A black hole is not a hole. In fact, they have immense matter packed into the least space it can hold. It’s like squeezing the entire city of New York into a single nucleus of a hydrogen atom. They are immensely dense objects, or preferably the core remnant of former stars, which wander across space without any definite destination. Their considered infinite density, with such intense gravitational attraction, makes it impossible for the matter, and even light, to escape its powerful gravitational pull.
How are they formed?
Every star needs a source of energy for its life, and like every star, this is achieved through the process of hydrogen fusion. Nuclear fusion is the ‘combining’ of existing elements to form new elements while releasing a considerable amount of energy, which is then converted into heat. When an average star comes to a near end of its life, it runs out of hydrogen in its core and starts fusing heavier and heavier elements including helium, carbon, and oxygen, eventually running out of fuel and collapsing, forming white dwarfs.
Stellar Black Holes
If a star is massive enough, this is if its mass is expected to be 5 to 10 solar masses, it begins fusing elements into iron. The force of gravity is strong enough to produce iron in the center of a massive star. However, iron is a substance that requires more energy to fuse than to release it, therefore, resulting in a catastrophic collapse, known as the supernova. It is said that we are made of the remnants of these explosions. With no opposing forces from the ‘dead’ remnant of the supernova to the force of gravity towards the center, the massive star begins to compress and shrink in itself to the point of zero volume and infinite density. Here, the gravity of the star can trap light inside of what is known as the event horizon. This is the point of which escape requires moving at the speed of light, which is surely impossible.
Supermassive Black Holes
These black holes have the exact process of formation as the ones above, only that they have an equivalent mass of millions of solar masses with only a corresponding radius of our closest star. For many years, the concept these black holes remained as a theorized construction. However, recently it is thought that Supermassive black holes are a keen source for the formation of a galaxy itself and that they are even found in the center of our galaxy, the Milky Way!
– In most images, some arrows demonstrate the compression towards the core of the star, while there is a pressure release because fusion is continuously occurring.
– There are also ‘releasing’ shapes that show the energy that is continuously being released from the star.
– Or also, a newly formed black hole with its supernova remnants. Its force of gravity towards the center has no opposing forces, therefore, shrinking the black hole into infinite density.
How do we know they exist?
As the black holes suck in a large amount of material, it forces the material to accelerate in a circular motion around it, known as the accretion disk. With the cluttering movement of the material in the accretion disk, there is a cause of friction which concludes in the release of light. The spectrum of this light is measured and studied how gravity affects light and matter around it. Also, astronomers can calculate the distance and the speed of these black holes, thus, directly proving their existence.
The black hole consists of mainly four arrangements.
The Schwarzschild radius is the event horizon of the black hole or the radius where the velocity that is required to escape the gravitational pull is the speed of light. This means that any object can have an infinite gravitational pull if it is compressed enough to infinite density.
The event horizon is the spot where the gravitational pull is so strong that it is impossible for matter and light to escape.
The singularity is a region in a black hole where space makes completely no sense. This is because all its mass has been compressed into a complete zero volume with infinite density, resulting in an intense gravitational pull. If an object approached the singularity, which is known as its center, it would stretch vertically into a long thin shape, before being swallowed directly into the ‘void.’ This process is known as spaghettification.
The accretion disk is a disk composed of a material that is accelerating in a circular motion around the black hole. Astronomers are currently studying the friction caused by the collision between the material accounts to the release of light, which’s spectrum.