General relativity predicts that the inner horizon of an astronomically
realistic rotating black hole is subject to the mass inflation instability. The
inflationary instability acts like a gravity-powered particle accelerator of
extraordinary power, accelerating accreted streams of particles along the
principal outgoing and ingoing null directions at the inner horizon to
collision energies that would, if nothing intervened, typically exceed
exponentially the Planck energy. The inflationary instability is fueled by
ongoing accretion, and is occurring inevitably in essentially every black hole
in our Universe. This extravagant machine, the Black Hole Particle Accelerator,
has the hallmarks of a device to make baby universes. Since collisions are most
numerous inside supermassive black holes, reproductive efficiency requires our
Universe to make supermassive black holes efficiently, as is observed.Comment: 7 pages, 2 figures. NO honorable mention in the 2013 Essay
Competition of the Gravity Research Foundatio