Because of their complexity, black holes are not only interesting for astronomy. Indirect procedures allow observers to detect and measure the black mass in the dark. This article explains in a simplified way what would actually happen if a person were dragged into a black hole.
What is a black hole?
A black hole is a dense mass that creates such a strong gravity that even the light cannot escape. The three fundamental forces of physics are not able to counteract, which is why the entire mass collapses and forms a physical singularity in the center of the black hole. According to the general theory of relativity, space and time are also strongly deformed. The event horizon of a black hole is the limit on which no information or matter can escape the suction.
What happens if a person falls into a black hole?
A person approaching the black hole initially does so at a normal speed. However, an outside observer would say after some time that the person slows down, comes to a stagnacy, and suddenly disappears the closer he or she gets to the black hole‘s event horizon. This happens due to the change in space-time, finite time intervals are drawn to infinity.
The approaching person experiences two realities simultaneously. For example, if the feet are closer to the black hole than the head, they are pulled to it with a higher gravity than the rest of the body. The closer a particle is to the center of the black hole, the faster the gravity gets stronger. So the body gets spaghettified: The feet get faster to the center, while the head is not yet pulled to it so much and therefore lingering outside. The body is stretched out and at the same time compressed laterally. Since the blood can no longer be pumped out of the feet towards the heart, the person passes out. Finally, all the bones break and the prolongation continues. The other reality is that the person burns near the event horizon.
From the outside, approaching objects seem to get darker. Inside the black hole, it is the other way round: the light is getting brighter and bluer. On the way to the event horizon, the person could see how space-time curves around him or her.
When does the earth fall into a black hole?
Humanity is unlikely to see Earth fall into a black hole. Like the stars that can not even be seen from here, these celestial objects are just too far away.