question: What is the source for gravity, or what causes it in things? I understand that way massive the object is, the force will be great (and depends on length between a second object too), then, the object creates it? How?
comment: TLDR: We aren't entirely sure yet Gravity is one of the fundamental forces of nature, but unlike the other forces like electromagnetism, the strong force, and the weak force, Gravity doesn't have an opposite (that we are aware of) that cancels it out. It is also the weakest of the forces by far but also seems to accumulate without limit. What we perceive as Gravity is a warping of the fabric of spacetime and appears to be directly linked to mass. Objects do not fall towards a massive object because there is some kind of particle or force pulling on it, but rather because spacetime itself has become warped so objects fall towards each other like a ball rolling down a hill. One current theory is that mass, and by extension gravity, is imparted onto things by the presence of sub atomic particles. This might be the Higgs Boson, or a theoretical particle called a Graviton. It wouldn't be gravitons flying out and pulling on an object that causes gravity, but rather the presence of gravitons warps or bends space
passages: Gravity
  
  Gravity (), or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or "gravitate" toward) one another. On Earth, gravity gives weight to physical objects, and the Moon's gravity causes the ocean tides. The gravitational attraction of the original gaseous matter present in the Universe caused it to begin coalescing, forming stars—and for the stars to group together into galaxies—so gravity is responsible for many of the large-scale structures in the Universe. Gravity has an infinite range, although its effects become increasingly weaker on farther objects.
   Section::::Definitions.:Origin.
  
  In theoretical physics, a mass generation mechanism is a theory which attempts to explain the origin of mass from the most fundamental laws of physics. To date, a number of different models have been proposed which advocate different views of the origin of mass. The problem is complicated by the fact that the notion of mass is strongly related to the gravitational interaction but a theory of the latter has not been yet reconciled with the currently popular model of particle physics, known as the Standard Model.
  
  Section::::Pre-Newtonian concepts.
  
  Section::::Pre-Newtonian concepts.:Weight as an amount.
   Disregarding this, we say that the earth on all its sides is the same; all people on the earth stand upright, and all heavy things fall down to the earth by a law of nature, for it is the nature of the earth to attract and to keep things, as it is the nature of water to flow, that of fire to burn, and that of the wind to set in motion. If a thing wants to go deeper down than the earth, let it try. The earth is the only "low" thing, and seeds always return to it, in whatever direction you may throw them away, and never rise upwards from the earth.
   Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein in 1915) which describes gravity not as a force, but as a consequence of the curvature of spacetime caused by the uneven distribution of mass. The most extreme example of this curvature of spacetime is a black hole, from which nothing—not even light—can escape once past the black hole's event horizon. However, for most applications, gravity is well approximated by Newton's law of universal gravitation, which describes gravity as a force which causes any two bodies to be attracted to each other, with the force proportional to the product of their masses and inversely proportional to the square of the distance between them.
   The earliest gravity (possibly in the form of quantum gravity, supergravity or a gravitational singularity), along with ordinary space and time, developed during the Planck epoch (up to 10 seconds after the birth of the Universe), possibly from a primeval state (such as a false vacuum, quantum vacuum or virtual particle), in a currently unknown manner.
  
  Section::::Specifics.:Gravitational radiation.
   Section::::Geometry and gravitation.:Sources of gravity.
  
  In Newton's description of gravity, the gravitational force is caused by matter. More precisely, it is caused by a specific property of material objects: their mass. In Einstein's theory and related theories of gravitation, curvature at every point in spacetime is also caused by whatever matter is present. Here, too, mass is a key property in determining the gravitational influence of matter. But in a relativistic theory of gravity, mass cannot be the only source of gravity. Relativity links mass with energy, and energy with momentum.
   Gravity is the weakest of the four fundamental interactions of physics, approximately 10 times weaker than the strong interaction, 10 times weaker than the electromagnetic force and 10 times weaker than the weak interaction. As a consequence, it has no significant influence at the level of subatomic particles. In contrast, it is the dominant interaction at the macroscopic scale, and is the cause of the formation, shape and trajectory (orbit) of astronomical bodies. For example, gravity causes the Earth and the other planets to orbit the Sun, it also causes the Moon to orbit the Earth, and causes the formation of tides, the formation and evolution of the Solar System, stars and galaxies.
   History of gravitational theory
  
  In physics, theories of gravitation postulate mechanisms of interaction governing the movements of bodies with mass. There have been numerous theories of gravitation since ancient times.
  
