The Mystery of Black Holes
Black Holes have been a mystery to humankind since we discovered them. While we have studied them, we have never fully understood them. There are a lot of theories regarding black holes, including what lies on the other side, if anything does lie beyond them. They are a fascinating aspect of space — even to renowned physicists, such as Professor Brian Cox.
What is a black hole? They are astronomical objects whose gravitational pull is so strong, not even light can escape it. Once anything — matter, radiation, man-made objects — falls into it, it is lost to the black hole permanently. Black holes move around our solar system, which already makes them hard to track. What makes it harder is that they can bend and distort light, an effect called gravitational lensing, which can isolate black holes and cause them to be invisible. Alongside this, there is a variety of other classifications.
Stellar black holes are formed when a star that is eight times the mass of our sun runs out of fuel. This process is called “supernova”. However, the result of this process depends on the star’s mass prior to the explosion. All the stellar black holes observed are always located next to stars. Another type is primordial. These are ones that scientists theorise to have formed within the first second of the universe’s birth, with hot material dense enough to form a black hole. Yet, as the universe has expanded and has cooled, the conditions have ended — and now, 13.8 billion years later, scientists do not yet have the evidence to prove they did, but it is a possibility, and it is believed that they evaporated as time went on.
Supermassive black holes are the centre of large galaxies, including our galaxy, the Milky Way (called Sagittarius A*). They are colossal, being between hundreds of thousands to billions of times the size of our sun’s mass. Sagittarius A* is four billion times the mass of our sun, which is relatively small. Some beliefs are that they formed in the first billion years after the birth of the universe, or it could be the collapse of a supermassive star, at the start of the universe. What scientists do know is that these black holes grow by feasting on smaller objects, such as neutron stars, and merge when galaxies collide.
The event horizon is found beneath the surface of the black hole and is the boundary that contains all the matter which makes up the black hole. This is strong enough to trap everything.
Yet, what would happen if you fell into a black hole? When any matter falls into a black hole. It undergoes a process called spaghettification. This is when it’s squeezed horizontally while being stretched vertically, in a way you would resemble noodles. But, first, you’d experience tidal forces. This is like the tides on earth, with high and low tide, due to the moon’s gravitational pull affecting Earth’s water, yet it’s different for black holes. Due to their density, the tidal force would pull objects apart. This is what Professor Brian Cox has stated, in an interview. But Einstein theorized that you could free fall into the horizon without feeling the tidal wave until you were passed it, at the singularity. Brian Cox stated that the mass dictated when you’d feel the spaghettification.
However, no one is exactly sure what lays on the other side of a black hole. We know they aren’t wormholes, meaning they can’t transport to different points of space, or to different dimensions or even another universe, and we know they aren’t cosmic vacuum cleaners, sucking all the matter in and consuming it. If anything, their gravitational effects are with similar objects of the same mass, from a far enough distance. Stephen Hawking has guessed it’s the end of time, with Brian Cox counterarguing by saying that it “breaks pretty much every law of physics” and that "everything comes back into the universe again.” As far as we can tell, we have no ideas as to what happens beyond the event horizon.
Izzy Bennett
Sources:
https://science.nasa.gov/universe/black-holes/
https://www.nasa.gov/universe/what-are-black-holes/ https://www.youtube.com/watch?v=88Q8-pOM9Ss (Professor Brian Cox – Physicist - explains black holes)
https://science.nasa.gov/universe/black-holes/types/#stellar-mass
science.nasa.gov/universe/what-happens-when-something-gets-too-close-to-a-black-hole/
https://www.youtube.com/shorts/26RVvCl0t0g (Professor Brian Cox talks about what would happen if you fell into a black hole)
