if gravity keeps us on the earth, what keeps us from having the impression that we're walking sideways in US?
828102
Going SIDEWAYS in the US? You mean BACKWARDS surely?
730247
Yes, there is gravity at the center of the earth, but it would exert the same force in all directions at once, resulting in a net acceleration of zero.  Therefore, yes, you would float in the same manner as if you were in outer space.
457303
Imagine a beach ball with two ladybugs on it, at opposite sides.  Hold your imaginary ball in front of you with one bug at the top and one at the bottom.  It does in fact appear that one bug is upside down to you.  Now hold the ball upside down.  You can't, because it is round, though the location of the bugs gives you an appearance of "upside down".  Taking the same application where Earth is now the beach ball and we are the ladybugs, gravity holds us to the Earth standing upright.  The apearance of "upside down" would occur if you could view a cut away, but you know now that you cannot turn the earth upside down in reality because of it's shape.
3001
That's an interesting question.  Very little would happen that you would notice at the edge.  The center of gravity for a sphere (like the Earth) is the geometric center of the shpere and at any point on the sphere, a straight line could pass from the center of the sphere, through your feet and through your head when you are standing erect.  Because the curvature of the Earth is hard to detect where you stand, you sense that you are standing perpendicular to the ground.\n\nThe center of gravity of an Earth-sized cube would also be the geometric center of the cube.  However a cube has six sides and the very center of each side would be the only six places on the cube where you could stand erect perpendicular to the surface.  At any other point, especially as you approach an edge or corner, a straight line should pass through the center of the cube, your feet and your head, but you would be standing erect at an angle to the surface.  Right on the edge, a straight line could pass throught the center of the cube, the edge, your feet and your head as you stand erect relative to gravity.  As you step over an edge, the slope of the angle would begin to tilt the opposite way as you leave the edge toward the center of the next side.\n\nThere is an interesting point that when the British performed the original land surveys of India near Mt. Everest, the results were in error because they neglected to account for the gravitational pull of the mountain that affected perpendicularity of their plumb bob.  This effect might also create an abberation near the edges and corners of your cube.  At any rate, you would stand erect parallel to any plumb bob that you held.
287936
if gravity was absent, teh earth would have moved away from sun...it would be dark, the plants would not grow, we would die out of cold. we maynot even be able to stand in oneplace.....
259238
You can't fall if you're in space, because there is no gravity, which is required in order to fall.  If you're in an atmosphere or using centrifugal force to simulate gravity, then you would still fall, but at a slower rate than you would on earth, assuming there is less gravity.
308538
All things are attracted to the center of the earth regardless of their orientation to it.So you could dig "down" into the earth but once you passed through the center you would start digging "up" because gravity would be pulling you back to the center which is behind and "below" you
627600
There's some confusion here, and some odd reality as well, which might be part of the source of the confusion. Our 'natural' impression of what's going on in many cases doesn't quite fit what's really going on in detail.\n\n1) Gravitational force doesn't exist 'on Earth'. You are aware of it, when you stand on something, only becuase you're standing on something, which is probably why the phrase 'on Earth' is used. The something is pushing back with a force equal to the force of attraction between you and the Earth. If you were to be falling free (as in skydiving, leaving aside air resistance, or in orbit on the Space Station), you would still be acted upon by the gravitational attractive force between you and the Earth, but you'd feel no such force. It's true the force diminishes (as the square of the distance between the bodies involved), but it still exists. And any body with the mass and size of the Earth will have the same gravitational attraction to you if you were near it (or on it) as the Earth.\n\n2) We can see such a force. Assorted satellites have orbited the Moon. Several folks have walked on the Moon (even hit a golf ball on the Moon) and, except that it's a smaller force (with the changes one would predict, including distance off the tee), the gravtational force of the Moon behaved just exactly as expected. The gravitational attraction of the Moon on you at the surface of the Earth is quite small (and easy to calculate) in comparison to that of the Earth. But in principle you are correct about its changing value. As you sit in your backyard (for 24 hours), and as the Moon orbits the Earth, you will indeed experience (but not really be aware of) the varying force between you and the Moon as it moves (and as the Earth rotates under it). Just as the Earth experiences changes in the direction of the gravitational attraction between itself and the Moon; but you are not so sloshy as sea water and so you don't actually feel (or diaplay) any tidal effects. And neither does the sea either feel its tides, I suppose. If you were quite close to a black hole, your height (and indeed your thickness) would be enough to experience very extreme tidal effects in a gravitational field of that intensity. Far worse than the high and fast tides in the Bay of Fundy in SE Canada, dramatic though they be. \n\n3) As long as the masses of the Earth and Moon remain the same, the gravitational force between them will be constant. The complication introduced by their motions about the common center of gravity in the two body system are mere complications. Hard to deal with mathematically, but mere complications none the less. \n\n4) There are thousands of planets in the Solar System, if your definition of planet is an independently orbiting chunk of stuff. On the other hand, there are only three planets (Jupiter, Saturn, Uranus) if you consider all the rest of those chunks (including the Earth) as merely trivial debris. Or some intermediate value if the orbit has to be primarily about the Sun, not another body. The Earth has one moon, Jupiter has lots (some largish), Mars has two (both smallish), ... Recently, the Hayden Planitarium in NYC revised an exhibit on the Solar System and demoted Pluto from planethood. With the expected storm of objection and discussion. And there have been found of late a couple of large, very distant, and very cold chunks rather farther out than Pluto. Are they planets? Or not? Jump in and join the arguement, it's pretty lively.\n\nAs for the claim that some 10th planet is really really magnetic and causing weather problems here... Magnets are rather hard to arrange in bulk form which is why so few materials have bulk magnetic properties; it requires alignment of the electrons at the atomic level across trillions of atoms, which is usually pretty haphazard and self cancelling. But even if a mountain could be made entirely magnetic (ie, no cancella
801793
and gravity does what?\n\nand why don't you fall off?
