High Quality Content by WIKIPEDIA articles! The black hole information paradox results from the combination of quantum mechanics and general relativity. It suggests that physical information could disappear in a black hole, allowing many physical states to evolve into the same state. This is a contentious subject since it violates a commonly assumed tenet of science—that in principle complete information about a physical system at one point in time should determine its state at any other time. A postulate of quantum mechanics is that complete information about a system is encoded in its wave function, an abstract concept not present in classical physics. The evolution of the wave function is determined by a unitary operator, and unitarity implies that information is conserved in the quantum sense.