Black holes are the most powerful things in the universe, strong enough to rip whole planets into the smallest elementary pieces. Well, if this wasn’t scary enough, black holes may actually delete the universe itself.
A black hole appears when an extraordinary amount of matter is concentrated in a tiny space. At their centre, gravity is almost infinitely strong, and whatever gets too close is wrapped into its elementary particles. Not even light can escape black holes, and so we perceive them as spheres of blackness. If you were to fall into a black hole, nothing bad would happen until well after you have crossed its outer border, the event horizon. This border completely separates black holes from the rest of the universe. Black Holes radiate their mass away, like a hot pot on a stove losing its water as steam. This is called Hawking radiation. Black holes are constantly losing an extremely tiny amount of their mass, a process that's unbelievably slow. But this is a problem because, in the process of disappearing, black holes might delete some fundamental information too.
What is information?
Information is nothing but property of the arrangement of particles.
According to the theory of quantum mechanics, information is indestructible. It might change shape, but it can never be lost. Information tells us how things are different from each other, and what used to be what. Black holes do the opposite, they take different things and make them the same. They destroy information. This creates the information paradox, and this is a serious problem.
It's fundamental for all our laws of physics that information can never be lost, existing or non-existing. Without information, everything is relative. When it comes to our understanding of reality, we absolutely need it. How can we solve this paradox?
We know that black holes trap information and might delete it later, but we never thought about what they do with it. In the meantime, where do black holes store their information?
Even the smallest black hole can store more information on its surface than all the data ever produced in human history. They do this by storing information in a type of pixel that is unbelievably tiny. Black holes are the ultimate hard drive.
If information is actually stored on the boundary of a black hole, the Hawking radiation has a chance of learning about the information encoded there and can carry it away. So, information is not lost in a sense, only trapped till the black hole fades away. This is in line with the laws of physics.
