Scientists detect gravitational waves from black holes collision 3 billion light years away

Astronomers said on Thursday that they had felt space-time vibrations called gravitational waves from the merger of a pair of mammoth black holes resulting in a pit of infinitely deep darkness that weighed as much as 49 Suns, and was 3 billion light-years from Earth.

This was the third black-hole collision detected by astronomers, since they started keeping watch on the cosmos back in September 2015, with Ligo, the Laser Interferometer Gravitational-Wave Observatory. In two short years, the observatory had been able to validate Einstein's long-standing prediction that space-time could shake when massive objects swung their weight around. It had also brought astronomers up close with the most extreme objects in the cosmos.

''We are moving in a substantial way away from novelty towards where we can seriously say we are developing black-hole astronomy,'' said David Shoemaker, a physicist at the Massachusetts Institute of Technology and spokesman for the Ligo Scientific Collaboration, an international network of about 1,000 astronomers and physicists who use the Ligo data.

''We're starting to fill in the mass spectrum of black holes in the universe,'' said David Reitze, director of the Ligo Laboratory, a group headquartered at Caltech that built and ran the observatory.

''Gravitational waves are distortions in the metric of space that we live in,'' Michael Landry, a LIGO physicist at California Institute of Technology, said during a news conference on Wednesday.

Two L-shaped LIGO detectors, one in Washington state and the other in Louisiana, check for these distortions by shooting synchronised laser beams down perpendicular vacuum tubes, each 2.5 miles long. When a gravitational wave passes by, one arm of the L will shrink or expand, and throw the beams out of alignment.

The project is spearheaded by the Massachusetts Institute of Technology and California Institute of Technology, with support from the National Science Foundation and scientific agencies from a host of other countries.