WHERE TO BEGIN
There are many mysteries about the birth of the universe, its evolution. But the most important and dangerous mysterious thing is a black hole. But nobody has ever seen it. This black hole has the capability to take away even a big planet. Whatever the thing that once entered into a black hole can never be returned. The thing that comes closest to this black hole can be swallowed by it. How much powerful a black hole is, it can make light travelling at a speed of 3 lakh kilometre per second towards it. And now you will know - what a black hole is? How does it grow? What will happen to an object that enters into a black hole?
STABILITY OF A PLANET
Hydrogen is the reason for a star to illuminate brightly. These hydrogen atoms convert into helium in the process of nuclear fusion and release an enormous amount of energy and radiation. At one side energy released from the core moves farther from it, at another side its gravitational force pulls the energy towards it. By these two equal and opposite forces acting together, a star can be in a stable state.
THE SUPERNOVA EXPLOSION
After some long years, the hydrogen present in a star will get reduced. Then gradually the nuclear reactions get degraded and no energy will be released. As a result, the core’s gravitational force pulls the star towards itself and its size is reduced to become like a small ball. Due to this density will be increased at the core and a sudden blast will happen to a star. This is called a “Supernova explosion”.
THE BLACK HOLE
If the blasted star size is small then it turns into a neutron star with high density. Its density is more i.e., 1 teaspoon weight of this star = 1 million tons weight on the earth. If the star size is big then after its explosion it will become a black hole. These posses high gravitational force than any other thing on the universe. Likewise, the dead star will become a black hole. The first image of black hole came last year with a high resolution proving the presence of one.
STAR AS A BLACK HOLE
Not all large stars will become a black hole,
to become like a black hole its size must be 20 times greater than our sun.
It means that there is no possibility of our sun to become a black hole.
Stars with a size greater than 20 times of our sun will become stellar black holes.
These are dangerous and are in lakhs over the entire universe.
SUPERMASSIVE BLACK HOLES
Next supermassive black holes,
if a star-sized is some lakhs times more than the sun. They were
usually situated in the middle of the universe.
The big black hole in our galaxy is Sagittarius-A-Star.
You know how its size would be,
it has a diameter of length 4,40,00,000 km.
Imagine how big it would be! It is at a distance of 25,640 light-years.
One light-year means- the speed of light is 3,00,000 km per second.
The distance travelled by light in one year is the light-year,
approximately light travels a distance of 94,60,00,00,00,000 km/year.
There is no need to worry about the Sagittarius black hole i.e., it is farther from our earth.
EVENT HORIZON
Blackhole is surrounded by an event horizon.
Any object that enters into the event horizon can never be returned.
Whatever the object entered into this, it goes round and round then it reaches the center of the black hole.
In the middle of this black hole, time runs very slowly.
Physics laws are applicable everywhere in the universe except inside a black hole. Nobody know what will happen inside a black hole.
But if a man enters into a black hole due to the high gravitational force,
our body gets stretched and torn apart like small pieces, there is
none who has seen a black hole.
An object reflects the light projected on to it,
but a black hole can attract even the light too into it.
So we cannot say that there is a black hole in a space of the universe.
Then there arises a doubt on how to detect a black hole.
Stars near a black hole revolve at a high speed or a star illuminates with more brightness when it is going into a black hole and releases x-rays.
By these 2 signs, scientists can identify the existence of black holes.
END OF A BLACK HOLE
We know every object in the universe must die in a particular situation than what about a black hole? Famous scientist Stephen Hawking told that there is an end for the black hole too.
Continuous radiation will be released from a black hole which is hawking radiation.
As a result, the black hole loses its mass and energy.
If no object will enter into it’s then after some years the black hole size gets reduced and finally evaporated.
But it takes a long time,
i.e., to reduce the size by 0.0000001% it takes nearly 10,000 billion billion billion billion billion billion years. Imagine how much time it costs for a black hole to get evaporated.
SPECULATIONS
Some scientists believe - “ a black hole connects 2 universes”,
if we enter into a black hole then we move through the wormhole and can reach the next universe.
Some people believe that there is a possibility of time traveling there.
Image source-Google
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