What is gravity?

Question

I don't understand how just because there is a large object (like the earth) that its "force" is holding us down. What is that force?

Answer 1

This is not an easy question to answer, but it is a given that the larger the mass of an object, the more gravity it has. A theoretical particle called a "graviton" is supposed to be the messenger particle of the gravitational force, but with gravity been the weakest known force in the universe, the smallest element of that force has been, and may always be, impossible to detect. Gravity only becomes immense because it does not have an upper limit and is not limited by distance. For example, the group of galaxies we belong to are gravitationally attracted to a larger group of galaxies, which in turn is being drawn to an even larger cluster of galaxies. In contrast the strong nuclear force is limited to the distance of the width of a proton.

Einstein showed us another way of thinking of gravity. Instead of it being some kind of attractive force, he theorized that a massive object curves the very fabric of space. That light, for example, isn't drawn towards a massive object through some kind of attracting force, but instead is following the path of least resistance, a straight line, through curved space, making the light look like it bends when it passes by a massive object like our sun. A famous experiment that more or less proved his relativity theories had to do with the bending of light from a distant star as it passed by our sun during a total eclipse.

The same with our planet oribting the sun. Einstein theorized that it is not some kind of "magnetic" force drawing our Earth towards the sun, but that the sun curves the space around it, and our Earth is just following the path of least resistance in a straight line through curved space.

This begs the question, however, of why does mass curve space? This is an unanswered question..

Answer 2

The fact that we are held down establishes that gravity is a real force. But what causes that force is still not proven. The hypothesis is that there are gravity particles, like the electromagnetic particles that produce magnetism, but, unlike magnetism, gravity has only an attractive force like the weak and strong forces that hold atoms together.

All the force particles (electromagnetic, weak and strong) have been detected in accelerator experiments except the gravity particle. Gravity wave detectors have been set up but so far have not detected any. This may be because our detectors are not sensitive enough yet. So the answer to your question is still uncertain.

Answer 3

Well lets think about Einsteins theory of relativity. Einstein said that a massive object such as the sun will bend space time around it. The Earth is supposed to be orbiting this bend in space time. What we feel as gravity is supposed to be the bend in time around the sun. Also we are trying to prove that gravity is actually a gravition.(a particle like an electron, neutron, and proton). Untill then we just have to accept that gravitiy is here and it holds us down.

Answer 4

The best way to describe it is the warping of space caused by the presence of matter.

The force itself is extraordinarily weak when compared with the other 3 forces, and there's been a theory floating around about how gravity is the "bleed through" of a much stronger force that is present (and experienced) in other dimensions.

Answer 5

definiton of gravity is a force that pulls everything towards the centre of the earth. it is this force that holds us down on the ground so we dont fly up into space.

Answer 6

It is something that we have given it a name and a value as well as an origin at the core of the earth but in reality no one knows what it is where it comes from, how it really works and why!

Answer 7

There is no sound theory that describes what causes gravity. We know it can be modeled bay various mathematical models but we do not understand the basic physical process of what causes it at the quantum level

Answer 8

It is gravity . I worked for NASA and we had 2 satellite orbiting in a polar orbit within a few miles of each other. There were enough gravity that we had to maneuver them to keep them separated.

Answer 9

gravity is a force (a push or pull) that pulls anything on earth towards it

Answer 10

the force which exists in all matter. universal attraction. that's what keeps us on the earth.