An Etymological Dictionary of Astronomy and Astrophysics

A hypothetical means of extracting energy from a rotating black hole. If a particle spirals into the ergosphere of a black hole in a direction counter to the rotation of the black hole, and if the particle then breaks up into two fragments inside the ergosphere, one of the fragments can escape with energy greater than the energy of the original particle.

See also: Named after Roger Penrose, English physicist (1931-), who devised the process; → process.