Earth's gravity comes from all its mass. All its mass makes a combined gravitational pull on all the mass in your body. That's what gives you weight. And if you were on a planet with less mass than Earth, you would weigh less than you do here.
According to theory, the reason mass is proportional to gravity is because everything with mass emits tiny particles called gravitons. These gravitons are responsible for gravitational attraction. The more mass, the more gravitons.
Einstein suggested that the shape of spacetime is what gives rise to the force we experience as gravity. A concentration of mass (or energy), such as the Earth or sun, bends space around it like a rock bends the flow of a river.
General Relativity says that any form of energy is a source of gravity. Think of light, which has energy but no rest mass.
It is true that gravity is "unlimited" in the sense that it never turns off. Earth's gravity will never go away as long as it has mass. But since this is just a force and not an energy, the never-ending nature of gravity cannot be used to extract infinite energy, or any energy at all, for that matter.
Every atom creates its own gravitational field which attracts all other matter in the universe. If you put a lot of atoms together, like in a planet or a star, all of the little gravitational fields add together, creating a much stronger pull.
The only known way to create artificial gravity it to supply a force on an astronaut that produces the same acceleration as on the surface of earth: 9.8 meters/sec2 or 32 feet/sec2. This can be done with bungee chords, body restraints or by spinning the spacecraft fast enough to create enough centrifugal acceleration.
Fortunately, there is more than one form of acceleration — and by using centrifugal force we can generate something equivalent to gravity on Earth. One possible way of creating artificial gravity in space is by utilizing a technology called an O'Neill cylinder.
When dealing with the force of gravity between two objects, there are only two things that are important – mass, and distance. The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them.
The strength of gravity between two objects depends on two factors: the masses of the objects and the distance between them. The force of gravity between two objects is greater if the objects are closer together.
The Four Fundamental Forces of Nature are Gravitational force, Weak Nuclear force, Electromagnetic force and Strong Nuclear force. The weak and strong forces are effective only over a very short range and dominate only at the level of subatomic particles. Gravity and Electromagnetic force have infinite range.
The only way to get gravity is with mass. The more mass, the more gravity you get. Without mass, you can't have gravity.
Universal Gravity is a theory, not a fact, regarding the natural law of attraction.
When a smaller mass passes near a larger mass, it curves toward the larger mass because spacetime itself is curved toward the larger mass. The smaller mass is not "attracted" to the larger mass by any force. The smaller mass simply follows the structure of curved spacetime near the larger mass.
No. The attractive force called gravity does not extend beyond galaxy groups. If you look at Newton's Law of Universal Gravitation, you see that the force of gravity on one mass due to another mass depends on their separation r according to the dependence 1/r2.
Contrary to popular belief, there's no such thing as zero gravity. Weightlessness and zero gravity are two different things. The earth's gravity keeps the moon in orbit. And astronauts are generally much closer to earth than the moon is, which means that the earth's pull on them has to be much stronger.
The strongest fundamental force is the strong nuclear force.
The gravitational force acts between all objects that have mass. This force always attracts objects together, and although it is the weakest of the four fundamental forces, gravity has an infinite range.
Gravity is indeed a real force, but not in the traditional sense. In other words, gravity is not a direct, classical, action-at-a-distance force between two objects. However, in the broader sense, gravity is indeed a force because it describes the resulting interaction between two masses.
In quantum theory, each particle acts both as a particle AND a wave. This is called duality. So if there is a graviton, we expect it to behave both as particle and as a wave as well. The electromagnetic force, for example, is transmitted by photons, and light is nothing but a large number of photons.
Quantum mechanics suggests everything is made of quanta, or packets of energy, that can behave like both a particle and a wave—for instance, quanta of light are called photons. Detecting gravitons, the hypothetical quanta of gravity, would prove gravity is quantum. The problem is that gravity is extraordinarily weak.
Dark Energy is a hypothetical form of energy that exerts a negative, repulsive pressure, behaving like the opposite of gravity.
Anant Virya ("infinite energy" or "perfect power"), a characteristic of the soul in Jainism.