1. GABA (gamma-aminobutyric acid), 1
2. Galápagos archipelago, 1, 2, 3
3. galaxies, 1, 2, 3, 4, 5, 6, 7 n. 10, 8 n. 1, 9 n. 5, 10 nn. 14, 15;
   1. ancient, 1;
   2. clusters, 1;
   3. distant, 1, 2;
   4. expansion, 1, 2;
   5. formation, 1, 2, 3, 4 n. 5, 5 n. 1, 6 n. 5, 7 n. 14;
   6. and gravity, 1, 2, 3, 4, 5, 6 n. 10;
   7. as image, 1, 2;
   8. intelligent life, 1;
   9. light from, 1, 2, 3, 4;
   10. number, 1, 2;
   11. radio emission, 1;
   12. recession, 1, 2;
   13. spiral, 1 n. 15;
   14. see also Andromeda Galaxy, black holes, dark matter, jets, Milky Way Galaxy, quasars, stars
4. Galbraith, John Kenneth, 1, 2
5. Galileo Galilei, 1, 2, 3 n. 9
6. gallium, 1
7. games consoles, 1
8. gametes, 1, 2;
   1. fusion, 1, 2 n. 15
9. gamma rays, 1 n. 11, 2 n. 6
10. gases, 1, 2, 3;
    1. inter -stellar, 1;
    2. pressure, 1 n. 13
11. gathering, 1, 2;
12. see also hunter-gatherers
13. Gauguin, Paul, 1
14. Gaussian distribution, 1
15. GDP (Gross Domestic Product), 1
16. Geiger, Hans, 1, 2
17. Gell-Mann, Murray, 1
18. genes, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 n. 15;
    1. activation, 1 n. 7;
    2. blood group, 1;
    3. combination, 1, 2;
    4. copying, 1;
    5. dominant, 1;
    6. expression, 1;
    7. eye colour, 1;
    8. human, 1;
    9. microbial, 1;
    10. mutation, 1, 2, 3, 4;
    11. recessive, 1;
    12. regulatory, 1, 2;
    13. sequence, 1 n. 6;
    14. see also alleles, diploid, haploid
19. genetic code, 1
20. genetic defects, 1
21. genetic engineering, 1, 2, 3
22. genetics, 1, 2, 3;
    1. see also DNA
23. Geneva, 1, 2, 3
24. genitalia, 1;
    1. insect, 1
25. genius, 1 n. 6
26. genome, human, 1
27. geology, 1
28. geometry, 1;
    1. see also space–time: warpage
29. Georgia, 1
30. Germany, 1
31. Germer, Lester, 1, 2 n. 8
32. Germonpré, Mietje, 1 n. 6
33. gibbons, 1
34. Gladstone, William, 1
35. glial cells, 1 n. 17
36. Global Positioning Satellites, 1;
    1. orbit, 1
37. global warming, 1, 2, 3, 4 n. 1
38. glucose, 1
39. gluon field, 1, 2
40. gluons, 1
41. glutamate, 1, 2, 3
42. gluteus maximus (bottom muscle), 1, 2
43. goats, 1
44. Gödel, Kurt, 1 n. 4
45. gold, 1, 2, 3;
    1. as currency, 1, 2
46. Gold, Thomas, 1 n. 5
47. Golgi apparatus, 1
48. gonad cells, 1, 2
49. gorillas, 1
50. Gould, Stephen Jay, 1
51. government, 1
52. Grahame, Kenneth, 1 n. 2
53. granite, 1, 2 n. 7
54. gravitational force, 1, 2, 3
55. graviton, 1, 2
56. gravity, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 n. 1 infra, 19 n. 2, 20 n. 5, 21 n. 21, 22 n. 13, 23 n. 15, 24 n. 18, 25 n. 4, 26 n. 6 infra, 27 nn. 8, 9, 10; 28 n. 12, 29 n. 10, 30 n. 8, 31 n. 11, 32 n. 13, 33 nn. 14, 15; 34 n. 5;
    1. Newton’s theory of, 1, 2, 3;
    2. and planets, 1, 2 n. 2, 3 n. 17, 4 n. 23;
    3. repulsive, 1, 2, 3 n. 16, 4 n. 11;
    4. universal law of, 1, 2, 3, 4, 5, 6 n. 3;
    5. see also acceleration, galaxies: and gravity, red shift: gravitational, waves: gravitational
57. Great Eastern, 1 n. 4
58. Greece, 1
59. Greeks, 1, 2, 3, 4
60. Greene, Graham, 1
61. greenhouse gases, 1, 2, 3 n. 22, 4 n. 1
62. Greenland, 1, 2;
    1. ice sheet, 1
63. Greenspan, Alan, 1, 2
64. guanine, 1
65. guns, see weapons
66. Guth, Alan, 1
67. Gwynne, Peter, 1