U.S.-based Laser Interferometer Gravitational Wave Observatory (LIGO)’s detectors have picked up signals of yet another merger of two black holes that are three billion light years away and have masses equal to 31 and 19 times the mass of the sun.
With this discovery emerges not only a pattern among black holes but also possibilities of gravitational wave astronomy, detection of new heavenly bodies and gaining a better understanding of that most elusive of theories — Einstein’s general theory of relativity, and the fundamental force of gravitation.
Contribution of Indians
Indians have made a significant contribution to this, with nearly 67 Indians from 13 institutions across the country taking part in the theory and experiment: CMI, Chennai; ICTS-TIFR, Bengaluru; IUCAA, Pune; and IISER Kolkata, to name just a few.
The jubilation over their participation is, however, tempered by the fact that the two existing detectors are not sufficient to locate exactly where in the sky the signals are coming from. With the Italy-based VIRGO detector set to join operations soon, this issue will be addressed. However, there will still remain some blind spots which can be overcome if the LIGO-India project enters the fray, as planned, in 2024.
Amidst such anticipation, it is necessary to take stock of the challenges ahead in building up this fourth player in the gravitational wave-detection game. There will be many firsts for India. Its experimental requirements will spearhead the evolution of many new research areas. Work on some of them has already begun in many centres: like the study of squeezed light in IIT-Delhi and IIT-Madras; mirror surface physics, in Saha Institute of Nuclear Physics, Kolkata, and TIFR, Hyderabad; and fibre-based laser technology in IIT-Madras.
Multiple constituents
On the theoretical side, too, there are major developments in store. The challenge will be to nurture these and take them towards implementation. Second, unlike experiments that are built up from a small core team, LIGO-India will start off as a complex organism, the many constituents of which will evolve simultaneously in different parts of the country. Assembling the parts to form a mature scientific enterprise, a first for India, will be an enormous challenge. Lastly, the Department of Atomic Energy, which is the main funding body for all big scientific investments in India, will also, in an unprecedented manner, take up the responsibility of building up the experiment.
The detected black hole mergers may seem simple compared with the dynamics of this massive coming together of so many theoreticians and experimentalists. However, what holds promise is that the level of the challenge is well-matched by the experience, the number and the ability of the scientists involved.
