The End of the World

How?

The origin of the world is unknown.

When geological time begins, some short thousand million years ago, the earth is already a globe, in shape if not in surface much as now, whirling around a star little different if at all from our sun today; a body with its given size and substance, its allotted place and path in heaven. How it came there is unknown.

Knowing nothing, Man has variously and valiantly guessed. Seven chief guesses jostle for primacy.

The nebular. There was once a great fluid cloud or rotating chaos of fire, far-flung beyond the present orbit of Neptune. Gradually, through prodigious years, it cooled and condensed, at its dwindling fringes throwing off successive rings which became the several planets, while the main mass shrank to form our central sun.

The attractional. The cosmic cloud did not throw matter off, but attracted new matter from outside. These captured masses formed the planets; the nebula itself became the sun.