What is a black hole and how is it formed?

A black hole is a region in space where gravity is so strong that nothing can escape, including light.

Black holes are fascinating and complex phenomena of the universe. They are formed from the remnants of massive stars that have undergone a supernova explosion. When a star has burnt out all its fuel, it collapses under its own gravity, leading to a supernova. If the star is large enough, the collapse will continue until all the matter is condensed into an incredibly small space. This results in a gravitational field so intense that not even light can escape, hence the term 'black hole'.

The boundary around a black hole where light cannot escape is called the event horizon. Anything that crosses this boundary, be it matter or light, is 'swallowed' by the black hole. The point within a black hole where matter is thought to be infinitely dense is known as the singularity.

Black holes are not visible through standard observation methods because they do not emit light or radiation. However, their presence can be inferred by observing the behaviour of nearby objects. For instance, if a star is orbiting an invisible object, that object could be a black hole. Scientists also use tools like X-ray telescopes to detect high-energy particles that are often present near a black hole.

In summary, black holes are regions of space with extremely strong gravitational forces, formed from the collapse of massive stars. They are invisible to the naked eye, but their presence can be detected through various scientific methods.