Einstein was always right-Gravitational Waves do exist!!

 

 

 

 

 Source: ligo.caltech.edu          

                                                  

"The joy of discovery is certainly the liveliest that the mind of man can ever feel” said Claude Bernard. In 2015, scientists detected gravitational waves for the very first time. Let us first understand that what gravitational waves are. Gravitational waves are disturbances in space-time caused by some violent and energetic processes in the Universe. Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity. The strongest gravitational waves are produced by events such as colliding black holes, supernovae (massive stars exploding), and colliding neutron stars.

  Source: ligo.caltech.edu

LIGO stands for Laser Interferometer Gravitational-wave Observatory. LIGO's interferometers basically works on principle of Michelson Interferometers .They are mostly L-shaped.  Mirrors at the ends of the arms reflect light in order to create an interference pattern called 'fringes'. A device called a photo detector measures these fringes, revealing minute details of phenomenon being studied. Each LIGO detector consists of two arms, each 4km long, comprising 1.2m-wide steel vacuum tubes arranged in an "L" shape, and covered by a 10-foot wide, 12-foot tall concrete shelter that protects the tubes from the environment. LIGO can also detect gravitational waves coming from any direction. A single LIGO detector could not initially confirm gravitational waves on its own.

 Source: public.virgo-gw.eu

                                                           

On September 14, 2015, at 5:51 a.m. Eastern Daylight Time, a fragment of that energy in the form of a “gravitational wave” reached Earth. The announcement was made by the LIGO and Virgo collaborations on 11 February 2016. The signal received was named GW150914 (from "Gravitational Wave" and the date of observation 2015-09-14). The waves given off by this merger of GW150914 reached Earth as a ripple in space-time that changed the length of a 4 km LIGO arm, proportionally equivalent to changing the distance to the nearest star outside the Solar System by one hair's width. The chirp signal lasted over 0.2 seconds, and was in the audible range and has been described as resembling the "chirp" of a bird. Initially there was a question as to whether the signals had been real or not but more detailed statistical analysis of the signal confirmed the authenticity of event happened.

 Analysis of the signal suggested that it was produced by the merger of two black holes resulting in a post-merger black hole. During the final 20 milliseconds of the merger, the power of the radiated gravitational waves peaked at about 50 times greater than the combined power of all light radiated by all the stars in the observable universe. Across the 0.2-second duration of the detectable signal, the relative tangential orbiting velocity of the black holes increased from 30% to 60% of the speed of light.  It was also the first observation of a binary black hole merger, demonstrating both the existence of binary stellar-mass black hole systems and the fact that such mergers still occur within the current age of the universe.

Source: npr.org

                                                             

The 2017 Nobel Prize in Physics was awarded to Rainer Weiss, Barry Barish and Kip Thorne for contributions to the LIGO detector and the observation of gravitational waves. Drever, Thorne, Weiss, and the LIGO discovery team also received the Gruber Prize in Cosmology. Many such awards and recognition were given for this breakthrough observation of gravitational waves. The observation was starting of a revolutionary era of gravitational-wave astronomy. Prior to this detection, astrophysicists and cosmologists were able to make observations based upon electromagnetic radiation (including visible light, X-rays, microwave, radio waves, gamma rays) and particle-like entities (cosmic rays, neutrinos, and so on).

Source: popsci.com

                                                      

The World Reacted to LIGO’s Discovery of Gravitational Waves. The world was understandably excited about the breakthrough, including the estate of Einstein himself. It states “If Einstein were alive, he had totally done a mic drop after today’s LIGO conference on gravitational waves”. Dr. Stephen Hawking also made a statement on his Facebook page. Facebook founder Mark Zuckerberg praised the scientists who made this discovery, calling their work “one of the biggest discoveries of modern science”. Detection and analyzing the information carried by gravitational waves is presently allowing astronomers and other scientists to observe the Universe in a way never before possible and to observe first glimpses of literally magnificent wonders. 

Also LIGO-India is a collaboration between the LIGO Laboratory (operated by Caltech and MIT) and three Institutes in India: the Raja Ramanna Center for Advanced Technology (RRCAT, in Indore), the Institute for Plasma Research (IPR in Ahmedabad), and the Inter-University Centre for Astronomy and Astrophysics (IUCAA, in Pune).

Motivations for constructing a third LIGO interferometer are primarily related to building a larger global network of gravitational wave detectors. So let’s all gear up and work hard to make our valuable contributions towards our country in the field of science and technology as cosmic curiosity is the new future of humankind.