LIGO-India- Background, Working & Significance
The Union Cabinet recently approved the LIGO-India project in Maharashtra. With this project, India would be joining the ongoing global effort to develop a better understanding of the universe by studying gravitational waves.
- Isaac Newton is credited with improving the understanding of gravity- the attractive force that makes objects fall to the ground and also makes celestial objects orbit each other.
- He explained that the gravitational force between two objects is directly proportional to their masses and inversely proportional to the square of the distance between them.
- However, Newton’s law of gravitation has several deficiencies. Some of the key shortcomings include:
- It doesn’t explain why the gravitational force exists between two bodies.
- Time doesn’t even figure in the equation. This doesn’t sit well with Einstein’s Special Theory of Relativity which established that nothing could travel faster than light in vacuum.
- With Einstein proposing the idea of spacetime i.e. a union of space and time, that behaves like a soft fabric that responds to objects placed on it, our understanding of gravity changed.
- As explained by physicist John Wheeler- “matter tells spacetime how to curve and spacetime tells matter how to move”.
- One of the key concepts put forth in General Relativity is gravitational wave. Gravitational waves can be understood as ‘ripples’ in the spacetime. These ripples are generated by energetic and violent events.
- When gravitational waves come in contact with objects, they can produce temporary deformation in the latter. This is because the spacetime, on which the objects sit, itself elongates/ contracts when the gravitational waves propagate through it.
- Since gravity is the weakest of all natural forces, this deformation is extremely difficult to detect.
What is the LIGO project?
- LIGO or Laser Interferometer Gravitational-wave Observatory is the largest gravitational wave observatory in the world.
- The first 2 LIGOs were constructed in the USA (Hanford and Livingston), with the funding support from the country’s National Science Foundation in the 1990s.
- It was redesigned in 2010 and 2014 to improve the sensitivity. This led to the first-ever detection of gravitational waves in 2015. These waves had been generated by the collision between 2 black holes.
- This led to a Nobel Prize being awarded in 2017.
- A 3rd instrument, named Virgo, started operations in 2017. This is located in Italy.
- Japan also has a LIGO called the KAGRA or (Kamioka Gravitational Wave Detector).
- Since the 1st detection, 9 other gravitational wave events have been detected.
- Recently, the Cabinet gave the green light for setting up a LIGO in Hingoli district of Maharashtra.
- This ₹2,600 crore facility would form the 5th node of the international LIGO network.
- It is expected to commence operations by 2030.
- The project is to involve multiple departments and research institutions- including India’s Department of Atomic Energy and Department of Science and Technology and USA’s National Science Foundation.
How does it work?
- The instrument is L-shaped, with each arm being 4 km long. These are vacuum chambers.
- There are highly reflective mirrors placed at the end of these chambers.
- Light rays are released into both these chambers simultaneously.
- They are reflected back after hitting the mirrors. Under normal circumstances, the rays would return simultaneously.
- However, when a gravitational wave passes through, there is a phase difference observed. Thus, gravitational waves are detected.
Why is LIGO-India significant?
- LIGOs are some of the most complex scientific instruments to be built.
- Given how sensitive these instruments are, establishing multiple observatories across the world will help address the issue of false readings. The Indian project would help revalidate signals picked up by the other observatories too.
- The LIGO-India project presents 2 opportunities:
- Development of India as a global hub for gravitational physics research
- Demonstration of ability to intelligently reckon society’s relationship with science in the country- especially given the land rights issue plaguing projects like the Challakere Science City and the Neutrino Observatory
What is the way ahead?
- India has been an active participant in a number of international scientific projects such as the LHC (Large Hadron Collider) and ITER (International Thermonuclear Experimental Reactor) experiments.
- However, India has been lagging behind when it comes to establishing large-scale cutting edge scientific facilities on its own soil. For instance, the Neutrino Observatory continues to face multiple delays.
- By establishing such infrastructure domestically, India can demonstrate its intent and capacity to undertake ground-breaking scientific work. In this regard, the recent go-ahead for the LIGO facility in Maharashtra is a welcome development.
- For this, timely release of funds would be vital for the construction part to go smoothly.
- To address the criticism that ‘Big Science’ undertakings are far removed from the concerns of the lay-people, it is important to keep the public in loop.
- Open discussions on concerns regarding access to natural resources.
- Organization of public outreach programs can help.
- The focus should be on what the project can do for the people.
While India has been an active collaborator in a number of international scientific projects, it is yet to establish a large scale facility on its own soil. The LIGO-India project is a significant opportunity for India to boost its standing in the global Big Science arena.
Practice Question for Mains:
Discuss the significance of the LIGO-India project that was recently approved by the Cabinet. (250 words)