Black Holes: A Fabric of Mystery
Written By Aadarsh Srinivasan
Whether it's because your astronomy teacher went on a rant about them, you watched Young Sheldon, or you are simply interested in physics, you have probably heard about black holes. Even though the idea of black holes has been introduced and researched since the late 1700s, there is still a fabric of mystery surrounding them.
Black holes are described as a region in space where a gravitational singularity is located; the curvature of space-time around that region becomes infinite. A classic example to think about this concept is to take a stretched-out tarp, and place a variety of different round objects on it. A ping pong ball, for example, would bend the fabric very little, so objects that roll across the tarp towards the dip created aren’t going to be attracted to the ping-pong ball unless they roll across it painfully slow. A tennis ball would create a larger dip in the fabric, and rolling objects at greater speeds would be attracted to it. Now to represent a black hole, you would need an object with infinite mass, as a black hole curves space-time infinitely. Objects that come across the ‘dip’ created by this object with infinite mass would not be able to get out whatsoever. This is a pretty simple analogy to black holes, but it is a good way for beginners to understand the way space-time and black holes work. You can try this at home, but if you do somehow manage to obtain an object with infinite mass, and you somehow manage to get the tarp to stretch infinitely, just know that the object will dig a hole through the earth, and it will take the tarp along with it, so don’t try that part at home.
Because black holes have such a strong gravitational force, anything that passes the event horizon of a black hole cannot escape. Not even light can travel fast enough to escape a black hole, which is why the center of a black hole is pitch black.
The event horizon of a black hole refers to the surface/exterior layer of the black hole. Once one passes this surface, the velocity needed to escape the black hole exceeds the speed of light, which means that one would be infinitely trapped in the endless abyss of the black hole.
When an object approaches a black hole, time slows down the closer it gets. At the event horizon, time stops for that person relative to the observer outside the black hole. This means that when you are at the event horizon, you still experience time normally, but when/if you come out of the black hole, the Earth could have progressed 50000 years.
This is NASA’s most recent picture of the black hole Messier 87, and you will notice that the black hole isn’t invisible. But how is that possible if light can’t escape it? This orange ring around it is caused by the event horizon. Past the event horizon the speed required to escape the black hole is greater than the speed of light. The orange ring is light that is just far enough from the black hole so that it doesn’t get sucked in, and thus, we see an orange ring in the picture. This orange ring is called the photon ring. Black holes also have a ring of dust and debris beyond the photon ring, and these pieces of matter travel at incredibly high speeds.
So, what would happen if YOU went inside a black hole? Well, one of the leading theories is that you would be stretched via a process called ‘spaghettification’ (yes, that is a real thing), and then your atoms would be absorbed into a single point inside that black hole called a quantum singularity. This is for smaller black holes though. What about larger black holes? Well, if you entered a supermassive black hole, you wouldn’t be made into spaghetti, but you wouldn’t be able to escape either. However, there is a theory that you would be spit out by a ‘white hole’ which sounds just as confusing, so let’s not go in-depth about that. Yet, even with all of this information, black holes are covered by more questions than answers. Even with all the technological advances that may occur over the next century, it will take a while to uncover many of the mysteries that surround black holes.
Works Cited
Freeman, L. (n.d.). What would happen if you fell into a black hole?. BBC Earth. https://www.bbcearth.com/news/what-would-happen-if-you-fell-into-a-black-hole
