In 1963, Roy C. Kerr solved Einstein's equations for a black hole that is rotating. The structure of a rotating black hole is a bit different from that of a stationary black hole. There is an additional zone called the ergosphere (from the Greek word ergon, meaning "work"), from within … (read more)

In 1963, Roy C. Kerr solved Einstein's equations for a black hole that is rotating. The structure of a rotating black hole is a bit different from that of a stationary black hole. There is an additional zone called the ergosphere (from the Greek word ergon, meaning "work"), from within which it is theoretically possible to extract energy and matter from the black hole.