how can gravity be lost? ( so that a heavy thing will stay floating for a long time)?

Answer 1

Gravity is universal. Therefore, the gravity associated with any body can never be "lost." However, you can make an object fall with a smaller acceleration by either placing it on the surface of a celestial body that has less gravity than the Earth, or by placing it in a fluid with a high density.

The acceleration due to gravity at the surface of a planet (or moon, or asteroid, etc.) is a function of the mass of the planet and its radius. The acceleration is proportional to the mass and inversely proportional to the square of the radius. If you double the mass, gravity doubles. If you double the radius without increasing the mass of the planet, then gravity is quartered. The acceleration due to gravity on the surface of the Moon is only about 1/6 the gravity on Earth because the Moon is much less massive than the Earth, and it is also less dense. If you put your heavy object on the surface of an asteroid, gravity would be even lower. And, of course, it is possible to place the object sufficient far from all massive objects that it would remain floating indefinitely.

You can also slow or stop an object's fall by immersing it in a fluid. When a fluid is displaced by an object, the fluid exerts a buoyant force that is equal to the weight of the fluid that was displaced. Fluid pressure increases with depth, and buoyant forces act in opposition to the gradient, so the buoyant force is upwards. Therefore, if the object weighs less than the fluid it displaced (i.e., the object is less dense than the fluid), the buoyant force is greater than the force of gravity, and the object rests on the surface such that only a volume of fluid equalling its own weight is displaced. An iceberg is incredibly heavy, but it floats on the water because water expands when it freezes, making the iceberg less dense than sea water. An object that is more dense than the fluid surrounding it will eventually fall to the bottom, but the buoyant force will cause it to fall with less acceleration than would be experienced in a vacuum. If you chose a very dense fluid, then the fall of even very compact objects would be noticeably slowed.

Answer 2

I assume you're talking about on a planet, like earth. Here, gravity can be seen as pointing towards the center of the earth. Therefore, in order to keep a heavy thing afloat, you have to find a counter-force to gravity: the electric force is a good starting point, because its equation is very similar to the universal gravitational force equation, but has a much larger constant. By that I mean these formulae:
F gravity = G x m1 x m2/ r^2
F electric = k x Q1 x Q2/r^2
The differences lie between G and k: they are both constants, and G is 6.67x10^-11, while k is 9x10^9! A HUGE difference in magnitude. The only problem is, its hard to gather 1 Q of charge; usually the charge is around 10^-6. So if you can gather up just 1 Q and 1Q of charge (or 1 Culoumb of charge-google it) you will create a HUGE force that can easily counteract gravity.

Answer 3

All matter has gravity, and it cannot be lost. If you want something to float unsupported, there are two ways of doing it.
Even supposedly non-magnetic objects do exhibit magnetic properties when a strong enough field is applied. I have seen this demonstrated by suspending a small frog in a super-conducting magnet's field. it just floated in mid air. The field required to do this is ridiculously strong though. Obviously, a magnetic object can be caused to float by balancing magnetic attraction against gravity. I have seen a novelty pen being 'balanced' on its point in this way.
The easiest way to make something float is to make its total density less than that of the fluid which surrounds it. This is how helium balloons float on air, and how boats float on water.

There is a third way to make something'float' in a gravity field- put it in orbit. Effectively, centrifuge then balances out gravity; that's why astronauts are weightless.

Answer 4

This is a quantum physics question by which one can only measure its effects by measuring the effects that gravity has upon objects measurable by common means. There are just a few theories relating to gravity and none by any means are anything other than theory, tho their effects are measurable given their influence upon materials we can measure. such as the expanding universes, revolution of an objects center of mass. try looking up 'Fusion'. and tho i don't use this site too often: http://fusedweb.pppl.gov/ It may give you some indication to the effects these processes have upon those of gravity. I have posted many article's on this subject on the once DG site, Darkgovernment forum ref Edwin or Edwin too. But this site has changed hands and some of those records are still to be updated. Only a final hint here is all i can offer, but gravity in its sense of the word should not be something you should be worrying about, but more the effects upon the subject in question. pulling my hair out here, but the answer to that is very dangerous tho some claim to have achieved this by methods of bombardment with multiple radio frequencies that could be very damaging to bystanders. All experiments should be carried out under the most stringent electromagnetic shielding and should you have the finance or will to pursue such an activity, don't be surprised when you receive that first persuasive government hint to leave such alone! 'Hutchinson Effect' comes to mind too.

Please, please, please! If your serious about this project, dont confuse electromagnatism with gravaty, your just using two apposing fields of streighth to compensate.

Answer 5

Like the other guys said, it is impossible to do that. What you CAN do is orbit the object, or tether it and drop it out past geosynchronous orbit, but in both cases the object is moving. You can't have two objects with mass both stopped and not have them start falling towards each other. Something has to move.

Answer 6

You cannot loose gravity. Its ever present all over the universe.

Answer 7

YOU can experience zero gravity!!!

Check this out:

http://www.incredible-adventures.com/zero-gravity-usa.html