Early this morning, I walked into my workplace and found my colleagues discussing something on the lines of gravitational waves. Being completely unaware of the topic, I decided not to advertise my ignorance and silently slipped away to continue with my work (that’s what I usually do when I am completely clueless about something). Later that day, I found the topic trending on all the social media websites, and that’s when my inquisitive mind jumped into action. I googled gravitational waves, and WOAH! A plethora of articles, images, and news popped up on my screen. After going through innumerable videos and articles, I realized that the concept of gravitational waves is not refined to science students alone. All of us who know a little about gravity must also know about gravitational waves because it is an incredible discovery.
What are these Gravitational Waves? Why this hullabaloo around its discovery?
Sticking to definitions, a gravitational wave is a distortion in the space-time environment. Let me give you an example; let’s assume that two people are standing at some distance from each other now. If a gravitational wave passes between them, their distance will fluctuate until the wave passes away. However, we cannot detect this change as the waves that reach the earth are really weak. Imagine what could have happened if these waves were strong enough to produce visible fluctuations!
All this began in 1916 when Albert Einstein first proposed the concept of gravitational waves as a part of his theory of relativity. He proposed the similarity between gravity and acceleration and described gravity as a repercussion of the warping of space-time (the fabric of the universe) by mass. He suggested that if hills and valleys appear to move in water waves, why can’t gravity, which curves space and time, produce distortions?
This thought planted the seeds of the gravitational waves, which are like ripples formed in the fabric of space. However, Einstein himself was skeptical of his theory but mind you, he was never insecure about his ideas and thoughts. He stoutly predicted the production of a visible bending of starlight around the sun due to the warping of space. And when questioned about the possible failure, oh! I love this man’s response – “Then I would feel sorry for the dear Lord. The theory is correct anyway.” And yes, he was proven right in 1919 when the British astronomer Arthur Eddington observed the bending of starlight around the sun following Einstein’s theory. But since it was just a logical result of the theory, Einstein died before proving the existence of gravitational waves.
How did the existence of these waves come to light so many years after it was first postulated?
In 1969, Joseph Weber, a physicist from Maryland, claimed to have detected gravitational waves by building wave detecting devices, but since he could not identify the source, his claim was refuted. In 1978, further evidence of gravitational waves was found while studying the change of orbits of two objects in the constellation ‘Aquila.’ After four years, the scientists were able to measure a change that was following Einstein’s calculations. The MIT physicist then proposed LIGO, an abbreviation for Laser Interferometer Gravitational-Wave Observatory, and the National Science Foundation was persuaded to fund the project. The rationale behind the experiment was not only to study the effects of the waves but also to detect the waves themselves.
It was September 2015 when the detector registered something that completely fit the description of two black holes colliding and coalescing to form a bigger, massive black hole. However, only after performing some replications and receiving positive results, the detection of gravitational waves was announced on February 11th, 2016, thus confirming Einstein’s theory.
Now, what’s next? Why so much hype around this discovery?
Well, the discovery is equivalent to discovering a new sense organ in the human body. The gravitational waves will provide a new way to see (more precisely, hear) things in the universe. Detection of more collisions can lead to a more efficient manner of finding the distance of the far away objects and a study of the nature of the cosmic objects like neutron stars. And maybe, something completely unexpected can be discovered because of this discovery! You never know.
Well, future generations are going to study a heavier version of science books than we did!