Planet Earth History, Creation, Composition and More
About the history creation and composition of planet Earth, the elements that make up the surface, the cooling process, water that covers the earth.
ANATOMY OF EARTH
The proto-sun and proto-planets, twirling, compacted more and more in upon themselves. Presently the sun began to shine, the start of thermonuclear fusion. First there was a dull red glow, then presently it began to put forth the golden sunshine that makes life possible on earth. Poets extol sunlight and sunbeams, yet the fact remains that living creatures must never look directly into the face of our life-giving star lest they be quickly blinded. No wonder generations of earthlings worshiped the sun as the supreme god of humanity.
As with the sun's warming up, the pressure of heavy elements at the earth's heart set fire to similar thermonuclear fusion: Earth's center is intensely hot, alive. At the present time, scientists do not know whether earth's basal temperature is rising or cooling, or is perhaps temporarily stationary at some median point.
During the 1st 4th of earth's life, the surface of the new liquid-from-dust planet was slowly cooling and hardening, forming a viscous crust. The most ancient rocks are estimated to be 3.6 billion years old. Above the primordial earth surface stretched an atmosphere of poisonous methane and ammonia and living steam--the strange admixture out of which eventually life forms would emerge.
Eventually the surface cooled sufficiently so that the water vapor could turn liquid, and the 1st rains began to come down. "Never have there been such rains since that time," said Rachel Carson, describing the primordial downpour. "They fell continuously, day and night, days passing into months, into years, into centuries. They poured into the waiting ocean basin. . . ."
Because of this watery surface--and saltwater oceans still occupy more than 72% of earth's exterior surface--one wonders why our planet is not more appropriately called "planet water." Eighty-five percent of all "planet water's" inhabitants still live in the seas, perpetual wanderers called plankton. To them, "planet earth" would seem a nomenclature given by an unimportant terrestrial minority.
Now dry land was thrust up above the saltwater oceans, a massive earth-island 1st described by an American, F. B. Taylor, in 1910, and then named "Pangaea" in 1915 by an Austrian meteorologist, Alfred Lothar Wegener. In time it broke into twin-continents--Gondwana (made up of combined South America, Africa, India, Australia, and Antarctica) and Laurasia (North America, Greenland, and Eurasia). A mere 200 million years ago the 2 super-islands began to break up into today's 7 continents, a process that is still going on.
Because the continents have been wandering over earth's surface, a false expression has crept into the language of geology: "drifting continents." But the continents are made of comparatively "light" granite and merely float high upon the tops of immense plates of heavy basalt, like croutons on a thick soup. The basalt is now known to be 20 mi. thick beneath the 40-mi.-thick granite continents, and only 3 mi. thick beneath the ocean basins.
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