So early this morning, I walked into my workplace only to find my colleagues discussing something on the lines of Gravitational Waves and I, being completely unaware of the topic, 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 blank on something.) But then again, 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! What do I see? A plethora of articles, images and news popping up on my screen. And after going through the videos and the articles, I realized that not only the science students but also people who understand gravity should be aware of this incredible discovery.
What are these Gravitational Waves? And what is this hullabaloo around this discovery?
Sticking to definitions, a gravitational wave is a distortion in the space-time environment. Let me give you an example, suppose that two people are standing at some distance from each other, now if a gravitational wave passes between them, the distance between them would keep on fluctuating until the wave passes away. However, we are unable to detect this change as the waves that reach the earth are really weak. Just imagine the case, had the waves been strong enough to produce visible fluctuations!
Gravitational Wave-Ripple in Space-time
THE PAST
How did these new kind of waves come into picture?
All this began in the year of 1916 when the concept of gravitational waves was first proposed by Albert Einstein as a part of his theory of relativity. He proposed the similarity between gravity and acceleration, and also described gravity as a repercussion of the warping of space-time (the fabric of universe) by mass. He suggested that if we could see moving hills and valleys in water that we call waves, then why can’t gravity, that 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 quite skeptical of his theory but mind you, he was never insecure. 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 just 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 in accordance with Einstein’s theory. But since it was just a logical result of the theory, Einstein died before proving the waves part of his theory in 1955.
Gravitational Waves as envisaged by Einstein
THE PRESENT
How did the existence of these waves come to light, so many years after it was first postulated?
In 1969, Maryland physicist Joseph Weber claimed to have detected gravitational waves by building wave detecting devices but since he could not identify the source, his claim was refuted. It was then in 1978 when further evidence of gravitational waves was found while studying the change of orbits of two objects in the constellation ‘Aquila’ and after four years, the scientists were able to measure a change that was in accordance with Einstein’s calculations. The MIT physicist then proposed the idea of LIGO, 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 the month of September 2015 when the detector registered something which 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.
THE FUTURE
Now, what’s next? Why so much hype around this discovery?
Well, the discovery is equivalent to discovering a new sense organ discovered in a 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 distance of the far away objects as well as a study of the nature of the cosmic objects like neutron stars. And maybe, something completely unexpected can be discovered! You never know. Guess the future generations are going to study a heavier version of the science books than we did!