Reading 14

This passage is taken from a book entitled Water: The Fate of Our Most Precious Resource by Marq De Villiers (© 1999 by Marq de Villiers).

1. Where did water come from? The 
2. most common assumption is that 
3. the earth itself is around 4.6 billion
4. years old, formed by gravity from 
5. cosmic junk, clouds of ionized 
6. particles around the sun, debris 
7. left over from the somewhere-
8. sometime explosion called the Big 
9. Bang. This cosmic garbage dump
10. coalesced to form a protoplanet, 
11. which grew by gravitational attraction 
12. of even more junk (what the 
13. cosmologists call “particulates”). 
14. This was the Hadeon Eon: a sort-of 
15. Earth existed, but there was no 
16. atmosphere, no ozone layer, no 
17. continents, and no oceans – and 
18. most definitely no life. 
19. Around half a billion years later, 
20. give or take an eon or two, things 
21. had settled down enough to 
22. precipitate rocks; the oldest known 
23. rocks are in Greenland, and have 
24. just celebrated their 3.9 billionth 
25. birthday. The earth was still aflame 
26. with volcanoes and bombarded by 
27. asteroids, meteorites, and whatever 
28. else was floating in the interstellar 
29. void and intersecting with our nascent 
30. planet, but those oldest rocks show 
31. signs of having been deposited in 
32. an environment that already 
33. contained water. There is no direct 
34. evidence for water for the period 
35. between 4.6 and 3.8 billions years 
36. ago. But suddenly, there it is. 
37. The prevailing theory is that the
38. atmosphere was created from the
39. release of gases from volcanic eruptions.
40. As the eons passed, the first lightweight
41. silica and aluminum rocks, which are
42. typical of continental land masses,
43. formed. The surface of the earth
44. cooled, and water vapor in this spanking
45. new atmosphere condensed to form the
46. water of the oceans. Which begs the
47. question: Where did the water vapor in
48. the atmosphere come from in the first
49. place? What was it in the volcanism
50. that was our first “weather” that
51. produced water? Or perhaps it was
52. already present in all that cosmic
53. junk – comets, after all, are sometimes
54. little more than frozen lakes of water –
55. and it came from space, an alien and
56. infinitely curious little molecule. For
57. water is curious, much more curious
58. than it might at first sight appear,
59. and is actually little understood. Why
60. is it, for instance, that water is the
61. only substance whose solid form is
62. less dense that its liquid one (a
63. phenomenon that has profound
64. implications for aquatic life)?
65. Scientists have discovered that water
66. is made up of hexagons of hydrogen
67. atoms arranged in what is called a
68. “cage” structure, and that the
69. smallest theoretical drop of water
70. is made up of six molecules arranged
71. as a cage. Which means what? No
72. one really knows.
73. In any case, water appeared,
74. precipitated from what were not
75. yet called the heavens. Then, around
76. 2.5 billion years ago, life on earth
77. began. And it almost certainly began
78. in water.
79. Darwin and the early evolutionists
80. imagined life evolving in a pool of
81. soupy, chemical- and nutrient-rich
82. water, an idea still pretty much
83. accepted today, although there is a
84. small but influential scientific subset
85. that believes that life, too, might have
86. come to us from space, ready formed,
87. cosmic nuggets among the infinite
88. dross.
89. “Runoff collected in a small volume
90. is the most likely means of achieving
91. the necessary concentration of
92. ingredients,” says Gustaf Arrhenius,
93. a geochemist at the Scripps Institute
94. of Oceanography. In the dry language
95. of chemists he writes: “Ponds may
96. have further concentrated
97. compounds on the internal
98. surfaces of sheet-like minerals,
99. which attract certain molecules
100. and act as a catalyst in the
101. subsequent reactions. Two
102. aldehyde phosphate molecules
103. thus united form a sugar phosphate,
104. a possible precursor to organic life”
105. – as though that explained anything
106. at all.