The "fuzzball model" is thought to describe these objects, from which energy can be harvested by means of the Penrose process. Ones described by the Kerr metric cause frame-dragging within their ergospheres. Their only known 
The "fuzzball model" is thought to describe these objects, from which energy can be harvested by means of the Penrose process. Ones described by the Kerr metric cause frame-dragging within their ergospheres. Their only known properties are mass, charge, and angular momentum, due to the no-hair theorem. For a given mass, the Schwarzschild radius gives the surface of their event horizons, which contain a singularity of infinite density. Studied by Stephen Hawking, for 10 points, identify these massive, compact space objects from which not even light can escape.
The "fuzzball model" is thought to describe these objects, from which energy can be harvested by means of the Penrose process.
black holes