The News
- The Environment Ministry has given forest clearance to test the suitability of land for LIGO India project in Hingoli district of Maharashtra.
Key Highlights
- In 2017, for the first time scientists directly detected gravitational waves — ripples in space-time.
- The discovery was made by two U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors.
- The LIGO project operates three gravitational-wave (GW) detectors- Two are at Hanford in the State of Washington, USA, and one is at Livingston in Louisiana, USA.
- The proposed LIGO-India project aims to move one Advanced LIGO detector from Hanford to India.
- This move will improve the chances of detecting more such gravitational waves.
About Gravitational waves
- Electric charges oscillating up and down produce electromagnetic radiation.
- In a similar way, the general theory of relativity predicts that oscillating massive objects should produce gravitational radiation, or gravitational waves.
- Gravitational waves are ripples in the overall geometry of space and time produced by moving masses.
- Some of the cosmic events that produce such ripples are exploding stars, collisions between ultradense neutron stars or merging black holes or supernovae.
- Gravitational radiation is exceedingly difficult to detect, because gravity by nature is much weaker than electromagnetic radiation.
How are gravitational-wave produced?
- In 2016, gravitational waves finally were observed from the merger of two neutron stars.
- Two neutron stars rotate around each other; the closer they get, the faster they spin.
- Eventually, they collide.
- The energy from their spiraling and merging releases energy in the form of gravitational waves, or ripples in space-time.
Significance of discovery
- The discovery of gravitational-waves is the beginning of new era in astronomy.
- So far all observations of universe are made through electromagnetic radiation emitted from the objects from visible light to ‘gamma rays.
- Gravitational waves are a new way of “seeing” what happens in space.
- We can now detect events that would otherwise leave little to no observable light, like black hole collisions.
- It will also help untangle mysteries about the dense, dead objects known as neutron stars.
About Gravitational-Wave Observatories
- The Gravitational-Wave Observatory (LIGO) is designed to directly detect gravitational waves.
- In 2017, for the first time, scientists directly detected gravitational waves from the collision of two neutron stars using the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO), the Europe-based Virgo detector; and some 70 ground- and space-based observatories
- LIGO detectors use laser interferometry to measure the minute ripples in space-time caused by gravitational waves from mergers of pairs of neutron stars or black holes, or supernovae.