  Greek philosopher Aristotle (f. 4th century BC) believed that objects tend toward a point due to their inner "gravitas" (heaviness). Vitruvius (f. 1st century BC) understood that objects fall based on their specific gravity. Sixth-century AD Indian mathematician Aryabhata developed a geocentric model incorporating gravity; in the next century, Brahmagupta spoke of gravity as an attractive force.
   Section::::Introduction to curved spacetime.:Sources of spacetime curvature.:Experimental verification.:• Pressure as a gravitational source.
  
  The classic experiment to measure the strength of a gravitational source (i.e. its active mass) was first conducted in 1797 by Henry Cavendish (Fig. 5‑9a). Two small but dense balls are suspended on a fine wire, making a torsion balance. Bringing two large test masses close to the balls introduces a detectable torque. Given the dimensions of the apparatus and the measurable spring constant of the torsion wire, the gravitational constant "G" can be determined.
   Section::::Physical characteristics.:Gravitational field.
  
  The gravity of Earth is the acceleration that is imparted to objects due to the distribution of mass within the Earth. Near the Earth's surface, gravitational acceleration is approximately . Local differences in topography, geology, and deeper tectonic structure cause local and broad, regional differences in the Earth's gravitational field, known as gravity anomalies.
  
  Section::::Physical characteristics.:Magnetic field.
   Section::::The Renaissance and Enlightenment.
  
  Influenced by Jean Buridan, Albert of Saxony (c. 1320–1390) developed a square law regarding the relationship between the speed of an object in free fall and either the time or space elapsed. He theorized that mountains and valleys are caused by erosion—displacing the Earth's center of gravity—and that the planet is in equilibrium when its center of gravity coincides with that of its mass.
   Section::::Theory.
  
  It is hypothesized that gravitational interactions are mediated by an as yet undiscovered elementary particle, dubbed the "graviton". The three other known forces of nature are mediated by elementary particles: electromagnetism by the photon, the strong interaction by gluons, and the weak interaction by the W and Z bosons. All three of these forces appear to be accurately described by the standard model of particle physics. In the classical limit, a successful theory of gravitons would reduce to general relativity, which itself reduces to Newton's law of gravitation in the weak-field limit.
   Section::::History of gravitational theory.
  
  Section::::History of gravitational theory.:Greco-Roman world.
  
  Archimedes discovered the center of gravity of a triangle. He also postulated that if the centers of gravity of two equal weights wasn't the same, it would be located in the middle of the line that joins them.
  
  The Roman architect and engineer Vitruvius in "De Architectura" postulated that gravity of an object didn't depend on weight but its "nature".
  
  Section::::History of gravitational theory.:Ancient India.
   In 1907, Albert Einstein, in what was described by him as "the happiest thought of my life", realized that an observer who is falling from the roof of a house experiences no gravitational field. In other words, gravitation is exactly equivalent to acceleration. Between 1911 and 1915 this idea, initially stated as the equivalence principle, was formally developed into Einstein's theory of general relativity.
  
  Paul Dirac developed the hypothesis that gravitation should have slowly and steadily decreased over the course of the history of the universe.
  
  Section::::Modern era.:General relativity.
   Section::::Theory.:Comparison with other forces.
   Section::::Main characters.:Eiri Yuki.
   In the early 20th century, Albert Einstein developed the special and general theory of relativity, evolving the understanding of gravity beyond Newton's classical mechanics. The interactive force of gravity remains an outlier in the search for a theory of everything, but has been incorporated into various models of quantum gravity.
  
