This is a Black Hole, one of the
strangest things in our universe. But,
what is a Black Hole and how do they
form? Let's understand the science of
these most mysterious objects in our
universe. A Black Hole is a region in
space-time where gravity is so strong
that nothing not even light can't escape
from them. They are formed when huge
amount of matter is compressed into a
very small space and because gravity at
surface of an object is directly
proportional to its mass and inversely
proportional to square of its radius
their gravity is too strong. Let's
imagine that there are two planets, one
is our own Earth and other one is Minor.
They both have same mass but Minor is
half the size of Earth. So gravity at Minor's
surface will be four times of our Earth.
And a spaceship on Minor will require
more velocity in order to escape
from its gravity than on Earth. This velocity
is also known as the Escape Velocity, it
also depends upon the mass and size of
the object. For Earth, this value is
almost equal to 11.2
kilometres per second.
But if we compress our Earth to a very
small sphere of radius approximately
equal to nine millimetres, this velocity
will be equal to the speed of light.
If we compress our Earth even more its
value will become greater than the speed
of light and light will never be able to
escape from it, in short you will be
having a small Black hole in front of
you. But who compresses the object in our
universe in order to form Black holes?
Generally, Black holes are formed when a
star collapses in upon itself. To
understand how a Black hole is formed we
first need to understand how a star
works. A star is like a balloon, the
pressure of air inside it expands the
balloon and the tension in rubber tries
to contracts it, the balloon will remain
stable until both forces are equal.
Similarly, stars have huge amount of
hydrogen in their core that fuses into
helium and releases tremendous amount of
energy. This energy balances out the
force of gravity to keep the star stable,
but there is one problem just like the
air inside the balloon escape out
slowly and the balloon starts
contracting, starts too run out of fuel, if
the stars are massive enough they fuse
helium into carbon and carbon into
further heavier elements until they each
iron. The problem is that the fusion
process that creates iron doesn't
generate any energy and as a result the
force of gravity starts contracting the
star. The star collapses and dies in a
supernova explosion that creates either
a Neutron star or if the star is massive
enough it will become a Black Hole.
On April 10 2019 researchers published the
first ever real image of a supermassive
Black Hole situated at the center of
Messier 87 galaxy. But we can't see
Black Holes right! Then how are they able
to take a picture of this? Well the image
actually shows the Accretion Disk, which
is a super hot dense disk of matter
that spins around the Black Hole.
Black Holes are mysterious right, we
don't know what happens beyond the Event
Horizon, maybe there is a shortcut to
another universe or it is a path to
never-ending nothingness. Although we
still don't know a lot about them but it
doesn't mean that we can never find
those answers.
Thanks For Watching!
 
