PADUA. A century after the theory of relativity, physics and astrophysics perform a mighty leap forward thanks to breakthroughs in which the University of Padua has a key role The Padua scientific research has helped to unravel the secrets of gravitational waves, vibrations “in the cosmos caused very violent phenomena such as collisions of blacks holes, supernovae explosions of stars or the Big Bang which, according to the most modern astronomical theories, gave rise to the universe.
Until now, their existence had only been assumed: it was Albert Einstein, father of the theory of relativity,
in drafting a formulation. As the waves generated by a falling stone in a pond, gravitational waves travel through the universe at the speed of light, creating ripples in space-time so far invisible.
So far, it finally became possible to observe them directly with a powerful scientific project to which he also worked the University of Padua, who explained all the news of the last months of research.
Gravitational waves were revealed the morning of September 14, 2015 (at 11:51 in Italy) by the pair of detectors LIGO (Laser Interfero meter Gravitational- wave Observatory) located in Livingstone in Louisiana and Hanford in Washington (USA). By joint efforts of a thousand scientists from US universities and those of 14 other countries, including Italy, have already made great strides in the reading of celestial phenomena.
But above all, the researchers said, by gravitational waves has been obtained the final confirmation of the theory of general relativity were the only phenomenon predicted by Einstein not yet been observed.
According to Einstein, when any mass (which is a stone, a star or a black hole) is accelerated, it emits gravitational waves. They are very weak signals and complicated to observe because they “swing” all space-time, including instruments should detect them.
Being able to see them has long been considered an impossible challenge.
Precisely because it seemed impossible to build tools that reveal them properly.
It took more than 50 years of experimentation, scientific and technological achievements research is needed to achieve three laser interferometers, ie the twin LIGO equipment in the US and the European Virgo in Cascina (Pisa), with which it was finally intercepted gravitational waves.
the first to give the ” alarm “to other researchers involved in the international project were just the Paduan: researchers from the group of Virgo Padova-Trento section of the INFN (national Institute of Padova and Trento center Tifpa nuclear) physics they have reported the presence of a possible signal within the first 3 minutes of the event. This crucial contribution was possible because Equipe Padua was assigned a specific part of the analysis; further tests, performed with the fundamental contribution of the Virgo group of Padua -Trento, provided the origin of the observed signal confirms Astrophysics.
Read it has been anything but simple: gravitational waves interact very little with matter, so retain the “memory” of the events They generated them. Their existence was hitherto supported only by circumstantial evidence but from now it becomes possible to observe them directly, along with a portion of the universe so far unseen and mysterious, like areas populated by blacks holes.
And it was the collision between two blacks holes occurred a billion years ago to cause the first sign of ever discovered gravitational waves, detected by the antennae of the LIGO-Virgo tool. For physics is an unprecedented achievement: in addition to confirming the existence of gravitational waves and the validity of the theory of relativity, also provides the first direct evidence for the existence of blacks holes.
“We have observed the first ever event in which a collision does not produce observable data, except through gravity waves, “explains the coordinator of the Virgo Fulvio Ricci collaboration. All, he added, “it lasted a split second, but the energy emitted was huge, amounting to 3 solar masses.” Before the collision, the two blacks holes formed a “couple”: one revolved around each other. “They had a mass, respectively 36 and 29 times that of the sun. They approached an impressive rate, close to that of light. The closer they got, the more the signal became large and frequent, as a shrill whistle; then the colliding, a giant battle from which it has formed a single black hole. Its mass is the sum of those of the two blacks holes, with the exception of the quantity released in the form of gravitational waves.
It ‘the first of countless phenomena that formed the history of the universe that today we can finally know and perceive through the study of gravitational waves. A study that the research group coordinated by Gabriele Vedovato Padua INFN, for many years engaged in the development of analysis for transient signals and generic – in connection with the researcher Paduan Marco Drago now under the AEI in Hannover – will continue to develop after what the minister for? universities and research Stefania Giannini has hailed as a huge success for the Italian physics.
“after the discovery of the Higgs boson – the minister noted in a statement in which It congratulates the Italian researchers – the international physics community is celebrating another important scientific milestone today: the first direct confirmation of the existence of gravitational waves. A perfect gift for the 100th anniversary of General Relativity of Albert Einstein, who was the first to think of them and describe them in his equations. ”
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