Recently, the government granted approval for the construction of the Laser Interferometer Gravitational-Wave Observatory (LIGO) project in India. This significant decision arrives seven years after the project initially received in-principle approval. The Department of Atomic Energy, Department of Science and Technology, the U.S. National Science Foundation, along with several international and national research institutions, will together be executing this project.
About the LIGO-India Project
The primary objective of the LIGO-India project is the detection of gravitational waves originating from the universe. The Indian LIGO will feature two perpendicular vacuum chambers, each spanning a length of 4 kilometers. These chambers form a part of the world’s most sensitive interferometers. Located about 450 km east of Mumbai in the Hingoli district of Maharashtra, LIGO-India is projected to begin scientific runs from 2030.
The Purpose and Significance of LIGO-India
LIGO-India shall serve as the fifth node in the planned network, positioning India in a prestigious international scientific experiment. The project will transform India into a unique platform, merging the frontiers of quantum science and technology with those of the cosmos.
Benefits of LIGO-India
Apart from integrating India into one of the most prominent international scientific experiments, the LIGO-India project would bestow several spin-off benefits to Indian science. The observatory will pave the way for substantial progress in the fields of astronomy and astrophysics, while simultaneously boosting Indian science and technology’s standing in the cutting-edge frontiers of great national relevance.
The Concept of Gravitational Waves
In Albert Einstein’s General Theory of Relativity, published in 1916, the concept of gravitational waves was first postulated. These waves are the by-product of massive celestial bodies’ movements, such as black holes or neutron stars, resulting in ripples in spacetime that propagate outward.
Insight into LIGO
Laser Interferometer Gravitational-Wave Observatory, or simply LIGO, is a network of international laboratories devoted to detecting gravitational waves. They are engineered to register changes in distance, which are several orders of magnitude smaller than the length of the proton. High-precision instruments are employed, given the extremely low strength of gravitational waves, which makes their detection quite challenging.
Early Detection of Gravitational Waves
In 2015, the US-based LIGO detected gravitational waves for the first time, an achievement honored by the Nobel Prize in Physics in 2017. These gravitational waves were the result of a merger between two black holes 1.3 billion years ago, each roughly 29 and 36 times the mass of our Sun. Such black hole mergers are known to generate some of the most potent gravitational waves.
Current Operational LIGOs
Presently, in addition to the United States (Hanford and Livingston), operational gravitational wave observatories exist in Italy (Virgo) and Japan (Kagra). For the effective detection of gravitational waves, it’s important to have four comparable detectors functioning simultaneously around the globe.
The Working Mechanism of LIGO
A typical LIGO setup encompasses two vacuum chambers, placed at right angles to each other, and extending up to 4 kilometers, with mirrors installed at the ends. While light rays are simultaneously released in both chambers, they ought to return at the same time. A gravitational wave, however, elongates one chamber while squishing the other, thus inducing a phase difference in the returning light rays. The detection of this phase difference verifies the existence of a gravitational wave.
The Relevance of Gravitational Waves
The strongest gravitational waves are produced by catastrophic events such as colliding black holes, coalescing neutron stars or white dwarf stars, or the collapse of supernovae. In a recent instance, scientists detected gravitational waves produced by the merger of two light black holes about a billion light-years away from the Earth. Recorded by LIGO, these findings reiterate the powerful role that the observatory plays in enhancing our understanding of the universe.
