LIGO will come back online on 1st April, 2019 after a big upgrade

LIGO (Laser Interferometer Gravitational wave observatory) is a facility that was responsible for the first Gravitational wave detection back in February, 2016. Gravitational waves are ripples in the fabric of space-time caused by highly explosive events like black hole mergers, collision of stellar remnants (white dwarfs, neutron stars, etc.), supernova, etc. Einstein predicted this almost 100 years back as a possible test of his theory of General Relativity. The 2017 Nobel prize in Physics went to three distinguished scientists Kip Thorne, Barry Barish and Rainer Weiss for their ground breaking work in designing and setting up LIGO. 

There are two set-ups one located at Hanford, Washington and the other at Livingstone, Louisiana. Last year both the facilities of LIGO was taken down so that its detectors could undergo some serious hardware upgrades. 

The set-ups basically consists of two perpendicular concrete pipes joined in the shape of a giant 'L' each extending to around two miles (3.2 kilometres). Inside these these pipes two powerful Laser beams are bounced off a series of mirrors. Since the two pipes are of the same length the two beams remain in phase with each other. But whenever a gravitational wave passes through the facility it extends one of the pipes and contracts the other one thus creating a difference in length. This distortion in space gets the beams off balance and they become out of phase. This is what is measured with extreme precision. 

Till date 11 such events have been recorded by the facilities. Out of these, 10 events were due to merging of black holes and 1 event arose from the collision of two neutron stars.

LIGO has recently announced that these upgrades are almost complete and the observatories will be up and working from 1st April, 2019. We hope that better technology will give us better observations and we will soon make serious breakthrough into gravitational wave astronomy.

LIGO facility

For more on LIGO visit  https://www.ligo.caltech.edu/




Image courtesy:  https://www.ligo.caltech.edu/images

By Prabir Rudra