What is gravity - how does it exist?

Answer 1

No one really knows. It remains one of physics most closely guarded secrets. There are some WAGs though and here are two.

First, gravity is the force resulting from messenger particles called gravitons. These gravitons are emtted at light speed from a mass to create a gravitational field density inversely proportional to the square of the distance between one mass and another. And that's why Newton's equation is F = GmM/R^2 where R is that distance between masses.

String/M theory is one such WAG that proposes the graviton. But, and this is a big BUT, no one has yet detected the graviton; so it remains a WAG (a hypothesis) and not a theory. [See source.]

Second, somethow mass bends space; not the stuff around space, but space itself. There is no proposal I know of that explains how mass does this, but space warps have been observed around massive galaxies. These bends in space form what is known as gravity lenses. And like all lenses, they bend light as it passes near the galaxies.

Also, like the funnel in a whirlpool, the bends in space leading into a mass cause whatever is in that bent space to fall into that whirlpool funnel of bent space. Black holes are an extreme case of bent space with everything falling into it. But this theory, which has been validated by the lenses and black holes, fails to explain why space bends; so it's not very satisfying.

There are a lot more questions about gravity than answers. For one, why is it so weak? Of the four fundamental forces in our universe, gravity is the weakest. Yet string/M theory predicts it ought to be much stronger; is it weak because part of each graviton lies outside our known universe? That's one SWAG.

Or another enigma of gravity, why does there seem to be an unlimited supply of gravitational force? No one has ever observed the force of gravity dying out as long as there is a mass around. It just goes on and on like the Everready battery. Where's the unlimited energy that creates the gravitational force coming from and why is it seemingly unlimited?

Bottom line, we don't know much about gravity and its origin. And that has kept a lot of physicists gainfully employed looking for the answers.

Answer 2

No-one can answer this question. Anyone who does give an hypothesis, immediately receives a 'Thumbs Down' from some clever dick who obviously knows all the answers but is reluctant to give them. It's not worth the effort even to put forward an idea.
...Edit:....On second thoughts, my original 'Hypothesis' is...
Centripetal force is a force pulling inwards as with a ball on the end of a piece of string being swung around at high speed. The inward pulling, centripetal force, exerted by the end of the string held in the hand, to me, is a form of Gravity which maintains the circular path of the ball. Should the string break or be released, the ball will 'Fly away' (Centrifugal force) from the centre (the hand).
Earth is rotating at about 1,000 miles per hour and the invisible force of gravity acting from the Earth's centre is holding our atmosphere and everything on and around earth in position. If Gravity fails, (broken string), then everything will fly away into space at an initial speed of 1,000mph.
Satellites are kept in orbit by the force of gravity that pulls the satellite inward against an equal and outward force (centrifugal) caused by the velocity of the satellite around Earth. Should the outward force (velocity) increase it will cause the outward force to exceed the centripetal force and, the satellite too will fly off into space. Should the satellite velocity decrease, then the centripetal force will be greater the the centrifugal and, the satellite will begin to move inwards and eventually come back to earth.
(I believe this is as good an Hypothesis as any other. Thanks in advance 'Mr. Thumbs Down' for the expected response).

Answer 3

Gravity exists because its built in to the fabric of the universe. To understand it you have to understand what Einstein's general theory of relativity comes down to, which is this:

Matter distorts spacetime.

People normally ask you to imagine a rubber sheet, a star in the middle pulls down the sheet and a planet is stopped by that deformation from flying off and instead falls towards the star, but as it moves round it maintains a stable orbit.

Everything with mass, has gravity. You have mass. The earth is pulling on you, but you are also pulling on the earth. Not much, but its there.

Answer 4

Dear,

Gravity; the force by which bodies are attracted towards the earth.

Term sometimes used for the force of gravity and sometimes for the acceleration of gravity. The attraction of the earth for a given body is the body's weight. By Newton's second law of motion, force acting on a body produces acceleration. The weight force, or the force of gravity, produces the acceleration of gravity, which is the acceleration experienced by a freely falling body, and which varies with elevation. At a standard location, the acceleration of gravity is referred to as standard gravity and has a value of 32.2 ft. per second per second, or 980 cm, per second per second.

(Please also see 'Specific Gravity'; W-wikipedia).

Answer 5

Gravitation is a natural phenomenon by which all objects with mass attract each other

Read up on Einstein's theory of general relativity to find out more. This theory is the supporting theory of gravity.

General relativity states that space is made up of a 'fabric' of four dimensions, length, breadth, height and time, otherwise known as spacetime.
The presence of mass would distort spacetime, similar to how a soccer Ball would distort the flatness of a stretched bath towel
In turn, the shape of the surrounding spacetime would tell mass how to behave itself, like a marble placed on the towel with the soccer ball would roll towards the soccer ball.

This is the general gist of it. If you want to find out more, read up on General Relativity.

Answer 6

gravity is a force that drags all objects within its field to the centre of a mass. it exists because mass is atracted to a supremly larger mass. i.e. the earth

Answer 7

Gravitation is a natural phenomenon by which all objects with mass attract each other.