why is the world round?
9991
To a first-order approximation the Earth is round.  This\nis due to gravity.  Gravity pulls with equal strength in all\ndirections; therefore any variations from a spherical\nshape will lead to gravitational forces that\nbring the shape back into that of a sphere.\n \nThis is without considering the rotation of the earth,\nhowever.  The rotation of the earth adds centrifugal\neffects, which cause the earth to bulge slightly at\nits equator and flatten slightly at its poles.\n(This is like twirling a rock on the end of a string\nand then letting go--the rock flies away from the\ntwirler.)  Because of these centrifugal effects, the\ndistance from the center of the earth to the surface\nof the earth is about 0.33% shorter at the poles\ncompared to the equator.
199932
The earth's rotation.
72797
A long time ago, there was a man who loved basketball. He loved basketball so much that he decided to make a new shiny basketball which was enormous. After a while he got bored of playing with the big basketball and he started drawing pictures of people, animals, cars, trucks  and everything else. Soon the pictures came to life and communities, countries and towns were made. Then people called the big basketball the world and that is why the world is  round.
224113
The same reason toilets flush in counterclockwise rotation in the southern hemisphere, the rotation of the earth.
285187
The are round, in short, because it takes the least enegry to do it.\n\nGravity pulls the matter that will make up the planets/sun/... together.  All the forces are pointed towards to the objects center of mass, everything is being pulled inward toward the center.  With everything trying to get as close as possible to the same center of mass, the object develops a round/sphereical shape.  This shape minimizes the amount of potential energy the matter has above the center of mass.\n\nThe reason why some objects (like the Earth for example) as not totally sphereical is because they are roating around an axis.  Since the Earth is rotating on its axis (causing our days and nights), there is a bulge around the equator as the matter located there is rotating faster [tangential speed] than the matter located at the poles.  This faster tangential speed requires more centripetal force [not to be confused with the fictional "centrifugal" force] or order to keep it rotating.  In order to lessen the required force, the matter bulges out a little bid, increasing its radius away from the axis.\nCentripetal force = m(v^2/r),\nyou can see that a larger radius (r) away from the center means a smaller centripetal force is needed.
465729
Two possibilities not previously mentioned: first, phone your various friends around the world, and ask them the time! You will then find out that the sun is at a different height in the sky at different places. So at least the world is not flat, since the sun is very much farther out than the distances between any two points on earth.\n\nSecond, wait for a lunar eclipse. This is the Earth's shadow projected on the moon. It is round. The Earth is not a disk (see first experiment) but casts a round shadow: a sphere seems indicated. In fact, it is a sliughtly flattened sphere (ellipsoid, in fancy language)
1059646
Because the circle, in its every form, is the most marbelous shape in the universe.  It really is when you think about it.....
821694
It's round because it has enough gravity to make it round, the force of gravity crushing away irregularities until a round shape is achieved. There's actually a limit in astronomy, anything with more mass then a certain amount will as a rule be round.\n\nAs for the holes, I assume you mean the craters. They are there because we're basically living in a shooting gallery of asteriods, comets, and meteors. On the moon there are no erosive forces so when one hits it the impact crater remains.
991215
Because the sun has a gravitational pull on all objects that rotate around it. The earth, like all the other planets revolving around the sun, is pulled toward it to a certain extent, which keeps the earth from floating away into outer space.
1001698
COZ OF ITS REVOLVING NATURE AND CENTRE OF GRAVITY.
582290
i am round\nlike earth
943945
Round seems to be our perception of the future, and of higher technology.  Look ar all our movies, the cars are always rounder than those of today.  WE think aliens are futuristic, so I guess that means they should be round.
551432
It's just an assumption...\n\ncoz it looks like a sphere... like how the moon looks round...\n\nBut can u be sure!!!
356041
There are various things that you might want to read about, horizon theory & donut theory might be a good place to start. Much as we once thought the world was flat and we'd fall off the edge, but then discovered that is was round when we sailed from one side of the world to the other the same is thought (by some) to also be true about the universe, you travel in a line for long enough, you start off where you left off!
91665
Its more of an elispse, not perfectly round due to the gravitational pull of the oceans by the moon and due to mountains.
816024
The earth's shape is not define.But , Aryabhatta tells that the earth is round.
64442
Planets are round because they have enough gravity to cut down elliptical or uneven parts in a sphere.