What is your definition of gravity?

Question

If you dont like the conventional theory, give me your own.

Answer 1

Gravity is the other common force. Newton was the first person to study it seriously, and he came up with the law of universal gravitation:

Each particle of matter attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
The standard formula for gravity is:

Gravitational force = (G * m1 * m2) / (d2)
where G is the gravitational constant, m1 and m2 are the masses of the two objects for which you are calculating the force, and d is the distance between the centers of gravity of the two masses.

G has the value of 6.67 x 10E-8 dyne * cm2/gm2. That means that if you put two 1-gram objects 1 centimeter apart from one another, they will attract each other with the force of 6.67 x 10E-8 dyne. A dyne is equal to about 0.001 gram weight, meaning that if you have a dyne of force available, it can lift 0.001 grams in Earth's gravitational field. So 6.67 x 10E-8 dyne is a miniscule force. When you deal with massive bodies like the Earth, however, which has a mass of 6E+24 kilograms (see this Question of the Day), it adds up to a rather powerful force. It is also interesting to think about the fact that every atom attracts every other atom in the universe in some small way!

Einstein later came along and redefined gravity, so there are now two models -- Newtonian and Einsteinian. Einsteinian gravitational theory has features that allow it to predict the motion of light around very massive objects and several other interesting phenomena. According to Encyclopedia Britannica:

The general theory of relativity addresses the problem of gravity and that of nonuniform, or accelerated, motion. In one of his famous thought-experiments, Einstein showed that it is not possible to distinguish between an inertial frame of reference in a gravitational field and an accelerated frame of reference. That is, an observer in a closed space capsule who found himself pressing down on his seat could not tell whether he and the capsule were at rest in a gravitational field, or whether he and the capsule were undergoing acceleration. From this principle of equivalence, Einstein moved to a geometric interpretation of gravitation. The presence of mass or concentrated energy causes a local curvature in the space-time continuum. This curvature is such that the inertial paths of bodies are no longer straight lines but some form of curved (orbital) path, and this acceleration is what is called gravitation.

If certain assumptions and simplifications are made, Einstein's equations handle Newtonian gravity as a subset.

The question of why atoms attract one another is still not understood. The goal is to combine gravity, electromagnetism and strong and weak nuclear forces into a single unified theory.

Answer 2

Gravity is the attraction caused by the mass of an object. This attraction seems to be due to a warping of space-time, which causes what would otherwise be the straight lines of space-time to curve towards a center of gravity. Without a mass, a wave would travel in a straight line. with a mass, the wave curves slightly towards the center of mass due to the warping of space-time due to the mass.
For example. In an area of space such as the space between galaxies, the gravitational forces would be weak due to the great distance from a large mass F = G m1 m2 / d^2
Therefore, assuming this gravitational force is negligible, a projectile fired here would travel in a completely straight line endlessly (or until it reached a significant mass).
However, if the same projectile was fired near the earths surface (slightly upwards for the sake of longer time of flight to observe the motion), the projectile will appear to curve towards the earths center. However, the projectile is still taking a completely straight path through a space-time line. A space-time line in my definition would appear different for objects travelling at different velocities such that a slower object would experience more curvature due to the fact that it is more easily pulled into a center of mass, in much the same way that an object launched radially outward from a center of mass M will increase maximum height with greater initial velocity until escape velocity is the initial velocity, where it escapes the gravitational pull. Also like how light is able to orbit a black hole given it is an appropriate distance from the black hole.

Answer 3

Sir Isaac Newton formulated the force of attraction, "f", between two masses "m1" and "m2" separated by a distance "d" as: f = k(m1 x m2)/ d squared, where k is a proportionality constant.

Albert Einstein's theory of general relativity described gravitational attraction as a curvature of space time, such curvature resulting from a mass acting on space-time. Mass in some way generates "gravitons", which act on space to curve it. (so space-time must be something for gravitons to act upon it). The graviton has never been discovered.

Answer 4

For me, gravity is the force that pushes/ pulls things down. That's all. I don't really know about the gravity and bla3.

Answer 5

one of the fundamental properties of mass. it concerns forces between masses and their tendecy to attract one another. less for great distances and small masses, while great for great masses and small distances(directly proportional to the product of their masses and inversely proportional to the square of the distance between them).
to me it is the reaction to the big bang. all the mas of the universe was concentrated in a tiny space. whaen the explosion happened all this mass was "distributed: to the universe. iun order to cavell this incident and be together as in the "before the big bang" state mass tends to attract it self and want to shrinki again under the same condifuration as it was initially.

Answer 6

The force that pulles everything, including people down.

Answer 7

there is nothing in this world as gravity. its just that the earth sucks :)

Answer 8

it natural phenomenon