ഭൂമിയെ മൂടാൻ അത്രയും ഉപ്പ് ! — Transcript

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1. 0:01Have you ever tasted
2. 0:03seawater? What a question, right?
3. 0:06It's a salt that completely
4. 0:08overwhelms our tongue, that
5. 0:10water. Have you ever wondered how
6. 0:12so much salt got into the sea?
7. 0:15Could it be through the rivers?
8. 0:18If so, the river water should
9. 0:20have salt too. But that's not the case.
10. 0:23River water is clear and pure.
11. 0:26Then is it through the rain? That's unlikely too.
12. 0:30Rain is pure water as well. So then,
13. 0:33where did all this salt come
14. 0:35from?
15. 0:53In any case, this much salt didn't
16. 0:56come to the sea all at once — that much we can be sure of. It
17. 0:59was accumulated,
18. 1:01drop by drop, over billions
19. 1:03of years. But how did that salt
20. 1:06come into the sea?
21. 1:10Rain — when a drop of rain falls
22. 1:13down from the sky, it is not just
23. 1:16water. The carbon dioxide in the
24. 1:18atmosphere dissolves into that
25. 1:20drop, and then it turns into a mild acid —
26. 1:23carbonic acid. That acid falls on the mountains,
27. 1:27falls on the rocks,
28. 1:29flows through the rocks. Each drop
29. 1:32draws something invisible out of
30. 1:34the rock — sodium, chlorine,
31. 1:37calcium, magnesium. In other
32. 1:41words, the ingredients of salt. With those
33. 1:44minerals, the water flows down
34. 1:46together, becomes a stream, then becomes a river.
35. 1:50The very same river water we call
36. 1:52"pure" and drink. Yes, that
37. 1:56water has salt in it — just not
38. 1:59in an amount our tongue's taste
39. 2:01buds can detect. And so, all the rivers finally
40. 2:04arrive at one place.
41. 2:16The journey of the water that reaches the sea
42. 2:18does not end there. It then enters
43. 2:20another process —
44. 2:22evaporation. In the sun's heat, the water
45. 2:25rises as vapor, becomes a cloud,
46. 2:28and becomes rain again. But the salt
47. 2:31that the water brought stays
48. 2:33right there. One year, a thousand years, ten
49. 2:37million years — for nearly 4 billion years, this
50. 2:41process has continued.
51. 2:44The rivers bring it, the sea keeps it.
52. 2:47Today, every liter of seawater has, on average,
53. 2:4935 grams of salt. If you gathered all the salt in the sea
54. 2:52and spread it over the land, you could create
55. 2:55a salt layer nearly 150 meters thick
56. 2:58over all the continents on Earth —
57. 3:01that is, as tall as a 40-storey building.
58. 3:07But here another question arises.
59. 3:10Rivers are still bringing salt,
60. 3:12billions of tons every year.
61. 3:15If so, shouldn't the sea be getting
62. 3:18saltier day by day?
63. 3:20But the reality is that it isn't.
64. 3:22For billions of years, the sea's
65. 3:25salt level has stayed roughly the same.
66. 3:28But how? At the ocean floor,
67. 3:31a portion of the salt binds with clay
68. 3:33and sediments and dissolves in.
69. 3:36Volcanic fissures beneath the sea
70. 3:38draw in the minerals from the salt.
71. 3:41When the waves break and shatter, salt particles
72. 3:44return to the land
73. 3:46along with the wind.
74. 3:48And finally, one more thing. When a
75. 3:51teardrop falls from your eye,
76. 3:53have you ever tasted it?
77. 3:56Yes — salt. In our blood,
78. 3:59our sweat and our tears are the same
79. 4:02minerals as the sea. Science says
80. 4:05that life was born in the sea.
81. 4:07Billions of years ago, our
82. 4:09earliest ancestors swam in that
83. 4:11salt water. Later we climbed onto land,
84. 4:14grew legs, and left the sea behind. But
85. 4:18the sea did not leave us. It still flows
86. 4:21through our veins.