Scientists announced, after decades of effort, they have succeeded in detecting gravitational waves from the violent merging of two black holes in deep space. The waves came from two black holes circling each other, closer and closer, until they finally collided.

The detection was hailed as a success of exquisitely crafted, billion-dollar physics experiment (LIGO) and as confirmation of a key prediction of Albert Einstein’s General Theory of Relativity. It may inaugurate a new era of astronomy in which gravitational waves are tools for studying the most mysterious and exotic objects in the universe.

Laser Interferometer Gravitational-wave Observatory (LIGO), is the measuring device, is actually two facilities in Livingston, Louisiana, and Hanford, Washington. They were built and operated with funding from the National Science Foundation, which has spent $1.1 billion on LIGO over the course of several decades.

Scientists already know that studying the sky in different wavelengths of light can reveal new data about the cosmos. For many centuries, astronomers could only work with optical light. But relatively recently, researchers built instruments allowing them to study the universe using X-rays, radio waves, ultraviolet waves and gamma-rays. Each time, scientists got a new view of the universe.In the same way, gravitational waves have the potential to show scientists totally new features of cosmic objects

Gravitational waves are — ripples in the fabric of space-time whose existence was first proposed by Albert Einstein, in 1916.  . The gravity of large objects warps-distort space and time, or “spacetime” as physicists call it, the way a bowling ball changes the shape of a trampoline as it rolls around on it. Smaller objects will move differently as a result – like marbles spiraling toward a bowling-ball-sized dent in a trampoline instead of sitting on a flat surface.

HOW THESE WAVES WILL BE USEFUL
Right now, we can currently only see celestial objects that emit electromagnetic radiation — visible light, X-rays, gamma rays, and so on. If you look with visible light as far as we can look in the universe, the universe is no longer transparent, it becomes opaque. There’s nothing you can do about that.

But some objects — like colliding black holes or the smoking gun of the Big Bang — don’t emit any electromagnetic radiation. They emit gravity. Invisible objects in the universe may soon become visible. Also, gravitational waves are unchanged by the matter they move through. Visible light can get absorbed or reflected by cosmic bodies or dust before it reaches our telescopes, leaving us with a cruddy view of things. Since they pass through matter without interacting with it, gravitational waves would come to Earth carrying undistorted information about their origin. They could also improve methods for estimating the distances to other galaxies. These waves will be particularly useful for studying black holes (the existence of which was first implied by Einstein’s theory) and other dark objects, because they’ll give scientists a bright beacon to search for even when objects don’t emit actual light. Mapping the abundance of black holes and frequency of their mergers could get a lot easier.    Gravitational waves will help scientists to see back past where one can’t see with physical light.

DEC 18. the Union cabinet has approved a proposal to establish a state-of-the-art gravitational wave observatory in India in collaboration with the Laser Interferometer Gravitational-wave Observatory (LIGO) in the US. The “in principle” approval for the LIGO-India project for research on gravitational waves – a discovery that is regarded as the breakthrough of the century – is piloted by the Department of Atomic Energy and Department of Science and Technology (DST).

Electromagnetic Radiation:

                              Energy radiated in the form of a wave as a result of the motion of electric charges. A moving charge gives rise to a magnetic field, and if the motion is changing (accelerated), then the magnetic field varies and in turn produces an electric field. These interacting electric and magnetic fields are at right angles to one another and also to the direction of propagation of the energy. Thus, an electromagnetic wave is a transverse wave.

The theory of electromagnetic radiation was developed by James Clerk Maxwell and published in 1865. He showed that the speed of propagation of electromagnetic radiation should be identical with that of light, about 186,000 mi (300,000 km) per sec. Subsequent experiments by Heinrich Hertz verified Maxwell’s prediction through the discovery of radio waves, also known as hertzian waves.

Light is a type of electromagnetic radiation, occupying only a small portion of the possible spectrum of this energy. The various types of electromagnetic radiation differ only in wavelength and frequency; they are alike in all other respects. In order of decreasing wavelength and increasing frequency, various types of electromagnetic radiation include: electric waves, radio waves (including AM, FM, TV, and shortwaves), microwaves, infrared radiation, visible light, ultraviolet radiation, X rays, and gamma radiation