COMPUTER GRAPHICS – An international collaboration including many French researchers, observed for the first time disturbances of space-time caused by the collision of two black holes
one hundred years and a few months after the publication of the theory of general relativity, a collaboration of US, French, Italian and German researchers brings a new experimental proof of the genius Albert Einstein with the first direct detection of gravitational waves. These disturbances of space issued by the brutal collision of two black holes were reported almost simultaneously by the two giant detectors of Ligo observatory, installed 3000 km from each other in the United States one installed Hanford (Washington State), the other in Livingston (Louisiana). In physics as in astronomy, this is a major discovery, expected for decades. It obviously speaks of a Nobel Prize for his main discoverers.
Original Document, preserved in Jerusalem, in which Einstein predicted the existence of gravitational waves . Copyright: Sebastian Scheiner / AP
the difference between a century predicting the existence of gravity waves and their detection illustrates how their observation is difficult, as the signal is weak. Because these waves are a direct result of how Einstein described in his theory of gravity that replaced the description that was Newton. For the German-born physicist, gravity is a warping of space. The masses, like planets or the Sun, curve space. A phenomenon that can be represented in two dimensions by looking at how a mass deforms the surface of a trampoline. The greater the mass, the greater the curvature of space will be large, the same way that a ball will have less effect on a trampoline than a bowling ball.
Like a stone thrown water
One of the arms of the French-Italian Virgo detector in Italy Copyright: CLAUDIO Giovannini / AFP
“From that a mass is accelerating, it produces gravitational waves, ripples in space that travel at the speed of light, “says Benoit Mours, CNRS researcher at the Laboratoire d’Annecy-le-Vieux particle physics and french official collaboration Virgo, another gravitational wave detector near Pisa (Italy) and founded by the CNRS and the Italian INFN. These distortions of space travel like ripples made by a stone thrown into water, reducing themselves as they move away from the initial point.
This is why we can now expect to detect on Earth that events produced by large masses greatly accelerated. This is exactly the scenario that was saved by Ligo: two heavy black holes each as thirty sun, falling towards each other by accelerating to very high speeds. These black holes are giant stars whose heart remains imploded in later life. Ligo instruments have detected the moment the most energy of this cosmic encounter: the precise moment when the two bodies are returned to collision, and merged
Cliquez here to enlarge the graphic
Joint Publication
The detection was performed by instruments installed in the US, but the publication of the discovery in the journal Physical Review Letters is the result of collaboration between the US and European researchers. Because since 2007, scientists at Ligo have joined their counterparts in Virgo. Faced with the difficulty of the problem they faced, and after several years where machines were not sensitive enough and had not detected anything, the two teams have decided to associate. “This association is not an empty word, we exchange all data in real time and analyzes are carried out by teams bringing together researchers from both sides of the Atlantic,” says Benoit Mours.
this first observation was made on 14 September 2015 at 11:51 Paris time (9:51 GMT). The two black holes have merged involved there are 1.3 billion years and their masses were respectively 29 and 36 times that of the sun. By merging, they formed a black hole “lighter” than the total of the two original, a small part of their weight (equivalent to 3 suns) is being converted into gravitational waves as the famous “E = mc2″ d Einstein. Gravitational waves observed in the two “arms” of Ligo detector arrived with 7 milliseconds apart and, according to the researchers, probably came from the southern hemisphere.
2014, false alarm on waves that would have been left by the big bang
in March 2014, US astronomers announced having detected with Bicep2 radio telescope at the South pole the first track of gravitational waves produced by the extremely rapid expansion of the universe less than a second after the big bang. The new
had the effect of a bomb in the scientific community, so the discovery was significant.
She brought including evidence that the universe had experienced an exponential expansion, called inflation, just after its formation.
The lesson is held
Unfortunately, observation, which had not yet been published in a journal review committee before his announcement, did not support the audit. The European Planck space telescope, which observes the traces of the first light emitted in the universe, has made it possible to determine, in cooperation with the US team, the “signal” observed Bicep2 not actually came from the first moments the universe.
very particular polarization of light was actually issued by a much closer source: dust in our own galaxy, the Milky Way
The American astronomers have recognized their error, and. lesson has been learned by researchers at Ligo and Virgo, who expected their work to be published, and thus verified, before making a sensational announcement.
No comments:
Post a Comment