“Why does the apple fall to the ground?” The usual answer is “due to gravity”. However, times have changed and modern physics formulates that action at a distance cannot happen without the intervening of some intermediary waves, and in case of gravity it is the gravitational waves. In 1916, Albert Einstein had predicted the existence of gravitational waves on the basis of his theory of general relativity. Einstein said that gravitational waves are ripples in the curvature of space time which propagate as waves. Now, almost a century later, physicists with the Laser Interferometer Gravitational- Wave Observatory (LIGO), have confirmed Einstein’s theory. Gravitational waves do indeed exist.
So what happened in the cosmic world to prove this theory? In layman terms, when two black holes millions of light years away collided with each other, the phenomenon produced a fleeting chirp which fulfilled the last prediction of Einstein’s general theory of relativity. You can listen to the sound here. Scientists say that the rising tone is evidence of the ripples created in the space-time. And, the ringing sound confirms the nature of the black holes which are vast, bottomless gravitational pits through which even light cannot pass.
But, what does this discovery mean to the common man? Why should the fact that gravitational waves the discovery of which is being touted as the next big thing in the cosmic world be important or relevant to him? It is important because it changes the way in which space and time have been perceived till date. It proves that space and time are not constant or standalone factors but interwoven and dynamic. They can expand, shrink and even jiggle in the cosmos. If further experiments cement the presence of gravitational waves in the universe it would open up new avenues in astronomy. It may allow measurements and discovery of faraway stars and galaxy and black holes on the basis of the waves made. Also, it can prove the existence of primordial waves, which are now thought to be resonating throughout the universe feebly. If discovered they can shed light on the rate of energy at which inflation occurs, shedding light on the Big Bang Theory, which is believed led to the creation of the Earth.
Gravitational waves have till now moved through universe without detection. They can be detected only when something catastrophic happens in the universe, like the collision between two black holes or a star exploding (supernova explosion). But, now that they have been discovered the future looks bright and exciting. It has now been proven that pairs of black holes do exist and as advances are made into technology, and horizons broaden, and scientists will be able to discover how the black hole is formed, which is still a mystery.