|
Two Massive Black Holes Merge - Simulation
Chargement en cours...
|
| Publier sur un service d'aggrégation |
 |
| Envoyer cette vidéo à un ami |
|
 Two Massive Black Holes Merge - Simulation http://www.nasa.gov/visio n/universe/starsgalaxies/ gwave.html 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 collision at light speed. Previous simulations had been plagued by computer crashes. The necessary equations, based on Einstein's theory of general relativity, were far too complex. But scientists at NASA's Goddard Space Flight Center in Greenbelt, Md., have found a method to translate Einstein's math in a way that computers can understand. "These mergers are by far the most powerful events occurring in the universe, with each one generating more energy than all of the stars in the universe combined. Now we have realistic simulations to guide gravitational wave detectors coming online," said Joan Centrella, head of the Gravitational Astrophysics Laboratory at Goddard. The simulations were performed on the Columbia supercomputer at NASA's Ames Research Center near Mountain View, Calif. This work appears in the March 26 issue of Physical Review Letters and will appear in an upcoming issue of Physical Review D. The lead author is John Baker of Goddard. Similar to ripples on a pond, gravitational waves are ripples in space and time, a four-dimensional concept that Einstein called spacetime. They haven't yet been directly detected. Gravitational waves hardly interact with matter and thus can penetrate the dust and gas that blocks our view of black holes and other objects. They offer a new window to explore the universe and provide a precise test for Einstein's theory of general relativity. The National Science Foundation's ground-based Laser Interferometer Gravitational-Wave Observatory and the proposed Laser Interferometer Space Antenna, a joint NASA - European Space Agency project, hope to detect these subtle waves, which would alter the shape of a human from head to toe by far less than the width of an atom. Black hole mergers produce copious gravitational waves, sometimes for years, as the black holes approach each other and collide. Black holes are regions where gravity is so extreme that nothing, not even light, can escape their pull. They alter spacetime. Therein lies the difficulty in creating black hole models: space and time shift, density becomes infinite and time can come to a standstill. Such variables cause computer simulations to crash.
Date : 05 avril 2008 - 11:48:23
Tags : Education Massive Black Holes Simulation gravitational waves Einstein's theory general relativity Columbia supercomputer
|
 |
Ajouter à votre site |
|
| Les vidéos sont stockées et diffusées au travers du site www.youtube.com conformément aux conditions d'utilisation de Youtube. Nous ne sommes pas responsables de leur contenu. |
|
|