  Section::::Antiquity.
  
  Section::::Antiquity.:Greece.
   BULLET::::- 1686 – Isaac Newton uses a fixed length pendulum with weights of varying composition to test the weak equivalence principle to 1 part in 1000
  
  Section::::1700s.
  
  BULLET::::- 1798 – Henry Cavendish measures the force of gravity between two masses, leading to the first accurate value for the gravitational constant
  
  Section::::1800s.
  
  BULLET::::- 1846 – Urbain Le Verrier and John Couch Adams, studying Uranus' orbit, independently prove that another, farther planet must exist. Neptune was found at the predicted moment and position.
   The Greek physicist Archimedes discovered the center of gravity of a triangle. He also postulated that if the centers of gravity of two equal weights was not the same, it would be located in the middle of the line that joins them.
  
  In Book VII of his "De architectura", the Roman engineer and architect Vitruvius contends that gravity is not dependent on a substance's weight but rather on its 'nature' (cf. specific gravity).
   All that is well and good, but are there any direct, quantitative experimental or observational measurements that confirm that these terms contribute to gravity with the correct strength?
  
  Section::::Introduction to curved spacetime.:Sources of spacetime curvature.:Experimental verification.:• Active, passive, and inertial mass.
  
  Before discussing the experimental evidence regarding these other sources of gravity, we need first to discuss Bondi's distinctions between different possible types of mass: (1) is the mass which acts as the source of a gravitational field; (2) is the mass which reacts to a gravitational field; (3) is the mass which reacts to acceleration.
   Based on observational evidence, it is now known that gravity interacts with all forms of energy, and not just with mass. The electrostatic binding energy of the nucleus, the energy of weak interactions in the nucleus, and the kinetic energy of electrons in atoms, all contribute to the gravitational mass of an atom, as has been confirmed to high precision in Eötvös type experiments.
  
  Section::::Non-gravitational applications and analogies.
  
  BULLET::::- Mock gravity:
   The long range of gravitation makes it responsible for such large-scale phenomena as the structure of galaxies and black holes and it retards the expansion of the universe. Gravitation also explains astronomical phenomena on more modest scales, such as planetary orbits, as well as everyday experience: objects fall; heavy objects act as if they were glued to the ground, and animals can only jump so high.
   Gravity of Earth
  
  The gravity of Earth, denoted by , is the net acceleration that is imparted to objects due to the combined effect of gravitation (from distribution of mass within Earth) and the centrifugal force (from the Earth's rotation).
   Massive gravity has a long and winding history, dating back to the 1930s when Wolfgang Pauli and Markus Fierz first developed a theory of a massive spin-2 field propagating on a flat spacetime background. It was later realized in the 1970s that theories of a massive graviton suffered from dangerous pathologies, including a ghost mode and a discontinuity with general relativity in the limit where the graviton mass goes to zero. While solutions to these problems had existed for some time in three spacetime dimensions, they were not solved in four dimensions and higher until the work of Claudia de Rham, Gregory Gabadadze, and Andrew Tolley in 2010.
   The earliest instance of gravity in the Universe, possibly in the form of quantum gravity, supergravity or a gravitational singularity, along with ordinary space and time, developed during the Planck epoch (up to 10 seconds after the birth of the Universe), possibly from a primeval state, such as a false vacuum, quantum vacuum or virtual particle, in a currently unknown manner. Attempts to develop a theory of gravity consistent with quantum mechanics, a quantum gravity theory, which would allow gravity to be united in a common mathematical framework (a theory of everything) with the other three fundamental interactions of physics, are a current area of research.
  
presuppositions: The source of gravity is known.
corrections: No one is entirely sure yet what the source of gravity is. 
raw_presuppositions: The source of gravity is known. An object creates gravity.
raw_corrections: No one is entirely sure yet what the source of gravity is.  One current theory is that mass, and by extension gravity, is imparted onto things by the presence of sub atomic particles.