Begining of the earth?

Question

i know how the earth began but i want to hear out some other theories.

Answer 1

some weird tribe believed that the earth was gods p**p

Answer 2

God created it, thats what i believe

Answer 3

all things are circular/from years and years of rollong about in space...thus earth might of started out as a large star.

Answer 4

Per-chance many planets belonged to that old-time system. Almost certainly they did not revolve in a plane, but moved at all angles and in all directions ; in an order beautiful enough of its kind, but not the order of our present system. Imagine an old-time astronomer watching from the then earth the erratic movements of another planet! He is startled by its being out of place; some unknown sister would, perhaps, account for this; but the variation is too sudden and too great. Is it a dead sun, or a small, burnt-out star cluster that draws near? He tells his fellow-observers, and presently every one is at work. By the movements of all the planets it becomes certain that another orb is coming. Will it collide with the earth—with some other planet—may it graze the sun? Presently some of the stars are eclipsed by the dark body. Now, with reflected solar light, it begins to glow, as a distant planet. Now, its orbit can be figured out. It will graze the sun ! It will be nearly a half graze. A new sun will be born—a fiery nebula produced that will envelop the earth. The old order is over, and, as a sum is sponged from a slate, so life is swept from the globe.

What was the nature of the two colliding bodies that gave birth to our solar system? Our imaginary astronomer can give us no information; we can only conjecture. For possibly no cosmic problem offers so fertile a field of inquiry as the impact of celestial bodies. If the paper in the Philosophical Magazine on Cosmic Evolution represents the truth, as a vast mass of evidence seems to show it does, then impact is the Promethean spark that gives life to decaying worlds and systems. The idea of an impact that is a mere graze is that a brilliant spark has been produced by the colliding part of the dead suns as they swept past each other. Such is probably the phenomenon that produces the new stars that occasionally burst forth suddenly with great splendor. But the new star is too hot to be stable; each molecule may have velocity enough to carry it entirely away into space to help in the formation of new and distant universes. The brilliant, flaming mass expands first into a hollow shell of gas called a planetary nebula, and then dissipates altogether. Nova Aurigæ was the first temporary star whose triple constitution was demonstrated. When instead of a mere graze the bodies plunge deeply into one another, then they join and whirl around one another ; and it is to such a whirling collision, it is suggested, that the solar system owes its genesis. Let us imagine the stupendous flash of the grazing collision to have passed; the planets have been swung by centrifugal force into a plane—as a twirled mop disperses its drops of water, or a Catherine wheel its sparks of fire. The planetary bodies fly in curves almost directly from the centre, but the pull of the central mass slowly stops them, just as the pull of the earth stops the upward motion of the ball thrown in triumph at a cricket match. Then they recurve towards the denser portions of the nebula. But countless agencies are at work to alter the curves of their orbits. Let us try to understand one of these.

Suppose a cup and ball with an elastic cord. You throw the ball, and the pull of the cord brings it back. Now you throw so hard that the cord breaks ; the ball does not come back, the attraction is gone. Suppose you throw a cricket-ball upward. Imagine the earth suddenly to disappear—the ball will not return; it will travel straight on in space. Now think of our earth : it was swung off ; it has curved over; it is returning. But suppose the nebula has expanded so much as to be largely outside the earth's orbit ; the part outside will not be pulling it back. If half were outside, the earth would net tend to return; it would revolve in a circle; hence the planets' highly elliptical orbits became approximate circles, and so, by this agency and by many others, the order of the solar system grew up. Our earth is an inner planet. In plunging into the fiery gaseous mass, it loses its light gas and picks up heavy molecules, and, so loaded, it cannot run away. It is a heavy gaseous body, revolving in a nebula. It picks up endless smaller bodies ; presently a larger mass plunges through it and gets entrapped—the earth has caught its moon.

As the solar nebula shrinks it leaves the earth outside, and the earth in its revolution in the surface of the nebula picks up its water and its atmosphere. In the earth's daytime the flaming sun covers its entire sky. Still the nebula shrinks, until Venus emerges. Now the sun is a fire covering the whole area within the orbit of Venus. Another won, and Mercury emerges.

