. identity, personal, 1, 2
  10. imagination, 1
  11. immigration, 1
  12. immunity, 1, 2
  13. import tariffs, 1
  14. incandescence, 1
  15. Incas, 1
  16. incompleteness theorem, 1 n. 4
  17. India, 1
  18. Indonesia, 1
  19. industrial revolution, 1, 2, 3
  20. infinity, 1, 2, 3 n. 10
  21. inflation, 1
  22. information, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 n. 4, 16 n. 8, 17 n. 14, 18 n. 5, 19 n. 14, 20 n. 5
  23. information storage, 1
  24. InfoWorld, 1, 2 n. 14
  25. inheritance, 1, 2
  26. Institute for Advanced Study, Princeton, 1
  27. insulation, see electricity: insulation
  28. Intel, 1, 2
  29. intelligence, extraterrestrial, 1
  30. interbreeding, 1
  31. interglacial periods, 1
  32. internet, 1
  33. ion channels, 1
  34. ions, 1, 2 n. 6
  35. Iraq, 1
  36. iron, 1, 2, 3, 4, 5
  37. iron oxide, 1
  38. isotopes, 1 n. 3
  39. It’s Only a Theory, 1 n. 9