The firewall phenomenon

Abstract

Black holes have presented us with some of the most baffling paradoxes in physics. From their original conception as dark stars, they have come to be understood as physical systems with their own thermodynamic behaviour. This same behaviour leads to paradoxical conflicts between some of the basic principles of physics whose resolution is not straightforward and that suggest a new structure—known as a firewall—may be present. This chapter provides an overview of the firewall problem, as it emerges from our understanding of black hole thermodynamics.