In our milky way Galaxy, there are certain regions in the space with very high densities, wraps space-time in such a way that nothing can escape out of them. These regions are Black Holes though they are not holes as the name suggests.
The Black Holes
When a massive star dies, a dense remnant core is left and forms into a black hole. It contains a large amount of matter – nearly ten times mass of the Sun, concentrated in a small diameter of a sphere. Thus, the space-time curvatures change, and the gravitation pull becomes infinitely strong.
Even if any object gets closer to it, it just grasps the object, and there is no point of return back, that point called the Event Horizon. It is the boundary of the space region around a black hole, from which nothing can escape. Even the light is unable to move fast enough to escape from the black hole. So, if you fall into a black hole, you can get out of it only if you have speed higher than the speed of light, which is obviously not possible.
If a space traveler falls into a black hole
As you go too deep into the black hole, space curvatures become much different. It becomes even curvier, but at the center, it becomes infinitely curved. It is where the singularity lies. Therefore, the gravitational pull of the Black Hole is extreme, and you will be lost.
If there is no escape from the black hole, then you will question – what would happen if a space traveler falls into the black hole? Will he able to survive in it? – It’s not just you who want the answer. Scientists also research the black holes and various related questions, like the question we are going to discuss. However, they have found the answers to these questions.
The gravitational force of a Black Hole is very, very high. So, if he falls feet-first, his legs would feel a stronger gravitational pull than his head. His body would stretch apart because his body would experience something called strong “Tidal Force”.
In this case, smaller Black Holes exert stronger tidal forces than the massive one. He would Spaghettify and rain down into the black hole as a single thread of material, and then disappears like nothing was there.
Stellar Black Holes – the most common Black Holes he will find in the galaxy. It has a stretch of about 15 kilometers and heavy as the twenty Suns. The heavyweight concentrated in the small distance creates this gravitational pull, which has mercy for no one. The immense gravitational pull will tear him even before he reaches the Event Horizon.
But a person outside the Black Hole would see a different thing. For him, the space traveler would freeze. He would observe him slowing down by time, getting dimmer, and then disappear. It is because, for the black hole, the time stops while space moves forward.
Super Massive Black Hole is millions of times heavier than the sun. But it will cause less harm to his body than the stellar one. In this, his body wouldn’t harm until he crosses the event horizon because his whole body would get the same gravitational pull. After crossing the event horizon, he wouldn’t exist for the observer outside the black hole, but for him, the singularity having infinite density would grasp him.
In both the Black Holes, the space traveler would go deeper inside the black hole, and eventually, wouldn’t exist anymore. The body would disintegrate into particles. The Black Hole would emit all the particles out of it when it dies. These particles include the human body. Therefore, It would become impossible to figure out whether the particle belonged to him or not.
Late physicist Stephen Hawking, in his studies, theorized the alternative universe, having different histories. In one, if he falls into the Black Hole, but in the second one, there was no Black Hole.
It is impossible to find from the outside whether there was a black hole or not. If he crosses the Horizon and gets into a Black Hole, then he wouldn’t survive. But in the latter case, he would be alive in a different universe, but wouldn’t be able to come back.
Overall, the black hole is not a safe place for humans to go inside. He would not exist for this universe. Even if Stephen’s theory of the alternate universe is right, the chances of survival in a black hole are zero.