Indian scientists play a pivotal role in gravity waves detection

Forty Indian scientists from 13 institutions, including two in Bengaluru, played a crucial role in the discovery of the strongest ever gravity wave signal reported by an international team of astronomers on Monday.

The waves emerged from a pair of colliding neutron stars — one of the dying phases of a heavy-duty star in the far away universe.

Albert Einstein had predicted the existence of these waves a century ago. But the first gravity wave signal was spotted only in September 2015.

In the last two years, scientists were able to detect only four of these weak signals, which came from collapsing black holes, billions of light years away.

The latest gravitational wave, on the other hand, is the first one from a neutron star and gave the strongest signal as it originated in the constellation of Hydra at a relatively close distance of 130 million light years (one light year is the distance travelled by the light in a year) from the earth.

Typical neutron stars are heavier than the sun, but have a diameter of just about 20 kilometres (objects so dense that a teaspoonful of neutron star material weighs more than the Mount Everest.)

The detection was confirmed by nearly 70 telescopes around the world that studied various forms of radiation from the merger. Observations from three Indian telescopes were also used in the final analysis.

The gravity wave was spotted first on August 17, following which hundreds of physicists from around the world studied the source and the waves in details.

“One of the key contributions from the Indian scholars was to find out ways to find whether a particular signal is of environmental origin or emanating from an astronomical source,” Sanjit Mitra, one of the team members from Inter-University Centre for Astronomy and Astrophysics, Pune told DH.

Mitra was one of the 11 Indian scientists, who are the part of the discovery team comprising scientists from US-based Laser Interferometer Gravitational-Wave Observatory (LIGO) and Europe’s Virgo detector.

The two Bengaluru institutes — Indian Institute of Astrophysics and International Centre for Theoretical Sciences — were part of the discovery.

In the last three decades, several Indian scholars richly contributed to the development of the underlying mathematics that led to the discovery of these extremely feeble waves from the other sides of the universe.

“The latest discovery would help us accurately measure the expansion rate of the universe from which its age can be calculated independently,” Mitra said. There are scientific debates on the Universe's age, which has been calculated as 13.82 billion years.

The Pune centre spearheads the Indian effort to set up another gravity wave observatory, which is to be operational by 2024.

“The observatory needs 350 acres of land. We hope that the land acquisition process would be over in another 6 months,” said Somak Raychaudhury, IUCAA director.