- Question
What is a black hole?
Black holes are one of the most mysterious objects in the Universe. They consist of an immense amount of matter packed into a tiny volume, giving them enormous density and gravity. The gravitational pull is so high that not even light can escape, so they are invisible. These objects have puzzled astronomers and physicists for decades - what is a black hole and what do we know about them?
Black hole structure
This position describes a black hole through its structure. It explains that a black hole consists of two key parts: an event horizon — the boundary or 'point of no return' beyond which nothing escapes — and a singularity, a core of effectively infinite density at its centre.
Life cycle of a black hole
This position describes a black hole through its life cycle — its birth, growth and death. It explains that black holes can form when large stars collapse at the end of their lives, and that, over immense timescales, Hawking radiation will cause them gradually to evaporate away.
Properties of a black hole
This entry surveys the properties of a black hole, whose strange attributes scientists have long studied. It examines ideas such as the 'no-hair theorem,' which holds black holes are defined by just a few simple traits, and the unresolved information paradox.
Inside a black hole
Descent into a black hole would result in certain death to us humans due to the high gravitational force. But if we could, what would happen if we traveled into a black hole?