After more than 100 years of searching , scientists from the California Institute of Technology, the Massachusetts Institute of Technology and the United States’ LIGO (Laser Interferometric Wave Interferometry Observatory) Scientific Collaboration – more than 1,000 scientists – have confirmed the existence of the gravitational waves predicted by Albert Einstein. A finding that will undoubtedly change astrophysics and cosmology as we know it today.
What are gravitational waves?
Gravitational waves are waves in space time, comparable to waves moving on the surface of a pond or sound in the air; they travel at the speed of light and spread out in a characteristic pattern. Thus, before the explosion of a supernova or a collision of black holes, waves or ripples are generated that spread throughout the space-time in the universe.
First direct evidence
Until now we had not been able to find them but now, for the first time, this team of scientists has observed in the fabric of space-time gravitational waves reaching the earth from a catastrophic event in the distant universe: that of two colliding black holes. about 1.3 billion light years distant from Earth.
Gravitational waves were detected on September 14, 2015, at 09:51 GMT by the twin observatories Advanced Laser Interferometer Gravitational Wave Observatory (LIGO), located in the US According to physicists, these gravitational waves were produced in the last fraction of a second during the merger of the two black holes that culminated in a more massive black hole.
This merger consisted of the “deadly kiss” of two black holes whose mass was between 29 and 36 times greater than that of the Sun. Their collision released an energy equivalent to three solar masses that propagated in the form of gravitational waves in a fraction of a second. .
“Our first priority was to make sure we weren’t fooling ourselves. We look at every possible non-astrophysical explanation and systematically rule them out. Only then do we turn our attention to the astrophysical implications. This first observation of gravitational waves opens a new field of astronomy, one in which we ‘listen’ to the vibrations of space itself using instruments of unprecedented sensitivity “, clarifies Keith Riles, co-author of the work and professor of physics at the University of Michigan.
The confirmation of the existence of gravitational waves or what we could call the “sound of the universe”, evidences the visionary predictions made by Einstein in the Theory of Relativity in 1916.
The landmark discovery has been published in the journal Physical Review Letters and could be worthy of the Nobel Prize in Physics.
Second confirmation of gravitational waves
Just three months after the historic discovery and announcement, the two twin detectors of the LIGO Observatory located in Livingston (Louisiana) and Hanford (Washington) in the United States have detected for the second time the gravitational waves predicted by Albert Einstein.
This second signal, baptized as GW151226, is somewhat weaker than the previous one but, be that as it may, and after the confirmation of the discovery with a certainty of more than 99.99999%, it represents a verification that this kind of space cataclysms are not facts. isolated and opens a new path to astronomy.
