can we produce such situations on earth (in lab)where gravitational field is zero?
925295
Since anti-gravitation is still SF, the only way I can think of is to take a steep dive with an aeroplane. You won't be weightless in relation to the earth, but in relation to the plane it seems like so.\nAnother situation may appear when you actually could get to the center of the Earth. There are still gravitational forces, but you are pulled equally in every direction by them, so you would be floating.
109471
Tests of general relativity
16892
yes, magnetic fields have nothing to do with air density or gravity or any conditions that differ between space and earth, so there is absolutely no reason at all they wouldnt work in space.
220230
You wouldn't. It would melt as it neared the center of the Earth. Assuming you are asking the hypothetical question, it would go to the middle of the earth and stay there...that is where gravity pulls from.
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.
373232
No, A BIG NO. even on outer space, the gravity is NOT zero. It is very near to Zero (maybe like 0.0000000000000000000001 or something), but never exactly zero. This is because gravity has a range of infinite, i.e. the effect of gravity reaches to every place in the universe and even more. However, it is also known that gravity's power is inverse square to the range (S/4*pi*a_huge_distance^2 = almost 0, but never exactly 0, unless S=0 which means there is no gravity source), thus after a certain distance, the effect of the gravity is negligible and won't affect almost anything. BUT it is not zero. There is no point in space that have completely zero gravity, if there is at least one gravity source in that space, even if the gravity source is placed very far away from that point or even if the gravity's power is very small.\n\nThe gravity is similar to light in this way of infinite range. If you fire an ideal laser (one that would not spread out even minutely after great distances), and you stand on a very far away point from the laser, you'd still be able to be pointed by the laser. Light is also a force that have an infinite distance. Light however, is not exactly the same as gravity.
477263
There are several cases where it can be solved.  There are a few solutions to cases of the circularly restricted 3-body problem, and situations where one of the bodies is of "zero" mass can be solved, but there is no general analytic solution to this problem.
223436
zero, the earth isn't that old
921042
If it has a strong gravitational field, light will bend towards it. No sucking involved.
887515
Please be warned - there are MANY incorrect responses above.\n\nThe theoretical answer to your theoretical question is that you would be weightless at the centre of the earth because the forces of attraction would exactly cancel out.\n\nTo address some of the errors above:\nYou would not be pulled apart because the mass of the earth is not enough.  Similarly, you are not pulled apart when standing ON the earth, even though the earth is pulling your feet more strongly than your head.  If the earth were enormously massive then you would be (it's called being spaghettified, although it ought to have a different name if you are the centre!).\n\nThe force of attraction does NOT increase as you get closer to the centre of the earth.  The responder is thinking about Newton's Law of Gravitation which applies to POINT masses.  If you apply it to a large body such as the earth then you find that only the sphere underneath you attracts - the rest of it cancels out.  ie The earth is roughly 6400km in radius.  If you are 5000km from the centre then you will feel the force of attraction of a 5000km radius sphere of the Earth at a distance of 5000km - the force of attraction of the remaining 1400km 'shell' exactly cancels out.\n\nYou would not 'feel' the force of the sun (any more than you do on the earth) since its force of attraction is providing the centripetal force required to move you in a circle around the sun.\n\nThe force of gravity is NOT caused by the rotation of the earth.  In fact, if the earth stopped rotating we would all be a little bit heavier since a part of the force of gravity is being used to provide the centripetal acceleration necessary to keep us spinning around once per day, with the earth (on the equator this amounts to about 0.3%).\n\nYou also ask about gravitons!!  How they work is a difficult question since they are theoretical!  According to classical Newtonian theory, gravity is simply a fundamental property of matter - matter attracts other matter and that's that.  Newton himself was always uncomfortable about the idea of "action at a distance" but even his genius could not solve the problem, given the limitations of the time that he lived in.  Along came Einstein and gave a solution - matter distorts the shape of space and the apparent force of gravity is actually simply the result of an object moving in the distorted space.  Think of a heavy ball on a rubber sheet and another ball moving along.  It does not 'know' about the heavy ball but it changes its path towards the ball because the surface on which it is rolling has been distorted.\n\nThe graviton is an attempt to explain the phenomenon of gravity without recourse to considering distortions of space-time.  Bodies with mass emit particles called gravitons.  They interact with other massive particles.  The degree of ineraction can be calculated and reasonably easily represented on a Feynman diagram.  Try an internet search.  Huge tanks full of washing up liquid have been built down abandoned deep mine shafts to try to detect these particles.  Some 'events' have been noted but they remain elusive, as far as I know.\n\nHope this goes some way to answering your interesting questions.
