Latest General relativity Stories

2008-01-10 18:05:00

It's well known that black holes can slow time to a crawl and tidally stretch large objects into spaghetti-like strands. But according to new theoretical research from two NASA astrophysicists, the wrenching gravity just outside the outer boundary of a black hole can produce yet another bizarre effect: light echoes. "The light echoes come about because of the severe warping of spacetime predicted by Einstein," says Keigo Fukumura of NASA's Goddard Space Flight Center in Greenbelt, Md. "If...

2008-01-10 11:00:51

NASA's Hubble Space Telescope has revealed a never-before-seen optical alignment in space: a pair of glowing rings, one nestled inside the other like a bull's-eye pattern. The double-ring pattern is caused by the complex bending of light from two distant galaxies strung directly behind a foreground massive galaxy, like three beads on a string. More than just a novelty, this very rare phenomenon can offer insight into dark matter, dark energy, the nature of distant galaxies, and even the...

2007-06-08 00:00:00

Picture the Milky Way galaxy -- a disk of stars and gas, a stellar spheroid and an enormous halo of dark matter. It spirals around a black hole that is supermassive-about three million solar masses. The Milky Way's total mass is about 100 billion solar masses-enormous to us but average among galaxies. Then imagine that galaxy encountering its identical twin. The first galaxy merges with the second to produce a galaxy that's even grander and greater. Cosmologists think that's how galaxies...

2007-05-18 17:00:00

In the folklore of physics, no story is better known than the tale of Galileo dropping balls from the Leaning Tower of Pisa and proving that gravity accelerates all objects equally regardless of their masses or composition. This is called the "equivalence principle," and it is a cornerstone of modern physics. But was Galileo correct? NASA -- Standing on the Moon in 1971, Apollo 15 astronaut Dave Scott held his hands out at shoulder height, a hammer in one hand and a feather in the other. And...

2007-04-17 13:00:00

For the past three years a satellite has circled the Earth, collecting data to determine whether two predictions of Albert Einstein's general theory of relativity are correct. Today, at the American Physical Society (APS) meeting in Jacksonville, Fla., Professor Francis Everitt, a Stanford University physicist and principal investigator of the Gravity Probe B (GP-B) Relativity Mission, a collaboration of Stanford, NASA and Lockheed Martin, will provide the first public peek at data that will...

2007-03-05 11:15:46

By analyzing the COSMOS field, the largest field of galaxies ever observed with the Hubble space telescope, an international team of scientists led by researchers from the California Institute of Technology (United States) and researchers from the associated laboratories of the CNRS and the CEA , made the first three-dimensional map of dark matter in the Universe using gravitational lensing effects. This historic first seems to confirm the standard theories on the formation of the large...

2006-12-21 09:01:10

Horizon Health Corporation (NASDAQ:HORC) today announced that it has signed a definitive agreement under which Psychiatric Solutions, Inc. (NASDAQ:PSYS) ("PSI") will acquire Horizon Health in a transaction valued at approximately $426 million including the assumption or repayment of approximately $105 million of debt. Under the terms of the agreement, Horizon Health stockholders will receive $20 in cash for each share of Horizon Common Stock they hold. The transaction is subject...

2006-11-20 15:35:00

Cambridge, MA - The existence of black holes is perhaps the most fascinating prediction of Einstein's General Theory of Relativity. When any mass, such as a star, becomes more compact than a certain limit, its own gravity becomes so strong that the object collapses to a singular point, a black hole. In the popular mind, this immense gravity well is a place where strange things happen. And now, a Center for Astrophysics-led team has measured a stellar-mass black hole spinning so rapidly -...

2006-10-11 14:33:07

At the core of ESA's LISA Pathfinder mission sit two small hearts. Each is a cube, just 5 centimetres across. Together they will allow LISA Pathfinder to lay the foundations for future space-based measurements that investigate the very core of Einstein's General Relativity. A cornerstone of relativity is the concept of a frame of reference. This is a set of bodies relative to which any motion can be measured. Without a reference frame, no motion through space can be detected. Scientists...

2006-04-19 09:10:00

NASA scientists have reached a breakthrough in computer modeling that allows them to simulate what gravitational waves from merging black holes look like. The three-dimensional simulations, the largest astrophysical calculations ever performed on a NASA supercomputer, provide the foundation to explore the universe in an entirely new way. According to Einstein's math, when two massive black holes merge, all of space jiggles like a bowl of Jell-O as gravitational waves race out from the...

Latest General relativity Reference Libraries

Nature Physics
2012-05-18 15:50:42

Nature Physics is a peer-reviewed scientific journal established in 2005 and published monthly by the Nature Publishing Group. The editor-in-chief is Alison Wright, who is a full-time professional editor employed by the journal. The journal publishes original research, letters, full-length articles, review articles, news, views, physics research highlights, commentaries, book reviews, and correspondence. The main focus is pure and applied physics research, encompassing core physics...

General Relativity and Gravitation
2012-04-29 19:54:56

General Relativity and Gravitation is a peer-reviewed scientific journal published monthly since its establishment in 1970. It is published by Springer on behalf of the International Society on General Relativity and Gravitation. G.F.R. Ellis and H. Nicolai are the editors-in-chief. The journal covers modern gravitational physics, encompassing all theoretical and experimental aspects of general relativity and gravitation. The journal’s main goals include public outreach through teaching...

Foundations of Physics
2012-04-29 19:30:54

Foundations of Physics is a monthly-published journal devoted to the conceptual bases and fundamental theories of modern physics and cosmology, emphasizing the logical, methodological, and philosophical premises of modern physical theories and procedures. The journal publishes results and observations based on fundamental questions from all major fields of physics: quantum mechanics, quantum field theory, special relativity, general relativity, string theory, M-theory, cosmology,...

2004-10-19 04:45:44

String Theory -- A string theory is a physical model whose fundamental building blocks are extended objects (strings, membranes and higher-dimensional objects) rather than points. String theories are able to avoid problems, such as infinite energy density, associated with the presence of mathematical points in a physical theory. The term 'string theory' properly refers to both the 26 dimensional bosonic string theories and to the 10 dimensional superstring theories discovered by...

2004-10-19 04:45:42

Spacetime -- In special relativity and general relativity, time and three-dimensional space are treated together as a single four-dimensional manifold called spacetime (alternatively, space-time; see below). A point in spacetime may be referred to as an event. Each event has four coordinates (t, x, y, z). Just as the x, y, z coordinates of a point depend on the axes one is using, so distances and time intervals, invariant in Newtonian physics, may depend on the reference frame of an...

More Articles (12 articles) »
Word of the Day
  • An evil spirit; a devil.
  • A nightmare.
  • In astrology, the twelfth house of a scheme or figure of the heavens: so called from its signifying dreadful things, such as secret enemies, great losses, imprisonment, etc.
'Cacodemon' comes from a Greek term meaning 'evil genius.'