why the earth round?

Answer 1

because if it was flat, we would fall off the edge

Answer 2

Now, the first question a person might ask : IS the earth round? And the answer is no, at least not perfectly round. But it is round compared to your average cube, that is for sure! Now, my understanding of how solar systems form is pretty inadequate; all I can tell you is what I see on "Nova." But basically, it has to do with gravity, which is a CENTRAL FORCE. What that means is that gravity pulls things together along a straight line, and the more massive one of the things is, the stronger it pulls. When the earth was forming, it was basically a big ball of dust left over from an exploded sun (a supernova). Gravity caused a lot of the matter to condense into a big fiery ball (our sun), but some of the dust was far enough away from the Sun so that the stronger forces were between planetary dust particles and not the sun. SO, they swirled together into a ball. You can see something similar when you make a painting with one of those "spin-art" machines; you put a card on the spinner, which whirls around real fast, and then you squirt paint on the card. The whirling causes the paint to go out away from the center (this is like the
explosion of the supernova) and droplets go out along an interesting path until they stop, which happens when the spinning force is equal and opposite to the force which attaches paint to the card (this is like gravity)

Answer 3

Above a certain size, any celestial body will be (roughly) a sphere because no material is strong enough to support an irregular shape against its own gravity. If the Earth had bits sticking out further than other bits, those bits would inevitably sink into the mass of the Earth and any hollows would fill in from underneath - Even solid rock 'flows' under the enormous pressure that gravity can exert on such a large body. Just consider mountains, for example - The Himalayas are formed as India pushes into the Asian landmass due to tectonic forces, crumpling up the Earth's crust, but take away that force and the mountains would, over millions of years, flow downwards again under their own weight.

So it's essentially due to the fact that above a certain size of celestial body, nothing can resist the force of its own gravity.

Answer 4

Notice that all the other heavenly bodies in our solar system, other than the asteroids are also spherical. The asteroids could each one be made hot enough to form into spheres by themselves.

It is obvious that the heat energy within all the planets, and sun, must be of a great magnitude in order to form their mass into the shape of a sphere. But, the question arises as to why would it be necessary for our planets to have this particular shape.

The heat energy within a planet does different things. First, it is this energy which forms a planet's gravitational field - c2=E/m. Were our planet to suddenly lose all of its heat energy, then our planet would have no gravitational field. Were the heat value of our planet to increase or decrease, then the gravitational field would do the same.

The manner in which the heat energy forms mass into a sphere is by the gravitational waves below the "Moho discontinuity" all heading directly toward the innermost point of our planet. These waves passing completely through the mass on the other side of the planet draw that mass, and heat energy, toward the center. In doing this they form a "round" planet whose heat energy is contained within its center. If this were not done, our planet would be molten throughout.

Second, the heat energy within our planet causes a plasma to form within it. A plasma is a state of matter where outer electrons become detached from individual atoms and so move about as though in a soup. When the energy forces moving from the poles toward the equator meet, they are moving in opposite directions (Coriolis Effect) and they cause a shearing action through the plane of the equator. When this happens vast magnetic fields form at a right angle to that of the electric one. This is what gives rise to our north and south magnetic poles.

Perhaps the last is most important. Because our planet is in shape of a sphere there are not weather forces forming that would cause cause major disruptions in our climate from time to time. The shape of our planet allows heat to flow back and forth from hot to cold through the seasons as our planet revolves about the sun. But, a person also has to consider that it is the 23.5 degree tilt of our planet that allows for this.

Overall I would say that God did a remarkable thing in creating a planet that is dependent upon a single feature - the heat energy. Lastly, I would remark that whenever energy associates with a mass, that mass must demonstrate that energy in some manner. So, if there is something going on effecting change in some place - there is an energy source somewhere, somehow bringing about the effect. Then, when a great deal of energy is contained within a mass, and it is apparentlly doing nothing - it isn't.

Answer 5

Gravity 'sucks' all the earth's mass inward, toward the center. The earth is obviously not a perfect sphere (mountains, etc.) and tends to bulge at the equator due to the centripetal force of rotation. That is, the equator measures longer than the prime meridian.

Answer 6

because of gravity. the earth is compacted and pulled in equally in all places. so its a circle. every place on earth has about the same distance from the center of the earth.
also, since the earth is spinning, it causes the earth to be forced into a spherical shape.

Answer 7

The Earth is not a perfect sphere or round. It is a shape called geoid. If it were a square or any other polygons, we would fall of but gravity sucks us.

Answer 8

Earth is round because as it gathered mass some 4.5 billion years ago it also had rotational energy and as this mass grew larger it also had gravititational energy equally all around it.

Answer 9

gravity gives equal pressure on all surface area. throw water in the air and see if it goes round most of it should.

Answer 10

Gravity forces the various bits of matter to clump around one central point.

Answer 11

It's not really round, it's a bit smushed.