Visualization - Gravitational waves generated by a binary system. [Photo/NASA]

Scientists at the Laser Interferometer Gravitational-wave Observatory in Livingston, Louisiana, the United States, said on Thursday they had directly detected the existence of gravitational waves.

Gravitational waves, ripples in the fabric of space time resulting from the most violent phenomena in the universe such as supernovae explosions or colliding black holes, were predicted by Albert Einstein's Theory of General Relativity 100 years ago. But this is the first time in human history that they had been directly observed.

Every prediction of Einstein's theory had been proven by direct experimental evidence - except for the existence of gravitational waves. Before the discovery, the existence of gravitational waves had only been demonstrated by circumstantial evidence in the 1970s and 1980s.

The detected gravitational waves were produced during the final fraction of a second of the merger of two black holes to produce a single, more massive spinning black hole. This collision of two black holes had been predicted but never observed.

The detection of gravitational waves is regarded as opening a new window on the universe, and the field of gravitational wave astronomy has become a reality promising to offer new insights.