Christiaan Brinkerink
Christiaan Brinkerink

What happens when you fall into a black hole?

Some people suffer from mental black holes, but black holes can also literally be found in the universe. We do not know what a black hole looks like inside, but a lot of strange things would happen to you if you were to fall in. Nijmegen astronomers are investigating these mysterious objects.

A black hole is an area in space with such strong gravity that nothing can escape from it, not even light. Hence the name 'black' hole. Black holes are common across the universe. In our own galaxy, there may be millions of them floating around, including one supermassive one, called Sagittarius A*.

This makes it difficult for scientists to find out precisely what goes on inside such a hole; it's not exactly easy to take a peek. But with theories and calculations, astronomers can predict what would happen to a person if they fell into it.


“It depends on how big the black hole you fall into is,” says astronomer Christiaan Brinkerink. With a relatively small hole, say 5 to 10 kilometres from the centre to the edge (the 'observation horizon'), you would be pulled apart into a long string. This would happen well before you reached that horizon. In a large black hole, heavier than approximately 5,000 suns put together, this would only happen once you had already disappeared behind the horizon.

This is due to what is known as tidal forces, which we are also familiar with on Earth: the Moon pulls on the Earth, and the Earth rotates on its axis. The Moon always pulls harder on the side of the Earth that is closer to it. These differences in tensile strength lead to such phenomena as ebb and flow in the sea.

Something similar happens in a black hole. “Imagine falling with your feet first towards a black hole,” says Christiaan. “The hole will pull harder on your feet than on your head, because your feet are closer to it. This will pull you apart. With a small hole, the difference in distance between your feet and your head is relatively larger than with a large hole (when compared to the size of the black hole itself), and the difference in gravity is therefore also stronger.”

First photograph ever of a black hole

At Radboud University, astronomers investigate the physical processes that take place when hot gas or stars come close to black holes. “Nearby stars are stretched into huge strings and a lot of radiation is released. We sometimes see this as a flash of light with our telescopes. We can also see very precisely what happens at the edge of a black hole. We do this with a set of telescopes stringed together, known as the 'Event Horizon Telescope'. This allowed us a few years ago to take the first photograph ever of a black hole in the universe.”

While you can literally fall into a black hole with a bit of imagination, you can also fall into a black hole psychologically. This is another area in which Radboud University researchers frequently conduct research. Would you like to know more about black holes in the universe, psychological black holes or other Radboud University research? At Radboud Recharge, you can find answers to all kinds of science-related questions.

100 Years of Radboud University

In 2023, Radboud University celebrates 100 years of playing a significant role in the life of our students, researchers, and staff, as well as in the world around us. For more information on the University’s 100th anniversary, see here.

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