Chances are if you are interested in Space
and the Universe, you might have probably
heard of black holes at one point or the other.
And, even if you aren’t interested in Space,
you might have seen this very first photo
of a black hole that went insanely viral last
year.
In order to clear up some of the mystery that surrounds these mind-defying
stellar phenomena, let's have a look at
how exactly these anomalies are formed.
First, let's talk about how stars work.
Initially, just after their formation, the
core of most stars mainly consists of an immensely
large number of hydrogen atoms whizzing around
at an exceedingly high speed and at a very high temperature.
Occasionally, these hydrogen atoms bump into each
other to form heavier elements like
helium, then helium into carbon, and so on
making the core very dense while also releasing
a tremendous amount of energy in the form
of electromagnetic radiation, one form of
which is the light that you see all around you.
However, at the same time, there is the force of Gravitation trying to bring all the mass in the star towards
its center trying to get it to collapse on itself.
So, what exactly prevents a star from gravitationally
collapsing on itself instantaneously?
To understand that, let’s look at this air
pump here.
As I pump air into it, I am doing work on
the pump which causes
the temperature of the pump to increase
However, at the same time, it becomes harder for me
to pump because the air molecules push back
with a greater thermal pressure because the
temperature has increased.
So, you can imagine that there is a tug of
war occurring between me and the pump pushing back over here
This is completely identical to what occurs
within stars except instead of me, it’s
the force of Gravitation pushing into the
core of the star and instead of the pump,
it is the thermal pressure due to the atoms   pushing out.
And it turns out that as the star keeps getting
denser, the force of gravitation keeps getting
stronger so in most cases, there is only one
winner in this tug of war, and it is Gravitation.
From here on, it depends on the mass of the
star, if the mass is comparable to our Sun,
the collapse is now halted by pressure exerted
by electrons instead of atoms being packed into
an incredibly small volume.
Such a star is called a white dwarf and our
own Sun is most likely going to end up this way.
However, if the mass is greater, the electrons and protons within the star's core fuse to form neutrons
due to the immense gravitational force. These stars are now supported by pressure exerted by these neutrons
These are called neutron stars and are some
of the densest objects known to man!
Lastly if the mass is very large, there is absolutely nothing that can stop the star from gravitational
collapse and the entire mass contained within
the star collapses to a single point of supposedly
infinite density and no dimension.
This is called a Singularity or what you more
commonly know as the black hole.
Understanding how black holes form is key
to unravelling the mystery that surrounds
these beautiful and at the same time, terrifying
objects.
To see what I mean, have a look, and thank
you!
