Of esoteric forces and invisible rippples!

Of late, Einstein's 'gravitational waves' has created quite some stir in the world of science. And I reckon that its repetitive appearance in news headlines' might have made even the laymen curious. But owing to the utterly pedantic explanations given in the various articles, I suppose they have not been of much help to the non scientific community. So the question still persists, WHAT EXACTLY ARE GRAVITATIONAL WAVES?

To start with let's recall what gravity is. Yes, it's the mysterious force that helps you to walk about on the surface of Earth. To be a bit more precise, it's the force with which everything attracts every other thing with a magnitude, which, in ordinary cases is so less that its effect becomes unnoticeable. Now according to Einstein, there is more to gravity than just this. He, in his general theory of relativity says that gravity is not a force at all! It's just a consequence of the space time curvature, meaning that the dark sea in which all our planets float around is not really shapeless. It's got some particular geometry. And gravity is a result of this geometry. Okay, now try to digest this fact without much speculation.  And according to Einstein, when any mass moves, it leads to a change in this geometry. And this change, people, is communicated throughout the whole universe in the form of waves or ripples. That is what a gravitational wave is. Come on, its not that recondite, is it? Read on.

Now you must be thinking that masses keep moving around all the time so how in the world it took them so long for its detection? You see, these waves are not emitted by all moving masses. That honour just belongs to certain accelerating ones! So even though a lot of ripples trespass earth every single second, their intensity is so less that it's beyond the measuring capacity of our present day detectors. Now it's worth mentioning what actually happens when a gravitational wave passes through a certain region.

If you have ever noticed, when you throw stones in a pond, rippples are seen to emerge from that point and spread out in the form of circular waves and if a cork is placed in their path, it is found to bob up and down. The same happens in the case of gravitational waves. The region through which it passes gets stretched and the region adjacent to that gets strained. This is exactly what was exploited by the LIGO detectors. So there happened to be a massive collision between two binary pulsars( they are just super dense, radiation emitting stars, duh!) billions of light years away. And the emissive gravitational waves contained such a huge amount of energy that even after reaching Earth the strain produced by them fell within the limits of detection of our earth bound detectors!

Now automatically the next question should be, what use are these mysterious ripples of? Now this would require some knowledge of science so I'll just skip the explanations and brief the result. You see, the radiations(EM radiations) that our present day astronomers use for the study of early universe cannot provide them with information about the first few minutes of the Big bang, nor about certain dark, sophisticated, mysterious objects located far far away from us, so gravitational waves now come to their rescue. This is what all that rejoicing was about. Of course, the detection of gravitational waves has paved way for new cutting edge research and it will forever remain one of the greatest scientific milestones in the history of humanity.