Introduction:
What are Gravitational Waves?
These are ripples in the space-time structure that occur when black holes meet and stars explode. "Gravitational waves are produced when objects accelerate.
Gravitational waves were first proposed 100 years ago by Albert Einstein as part of the theory of relativity.
The discovery can pave the way for testing the general theory of relativity so that we can look deeper and deeper into the universe. It also offers the possibility of detectors that can monitor the beginning of the universe.
How these Gravitational Waves have been Identified?
On February 11, 2016, scientists from the Gravitational Wave Observatory (LIGO), a laser interferometer, made history by announcing the first detection of gravitational waves.
The Nobel Prize in Physics 2017 has been awarded "for his decisive contributions to the LIGO detector and the observation of gravitational waves".
The waves detected by the laureates came from the collision of two black holes with a difference of 1,300 million light years. One light year is about 9.5 billion km.
The operation of LIGO has been one of the most electrifying announcements of recent years.
According to the theory of general relativity, the pair of black holes that orbit each other has lost energy, due to the emission of gravitational waves.
Black holes are a region of spacetime. It has powerful gravitational effects, which prevent particles and electromagnetic radiation from escaping.
It acts as an ideal black body that does not reflect light. It continues growing by absorbing the mass of its surroundings.
Why do gravitational waves matter to us?
The discovery is due to an extremely delicate experience. Einstein predicted gravitational waves almost 100 years ago. After about 50 years of experimentation, the waves were first detected in September 2015.
Discovery and repeated detection (four times now) have made astronomy into gravitational waves very real.
Gravitational wave astronomy is a way to trace some of the most violent processes in the universe, such as the black hole or fusion of neutron stars that can not be detected by light or conventional methods.
Gravitational waves carry energy in the form of gravitational radiation, a form of radiant energy similar to electromagnetic radiation.
Newton's law of universal gravitation, which is part of classical mechanics, does not contemplate its existence since it is based on the assumption that physical interactions propagate instantaneously (at infinite speed).
Gravitational waves can penetrate into regions of space that electromagnetic waves can not. They can make it possible to observe the fusion of black holes and possibly other exotic objects in the distant universe.
In 2017, some group of scientists questioned the validity:
They argued that the two detectors belonging to LIGO were correlated, which led to a correlation of the noise factor. The elimination of signal noise is crucial in such an experiment.
This had not been done correctly in the framework of the scientific collaboration of LIGO (LSC). Since then, a version of his preprint has been published in the Journal of Cosmology and Astroparticle Physics.
After a long silence, the LSC published a clarification on its website.
Benefits for India of the LIGO-India project:
The project will offer scientists and engineers an unprecedented opportunity to deepen the field of gravitational waves and take the global leader in this new astronomical frontier.
The LIGO-India project will also provide significant opportunities for advanced technology for Indian industry, which will participate in the construction of the eight-kilometer ultra-vacuum beam tube on a flat surface.
With its creation, India will join the global network of gravitational wave detectors.
The establishment of an observatory in India is also of utmost importance, since the greater the distance between the observatories, the greater the precision of the location of the gravity waves.
Adding a new detector to the existing network will increase the expected event rates, increase confidence in detecting new sources and improve the ability to locate GW sources in the sky. It will also have an aspiration value for young Indian scientists.
LIGO can serve as a platform to solve the mysteries of the universe and the association of India with it will help us in the future.
Things predicted by the General theory of relativity by Einstein include:
As the light approaches the sun, twice as much as classical physics predicts (the system used before general relativity) doubles towards the sun.
The redshift of gravity: when the light moves away from an object subjected to gravity (far from the center of the valley), it extends over longer wavelengths. This has been confirmed by the Pound-Rebka experiment.
The delay of Shapiro: the light seems to slow when it passes near a massive object. This was observed for the first time in the 1960s by space probes targeting the planet Venus.
Gravitational waves: they were observed for the first time on September 14, 2015.
Way to follow in gravitational waves:
This is how science advances with giant steps, with reflexive criticisms and intermediate interventions.
In this case, the concomitant controversy has captured the very interest of those who are beyond the world of science. The LSC now plans to submit a document with detailed explanations.
At first, there is disagreement about Einstein's theory of relativity. But now, a consortium of astronomers has confirmed the prediction of Einstein's key relativity theory.
Einstein had argued that significant gravitational forces could stretch the light, as well as the compression and stretching of the sound waves that we perceive with the change of tone of a passing train.
India is also working to have its own detector under the INDIGO consortium.
However, the success and the discovery of the gravitational waves of the Indian consortium require the cooperation of the whole world, because they can not be realized by a single country because of technical problems.
It is necessary to develop this to offer more opportunities of this kind to the Indian scientific community.