Gravitational waves: Astronomy tomorrow is running – The Point

February 11, 2015 will go down in the history of science. Yesterday, from France, Italy and the United States, scientists of LIGO collaborations (Laser Interferometer Gravitational-Wave Observatory) and Virgo (named after the French-Italian detector based in Cascina, Italy) officially launched the world first detection of gravitational waves predicted by Einstein ago just 100 years. Quèsaco? This is tiny ripples in space-time, born of violent astrophysical phenomena such as explosions or collisions movement of huge masses, which then spread through the universe at the speed of light, but in stealth mode.

a first that hides another

the signal, tiny, was received on 14 September 2015 to 11 h 51 (Paris time) by the two detectors of gravitational waves LIGO US. Even as these twin equipment, called interferometers and separated from each other by a thousand kilometers, had just restart after several years of work to significantly increase their sensitivity. “We had, somehow, immediate proof of the effectiveness of the transition from LIGO to Advanced LIGO,” said Antoine Heidmann, member of the Virgo collaboration with the detector, based in Cascina, Italy, is undergoing the same kind of upgrade. “And that day, not only have we detected a signal, but it also says something very interesting,” says laboratory director Kastler Brossel (UPMC-ENS), enthusiastic.

After five months of analysis and verification of all kinds, scientists are in fact able to describe the source of that burst of gravitational waves. Their results just published in the journal Physical Review Letters , it originated somewhere to 1.3 billion light years from Earth (which also amounts to saying there 1.3 billion years ago), in the frenzied tango two stellar black holes, that is to say, the fruit of massive stars collapse in on themselves. Two stars of respectively 29 and 36 solar masses about to merge into a single black hole more massive and rotating on itself. Now this is a second-first collision since this merger had been predicted, but had never been observed until now.

Observing the cosmos in a whole new angle

and discoveries and firsts, there will probably still many others. Indeed, gravitational waves are not only reinforce the theory of general relativity of Einstein. They also open a new window on the Universe around us. A window through which scientists will tomorrow observe celestial objects in a whole new angle. So far, astronomy saw through different radiation they emitted; Astronomy tomorrow, thanks to gravitational wave detectors such as LIGO and Virgo, will access directly to their mass. What obtain new information not only on the range of cataclysmic events that can generate this type of waves but also about the nature of gravity itself. And what better, also, to pierce the darkest secrets of the cosmos, such as black holes and dark matter …