What happens to humans when they approach a black hole where even light cannot escape?

by Ashok Boghani

A black hole is a celestial body whose gravity is so great that even the fastest light in the world cannot escape. Black holes are not within reach of humans, but what happens if humans approach a black hole is explained by Associate Professors Leo Rodriguez and Shanshan Rodriguez of the Department of Physics, Grinnell College. doing.

Could a human enter a black hole to study it?
https://theconversation.com/could-a-human-enter-a-black-hole-to-study-it-153364

The size of a black hole is different from that of a general celestial body, and is measured by a distance called the Schwarzschild radius . Roughly speaking, this Schwarzschild radius is the 'radius of the range where even light cannot escape from the mass point of the black hole', and this range is called the ' event horizon '.

by Leo and Shanshan Rodriguez

There are three physical quantities that characterize black holes: 'mass,' ' angular momentum, ' and ' charge. ' The heavier the mass, the larger the Schwarzschild radius. For example, a black hole with the same mass as the sun would have a Schwarzschild radius of about 2.98 km.

In addition, it is thought that there is a black hole in the center of the Milky Way galaxy, which is a galaxy including our solar system, with a mass about 4 million times that of the Sun, and the Schwarzschild radius of this black hole is about 12 million km. I will.

When a human approaches a black hole of the same mass as the sun, the Schwarzschild radius is so small that the human body attempts to 'fall' toward the mass point of the black hole. At this time, the tidal force creates a gravity gradient on the head and toes. When falling from a foot toward the mass point of a black hole, the gravity on the foot is much greater than the gravity on the head, and the body is compressed horizontally, so it's like pulling the kneaded flour into noodles. It is thought that it will be stretched and crushed as if it were. The phenomenon in which an object approaching a black hole becomes elongated is called ' spaghettification ' or 'noodle effect'.

by Leo and Shanshan Rodriguez

On the other hand, in the case of a supermassive black hole such as the one in the center of the galaxy, the Schwarzschild radius is so large that the effect of tidal force is almost zero. Upon entering the event horizon, humans will fall toward the mass point of the black hole, but will not become spaghetti for a while and can pass through the event horizon alive.

by Leo and Shanshan Rodriguez

Of course, it may fall to the mass point of a supermassive black hole as it is, and if the influence of tidal force becomes large, it may become spaghettification, but the black hole is an accretion disk in which celestial gas and dust fall in a spiral shape. It forms a strong X-ray and emits strong X-rays. Therefore, when approaching a supermassive black hole, humans will surely die before becoming spaghetti.

Associate Professor Rodriguez argues, 'In order to be safely sucked into a black hole, we must find a supermassive black hole that is completely isolated and does not absorb surrounding dust, gas, or celestial bodies.' , 'Even if we can cross the event horizon, we cannot send information about the discovery to the Earth from within the Schwarzschild radius. The journey and discovery of the inhaled person is lost as part of the universe. It will end up. '