Explore the intricate world of relativistic heavy ion collisions in this theoretical physics colloquium by Prof. Berndt Mueller. Delve into the dual holographic description's successes in explaining fundamental properties of early collision stages and its potential extension beyond hadronization. Examine the ER = EPR duality, connecting entanglement properties of field theory states to non-trivial horizon topologies in Anti-de Sitter space. Gain insights into heavy-ion phenomenology, quantum mechanics, eigenstate thermalization, chaos in quantum systems, and the interplay between local and global equilibrium. Investigate the concepts of entanglement, holography, boundary gauge theory, and black hole evaporation. Discover a comprehensive approach to understanding relativistic heavy ion collisions, combining various theoretical concepts and exploring future research directions in this fascinating field of theoretical physics.