The existence of black holes has been confirmed. This is a miracle of gravity in the universe. Because gravity is too great, people can't imagine that it will distort time and space. However, black holes also have a life span. They will age and be destroyed.

Off-topic, if you want to know the basic knowledge of the universe, I recommend a movie "Universe and Man", a science and education film, which is really good and will be wonderful every time you watch it.