What is a black hole?
A black hole is a region in space where gravity pulls so much that even light cannot get out. The gravity is so strong because of how dense they are. These mysterious phenomenon form when a dying star can no longer put out any energy so the gravity of the star will cause it to collapse on itself. All the mass will be concentrated into one space, forming the black hole. To give you some perspective, if the earth magically collapsed into a black hole, it would be about the size of a nickel.
The 3 types of black holes
Primordial: Tiny black holes; could be the size of an atom or a mountain.
Stellar: The most common type; they’re about 20 times larger than the sun.
Supermassive: These behemoths can have the mass of about 1 billion suns. They can dwarves the size of our solar system!
Did you know? Our very own galaxy, the milky way, has a supermassive black hole at the center. Don’t worry though, it’s 26 000 light years away.
“Parts” of a black hole
Point of singularity: All the matter of the star before it died and anything that the black hole eats will be squeezed into the center of a black hole is a gravitational singularity, a one-dimensional point which contains a huge mass in an infinitely small space, where density and gravity become infinite and space-time curves infinitely. Scientist are still trying to discover more about this singularity as our modern laws of physics wouldn’t work in such an environment.
Accretion disc: Material such as gas, dust, and stellar debris that has not quite fallen in yet forms a flattened band of super high speed spinning matter around the event horizon. This accretion disk can be seen, because the spinning particles are accelerated to tremendous speeds by the huge gravity of the black hole, releasing heat and powerful x-rays and gamma rays out into the universe as they smash into each other. The most powerful gamma ray bursts are produced by black holes, and can be seen from millions of light years away.
Event horizon: It’s sort of like the point of no return, once you go past it, you will never be able to come out.
How can we see a black hole?
Because no light can get out, people can’t see black holes; they are invisible. However, scientists can see the accretion disc formed by the black hole. They can also observe how the strong gravity affects the stars and gas around the black hole. By looking what’s around the black hole, scientists can determine the mass of the black hole too.
We still have much to learn on this topic, but scientists are learning more and more every day. Black holes are one of the most puzzling aspects of space, but that’s what makes them interesting!