Serge Haroche, Nobel laureate in Physics of 2012, spoke at the Physics Colloquium on the topic of “The Physics of Rydberg Atoms: from Bohr’s Hydrogen Model to Quantum Information.” Professor Serge Haroche is a pioneer in the field of experimental verification of fundamental principles of quantum theory. With his work on cavity quantum electrodynamics, in which individual photons could be captured in resonators and detected through their interaction with so-called Rydberg atoms, he succeeded in experimentally confirming quantum decoherence, which is equivalent to a realization of the thought experiment of Schrödinger’s cat. He was awarded the 2012 Nobel Prize in Physics (together with David J. Wineland) for the development of “ground-breaking experimental methods for measuring and manipulating individual quantum systems.” His work has decisively advanced quantum optics and quantum information. The 100th anniversary of the development of modern quantum theory forms the temporal framework for Professor Haroche’s lecture at the Physics Colloquium on his pioneering achievements. In the run-up to the event, Serge Haroche signed the university’s Golden Book.