Observation of gravitational waves proves Einstein right

(AGI) Pisa, Feb 11 - After weeks of rumours, it is now official: for the first time, scientists have directly observed gravitational waves. The announcement was made by the LIGO and Virgo collaborations in the U.S. and Italy, during two simultaneous conferences, in Washington and Cascina (Pisa), at the headquarters of the European Gravitational Observatory (EGO), the laboratory that houses an interferometer made by the National Institute for Nuclear Physics (INFN) and the French "Centre National de la Recherche Scientifique" (CNRS). The results have been published in the journal Physical Review Letters. Gravitational waves are ripples in the "fabric" of spacetime, field disturbances which arrive on Earth after being produced by an astrophysical cataclysm deep in the universe. Their observation confirms an important prediction contained in Albert Einstein's General Theory of Relativity in 1915, and opens the way for unprecedented discoveries about the cosmos. Gravitational waves were revealed on Sept. 14 at 10:50:45 a.m. CET, having been produced in the last split second of the merger between two black holes. From the two black holes, equivalent to about 29 and 36 solar masses, a single larger rotating black hole of about 62 solar masses emerged. The three 'missing' solar masses equal the energy emitted during the fusion process between the two black holes, in the form of gravitational waves. The two black holes spiralled before merging and then collided at a speed of about 150,000 km/s, half the speed of light. The observation also confirms the existence of binary systems of "black holes of stellar mass", in particular with a mass greater than 25 solar masses. The merging of the two black holes responsible for these gravitational waves happened nearly half a billion years ago, when the first cells able to use oxygen appeared on the Earth. Einstein's General Theory of Relativity formulated in 1915 describes gravity as a manifestation of the curvature of spacetime. Spacetime is like a fabric, but in four dimensions: the three spatial ones, plus time. According to General Relativity it permeates the whole universe, and is deformed by bodies and disturbed by moving masses. These disturbances are the gravitational waves that spread from their source like ripples on the surface of a pond, travelling at the speed of light.. .