Black Holes
Imagine yourself drifting through space staring at the beauty it has to offer out of your shuttle’s window when all of a sudden, your systems go haywire and you can feel yourself getting sucked in with great force towards something. Lights are blaring around you and everything is falling into chaos. However, in a single moment, there is nothing; there is only darkness. The aforementioned scene was an example of a black hole’s strong gravitational force at work. With their huge amount of density, the strength of their gravity consumes anything within its radius. This includes the gases around nearby stars, allowing a black hole to form accretion disks. These disks give black holes a notable appearance and a way to see them from light-years away. Black holes can even consume photons (force carriers for electromagnetic radiation, such as light). Since not even light can escape from its strong gravitational pull, black holes give off the appearance of a dark night sky. Their density is caused due to a black hole’s space being very, very small compared to that of its mass making black holes a menace to behold.
“Because sometimes people who seem good
end up being not as good as you might have hoped.”
― Jonathan Safran Foer
This is especially true with stars. Everyone who sees a star immediately thinks of it as bright and beautiful, but these small packages of light can evolve into many dangerous bodies. An example would be a black hole. These monstrous bodies are created on the death bed of a massive star when it implodes and collapses on itself. A star can also form a white dwarf star near the end of its life. When a low mass star has exhausted its nuclear fuel, it begins to produce heat from its core which travels in an outward direction. This causes the star to expel its outer material and leaves only the hot core of the star known as a white dwarf star. Similar to that of a white dwarf star, when a high mass star runs out of hydrogen “fuel”, the star can no longer resist its mass’s gravitational pressures. This causes the central region of itself, or the core, to collapse and crush every proton and electron into a neutron, forming a neutron star. Whether the death of a star creates a dwarf star, a neutron star, or a black hole, depends on its mass. If the mass of the star is less than one and a half than the mass of the Sun, it will become a dwarf star. If the star’s mass is less than about two or three masses of the Sun, the formation of a neutron star will occur, and finally, a black hole will form if the mass of the star is greater than the three masses of the Sun. These destructive packages not only come by themselves but very rarely can come in pairs, otherwise known as binary black holes. These pairs are hypothetically formed when two galaxies collide with each other or when binary stars collapse. These menaces were proven to exist only four years ago through the sheer amount of gravitational energy that binary black holes release when merging with each other.
Referring back to the neutron star, it has the potential to create a supermassive black hole. Similar to how a star will evolve into something different depending on its mass, a stellar black hole can be formed if a neutron’s mass is increased. If the core is greater than about 2-3 solar masses, then there is so much pressure in the star that it is unable to stop itself from collapsing which leads to the formation of the stellar black hole. These black holes are medium-sized ones compared to their peers with masses up to that of 20 suns contained in a sphere with a mere 5-mile radius. This “sphere” has a volume of approximately 524 miles cubed or approximately 2.2 x 10¹² meters cubed. If you think that’s huge, the world has another thing coming for you. Supermassive black holes have masses greater than 1 million suns and could easily fit in a sphere with the diameter of the solar system. Their “spheres” have a volume of approximately 2.4 x 10³⁴ miles cubed or approximately 9.95 x 10⁴³ meters cubed -- that’s about 4.5 times as large as the volume of a stellar black hole! An example of these gargantuan figures is the Milky Way’s black hole named Sagittarius A which has a mass of around 4 million Suns and is about the same size as the Sun. With these absolutely huge black holes, it is easy to think of how insignificant our Earth can be compared to these masses.
Sources: Briggs, Andy. “What Are Black Holes?” EarthSky, 11 Jan. 2020,
earthsky.org/space/definition-what-are-black-holes/.
“Black Holes.” NASA, NASA, science.nasa.gov/astrophysics/focus-areas/black-holes.