What is Gravity?

Question

seen a lot of web pages post statements that all we really know are the effects of gravity, but dont really understand what it is! Maybe thats why no one can truly tell anti-gravitational scientists that they are wasting their time!

Answer 1

Gravity is simply curvature in the fabric of space-time caused by masses. The bigger the mass the more curvature it causes in space and time, this is why objects are drawn towards large masses.
Like for example a basketball resting on your bed, it curves the surface of the bed so if there were any small objects close enough to it they would move towards it. Now picture the same effect in the three dimensions of space as well as in the time dimension. That's Gravity.

Answer 2

The force of gravity is due to a mass - energy relationship within our planet. The equation for it is, c2 = E/m, which may be considered as either a field of time or a gravitational field. The reason there will be no anti-gravitational fields found, is that what determines matter/antimatter is the mass spin. When using the small units of gravity these values no longer exist.

If you have an interest, there is a yahoo blog "timebones" and the blog http://timebones.blogspot.com that speak to this question. The posting you would be interested in is "The Problem and Repair of Relativity".

Answer 3

We don't really know. We can define what it is as a field of influence, because we know how it operates in the Universe. And some scientists think that it is made up of particles called gravitons which travel at the speed of light. However, if we are to be honest, we do not know what gravity "is" in any fundamental way - we only know how it behaves.

Here is what we do know...

Gravity is a force of attraction that exists between any two masses, any two bodies, any two particles. Gravity is not just the attraction between objects and the Earth. It is an attraction that exists between all objects, everywhere in the Universe. Sir Isaac Newton (1642 -- 1727) discovered that a force is required to change the speed or direction of movement of an object. He also realized that the force called "gravity" must make an apple fall from a tree, or humans and animals live on the surface of our spinning planet without being flung off. Furthermore, he deduced that gravity forces exist between all objects.

Newton's "law" of gravity is a mathematical description of the way bodies are observed to attract one another, based on many scientific experiments and observations. The gravitational equation says that the force of gravity is proportional to the product of the two masses (m1 and m2), and inversely proportional to the square of the distance (r) between their centers of mass. Mathematically speaking,

F=Gm1m2 / r2,

where G is called the Gravitational Constant. It has a value of 6.6726 x 10-11 m3 kg-1 s-2.

The effect of gravity extends from each object out into space in all directions, and for an infinite distance. However, the strength of the gravitational force reduces quickly with distance. Humans are never aware of the Sun's gravity pulling them, because the pull is so small at the distance between the Earth and Sun. Yet, it is the Sun's gravity that keeps the Earth in its orbit! Neither are we aware of the pull of lunar gravity on our bodies, but the Moon's gravity is responsible for the ocean tides on Earth.


Yours: Grumpy

Answer 4

physics, gravitation or gravity is the tendency of objects with mass to accelerate toward each other. Gravitation is one of the four fundamental interactions in nature, the other three being the electromagnetic force, the weak nuclear force, and the strong nuclear force. Gravitation is the weakest of these interactions, but acts over great distances and is always attractive. In classical mechanics, gravitation arises out of the force of gravity (which is often used as a synonym for gravitation). In general relativity, gravitation arises out of spacetime being curved by the presence of mass, and is not a force. In quantum gravity theories, either the graviton is the postulated carrier of the gravitational force[1], or time-space itself is envisioned as discrete in nature, or both.

The gravitational attraction of the earth endows objects with weight and causes them to fall to the ground when dropped (the earth also moves toward the object, but only by an infinitesimal amount). Moreover, gravitation is the reason for the very existence of the earth, the sun and other celestial bodies; without it matter would not have coalesced into these bodies and life as we know it would not exist. Gravitation is also responsible for keeping the earth and the other planets in their orbits around the sun, the moon in its orbit around the earth, for the formation of tides, and for various other natural phenomena that we observe

Answer 5

Scientists don't know.

Gravitational forces are not magnetic or vacuum.

My theory is that since gravity creates compression it must be compression. This creates a new model for the earth and other planets where mountains, made of denser more compressed material that is harder to compress, are squeezed up as a result of the earth's constant compression of less dense material. As the mountains erode, they become fuel for compression again. The earth's constant compression is constantly providing fuel for itself. This, of course, explains things like the sinking of New Orleans, Venice, and smaller sink holes.

If you let your point of reference become infinity, the mass of the universe becomes very dense. Any force of compression, would have an effect on anything else in the universe as the mass fills the space the compression tries to make empty and holds the physical law that a vacuum and gravity can not co-exist true.

If you then let your point of reference become a galaxy, the amount of force required to change direction of a mass, which has weight only relative to the gravitation pull of another mass, becomes very small explaining orbits of masses with gravity around larger masses with more compression. If you think of the earth floating in space, it has weight only relative to the sun's compression. Various elements on the earth have weight only relative to the earth's compression. More dense material towards the center of the compression holds less dense material like air and water above it. In this sense, the air does not float above the water and the water does not float above the ground. The water is squeezed above the ground by it's compression and the air is squeezed above the water by it's compression. Space is squeezed above the air.

What caused the compression? The rush to fill the vacuum.

Answer 6

gravity is the sum of molecular charges of bonded matter in a given area e the earth or the moon every particle of matter is charged so it attracts to something else usuallyy these bonds are considered to be ionic or covalent well this is learned in chemistry however everything is still unbalanced the leftover outer shell electrons are spinning creating very tiny amounts of electromagnetic force that is for the most part useless however when billion or trillions of substances are all compacted together this small amount of useless energy all combines to create a charge that attracts anything it is called gravity now for the secret gravity does not affect single atoms as much as it does compounds unless the single atoms have high numbers of protons in the nucleus the reason is every atom in the area is trying to bond with everything else but cant so just draws other atoms close but cannot bond some call it adhesion when it is liquids and solids it is a form of gravity also

Answer 7

Gravity is a drag. It weighs heavy on my poor sore feet. Climbing stairs gets harder each year! That is what gravity is, a drag.

I hope that somebody figures out a gravity shield! Like an umbrella for rain, an umbrella for gravity. Hey! Didn't you see Mary Poppins? I want one of those umbrellas!

;-D Don't criticize a scientist who is trying to invent anti gravity! What if he makes an anti gravity machine. I don't care if nobody knows what it is. Just invent a machine that can block it! I may not know what nuclear fusion is, but a parasol will block it! Otherwise ya get a bad sunburn!

Answer 8

Gravity is the attraction of mass to other bodies of mass. General relativity states that mass curves the spacetime fabric, and anything else on the fabric (including light) is affected by that curve. See the following link for a meatier explanation.

Answer 9

A few good answers here, for the space model of gravity i.e., the earth holding the sun in place. You can think of it as a big 'waterbed', where the bed itself is space-time, and dips in it a gravity.
Of course that an extremely simplified but it starts to give you a start in the field.
...
I personally don't believe in 'particle' based science, hence its easier to understand everything as little fields of energy bubbling and swirling about in a sea of gravity.

Answer 10

Gravity is the bending and reshaping of spacetime by large objects that causes them to sit inside a kind of crater, and pull in smaller objects that orbit around the ledge around the crater.

At least that's what I got from watching 3 hours of Nova.