# Black Holes By [Untitled](https://paragraph.com/@0x3be86afbde3706e24a4f06f3fbc265af4c6237aa) · 2024-01-20 --- Black holes are areas in the universe where [**gravity**](https://www.english-online.at/science/gravity/gravity-mass-weight.htm) pulls in everything, even [light](https://www.english-online.at/science/light-and-optics/light-optics-electromagnetic-waves.htm). Nothing can get out and all objects are **squeezed** into a **tiny** space.  Because there is no light in black holes we cannot see them.  But **scientists** can **detect** the **immense** gravity and **radiation** around them. They are the most **mysterious** objects in [astronomy](https://www.english-online.at/science/astronomy/astronomy.htm). Scientists think that the first black holes were formed when the universe began about 13 billion of years ago. [Albert Einstein](https://www.english-online.at/people/albert-einstein/albert-einstein-life-and-discoveries.htm) was the first scientist to **predict** that black holes existed. But it was in 1971 that the first black hole was actually **discovered**. Black holes can have **various sizes**, some may be even as small as an [atom](https://www.english-online.at/science/atoms-and-elements/atoms-and-important-chemical-elements.htm). But they all have one thing **in common** – a very large **mass**. There are three kinds of black holes : * A stellar **occurs** when very large stars burn away the rest of the **fuel** that they have and **collapse**. It is so **massive** that several of our suns could fit in it. Our [sun](https://www.english-online.at/science/solar-system/sun-center-of-the-solar-system.htm), **however**, could never become a stellar because it is too small. * Supermassives are the largest and most **dominating** black holes in our universe. They have masses of a million or more suns put together. Every **galaxy** has a supermassive in its centre. As they become larger and larger they pull in more material. The black hole at the centre of our [Milky Way](https://www.english-online.at/science/milky-way/galaxy-milky-way.htm) is four million times as massive as our sun and **surrounded** by very hot gas. * **Intermediate** mass black holes have not been found yet, but scientists think they **probably** exist. They have the mass of between a hundred and a thousand suns. A black hole **consists of** three parts: * The outer event horizon is the **farthest** away from the centre. Gravity here is not so strong and you would be able to **escape** from it. * The inner event horizon is the middle part of a black hole. In this area an object would be slowly pulled to the centre. * The singularity is the centre of a black hole, where gravity is strongest. --- *Originally published on [Untitled](https://paragraph.com/@0x3be86afbde3706e24a4f06f3fbc265af4c6237aa/black-holes)*