Why is most of the information about the matter that went into forming the black hole lost ?
Combining the formulas for the Schwarzschild radius of the black hole , the Stefan – Boltzmann law of black - body radiation , the above formula for the temperature of the radiation , and the formula for the surface area of a sphere ( the black hole 's event horizon ) , equation derivation:Stefan – Boltzmann constant : formula_23 Schwarzschild radius : formula_24 Black hole surface gravity at the horizon : formula_25 Hawking radiation has a black - body ( Planck ) spectrum with a temperature T given by : formula_26 Hawking radiation temperature:Schwarzschild sphere surface area of Schwarzschild radius formula_27 : formula_28 Stefan – Boltzmann power law : formula_29 A black hole is a perfect black - body : formula_30 Stefan – Boltzmann – Schwarzschild – Hawking black hole radiation power law derivation : formula_31 Stefan – Boltzmann - Schwarzschild - Hawking power law:Where formula_32 is the energy outflow , " formula_18 " is the reduced Planck constant , formula_34 is the speed of light , and formula_35 is the gravitational constant .