Related topics: galaxies · physical review letters · dark matter · moon · nasa

Tug of war around gravity

In the summer of 2009, theoretical physicist Erik Verlinde had a brainwave that developed into a radical new idea about gravity and the universe as an ocean of information. Ten years later, the last word about this has not ...

Researchers to study physics of underwater walking

Around 360 million years ago, creatures trekked out of the water and onto dry land, becoming the first terrestrial animals. The colonization of land by animals may be one of the greatest evolutionary events in the history ...

Dark energy vs. modified gravity: Which one will prevail?

Einstein's theory of general relativity predicts the existence of dark energy—a mysterious form of energy that permeates space and accelerates the expansion of the Universe. But what if Einstein was wrong and there was ...

When plant roots learned to follow gravity

Highly developed seed plants evolved deep root systems that are able to sense Earth's gravity. The how and when of this evolutionary step has, until now, remained unknown. Plant biologists at the Institute of Science and ...

Gravity observations confirm that Louisiana is sinking

Louisiana is officially sinking. It has been 29 years since the National Geodetic Survey, or NGS, measured the state's subsidence. After completing four absolute gravity observations this past year, with the help of LSU's ...

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Gravitation

Gravitation is a natural phenomenon by which objects with mass attract one another. In everyday life, gravitation is most commonly thought of as the agency which lends weight to objects with mass. Gravitation compels dispersed matter to coalesce, thus accounting for the existence of the Earth, the Sun, and most of the macroscopic objects in the universe. It is responsible for keeping the Earth and the other planets in their orbits around the Sun; for keeping the Moon in its orbit around the Earth; for the formation of tides; for convection, by which fluid flow occurs under the influence of a temperature gradient and gravity; for heating the interiors of forming stars and planets to very high temperatures; and for various other phenomena observed on Earth. Modern physics describes gravitation using the general theory of relativity, in which gravitation is a consequence of the curvature of spacetime which governs the motion of inertial objects. The simpler Newton's law of universal gravitation provides an accurate approximation for most calculations.

The terms gravitation and gravity are mostly interchangeable in everyday use, but a distinction is made in scientific circles. "Gravitation" is a general term describing the phenomenon by which bodies with mass are attracted to one another, while "gravity" refers specifically to the net force exerted by the Earth on objects in its vicinity as well as by other factors, such as the Earth's rotation.

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