For first time Scientists discover Gravitational Waves
After decades of effort, scientist for the first time have discovered Gravitational Waves (GW) whose existence Albert Einstein had hypothesised, in 1915 in his Theory of General Relativity. These waves were detected by the scientists working at two LIGO (Laser Interferometer Gravitational-wave Observatory) facilities in United States. Sixty Indian scientists from across nine Indian institutes are involved in the experiment.
Long time ago, in a galaxy far, far away two black holes located 1.3 billion light years away from earth collided. The resulting explosion created ripples in the fabric of spacetime known as gravity waves. These ripples reached Earth on 14 September last year, where they were picked up by a pair of detectors known as the Laser Interferometer Gravitational Wave Observatory (Ligo) now that the first gravitational wave signals have been detected.
Laser Interferometer Gravitational-Wave Observatory (LIGO) : LIGO is a large-scale physics experiment and observatory to detect gravitational waves. LIGO is a joint project between scientists at MIT, Caltech, and many other colleges and universities. It was cofounded in 1992 by Kip Thorne and Ronald Drever of Caltech and Rainer Weiss of MIT. It is the world's largest gravitational-wave facility. It includes more than 900 scientists worldwide. LIGO is funded by the National Science Foundation.
Discovery of Gravitational Waves : The LIGO experiment has 4km long L-shaped tunnels, it 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.
What are Gravitational Waves?
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. It was Predicted by Albert Einstein in 1916 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 Research Work : Earlier in 1974, Russel Hulse (America) and his thesis advisor Joseph Hooton Taylor Jr., had disovered indirect evidence for the existence of gravitational waves emitted from the decaying orbital period of objects called binary pulsars. Both of them were awarded Nobel Prize in Physics, in 1993.
What does it mean for Science and Humanity ?
Till date everything that we have learnt about the universe has been based on studies of electromagnetic radiation – from infrared to visible light to gamma rays but the Gravitational waves will give us a new way of looking at the universe. It will open new window in studying cosmos and unlock secrets about the early universe and mysterious objects like black holes and neutron stars.
The discovery of Gravitational Waves 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. It will also confrim the key predictionsof Albert Einstein’s General Theory of Relativity.
Since Gravitational waves do not interact with matter, the gravitational waves coming to Earth may be carrying undistorted information about its origin. It may be useful for studying black holes and other dark objects.