121066
kfawl has the most accurate answer... that although we can realistically simulate zero gravity, and the only real way to do that is to use the aforementioned Vomit Comit - I mean we can't realistically put someone at the center of the earth, and sure, if you put someone in an elevator and cut the cords, for some time, the person will experience weightlessness - not that they'll notice since they'll be thinking of their impending death.\n\nAnd you can even go in orbit and although it will feel like you're in a zero G environment, logically thinking - the earth is gigantc and you've not travelled very far from it - how can there suddenly be no gravity? Because the shuttle is actually falling, but travelling sideways so fast that it keeps "missing the earth". This also applies to sattelites or anything orbit. The only reason Earth doesn't fall into the sun is because it is rotating so fast, it "keeps missing the sun."\n\nAnd although its been said that it is impossible to really be in a zero g environment, I believe if you go out far enough, the pull of the planets or stars will be so negligable, that for all intents and purposes, you'll be in a zero-g environment,
821321
All the mass on the earth is being pulled in by gravity, you and me included. the more mass you have the more an object pulls towards itself and others (basically heavy things have a sort of pull, so when you are by a huge mountain you are actually being pulled towards it) \n\nThe easiest way of all the mass to be pulled together is in a sphere, there are no corners and its cannot be compressed without other areas moving further away from the centre, so theoreticlaly the earth SHOULD be a sphere\n\nBUT it isn't; due to its rotation it is fatter than it is tall, because of mass being moved out by centrifugal force. \n\nhope this helps
329257
Because the Earth is so large, our only reference frames are on Earth, and to us our reference frame is flat.  If we were large enough so that our size could be comparable to Earth, then we would see planets and stars sideways or upside down, if they even had an orientation.\n\nOur sense of "down" is due to gravity, and on every place on Earth "down" is really toward the center of the Earth.  Since our natural position is to be standing on our feet, our weight pulls "down" toward our feet and we perceive to be standing "up."
1054239
no it doesn't affect gravity.  it's a double reversal, so everything is perceived right side up.  hold something in front of your face.  then turn it upside down, that's how your eyes see it, flip it around again (notice how it's right side up now?) this is how your brain sees it.\n\nit's all cool, you won't fall off the face of the earth...  ;-)
413242
The earth revolves around its axis and the reason we don’t feel it is because we live inside a bubble called the atmosphere and we’re moving along with it. It’s kinda like you in a car… you don’t feel your seat or CD case moving but they are.
876349
Our atmosphere is considered the upper layer of our planet, meaning that it rotates with the planet.  So due to friction and gravity you will stay in the smae position relative to the ground below you basically rotating with the Earth, unless it is windy.
12149
****Edit based on further details from asker *****\nSailing around the world is sailing within the sperhical confines of our planet.  If there were no athmosphere, or gravity, then we would simply fall off the earth.  However, as gravity is pushing us down, and is affecting the winds, ect within the athmosphere, we are bound to the surface of the water.  \n\nEven though a sphere is included in the define of spheroid, it is a type of spheroid, not the inclusive answer.  The fact that gravity pushes down on us from all around, mainly because the earth is spinning so fast, and other more complicated reasons; the sphereoid holds whatever is on it's surface down to adhere to the confines and shape of such a surface.\n\nEven if the world were flat, or a flattned sphereoid, we woudln't fall off, instead, we'd loop around to the otherside becasue gravity wouldn't allow us to actually 'drop' off the side of the cliff.  The inverse gravity on the other side of the plane would pull us to it's confine, or surface.\n\nSo, there's your answer.  Sorry i didn't get it more clear the first time.\n\nMathamatically you can say that gravity pushes us from all around using a tangent direction.  That means that no matter the point you are on this earth, gravity is pushing down on you within the same confines as any other like region.  As to falling off the earth, if gravity didn't exist, we wouldn't 'fall' exactly; we would more likely be thrown or float off the earth (thrown if the world is spinning).\n\n****End Edit.******\n\nThe world indeed is a sphere, but it is not a perfect sphere, due to the rotation of the earth around it's axis, as well as the rotation of the earth around the sun (central axis), the spinning and speed of the planet make it more of a spehere that jiggles, sometimes squeezed, and sometimes elongated.  But, not by much :) Just a bit :)
1155257
We won't feel it because we are moving along with it. We will only notice any movement if the acceleration changes. It's like being in a car, when you speed up, you kind of stay in place for a moment and go back in your seat. If you stop suddenly, you go forward in your seat. If the Earth slows down, we will continue to move at the previous rate of speed and we will shoot through the atmosphere and land back on Earth many miles east of our original location.