Related topics: galaxies , dark matter , dark energy



Gravitation

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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.

For more information about Gravitation, read the full article at Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with gravity

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Auspicious orbit marks run-up to Phobos flyby

Auspicious orbit marks run-up to Phobos flyby

Space & Earth / Space Exploration

created Jan 29, 2010 | popularity 4.5 / 5 (8) | comments 6 | with audio podcast

(PhysOrg.com) -- On 26 January, Mars Express completed its 7777th orbit around the Red Planet, an auspicious milestone as the satellite is readied for the closest-ever flyby of Phobos, scheduled for just a ...


Story of Newton's encounter with apple goes online (AP)

Story of Newton's encounter with apple goes online

Other Sciences / Other

created Jan 18, 2010 | popularity 4.5 / 5 (6) | comments 4

(AP) -- It always falls down. That's how the apple helped Isaac Newton.


Proposed Spacetime Structure Could Provide Hints for Quantum Gravity Theory

Proposed Spacetime Structure Could Provide Hints for Quantum Gravity Theory

Physics / Quantum Physics

created Dec 16, 2009 | popularity 4.6 / 5 (58) | comments 16 feature

(PhysOrg.com) -- Spacetime, which consists of three dimensions of space and one time dimension, is such a large, abstract concept that scientists have a very difficult time understanding and defining it. Moreover, ...


Yellowstone's plumbing exposed

Yellowstone's plumbing exposed

Space & Earth / Earth Sciences

created Dec 14, 2009 | popularity 4.8 / 5 (49) | comments 18

(PhysOrg.com) -- The most detailed seismic images yet published of the plumbing that feeds the Yellowstone supervolcano shows a plume of hot and molten rock rising at an angle from the northwest at a depth ...


Astronaut balancing act: Training to help explorers adapt to a return to gravity

Space & Earth / Space Exploration

created Dec 09, 2009 | popularity 5 / 5 (3) | comments 0

Astronauts returning from challenging long-duration missions face one more challenge when they get back to Earth - standing up and walking.


Prof gets messages from space

Space & Earth / Space Exploration

created Dec 08, 2009 | popularity 4.3 / 5 (6) | comments 0

(PhysOrg.com) -- Barbara Frisken received several messages from outer space this year on her answering machine.


Robert Thirsk

ISS astronauts land safely in Kazakhstan

Space & Earth / Space Exploration

created Dec 01, 2009 | popularity 5 / 5 (3) | comments 0

A space capsule carrying a Belgian, a Canadian and a Russian landed safely in the steppes of Kazakhstan on Tuesday after the trio spent half a year on the International Space Station (ISS).


Do we need dark matter?

Do we need dark matter?

Physics / General Physics

created Nov 12, 2009 | popularity 4.2 / 5 (21) | comments 34

It's the biggest problem in physics: the matter we can see in the universe accounts for just five per cent of the observed gravity that holds galaxies together.


Dark Matter in a Galaxy

Dark Matter in a Galaxy

Space & Earth / Astronomy

created Oct 30, 2009 | popularity 4.1 / 5 (20) | comments 19

(PhysOrg.com) -- Stars, the most familiar objects in the night sky, make up only a tiny percentage of the total amount of matter in the universe -- about 2%.


Gamma-ray photon race ends in dead heat; Einstein wins this round

Gamma-ray photon race ends in dead heat; Einstein wins this round

Physics / General Physics

created Oct 28, 2009 | popularity 4.7 / 5 (35) | comments 62

Racing across the universe for the last 7.3 billion years, two gamma-ray photons arrived at NASA's orbiting Fermi Gamma-ray Space Telescope within nine-tenths of a second of one another. The dead-heat finish ...


Fermi telescope caps its first year with a glimpse of space-time

Fermi Telescope Caps First Year With Glimpse of Space-Time (w/ Video)

Space & Earth / Astronomy

created Oct 28, 2009 | popularity 4.6 / 5 (14) | comments 5

During its first year of operations, NASA's Fermi Gamma Ray Space Telescope mapped the extreme sky with unprecedented resolution and sensitivity. It captured more than one thousand discrete sources of gamma ...


Students demonstrate flux pinning in low gravity

Students demonstrate flux pinning in low gravity

Physics / General Physics

created Oct 27, 2009 | popularity 5 / 5 (7) | comments 1

(PhysOrg.com) -- A team of Cornell researchers recently tested their work on the mysterious physical phenomenon of flux pinning aboard a near-zero gravity aircraft.


Last visit home for ESA's comet chaser Rosetta

Last visit home for ESA's comet chaser Rosetta

Space & Earth / Space Exploration

created Oct 20, 2009 | popularity 5 / 5 (6) | comments 0

ESA's Rosetta comet chaser will swing by Earth on 13 November to pick up orbital energy and begin the final leg of its 10-year journey to the outer Solar System. Several observations of the Earth-Moon system ...


Look Ma, No Parachute!

'Look Ma, No Parachute!' Lunar Lander Floats on Electric-blue Jets

Space & Earth / Space Exploration

created Oct 15, 2009 | popularity 3.9 / 5 (15) | comments 5

How do you fly on a world with no atmosphere? Wings won't work and neither do propellers. And don't even try that parachute!


Forgotten treasures shed new light on Little Grey Rabbit author

Forgotten treasures shed new light on Little Grey Rabbit author

Other Sciences / Other

created Oct 12, 2009 | popularity 4.5 / 5 (2) | comments 0

(PhysOrg.com) -- A suffragette poem, penned by a world-famous children’s author and kept privately at a University of Manchester Hall of Residence for over a century, has been made available online.