News tagged with gravitation
NASA lunar spacecraft GRAIL complete prime mission ahead of schedule
(Phys.org) -- A NASA mission to study the moon from crust to core has completed its prime mission earlier than expected. The team of NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission, with twin ...
Space & Earth / Space Exploration
May 29, 2012 |
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Cassini spots tiny moon, begins to tilt orbit
(Phys.org) -- NASA's Cassini spacecraft made its closest approach to Saturn's tiny moon Methone as part of a trajectory that will take it on a close flyby of another of Saturn's moons, Titan. The Titan flyby ...
Space & Earth / Space Exploration
May 22, 2012 |
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Free-floating planets in the Milky Way outnumber stars by factors of thousands
A few hundred thousand billion free-floating life-bearing Earth-sized planets may exist in the space between stars in the Milky Way. So argues an international team of scientists led by Professor Chandra Wickramasinghe, Director ...
May 10, 2012 |
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Black hole caught red-handed in a stellar homicide
(Phys.org) -- Astronomers have gathered the most direct evidence yet of a supermassive black hole shredding a star that wandered too close.
May 07, 2012 |
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Scientists watch black hole feast on unlucky star
Scientists have witnessed the rare spectacle of a supermassive black hole devouring a star that had ventured too close -- an event that occurs about once in 10,000 years, they reported on Wednesday.
May 02, 2012 |
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Prof explores universe through gravity lens studies
(Phys.org) -- The National Science Foundation recently awarded Dr. Mustapha Ishak-Boushaki, associate professor of physics at UT Dallas, a $222,000 research grant for his investigations of the gravitational lensing technique ...
Apr 30, 2012 |
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Serious blow to dark matter theories? New study finds mysterious lack of dark matter in Sun's neighborhood
(Phys.org) -- The most accurate study so far of the motions of stars in the Milky Way has found no evidence for dark matter in a large volume around the Sun. According to widely accepted theories, the solar ...
Apr 18, 2012 |
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Hubble sees Messier 70: Tight and bright
(Phys.org) -- In this image, the NASA/ESA Hubble Space Telescope has captured the brilliance of the compact center of Messier 70, a globular cluster. Quarters are always tight in globular clusters, where the ...
Apr 13, 2012 |
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ALMA reveals workings of nearby planetary system
A new observatory still under construction has given astronomers a major breakthrough in understanding a nearby planetary system that can provide valuable clues about how such systems form and evolve. The ...
Apr 12, 2012 |
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'Cosmic mirages' confirm accelerated cosmic expansion
(Phys.org) -- An international team of researchers led by Masamune Oguri at Kavli IPMU and Naohisa Inada at Nara National College of Technology conduced an unprecedented survey of gravitationally lensed quasars, ...
Apr 11, 2012 |
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Fermi observations of dwarf galaxies provide new insights on dark matter
(PhysOrg.com) -- There's more to the cosmos than meets the eye. About 80 percent of the matter in the universe is invisible to telescopes, yet its gravitational influence is manifest in the orbital speeds ...
Apr 02, 2012 |
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When dark energy turned on (Update)
(PhysOrg.com) -- Some six billion light years distant, almost halfway from now back to the big bang, the universe was undergoing an elemental change. Held back until then by the mutual gravitational attraction ...
Mar 30, 2012 |
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The earliest stages of planet formation
(PhysOrg.com) -- Small dust particles in a disk of gas around a young star, according to current models, gradually coagulate during the first million years until kilometer-sized objects are formed. These in ...
Mar 26, 2012 |
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Runaway planets zoom at a fraction of light speed
Seven years ago, astronomers boggled when they found the first runaway star flying out of our Galaxy at a speed of 1.5 million miles per hour. The discovery intrigued theorists, who wondered: If a star can ...
Mar 22, 2012 |
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Glittering jewels of Messier 9
(PhysOrg.com) -- The NASA/ESA Hubble Space Telescope has produced the most detailed image so far of Messier 9, a globular star cluster located close to the center of the galaxy. This ball of stars is too faint ...
Mar 16, 2012 |
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Gravitation
Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped. Gravitation causes dispersed matter to coalesce, and coalesced matter to remain intact, thus accounting for the existence of the Earth, the Sun, and most of the macroscopic objects in the universe.
Gravitation 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 natural convection, by which fluid flow occurs under the influence of a density gradient and gravity; for heating the interiors of forming stars and planets to very high temperatures; and for various other phenomena observed on Earth.
Gravitation is one of the four fundamental interactions of nature, along with electromagnetism, and the nuclear strong force and weak force. Modern physics describes gravitation using the general theory of relativity by Einstein, in which it is a consequence of the curvature of spacetime governing the motion of inertial objects. The simpler Newton's law of universal gravitation provides an accurate approximation for most physical situations.
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.
