Black holes have intrigued scientists since Einstein first proposed their existence in relation to his theory of relativity. The idea was so bizarre, that even he himself was skeptical of the subject, stating that it was “not convincing” and that they did not exist “in the real world.”
But, as time passed (over 80 years later), scientists studying the mind-boggling phenomena took the first ever picture of a black hole, an image that required a whole array of telescopes, known as the Event Horizon Telescope, and a team of international scientists to acquire.
For those of you who don’t know, a black hole is an area of space that sucks everything, and I mean everything, into itself. Even light can’t escape the pull of a black hole, (hence the name).
But how could you take a picture of something that has no light?
The event horizon of a black hole is the line of no return. Once light hits that line, it’s never coming back, which means we’ll never see it.
However, gases that approach the black hole’s event horizon glow before they are sucked in. This produces a ring effect, outlining the silhouette of the black hole. This can be seen by a telescope, and therefore, by us.
Black holes can vary in size, but the ones that we are most familiar with are known as stellar black holes. They are the result of a star collapsing into itself, and due to the law of the conservation of energy (energy cannot be created, nor destroyed), that mass has to go somewhere. Some of it explodes out into the void, during an event called a supernova, but the rest is compressed into an incredibly small amount of space. Such a situation produces a ‘well’ of sorts in the fabric of space-time, or a ‘hole’.
If you are having trouble conceptualizing this, think of a large blanket being spread out in all directions. This can be metaphorically thought of as the fabric of space time. Now place a tennis ball on the blanket; you’ll notice that it bends the blanket.
Planets, because they are so massive, bend the fabric of space-time slightly. This is thought to be the source of gravity. But in the case of larger objects, like stars for instance, the bend is more pronounced, therefore, the pull of gravity is greater. This is why we have solar systems, where objects like planets orbit the star in a relatively predictable manner. They, in a sense, are riding that curvature in space-time that is being produced by the stars immense mass. We also have moons, which orbit planets. This, is the same phenomena, but on a smaller scale.
In the case of black holes, that bend is less a bend, and more a deep, deep well. The amount of mass is so high, and contained within such a small space (due to the star collapsing in on itself after a supernova), that it’s able to essentially alter the fabric of space-time so much so that the pull of gravity becomes unstoppable.
Now, this baffling occurrence I write about is merely on the level of a stellar black hole. What about supermassive black holes?
Supermassive black holes are of an entirely different level of mass.
Think of the Sun for a moment. Think of how massive our Sun is, and how powerful it’s pull of gravity is on our planet, as well as the other eight that are in our solar system. Take that mass, and multiply it by four million. That is how gargantuan a supermassive black hole is.
These are thought to exist at the center of galaxies, and in fact have been confirmed in the case Sagittarius A.
But how do these things even exist?
The prevailing theory is that perhaps within compact star clusters a chain reaction of stars colliding into one another produced larger stars which then collapsed into larger black holes. These larger-than- average black holes eventually sunk into the center of mass of the galaxy, came together, and produced a supermassive black hole.
So, there you have it! There are mind-bending (as well as reality-bending), massively huge, all-devouring black holes at the center of possibly every galaxy in the universe.
Who said space wasn’t fun?