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In all other cases, he used the phenomenon of motion to explain the origin of various forces acting on bodies, but in the case of gravity, he was unable to experimentally identify the motion that produces the force of gravity (although he invented two mechanical hypotheses in 1675 and 1717). Moreover, he refused to even offer a hypothesis as to ...
Nevertheless, one object will always weigh more than another with less mass if both are subject to the same gravity (i.e. the same gravitational field strength). In scientific contexts, mass is the amount of "matter" in an object (though "matter" may be difficult to define), but weight is the force exerted on an object's matter by gravity. [1]
But in a relativistic theory of gravity, mass cannot be the only source of gravity. Relativity links mass with energy, and energy with momentum. The equivalence between mass and energy, as expressed by the formula E = mc 2, is the most famous consequence of special relativity. In relativity, mass and energy are two different ways of describing ...
In physics, gravity (from Latin gravitas 'weight' [1]) is a fundamental interaction primarily observed as mutual attraction between all things that have mass.Gravity is, by far, the weakest of the four fundamental interactions, approximately 10 38 times weaker than the strong interaction, 10 36 times weaker than the electromagnetic force and 10 29 times weaker than the weak interaction.
According to general relativity, mass distorts spacetime and gravity is a natural consequence of Newton's First Law. Mass tells spacetime how to bend, and spacetime tells mass how to move. In general relativity gravitational energy is extremely complex, and there is no single agreed upon definition of the concept.
In Newtonian gravity, the source is mass. In special relativity, mass turns out to be part of a more general quantity called the energy–momentum tensor, which includes both energy and momentum densities as well as stress: pressure and shear. [40] Using the equivalence principle, this tensor is readily generalized to curved spacetime.
Newton's laws are often stated in terms of point or particle masses, that is, bodies whose volume is negligible. This is a reasonable approximation for real bodies when the motion of internal parts can be neglected, and when the separation between bodies is much larger than the size of each.
G is quite difficult to measure because gravity is much weaker than other fundamental forces, and an experimental apparatus cannot be separated from the gravitational influence of other bodies. Measurements with pendulums were made by Francesco Carlini (1821, 4.39 g/cm 3 ), Edward Sabine (1827, 4.77 g/cm 3 ), Carlo Ignazio Giulio (1841, 4.95 g ...