What happens if a person falls into a black hole

What happens if a person falls into a black hole

What happens if a person falls into a black hole

April 12, 2022


If an astronaut approaches a black hole, his prospects are not very bright.
Photo by Dmitry Sazhko

Dmitry Sazhko

Author of Lifehacker

What happens if a person falls into a black hole


The short answer is that he will die. More detailed – it is not known exactly what will happen. Science can only speculate. But nothing particularly pleasant will happen, believe me.

At a respectful distance, a black hole behaves like a star of similar mass – you can enter a stable orbit around it and rotate there for years. By assumptions scientists, even habitable planets can exist there. But the closer to the hole, the more problems there will be.

Radiation will kill a person

A black hole with an accretion disk and a “crown” – a stream of energetic X-ray particles. Artistic concept. Image: NASA/JPL‑Caltech

If you think that a black hole will harm a person only when he crosses the event horizon (the border around the hole, due to which not even light can return), then you are mistaken. Difficulties will begin much earlier, and literally deadly.

Black holes are rarely alone. As a rule, they are surrounded by a huge pile of matter – gas, which was left after the hole bit some star. The gas flies in orbit at great speed, therefore it has a monstrous kinetic energy and is heated to gigantic temperatures.

This rapidly spinning and sizzling hot thing around a black hole is called an accretion disk.

Viewers of the movie Interstellar know what an accretion disk should look like. The black hole itself is invisible, because it absorbs any light that falls on it, but the whirlpool of matter around it can be seen. It is the accretion disk, the glowing orange thing that filmed telescopes of the Event Horizon Telescope project in April 2019.

The first picture of a black hole. Image: The Event Horizon Telescope Collaboration

The accretion disks of black holes emit a powerful electromagnetic radiation. The energy of X-rays and gamma rays is a million million times greater than the energy of visible light.

In addition, theoretically, the black hole itself can also emit Hawking radiation. True, astrophysicists are not yet sure about this, and the radiation power is dismissive small.

All these streams of charged particles that a black hole scatters hundreds of light years around it are unlikely to add health. The celestial body will kill a person even on the approach with ordinary radiation, without resorting to violations of the topology of space and curvature of time.

It will be burned by the substance of the accretion disk

The motion of matter in the accretion disk of a black hole. NASA visualization. Image: NASA’s Goddard Space Flight Center / Jeremy Schnittman

Suppose that the astronaut took care of radiation safety in advance – for example, put on a coat with a meter-thick lead lining over the spacesuit. And, determined to find out what is in the mysterious depths of the black hole, he continues his free fall towards it.

But another obstacle awaits the researcher, namely, the accretion disk already familiar to us. It is made up of very hot gas.

The disk heats up as gas particles collide with each other, circling at breakneck speed around the black hole. Kinetic energy transforms into thermal energy, and it does so quite well — matter near an average black hole can warm up up to millions or even trillions of kelvins. This is slightly higher than, for example, the temperature of our Sun – 5,778 K on the surface, 15 million K in the core.

Probably, it is not worth reminding that it is unsafe to fly through the streams of hot plasma. If a person is killed not by radiation, then by high temperature.

In general, the accretion disks of supermassive black holes at the centers of galaxies are among the brightest objects in space. They are called “quasars”. The hottest one, J043947.08+163415.7, roasts like 600 trillion normal yellow dwarfs like the Sun, if they conspired and acted at once.

The supermassive black hole at the center of the Messier 87 galaxy is sending beams of plasma and destruction into the surrounding space. Image: NASA / The Hubble Heritage Team (STScI / AURA)

Periodically, by the way, black holes send into the Universe, relativistic jets, or jets, are plasma streams at near-light speed, usually in pairs, directed from the poles in opposite directions.

Astrophysicists are still debating why this is happening, but the magnetic fields around the hole seem to be doing something interesting to the gas in the accretion disk. jet may erupt continuously for 10 to 100 million years.

So, falling into a black hole, a person must avoid its poles, so as not to fall under the relativistic jets.

Spaghettis it

The starving black hole at the center of the Markarian 1018 galaxy. Image: NASA / ESA / CARS Survey

In view of the above, it would probably be better to travel into a black hole without an accretion disk. These also happen – if there are no stars in the neighborhood from which gas can be pumped out. That is, the hole has already safely swallowed them all.

For example, the black hole at the center of the Markarian 1018 galaxy sucked in all the matter around it and was left without gas nearby. Astrophysicists call such holes starving. Poor things.

Or the supermassive hole Sagittarius A at the center of our Milky Way – it has an extremely small, barely noticeable disk. That’s why it’s so hard to keep an eye on her.

All in all, it’s possible…






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