The term black hole is probably one that fills you with awe and wonder. If it does, don’t worry about it, it has that effect on most scientists too. They are one of the least understood and most intriguing things in the cosmos. But what are they and how did they come to be?
Born from stars
We are all born from stars, technically. The atoms that make us up all came from the life cycle of a star. This is also the case for black holes. They couldn’t be formed if not for stars. In order to see this, we need to examine what stars are and how their life cycle works.
What is a star
Stars are effectively large nuclear reactors. They began life as a swirling cloud of Hydrogen that collapsed under their own gravity to form a sphere. Within that sphere is a core and in the core, there is a cycle of constant nuclear reactions. With hydrogen getting crushed into helium (mostly). These reactions create radioactive energy which radiates away from the star. Gravity pushes in the opposite direction to the radiation. The two forces are roughly balanced and it is this balance that keeps stars stable.
The death of a star
When an astral body runs out of fuel eventually it will implode. With smaller stars, this will either lead to something called a White Dwarf or a neutron star. We won’t go into the science behind those things, but trust us – it’s pretty cool!
Due to the gravity, the pressure in the core of larger stars is far greater. Because of this more massive stars are able to fuse far heavier elements in their core. Sometimes they fuse into iron. When iron is formed energy is not given off. As Iron builds up in the core, less and less energy is produced and eventually, the balance between energy and gravity becomes out of kilter and this leads to an implosion.
Feel the force
Because the stars are so massive the implosion creates a super dense area. Because it is so dense it has a higher gravitational pull. As the matter is drawn towards it, it becomes more massive and so it’s gravitational pull increases to the point where its gravitational pull is so great that not even light can escape from it. This is when it becomes a black hole.
Black holes come in various sizes but at the centre of every galaxy are large blackholes known as supermassive black holes.
What we see
Although black holes appear to be just that “black”. We can’t actually see what a black hole looks like. Here’s the issue our eyes only see because of light hitting our retinas. That’s how the ability to see works. Because light cannot escape black hole what we are seeing is what is known as the event horizon. This is sort of like the “point of no return” for black holes. If you travel through the event horizon you aren’t coming back!
But what happens if I pass?
If you were somehow able to travel beyond the event horizon there is no way you would be able to escape. There is also no way you could report what it was like because you would have to travel faster than the speed of light to escape and nothing can do that. Not even radio waves, so you wouldn’t be able to communicate to let anyone know what it is like. The prevailing theory is that if you passed the event horizon you would die. The only real debate is over how quickly that would happen.