Why earth is speherical in shape?

Question

Why earth is speherical in shape?

Answer 1

The concept of a spherical Earth dates back to around the 6th century BC in ancient Greek philosophy[1].

The concept of a spherical Earth displaced earlier beliefs in a flat Earth: In early Mesopotamian thought, the world was portrayed as a flat disk floating in the ocean, and this forms the premise for early Greek maps like those of Anaximander and Hecataeus of Miletus. Other speculations on the shape of Earth include a seven-layered ziggurat or cosmic mountain, alluded to in the Avesta and ancient Persian writings (see seven climes).

As determined by modern instruments, a sphere approximates the earth's shape to within one part in 300. An oblate ellipsoid with a flattening of 1/300 approximates the earth exceedingly well.

Answer 2

God wanted a Basketball to play with.

Answer 3

Above a certain mass threshold, the rotational forces exerted by a spinning object in space, combined with its own gravity work to pull itself inward, equally from all directions at once, resulting in a ball shape. Earth has a bit of an equitorial 'bulge' since rotational energies affect our liquid seas.

That's why asteroids above a certain mass tend towards a spherical shape, and are called planetoids.