819820
Gravity is everwhere but less or more, depends on the matter.
534088
gravitational pull is different in different places on earth. but it is fixed. we cannot change it locally or globally. bcoz it depends on earth's mass, which we cant change.
659657
We know of no science that would permit Star Trek like gravity, which appears to be some kind of machine that can be turned off and on to make gravity. But I suppose some new discovery could make it possible. We just can't count on that.
463808
In order to combat gravity, we would need to be able to understand what it is. At the moment, we don't. If we did, it still would be a tall order to mess with the field of a whole planet. Assuming we could "stabilize" gravity at the quantum level, whatever device we invented to do this would undoubtedly require huge amounts of energy.\n\nA much easier method would be to install a system of shock absorbers and hydraulics underneath the floor. Controlled by a computer, these could make up for some weakenings in the field and simulate to the human feet an equal field. This wouldn't actually solve the problem, just treat the syptoms. The air pressure of the cabin could also be increased to press our feet down on the ground more, but if we mess with this too much, we will implode. Also, there is the idea of placing a large verticaly aligned doughnut-shaped cabin to produce "gravity" in the form of centrifugal force, but this would be extremely impractical and require a lot of digging. I hope this helps, because until we have Artificial Gravity, there isn't really a lot that can be done. Cool question, though.
539221
Due to Newton's Law of Gravitational Force (see link), as the distance between two objects decreases, the gravitational force will increase exponentially.  \n\nIt all depends on your position in reference to the center of mass.  If you are on the surface of the earth, your distance from the earth is normally defined as the distance from you to the center of the earth, or center of mass.  \n\nAs you get closer to the center though, the force due to gravity changes differentially since your position in the mass itself is changing and gravitational forces are acting on you from various directions (the earth can be thought of as a sum of different aggregate masses at this point).  Therefore, the gravitational force of the earth will be "less" at the center, since the sum of all aggregate forces would be acting in opposition of each other.  However, since gravity is a relatively weak force, it would not be your biggest concern, because, at the center of the earth, it's not the force of gravity on you that matters, it's the pressure and temperature that will kill you.\n\nMagnetic and gravitational forces are completely separate types of forces and should not be considered in the formulation of this answer.
1013381
This would be an awesome inexpensive experiment. as I believe that it does with respect to the diameter of the bubble gravity attraction should be increased with respect to surface area, however this experiment should be conducted in an environment free from draft and circulating air flow.
844498
You have uncovered one of the secrets of the universe. Simple Harmonic Motion (SHM) surrounds us in every aspect of the universe. It is the lowest common denominator. Even Newton got it slightly wrong in his First Law where he said that a body will continue in uniform motion until an external force acts upon it. There is nowhere in the known universe that gravity does not exist.\n\nConsider an air table which is flat and which extends in all directions by a million miles, and it rests on the earth. place a puck on it and give it a gentle nudge. It will move off in the direction you push it at an apparently constant velocity, however it will eventually stop and return to the point where it started because of the earth's gravitational field. It will shoot past and head off in the opposite direction until it stops again, being pulled back by the earth's gravitational field. It will continue this way forever (ignoring all friction), oscillating in simple harmonic motion. \n\nNewton's problem was that he was restricted to observing a very small portion of the SHM path, so it seemed linear.\n\nAnyway, congratulations, you are on the path to unlocking the secrets of the universe.