Scientists detect fourth gravitational wave after two black holes collide

Scientists have detected the fourth gravitational wave from the collision of two black holes 1.8 billion light years away, The New York Times reported on Thursday. Gravitational waves are ripples through space and time that Albert Einstein predicted a century ago.

The waves were recorded on August 14 by the Virgo detector in Italy and two Laser Interferometer Gravitational-Wave Observatory detectors in the United States. This is the first among the four such waves that both the Italy and the US detectors have recorded.

The transient gravitational wave was produced by the collision of two black holes, one of which is 31 times as heavy as the Sun and the other 25 times, researchers said.

“We are all over the moon and back,” said Gabriela González of the LIGO Scientific Collaboration. “Einstein would be very happy, I think.”

The announcement was made at a meeting of G7 science ministers in Turin, Italy. The LIGO detectors have picked up the previous three gravitational waves in the last two years.

According to Einstein’s theory, gravitational waves do not disperse as they travel through space. Gravitational waves are ripples in the curvature of space-time, which is the very fabric of the universe. These waves are actual physical ripples that move away from each other and closer together, thus stretching and squeezing the space they exist in.

The first breakthrough into discovery of such waves was announced in February 2016, nearly a century after Einstein’s prediction. Another was announced in June 2017.

Ligo has a system of two detectors, one in Louisiana and another in Washington, to detect miniscule vibrations passing between gravitational waves. In 1974, the indirect detection of gravitational waves won scientists the Nobel Physics Prize. Experts say the first detection of the waves will be the discovery of the century, and will likely win the same honour.