Gravitational waves are ripples in the space time curvature traveling outward from the source produced by violent events such as collision of 2 black holes or by supernova explosion. They are produced by accelerating masses just the same as accelerating charged particles produce radio waves (electrons in antennas).
GW are akin to Electromagnetic Waves (EM) waves, but emitted by gravitating bodies in motion such as black holes, spiraling towards each other in binary orbits.
• Can penetrate regions of space where EM has no reach
• Gravitational waves are hypothesize to arise from cosmic inflation (expansion of universe after bigbang)
Gravitational waves travel at the speed of light and distort space-time on their path. The effect would be such that the length between 2 objects on earth would vary with time whenever a wave is passing through them. But these variations are so small, it is impossible to directly measure them even with the most accurate measuring techniques.
What is the significance of the discovery?
This discovery opens a new avenue for space exploration. Our primary tool for exploring the universe is observation through telescopes that rely only on light waves reaching us from outer space. But objects like black-hole and dark matter do not emit light and there is no easy way to detect them. However, they can interact via gravity, and gravitational waves might be the only agent which carries their information to us. Though the current technology is not adequate to make large-scale detections using gravitational waves, this might be a first step to unveiling a brand new technique of observing the unobserved part of universe.
Lastly, the discovery almost confirms Einstein’s General Relativity beyond doubt. This will help in developing further research in several theoretical fields such as Quantum Gravity and unification of the fundamental forces.
Light could not pass through the opaque plasma medium of early universe. However GW could easily propagate. Hence carry the clue to origin of the universe
Laser Interferometer Gravitational-wave Observatory (LIGO) and the Indian Initiative in Gravitational Observations (IndIGO) have proposed a collaborative project to create a world-class gravitational-wave detector in India. Final approval has not been granted yet. If approved, this project would mark a giant leap in India’s research in Observational Astronomy.