A consortium of astronomers from across the world, including from India, have detected the signature for the background hum of the universe. Called the gravitational wave background (GWB), these are ripples in the fabric of spacetime pervading all of the space around us. The Global collaboration of radio astronomers called the International Pulsar Timing Array (IPTA) made the announcement of the detection on June 29, 2023.

^{Snapshot of simulation showing two black holes colliding with each other. [Image Credits: Wikimedia Commons]}

Astronomers detect gravitational waves from the merging of neutron stars and black holes, but no electromagnetic waves.

On April 26 2019, scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo Interferometer detected gravitational waves from a possible black hole-neutron star collision thought to have taken place 1.2 billion light years away. The event was observed by both LIGO observatories, based in Louisiana and Washington state in the USA, and the Virgo facility based in the European Gravitational Observatory (EGO) in Italy.

The Research Matters team caught up with Nobel Laureate Professor Brian Schmidt, Vice-Chancellor of the Australian National University, when he was in Bengaluru in June, 2017. Having won the Nobel Prize in Physics in 2011 for the discovery of the accelerating expansion of the universe through observations of distant supernovae, our team wanted to know his views about the recent discovery of gravitational waves by LIGO and the Virgo Observatory. Read on to know more about his work on type 1A supernovae and share his excitement for the future of cosmology, after the discovery of gravitational waves.