LIGO-India

The government has approved the LIGO-India project after seven years of in-principle approval. Laser Interferometer Gravitational-Wave Observatory (LIGO) project is part of a worldwide network of observatories. Read here to learn more about LIGO-India.

LIGO-India received the Indian Government’s in-principle approval in February 2016. Since then, the project reached several milestones toward selecting and acquiring a site and building the observatory.

The Laser Interferometer Gravitational-Wave Observatory (LIGO) – India is a planned advanced gravitational-wave observatory to be located in India as part of the worldwide network, whose concept proposal is now under active consideration in India and the USA.

LIGO-India is envisaged as a collaborative project between a consortium of Indian research institutions and the LIGO Laboratory in the USA, along with its international partners.

LIGO-India Project

The LIGO-India project will be built by the Department of Atomic Energy (DAE) and the Department of Science and Technology (DST), Government of India, with a Memorandum of Understanding (MoU) with the National Science Foundation (NSF), USA, along with several national and international research and academic institutions.

The project is being led by four institutions in collaboration with LIGO Laboratory operated by Caltech and MIT.

• Institute of Plasma Research (IPR), Ahmedabad
• Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune
• Raja Ramanna Centre for Advanced Technology (RRCAT), Indore
• Directorate of Construction, Services & Estate Management (DCSEM), Mumbai

LIGO-India is intrinsically a multidisciplinary mega-science project that requires expertise from a variety of fields (e.g., laser, vacuum, optics, computer, Physics) and provides cutting-edge research opportunities.

The motivations for LIGO interferometers are primarily related to building a larger global network of gravitational wave detectors.

• Such a worldwide network of widely- constructed separated facilities is needed to extract the best information from gravitational waves.
• Specifically, adding more detectors to the network improves our ability to locate sources, test theories of gravity, space, and time, and provide important clues to puzzles in astrophysics and cosmology.

Ultimately, the goal is to localize a source of gravitational waves anywhere in the sky.

• To do this, four comparable detectors need to be operating simultaneously around the globe. Hanford and Livingston in the USA and Virgo in Italy are the first three LIGO interferometers.
• Given the complexity of gravitational wave detectors, to increase the odds that four detectors are running at the same time, there is a need for more than four in a network.
• The fourth detector, Kagra, in Japan, is also online since 2021.
•  The Virgo detector is a 3 km interferometer in Cascina, Italy. It is operated by the European Gravitational Observatory and funded by INFN (Italy), CNRS (France), and Nikhef (Netherlands).
• The KAGRA observatory is an underground 3 km interferometer in Kamioka, Japan.
• LIGO India will be the all-important fifth, located in the Hingoli district of Maharashtra.
• When it begins operation, LIGO India will significantly improve the likelihood that four detectors are operating at any given moment. This is the critical role that LIGO India will play in the global gravitational wave detector network.

The LIGO Laboratory and India are both making significant financial and intellectual contributions to the project:

• The LIGO Laboratory is providing the hardware for a complete LIGO interferometer, technical data on its design, installation, and commissioning, training and assistance with installation and commissioning, and the requirements and designs for the necessary infrastructure (including the vacuum system).
• India is providing the site, the vacuum system, and other infrastructure required to house and operate the interferometer, as all labor, materials, and supplies for installation, commissioning, and operations.
• Funding for the LIGO-India facilities comes from the Indian Department of Atomic Energy (DAE) and the Department of Science and Technology (DST), with DAE acting as the lead agency.

Once it becomes operational, LIGO-India will be scientifically managed and operated in collaboration with the US LIGO detectors to optimize the scientific return.

Benefits of LIGO-India

The scientific benefits of the project are manifold-

• Adding a new detector to the existing network will increase the expected event rates, and will boost the detection confidence of new sources.
• It will increase the sensitivity, sky coverage, and duty cycle of the network.
• LIGO-India would help in localizing gravitational wave sources in the sky. Sky-location of the gravitational wave sources is computed by combining data from geographically separated detectors.
• Adding a new detector in India, geographically well separated from the existing LIGO-Virgo detector array, will dramatically improve the source-localization accuracies (5 to 10 times).

Impact on Indian Science, Industry, and Education

Indian science:

• The proposed LIGO-India project will help the Indian scientific community to be a major player in the emerging research frontier of gravitational wave astronomy.
• A major initiative like LIGO-India will further inspire frontier research and development projects in India.
• It will bring together scientists and engineers from different fields like optics, lasers, gravitational physics, astronomy and astrophysics, cosmology, computational science, mathematics, and various branches of engineering.
• The LIGO-India project will join forces with several Indian astronomy projects like the Astrosat project, future upgrades of the India-based Neutrino Observatory, and optical/radio telescopes.

Impact on industry:

• The high-end engineering requirements of the project such as the world’s largest ultra-high vacuum facility will provide unparalleled opportunities for Indian industries in collaboration with academic research institutions.
• LIGO project has facilitated major industry-academic research partnerships in the USA and Europe and has produced several important technological spin-offs.

Education and public outreach:

• This cutting-edge project in India can serve as a local focus to interest and inspire students and young scientists.
• The LIGO-India project involves high-technology instrumentation and its scale will motivate young students to choose experimental physics and engineering physics as career options.
• Also, the observatory will be one of the very few research facilities in India of this scale, international relevance, and technological innovation to which the general public and students can have access.

About LIGO

 

The Laser Interferometer Gravitational-Wave Observatory (LIGO) was designed to open the field of gravitational-wave astrophysics through the direct detection of gravitational waves predicted by Einstein’s General Theory of Relativity.

• LIGO’s multi-kilometer-scale gravitational wave detectors use laser interferometry to measure the minute ripples in space-time caused by passing gravitational waves from cataclysmic cosmic events such as colliding neutron stars or black holes, or by supernovae.
• LIGO consists of two widely separated interferometers within the United States, one in Hanford, Washington, and the other in Livingston, Louisiana, operated in unison to detect gravitational waves.

The LIGO in the US first detected gravitational waves in 2015, which led to a Nobel Prize in Physics in 2017.

• These gravitational waves were produced by the merger of two black holes, which were about 29 and 36 times the mass of the Sun, 1.3 billion years ago.

Gravitational waves

Gravitational waves are ‘ripples’ in space-time caused by some of the most violent and energetic processes in the Universe.

Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity.

• Einstein’s mathematics showed that massive accelerating objects (such as neutron stars or black holes orbiting each other) would disrupt space-time in such a way that ‘waves’ of undulating space-time would propagate in all directions away from the source.
• These cosmic ripples would travel at the speed of light, carrying with them information about their origins, as well as clues to the nature of gravity itself.

The strongest gravitational waves are produced by cataclysmic events such as colliding black holes, supernovae (massive stars exploding at the end of their lifetimes), and colliding neutron stars.

Other waves are predicted to be caused by the rotation of neutron stars that are not perfect spheres, and possibly even the remnants of gravitational radiation created by the Big Bang.

Related article: Indian Neutrino Observatory

-Article written by Swathi Satish