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Lesson 40 |
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Waves |
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What false impression does an ocean wave convey to the observer? |
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Waves are the children of the struggle between ocean and atmosphere, the ongoing signatures of infinity. |
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Rays from the sun excite and energize the atmosphere of the earth, awakening it to flow, to movement, to rhythm, to life. |
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The wind then speaks the message of the sun to the sea |
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and the sea transmits it on through waves--an ancient, exquisite powerful message. |
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These ocean waves are among the earth's most complicated natural phenomena. |
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The basic features include a crest (the highest point of the wave), |
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a trough (the lowest point), a height (the vertical distance from the trough to the crest), |
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a wave length (the horizontal distance between two wave crests), |
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and a period (which is the time it takes awave crest to travel one wave length). |
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Although an ocean wave give the impression of a wall of water moving in your direction, |
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in actuality waves move through the water leaving the water about where it was. |
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If the water was moving with the wave, |
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the ocean and everything on it would be racing in to the shore with obviously catastrophic results. |
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An ocean wave passing through deep water causes a particle on the surface to move in a roughly circular orbit, |
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drawing the particle first towards the advancing wave, then up into the wave, |
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then forward with it and then--as the wave leaves the particles behind--back to its starting point again. |
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From both maturity to death, a wave is subject to the same laws as any other 'living' thing. |
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For a time it assumes a miraculous individuality that, in the end, is reabsorbed into the great ocean of life. |
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The undulating waves of the open sea are generated by three natural causes: |
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wind, earth movements or tremors, and the gravitational pull of the moon and the sun. |
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Once waves have been generated, |
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gravity is the force that drives them in a continual attempt to restore the ocean surface to a flat plain. |