In the distant universe, black holes merge, supernovae explode, neutron stars collide. Colossal events such as these create cosmic ripples in space-time called gravitational waves. In 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO for short) observed this phenomenon for the first time, expanding our understanding of the universe around us. Now, the United States National Science Foundation is partnering with top U.S. universities and India’s Raja Ramanna Centre for Advanced Technology, or RRCAT (a unit of Department of Atomic Energy, Government of India) to launch LIGO-India, a ground-breaking collaboration, fuelled by a $320 million investment from India, that will accelerate discovery and innovation in India and around the world.
Albert Einstein’s 1916 general theory of relativity first predicted the phenomenon of gravitational waves. But it took physicists another century to prove Einstein right by observing them directly. Most of the history of astronomy has been accomplished by observing light and the electromagnetic spectrum — everything from radio waves to infrared and visible light to high-energy x-rays and gamma rays — but gravitational waves are fundamentally different; they are ripples in space-time, the fabric of the universe itself.
In 2015, for the first time in human history, physicists observed the gravitational waves emanating from two merging black holes, 1.3 million light years from earth. This Nobel prize-winning breakthrough was accomplished by the Laser Interferometer Gravitational-Wave Observatory, known as LIGO, a research initiative that the U.S. National Science Foundation first began investing in the late 1970s.
More experiment than observatory
LIGO is the world’s largest gravitational wave observatory, a scientific collaboration and marvel of engineering that consists of two facilities in the United States, one in the Pacific Northwest at Hanford, Washington, and another near the Gulf of Mexico in Livingston, Louisiana. LIGO uses lasers to detect ripples in space-time through a method called interferometry: as gravitational waves pass by, they cause space itself to stretch and squeeze, which scientists can measure through changes in the beams of the LIGO lasers.
More than an observatory, LIGO is an experiment of pre-eminent scale and complexity. The data LIGO collects have far-reaching implications in many areas of physics. LIGO has provided new clues about merging black holes, the existence of neutron stars and the origin of the universe. It has opened an entirely new way of observing the universe — astronomers have been studying light from the universe for thousands of years, but now we can also “hear” the universe through gravitational waves.
That is why I applaud the recent announcement of the $320 million investment in LIGO-India. Just like LIGO in the U.S. has become a resource for students, researchers, and educators throughout local communities, LIGO-India will create new opportunities in Maharashtra’s Hingoli district. Projects such as LIGO-India can create jobs across the technical workforce, unleash new avenues for scientific talent and inspire the next generation of science, technology, engineering, and mathematics (STEM) leaders.
The benefits of collaboration
By joining the global network, i.e., the two LIGO detectors in the U.S., Virgo in Italy, and the Kamioka Gravitational-wave Detector (KAGRA) in Japan, LIGO-India will push forward the boundaries of what science and technology can achieve and help unlock some of the universe’s greatest mysteries.
LIGO-India is a collaboration between the LIGO Laboratory — operated by Caltech and MIT and funded by the National Science Foundation (NSF) — and India’s RRCAT, the Institute for Plasma Research (IPR), the Inter-University Centre for Astronomy and Astrophysics (IUCAA), and the Department of Atomic Energy Directorate of Construction, Services and Estate Management (DCSEM).
The construction of LIGO-India is a major milestone for gravitational wave science and for the universal progress of science that transcends borders. The observatory will help to answer some of the most fundamental questions about the cosmos. And through collaboration with like-minded partners, it will provide current and aspiring scientists with a wider window into the universe while inspiring the next generation.
Sethuraman Panchanathan is Director, United States National Science Foundation
