Introduction to Gravitational Waves

Nisarg Bhatt
3 min readFeb 17, 2021

Hey, Enthusiast! If you are reading this blog, you are having a curious mind and I assure you that you will definitely get the knowledge and motivation to work in this direction.

So, What is The Gravitational Wave??

We know that the universe is made of Space-Time Fabric. In this fabric, the matter those are having mass bends the fabric. More mass bends more and less mass bends less. So imagine you are in water and you are waving a stick left to right, it will generate waves, right? Similarly in Space-Time fabric when two masses are moved it creates a wave. As the wave is generated by masses it is called Gravitational Waves.

The main property of this wave is when it passes through the matter, the matter stretches or shrinks for a fraction of time. These Gravitational Waves are very weak waves because gravitational force is the weakest force in the natural forces. So to detect these waves either we need extremely sensitive sensors that are practically impossible, or the object that is moving needs to be very heavy(must have extremely high masses). So we look upside and thank black holes!

In laymen's terms when a star (that is having more mass than the sun) dies it becomes a Black Hole. Basically, it is heavy.

Binary System Coalescences

So when two black holes are near each other, they attract each other and make a binary system. In this system, both black holes revolve around and lose energy. This process goes on, and when they collide, an explosion happens. An explosion that releases the amount of energy that is more than the combined energy of all the stars of the observant universe.

As it is said, “what happens in Black Hole stays in Black Hole ;)”. Nothing can come out from a Black Hole. Not even the light… But we get ‘The Great Gravitational Waves’.

We can put it like this, before the discovery of Gravitational Waves we were exploring the universe with electromagnetic waves (eg. Light, X-Rays, Radio Waves, etc.), So now we are having a new set of eyes by which we may see the previously unseen.

To detect Gravitational Waves there are several observatories in the world. They are LIGO(Laser Interferometer Gravitational-wave Observatory) and VIRGO. In these observatories, there are 4km long sensors placed in ‘L’ shape, perpendicular to each other. When a Gravitational Wave passes through the size of these shrinks and expands. By measuring the distance of each with light, we get the wave data.

In my next blog, I am addressing the Data Science approach to Gravitational Wave Data and performing Data Analysis.

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Nisarg Bhatt

Master of Computing in AI @ National University of Singapore