Demon of The Universe....

             B l a c k    H o l e                       

    So what is Black Hole..?

   Maybe many of you have heard about it and many of you haven't. The black hole is just a object wandering in Universe like planets and stars but the black hole is much heavier than stars or planets.

First let's have a glimpse at a 'History of a Black Hole'. 

   The first person who expressed his thoughts about black hole is 'John Michell' in 1783. After many years french scientist named 'Pierre Simon' uttered about  holes in his book 'The System Of the World' in 1796.

Now history is enough. It was really boring. Let's talk about some interesting information of Black holes which will make you thunderstruck.

   Black Holes are not literally holes, they are just the remains of dead star.Black hole is object present in the universe which has very powerful Gravitational Force. You can imagine it's power by the fact which is Black hole cannot even allow light to pass from it. Howw..??? I'll explain later about it. Black Hole swallow everything passes nearby. Black hole is like a Demon full of mysteries. The time slows down near the Black Hole. And in singularity time doesn't exist. Amazing...isn't it..??

How this demon called Black Hole born in Universe..??

   Black Hole is an object having really great mass and density but very small volume. If we compress an object keeping same mass but decreasing volume it will convert into a black hole at a particular point. For example if we compress a sun keeping same mass in volume of a small ball it will covert into a black hole, but we all know that it is nearly impossible. But what if a star has mass many times of sun... Mostly Black Holes are made up of stars. As we all know any star emits its energy throughout the Hydrogen gas. This hydrogen also helps to limit the gravitational force of a star. At a age, star is done with it's hydrogen gas or energy. At this age, due disturbance in co-ordination of a gravity and mass star explodes. This explode is called 'Supernova'. After supernova if any part of a star with high mass remains then it stars to attract nearby objects towards itself. This is called 'Neutron Star'. Neutron Star starts to pull any object passing near it. And after consuming too much mass and having less volume it starts to become an invisible. And this invisible part of universe called as 'Black Hole'. 

   

Mass and density of a Black Hole is centred at its centre which is called as Singularity. As we all know, density is inversely proportional to volume, hence volume of a Black Hole is very low comparatively. Out of an Singularity, some particles keep revolving around black hole. This part is called 'Event Horizon'.Apart from attracting everything black holes also emits a radiation called Hawking Radiation. We will discuss about it at some another day.

Do you not thinking about what if any object go into singularity?

   Scientists are still finding the answer of this question. By their theories they called that if an object is going inside the black hole, that object starts to divide into small atoms and slowly it disappears....Astonishing..!!!

   

Types of Black Hole:

   Black Holes are classified into 3 types by their unique properties,

   1: The Black Hole having mass in some multiples of our sun are called Stellar Mass         Black Hole

   2: The black holes having crores of times of mass of sun and found at a centre of galaxies are called Supermassive Black Holes. Our galaxy Milky Way's Black Hole's name is sgr a*(sagittarius a*).

   3: Third type has mass less than our sun but due to substance in centre. This type is called Small Black Holes.

   

   Now as i mentioned above, i'll tell you why a Black Hole cannot allow light to pierce from singularity../?

      So first tell me, we send rockets to the outer space and why those rockets beat the gravity of Earth. Yes, exactly due to a term called Escape Velocity. 

              This velocity decides the initial velocity of an object, if object has more initial velocity than escape velocity, that object can free from gravitational downward pull of an planet or any celestial object. Formula for Escape velocity is. Escape velocity of our Earth is 11.19km/sec. As you can see mass is directly proportional to the escape velocity and radius is inversely proportional. Hence the Escape velocity of black hole reaches more than speed of light(3*10^8 m/s).Hence light cannot come back from singularity of black hole. 

All we discussed above aren't proven practically. But at the bright day 10 April 2019 we got the first ever real image of Black Hole.

Image

This image is officially uploaded by nasa. This image is of a Supermassive Black hole present in M-87 galaxy which is 53.5 million years away from us. And its mass is 6 billions times the mass of our sun. This blurred image consumed 10 lakh GB of data for scientists.

If you are more curious about Black Hole then you can watch a movie 'Interstellar' which will make you the person having very much information about black holes in your friend circle and show off.

This was little basic information about Black Holes. If you want more information about Black Holes then you can check these websites : Wikipedia      NASA

Have a good day...😊