About the Project:

• The Government has given ‘in-principle’ approval for setting up Laser Interferometer Gravitational Wave Observatory (LIGO) in India.
• The LIGO-India project will establish a state-of-the-art gravitational wave observatory on the Indian soil in collaboration with the LIGO Laboratory in the U.S. run by Caltech and Massachusetts Institute of Technology.
• The project will bring unprecedented opportunities for our scientists and engineers to dig deeper into the realm of gravitational wave and take global leadership in this new astronomical frontier. LIGO-India will also bring considerable opportunities in cutting edge technology for the Indian industry which will be engaged in the construction of eight kilometre long beam tube at ultra-high vacuum on a levelled terrain.
• The LIGO-India project will be jointly coordinated and executed by three premier Indian lead institutions viz., the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, the Institute for Plasma Research (IPR), Gandhinagar and the Raja Ramanna Centre for Advanced Technology (RRCAT), Indore. Some of the Universities in the country will also participate in the project. 

The concept of Gravitational Waves:

• The concept of gravitational waves flowed from Einstein’s attempt to explain two inexplicable facets of an otherwise extremely successful and beautiful theory of gravitation proposed by Isaac Newton in the 17th century, one that every high school student is aware of.
• Though mathematically accurate — it continues to be so — Newton’s theory does not say why any two bodies in the universe feel an attractive force towards each other. Newton himself was aware of this shortcoming — and had acknowledged it while proposing the theory in 1687. 
• The second flaw became evident only after Einstein’s special theory of relativity was established in the first decade of the 20th century.
• Newton’s law of gravitation seemed to suggest that the attractive force was evident on the two bodies instantaneously, irrespective of the distance between them, while Einstein had shown that nothing, not even information, could travel faster than light
• The discrepancies in Newton’s theory were resolved by Einstein’s proposal that massive objects actually bend space-time around them, just like a large ball, when placed on a rubber sheet, creates a depression around it. And, it is this curvature of space-time that forces smaller bodies to feel ‘attracted’ towards more massive objects
• The consequence of this proposal was that when bodies move in space-time, they carry the curvature with them, creating ripples, or waves, just like a moving boat would in water. And that these gravitational waves, as they were named, indeed move with finite speed, so that the ‘attractive’ force would not be propagated instantaneously.
• The detection of the gravitational waves was made possible by global scientific collaboration and incredible precision in recording unimaginably faint signals.
• The Ligo detectors at two sites in the US are among the most sophisticated scientific facilities in the world. The paper in which the results of the detection were published had more than 1,000 authors, 37 of them working in Indian scientific institutions. After the first one in September 2015, three more detections have been announced, the latest one just last week, in which the European detector Virgo, too, participated. Data collected from these detections have provided new insights into the working of the universe.
• Evidence of black holes, the size of which had so far not been directly observed, have now been found.
• Much before the first detection was made, a proposal to set up a new Ligo-like detector in India had been awaiting government clearance. Within a week of the announcement of detection in February last year, the Indian government gave the go-ahead. The Indian Ligo, as it has come to be called, will be a replica of the two US observatories, and the three will together to form an array of Ligo facilities
• The Indian Ligo is slated to begin scientific operations in 2024. Which means the facility has to be ready at least two years before that.
• By the time the Indian facility comes online, it is expected that detection of gravitational waves would become a weekly, if not more frequent, affair.
• The novelty and excitement of first detection will no longer be there, but the data from every such instance would continue to be valuable. Scientists expect that very soon gravitational waves would become as common a tool as light and other electromagnetic waves are today in unveiling the secrets of the universe.

Source:PIB & IE