For Fully Mature Black Holes, Time Stands Still | Kerr Black Holes & General Relativity, Space & Physics | Space.com: "The end of a black hole’s evolution may be a mind-bending kind of space-time independent of time. A new study proposes a method to tell how far any black hole is from reaching this end state.
Black holes are some of the weirdest things in the universe. They occur when mass is packed into a tiny volume, squished to its ultimate density."
