1. labour, 1
2. lactic acid, 1
3. Laetoli, Tanzania, 1, 2
4. lakes, 1, 2 n. 2
5. land, 1
6. Landau, Lev, 1
7. Lane, Nick, 1
8. language, 1, 2, 3, 4, 5, 6
9. Large Hadron Collider, 1, 2, 3, 4, 5
10. Larkin, Philip, 1
11. laser interferometer, 1
12. lasers, 1, 2, 3
13. ‘last scattering, epoch of ’, 1, 2 n. 2, 3 n. 10, 4 n. 8, 5 n. 14
14. latitude, 1 n. 11
15. lava, 1, 2
16. Lavoisier, Antoine, 1
17. lead, 1, 2
18. Leakey, Louis, 1
19. Leakey, Mary, 1
20. learning, see neurons
21. Leeson, Nick, 1
22. Leeuwenhoek, Antonie van, 1, 2
23. Leibniz, Gottfried, 1
24. Lemaître, George, 1
25. leptons, 1, 2, 3;
    1. indistinguishability, 1
26. Lessing, Doris, 1
27. Lewis, Gilbert Newton, 1
28. LHB (Late Heavy Bombardment), 1, 2 n. 2
29. light, 1, 2, 3, 4, 5, 6, 7, 8, 9 n. 21, 10 n. 14, 11 n. 2;
    1. bending, 1, 2, 3, 4;
    2. and black holes, 1 n. 4;
    3. blue, 1;
    4. diffraction, 1;
    5. interference, 1, 2;
    6. laser, 1, 2;
    7. and matter, 1;
    8. oscillation, 1;
    9. as particles, 1, 2 n. 4;
    10. red, 1;
    11. reflection, 1;
    12. speed of, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 n. 1, 13 n. 9;
    13. theory of, 1;
    14. transmission, 1;
    15. visible, 1, 2, 3, 4 n. 11;
    16. as waves, 1, 2, 3, 4, 5 n. 21, 6 n. 4;
    17. see also energy: light, lasers, light horizon, photons, red shift, ultraviolet light, wavelength, X-rays
30. light bulbs, 1, 2, 3, 4, 5, 6 n. 8
31. light horizon, 1
32. lightning, 1, 2, 3, 4, 5, 6 nn. 6, 7; 7 n. 18, 8 n. 19
33. LIGO (Laser Interferometer Gravitational Observatory), 1
34. limbic system, 1;
35. amygdala, 1;
    1. hippocampus, 1;
    2. hypothalamus, 1
36. lipids (fatty acids), 1
37. liquids, 1
38. literacy, 1
39. lithium, 1, 2
40. liver, 1
41. liver cells, 1
42. Livio, Mario, 1 n. 23
43. llamas, 1
44. Llinás, Rodolfo R., 1
45. location, 1, 2, 3, 4, 5, 6 n. 6, 7 n. 3, 8 n. 5;
    1. dual, 1
46. logic gate, see computers
47. Lorentz contraction, 1
48. Lorenz, Edward, 1
49. Los Angeles, 1
50. Lovelock, James, 1
51. LSD (lysergic acid diethylamide), 1
52. LUCA (last universal common ancestor), 1
53. lungs, 1
54. Luther, Martin, 1
55. lysosomes, 1