What are Gravitational Waves?

Gravitational waves are 'ripples' in the fabric of space-time caused by some of the most violent and energetic processes in the Universe. Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity. Einstein's mathematics showed that massive accelerating objects (such as neutron stars or black holes orbiting each other) would disrupt space-time in such a way that 'waves' of distorted space would radiate from the source (like the movement of waves away from a stone thrown into a pond). Furthermore, these ripples would travel at the speed of light through the Universe, carrying with them information about their cataclysmic origins, as well as invaluable clues to the nature of gravity itself.

The strongest gravitational waves are produced by catastrophic events such as colliding black holes, the collapse of stellar cores (supernovae), coalescing neutron stars or white dwarf stars, the slightly wobbly rotation of neutron stars that are not perfect spheres, and the remnants of gravitational radiation created by the birth of the Universe itself.

The animation below illustrates how gravitational waves are emitted by two neutron stars as they first orbit each other and then coalesce. (Credit: NASA/Goddard Space Flight Center)

Though gravitational waves were predicted to exist in 1916, actual proof of their existence wouldn't arrive until 1974, 20 years after Einstein's death. In that year, two astronomers working at the Arecibo Radio Observatory in Puerto Rico discovered a binary pulsar--two extremely dense and heavy stars in orbit around each other. This was exactly the type of system that, according to general relativity, should radiate gravitational waves. Knowing that this discovery could be used to test Einstein's audacious prediction, astronomers began measuring how the period of the stars' orbits changed over time. After eight years of observations, it was determined that the stars were getting closer to each other at precisely the rate predicted by general relativity. This system has now been monitored for over 40 years and the observed changes in the orbit agree so well with general relativity, there is no doubt that it is emitting gravitational waves. For a more detailed discussion of this discovery and work, see Look Deeper.

maxresdefault

GWvisual

e then, many astronomers have studied the timing of pulsar radio emissions and found similar effects, further confirming the existence of gravitational waves. But these confirmations had always come indirectly or mathematically and not through actual 'physical' contact.

That was the case up until September 14, 2015, when LIGO, for the first time, physically sensed distortions in spacetime itself caused by passing gravitational waves generated by two colliding black holes nearly 1.3 billion light years away! LIGO and its discovery will go down in history as one of the greatest human scientific achievements.

GRAVITATIONAL WAVE DETECTOR FOR INDIA

A new ligo gravitational wave detector to measure ripple in the fabric of space and time is set to built in India, In a yet-to-be-disclosed site by 2025, In collaboration with universities from across the globe.

A third ligo detector will help pinpoint the origin of the gravitational waves that are detected in future.

The new Laser Interference gravitational waves that are detected in future .

These are observatory detector will add to the two already operational in the U.S

MAJOR FINDING

The Ligo detectors discovered the first research gravitational wave won a by two gaint merging Nobel prize Black holes last year in Physics .

Existence of these waves were first predicted by german scientist Albert Einstein 100 years ago in his general theory of relativity .

Massive accelerating object such as neutron stars or black holes orbiting each other would disrupt space time in such a way that ‘wave’ of distorted space would radiate from the source.

These Ripples at the speed of light through the universe, carrying with them information about their origins.

HOW DOES LIGO WORK??

THE laser interferometer Gravitational wave Observatory searches for distortion in the space time that would indicate the passage of gravitational waves.

A laser beam is split down into two 4 kilometers arms containing mirror .

The laser beam reflects back and forth off of mirror coming back to converge at the crux of the arms cancelling each other out.

The passage of gravitational wave would alter the length of the arms causing the beams to travel different distances. The mismatch would be measurable with a light detector.