But, while the sun is shrinking, wonderful changes are occurring in the earth itself. The gaseous mass has become liquid, and the liquid cools on the surface and sinks, while the hotter molten material rises up from below to take its place. A circulation is thus set up that tends to cool the liquid rock to its limits. Some of the rock gradually begins to solidify on the surface and to sink. For rock is the reverse of water; water solidifies, expands, and floats; rock matter solidifies, contracts, and sinks. The molecules in the lovely ice crystals are not packed tight like bricks in a box—the crystals are structures to some extent hollow. Pressure tends to fill the spaces, to crush the crystals; in other words, to make the ice into water. But rock, when it solidifies, contracts ; so, when the molecules are rigidly locked into the solid state, pressure tends to keep it solid.

As the rock sinks it is subject to pressure, and may remain solid; but it is also subject to intense heat, and may become more or less soft or plastic, or it may melt in such fervid temperature. The centre of the earth is probably composed of dense metals, like gold, platinum, lead, and mercury. Their density would limit the sinking tendency, so that the crystals of rock would float on the surface of the molten metal and gradually silt up the lava ocean, in places reaching to the surface. The space between the crystals would still be filled with molten matter, and—when the silting reached the surface—this would also begin to solidify. This silting up would be very uneven, and molten lakes would be left which would afterwards cool, solidify, and shrink, producing vast hollows—perchance our present ocean beds. Eventually the crusts would join and coat the earth with a continuous white-hot shell.

In the far back epoch we are thinking of, the carbon of the planet is probably not yet in a solid state. It is possibly all combined with oxygen as carbonic acid gas. The base of the limestone rock is still caustic, not carbonate, the date of the coal measures is still in the distant future. Some of the earth's salts and most of its chlorides are in a state of vapor, gradually condensing on the poles and other cooler parts; falling here and there as molten saline rain, and flowing as glowing lava streams into molten lakes to be boiled off again. Possibly showers of meteorites contribute towards inequalities of temperature. By-and-by, the salt is solidified, and water begins to fall as rain on the poles and other cooler regions, forming boiling lakes; some parts are still too hot for this, and the raindrops fall, to dance up again as quivering spheres buoyed up on their own steam. To boil water requires heat; thus the boiling arctic and ant-arctic seas cool the poles, and thus the rocks shrink and become denser, tending to sink under the increasing weight. As the water stands where the molten saline lakes solidified, it dissolves the saline matter, and the sea becomes salt.

THE MAKING OF THE EARTH'S CRUST

Though it is by no means easy, it is worth trying to gain a living picture of the way in which the surface of the earth came to be what it is. First, the crust cools, shrinks, gets too tight, and splits; then the cool crust becomes too big for the contracting interior, so that it crumples up and breaks. All the while steam explodes, and torrents of boiling water, bearing débris, rush in tumult over the surface. Then, owing to the great world-changes already spoken of, ice accumulates alternately upon either pole and pushes forward upon the polar hemisphere; consequently the centre of gravity of the earth is altered, and the water is dragged to the icy hemisphere, while the opposite hemisphere is left almost dry land, with an equably temperate climate. After a long time, vegetation begins to clothe the surface, modifying all the other agencies. Evidently, while considering such a conflict of forces, we need patience as we try to thread our way through the labyrinth, with its many tortuous twists.

Although, in comparatively early epochs, the poles of the earth would, doubtless, be slightly cooler than the other parts, we must remember how water and carbonic acid oppose the penetrating power of the sun's radiant heat, so that the equator would not be much hotter than the poles. Think of all the water of seas and lakes, and all that is now contained in plants and animals, and in crystals—think of all this water existing as steam in the atmosphere along with the enormous quantities of carbonic acid not yet absorbed or decomposed! An atmosphere surpassing our own many hundred times ! The sunlight would scarcely penetrate such dense clouds as the upper regions of that atmosphere would present; and, even if it did penetrate, it would be "refracted" or curved round the poles, so that polar cold would not be an important factor in producing condensation. Pressure alters the temperature of boiling water; in a perfect vacuum ice-cold water will boil ; so that imagine the high temperature of the steam and rain under the pressure of an atmosphere many hundred times greater than ours now is—equalling tons to the square inch ! All these agencies would tend to produce a general equalit