Kerr black holes have 2 horizons: outer (event horizon) and inner (cauchy horizon). I also heard that inner horizon is called a Killing horizon, which is actually funny because it can KILL - literally. Even it is not proven yet, but it is possible that there is an infinite density of evergy on the second horizon (called a "blue sheet"), so any infalling bserver will be burnt to quark-gluon ashes (9-degree burns :) ) or killed by infinite tidal forces (infinite gravity as a result of infitite density there), or both So lets assume that it is true. Now my question. No observer can arrive safe and sound inside the second horizon to see the ring sigularity. In that case, is any theory which describes what happens there falsiable?