Albert Einstein is one of those scientists who has given the basis of almost all the phenomena we see around us. From Photoelectric effect which later helped develop Television to Gravitation the reason why we don’t fly. One such discovery of Einstein was the Theory of Relativity which comprises of General Relativity and Special Relativity. For simple understanding, just remember this theory forms the backbone for modern-day Physics and every principle is based on relativity in some way or the other. Now you know how important discovery that is ! If you have not been staying under the rock, you would have read the news all around about the discovery of Gravitational Waves and how scientists used some of the most advanced technology to prove a part of Einstein’s Theory of Relativity after 100 years ! See the impact of technology ? Proving something after 100 years !
I’m not Sheldon nor am I a Physicist, so this post won’t be too technical. Whatever I’ve read and understood over the past few days is what I’ll write here. I don’t know how much of an impact this will have on others, but this will definitely help me and you get a gist of it.
So before we begin, a heads up on what exactly are Gravitational Waves. Imagine a rubber sheet stretched to its max. Now you place two objects of different mass (say a football and Cricket Ball). Then the heavier object will pull down the sheet more than the Cricket ball because of its higher mass. Now when these two objects move about on the sheet, it will create disturbance or ripples – just like ripples created in water when you throw a stone. So the same thing happens in space, when two heavenly bodies like Black holes move about in the space they send out these high energy Gravitational Waves which ripple through the universe.
Way back in 1916 Einstein predicted Gravitational Waves existed as a part of his Theory of Relativity. And he had also mentioned that proving this practically was literally impossible since creating such a technology which would capture movements of particles of the size of one thousandth of the diameter of a sub-atomic proton. Over the years technology has had a huge impact on how Physicists interacted with the universe. And thanks to it that they have confirmed Einstein’s prediction of Gravitational Waves that they have detected emanating from collision of black holes some 1.3 billion light years away in deep space. With the discovery of these Gravitational Waves, scientists can now witness collisions between black holes and other stellar objects and with this they would eventually be able to ‘track back’ to the origin of everything – The Big Bang.
To detect Gravitational Waves, scientists used an advanced instrument called LIGO: Laser Interferometer Gravitational-Wave Observatory. This has been setup at two places in the US, one in Washington and the other in Louisiana. What I’ve understood of them is: They are large L shaped vacuum system tubes that measure about 4km on each side. So How does LIGO work ? There is a LASER which sends a beam of light that hits a beam splitter due to which the beam travels in the arm passing through mirrors. The beam bounces between the mirror and returns to splitter which directs the light back to the LASER. But if there is any difference in length of the arms, light will be recorded by a photo-detector.
So when a gravitational wave passes by, some amount of light falling on the photo-detector varies which then generates electrical signal based on the variation. And similar variations were observed in September last year when one arm in Washington saw some disturbance and the same was observed seven thousands of a second later in Louisiana confirming the existence of Gravitational Waves.
Confirmation of existence of Gravitational Waves is dubbed to be the “Discovery of the Century” by many and why not since that was missing the practical existence from Einstein’s Theory of Relativity. Who would have thought that technology would evolve so much that it would still make an impact and help confirm something that way predicted 100 years ago.