The recent Union Cabinet approval for the LIGO-India project marked a great day for global science, a great day for science in India, and a triumph for Prime Minister (PM) Narendra Modi and his science team, who have shown great imagination in reposing their confidence in this project in the face of many competing priorities. They will not be disappointed.
First, some background. The Laser Interferometer Gravitational-wave Observatory (LIGO) project began in the United States (US) as an ambitious effort, led by Caltech and MIT, to directly detect gravitational waves — first deduced by Einstein in 1916 from the radically new theory of gravity he constructed. The strongest waves that LIGO was expected to detect were predicted to come from some of the most energetic events in the cosmos. Indeed, the first detection in 2015, almost a century after their prediction, came from a merger of two black holes 1.3 billion light years away. This first discovery was awarded the Nobel Prize in Physics in 2017.
Since that first day, LIGO has turned into an entirely new pair of eyes looking at the universe with the help of gravitational waves, and not electromagnetic waves. When combined with neutrinos and cosmic rays, this gives us multiple ways of examining the same phenomena in space — which has brought the era of multi-messenger astronomy.
While two eyes are better than one, more are even better.
With the dawn of LIGO-India, the world can watch the entire sky and determine precisely where and when cosmic collisions happened. This joint project with the US will create a new detector at Hingoli, Maharashtra. It will work with the North American sites to scan the sky for significant gravitational events, involving black holes and neutron stars, and perhaps even vibrations from the beginning of the universe. Similar detectors in Europe and Japan will further add to the capabilities of this worldwide network. Once the LIGO-India detector comes online, it will stimulate more discoveries from existing optical and radio telescopes by pointing them accurately minutes before the fireworks begin. Being separated geographically from the US detectors, the LIGO-India detector will enable discoveries by looking for signals in blind spots in the existing network.
From the perspective of global science, it will significantly advance our capacity to detect new astrophysical and cosmological phenomena. From the standpoint of science in India, LIGO-India will be that rare laboratory on Indian soil that will be doing fundamental science at the global frontier from the very day it starts operating. Moreover, since it will be a part of a worldwide effort, in real-time, it will have its siblings’ intellectual and technical resources, enabling the Indian scientists to rapidly master the needed operational expertise and take their place among the world leaders in this extraordinarily complex area of science. (It would be not at all surprising, indeed it is expected, that the findings from LIGO detectors will yield great science that may be rewarded by Nobel Prizes, including from India.)
In addition to the exciting science, there will be two significant additional benefits to India.
First, during the construction phase, much cutting-edge fabrication will be done in India: Large, ultra-high vacuum equipment, stable lasers, atomically flat mirrors, quantum sensing, and advanced control systems. These efforts will improve precision engineering capabilities, expand modern industrial capability in India, and create high-tech opportunities for new entrepreneurs and established firms. The laboratories of the department of atomic energy are already on this job, which started after the in-principle approval in 2016.
Second, LIGO-India will serve as a focal point for enthusing an entire generation of young Indians about participating in the search for understanding the deepest mysteries of nature as they see the discoveries issue from this new observatory on Indian soil and come to grips with the ultra-sophisticated technology.
This is an exciting moment. The scientists leading this effort can now focus on constructing the laboratory quickly. Likewise, science educators, communicators, and enthusiasts in India should seize the day and join the effort to connect the young to this exciting enterprise and the extraordinary science that underlies it, and more of which is yet to come.
For Indian undergraduates in physics and allied fields, this is an exceptional opportunity — to opt for post-graduate research in gravitational wave physics and become part of the group that builds the laboratory and begins to take data around 2030, which is the current project’s start of scientific operations.
Rana Adhikari is professor of Physics, California Institute of Technology, US. K VijayRaghavan, is with the department of atomic energy and Homi Bhabha Chair at the TIFR-National Centre for Biological Sciences and former principal scientific adviser to the Government of India. Shivaji Sondhi is Wykeham Professor of Physics at Oxford The views expressed are personal
