Gravity

Newton's law of universal gravitation: The force of atraction between objects is proportional to the product of their masses and inversely proportional to the square of the distance between their centers

Gravity, in physics, is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions. As a result, it has no significant influence at the level of subatomic particles. However, gravity is the most significant interaction between objects at the astronomical scale, since it doesn’t cancel itself out, and it determines the motion of planets, stars, galaxies, and even light.

On Earth, gravity gives weight to physical objects, and the Moon's gravity is responsible for sublunar tides in the oceans. Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing the circulation of fluids in multicellular organisms. The gravitational attraction between the original gaseous matter in the Universe allowed it to coalesce and form stars which eventually condensed 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 weaker as objects get farther away.

Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein), which describes gravity not as a force, but as the curvature of spacetime, caused by the uneven distribution of mass, and causing masses to move along geodesic lines. However, for most applications, gravity is well approximated by Newton's law of universal gravitation, which describes gravity as a force causing any two bodies to be attracted toward each other, with magnitude proportional to the product of their masses and inversely proportional to the square of the distance between them.

See also

• Energy
• Friction
• Inclined Plane
• Wedge

References

This article uses material from the Wikipedia article Gravity, which is released under the Creative Commons Attribution-ShareAlike 3.0 Unported License (view authors).