UK invests in blackhole-hunting LIGO facilities in Louisiana and Washington to get an upgrade to 'see' further

Scientists will be able to detect three blackhole collision events in a single day after upgrading work is completed by the mid-2020s

A planned $35 million upgrade could enable the Laser Interferometer Gravitational-Wave Observatory (LIGO) facilities in Louisiana and Washington to detect black hole mergers nearly twice as far away.

The grants for the Advanced LIGO Plus phase will come from the US National Science Foundation (US$20.4 million), UK Research and Innovation (US$13.7 million) and the Australian Research Council.

"I'm extremely excited about the future prospects that the Advanced LIGO Plus upgrade affords gravitational-wave astrophysics," said Caltech's David Reitze, executive director of LIGO.

Gravitational waves are the ripples in the fabric of space-time that are sent across the Universe due to sudden changes in the gravity in a specific point in space, for example due to the collision of two black holes, coalescing neutron stars, or collapse of stellar cores (supernovae).

Einstein was the first to predict the existence of such waves in his general theory of relativity in 1916. However, he believed that it would be difficult to detect these waves as they would be too small to sense.

In 2015, Einstein was proved both right and wrong, when scientists reported first detection of gravitational waves using a pair of L-shaped machines called Advanced LIGO. It was the first instance of sensing of gravitational waves by any scientific instrument in the world.

Since 2015, scientists have reported gravitational waves detection 10 more times - nine times from black hole collisions and one time from neutron star collision.

A UK team led by the researchers at the Institute for Gravitational Research at Glasgow University will carry out most of the upgrading work to increase the sensitivity of instruments.

It will include the addition of a high-vacuum optical cavity to enable scientists manipulate the quantum properties of the laser and reduce noise.

The Advanced LIGO Plus phase will have better, shinier mirrors with improved coating. The new LIGO version will also have a more stable suspension system for the mirrors.

After the upgrading of LIGO is completed by the mid-2020s, scientists will be able to detect three black-hole collision events in a single day.

"I'm thrilled that NSF, UK Research, and Innovation and the Australian Research Council are joining forces to make this key investment possible," said Michael Zucker, the Advanced LIGO Plus leader and co-principal investigator.

"Advanced LIGO has altered the course of astrophysics with 11 confirmed gravitational-wave events over the last three years.

"Advanced LIGO Plus can expand LIGO's horizons enough to capture this many events each week, and it will enable powerful new probes of extreme nuclear matter as well as Albert Einstein's general theory of relativity."