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

A new way to measure cosmic black holes

Supermassive black holes are the largest black holes, with masses that can exceed a billion Suns. Just this spring, the first-ever image of the supermassive black hole at the center of the Messier 87 galaxy was taken, and ...

Making planets in a rocket

How are celestial bodies created? Aside from philosophical questions, researchers are taking practical steps to investigate the very first moments when planets are born—on a sounding rocket launching from Sweden next week.

A new way to measure gravity: Using floating atoms

A team of researchers at the University of California, Berkeley, has found a new way to measure gravity—by noting differences in atoms in a superposition state, suspended in the air by lasers. In their paper published in ...

Black holes sometimes behave like conventional quantum systems

A group of Skoltech researchers led by Professor Anatoly Dymarsky have studied the emergence of generalized thermal ensembles in quantum systems with additional symmetries. As a result they found that black holes thermalize ...

Quantum spacetime on a quantum simulator

Quantum simulation plays an irreplaceable role in diverse fields, beyond the scope of classical computers. In a recent study, Keren Li and an interdisciplinary research team at the Center for Quantum Computing, Quantum Science ...

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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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