How quantum black holes explain why we don’t see the end of space and time

Albert Einstein’s theory of gravity, general relativity, is famously incomplete. Penrose postulated that all the singularities of gravitational collapse are “clothed” by the event horizons of black holes – meaning we could never observe one. Now, all known constructions of quantum black holes share this feature, suggesting a more rigorous formulation of quantum cosmic censorship exists. In our work, we discovered a quantum Penrose inequality that applies to all known examples of quantum black holes, even in the presence of strong quantum effects. The quantum Penrose inequality limits the energy of space-time in terms of the total entropy – a statistical measure of a system’s disorder – of the black holes and quantum matter contained within it.