Why is the earth a sphere and how did it come to be that way?

Question

Any answers or websites are great

Answer 1

Any parts that stick out from the spherical surface are called mountains. A mountain's weight is proportional to its height to the third power (H^3), but its basal area, and therefore, strength, is proportional to H^2. The weight to strength ratio, therefore, increases in proportion to H. If H get too big, it collapses from its own weight. Conclusion: nothing can stick out too far from the sphere.

Answer 2

Gravity is the culprit in this situation. Since gravity is in all directions, the mass attracted will tend to form a sphere. Although no one has proven exactly a limit, somewhere around 1000 km diameter, gravitational force will orient the masses into a sphere, less some allowance for surface features such as craters, mountains, valleys and the like.

Answer 3

A sphere has the lowest volume to surface area ratio and therefore is the most efficient shape to form... this is also why bubble are spherical as is any liquid in zero gravity.

Answer 4

Check wikipedia. But from what I understand, there are two forces at work. One is gravity which pushes things to the center. To keep the earth from collapsing in on itself, there's the force of pushing out created by the heat in the center of the earth. I don't know the technical word for that. The sun works similarily but because of its much larger size it still generates much more heat than planets do.

Please tell me if I got something wrong here.