Gravitational Waves

Gravitational Waves were for the first time discovered in February, 2016, 100 years after they were hypothesized by Albert Einstein in 1916. These waves were detected by the scientists working at two LIGO (Laser Interferometer Gravitational-wave Observatory) facilities in United States. LIGO scientists detected these gravitational waves produced by collision of two black holes located 1.3 billion light years away from earth.

• Process of Discovery: The LIGO experiment has 4km long L-shaped tunnels and uses lasers to measures changes in the distance between two ends.
• When the GW enters into LIGO, it stretches space and direction, and disperses space in another direction i.e. these waves disturb the light emitted lasers.
• Scientists by measuring the interference (disturbances) of lasers light map the disturbed space which has been compressed or stretched.
• In physics, gravitational waves are ripples in the curvature of spacetime which propagate as waves, travelling outward from the source at the speed of light.
• Predicted in 1916 by Albert Einstein on the basis of his Theory of General Relativity.
• Gravitational waves transport energy as gravitational radiation and pass through matter without interacting with it.
• Previous evidences:Earlier in 1974, Russel Hulse and Joseph Taylor had disovered indirect evidence for the existence of gravitational waves emitted from the decaying orbital period of objects called binary pulsars. Both of them for their discovery were awarded the Nobel Prize in Physics in 1993.

Significance

• This discovery opens new window in studying cosmos and unlock secrets about the early universe and mysterious objects like black holes and neutron stars.
• Confirms a key prediction of Albert Einstein’s General Theory of Relativity.
• Gravitational waves may be useful for studying black holes and other dark objects.
• As these waves do not interact with matter, gravitational waves coming to Earth may be carrying undistorted information about its origin.

It may also improve methods for estimating the distances to other galaxies. It may also help in mapping the abundance of black holes and frequency of their mergers.