From the nonlinear dynamical systems theory to observational chaos

Otto E. Rössler completed his studies in medicine but was never a physician. He spent a post-doc with Konrad Lorenz about socio-biology and cognitive science. He continued with a second post-doc with Robert Rosen with whom he learned to reproduce observed dynamics with differential equations. He then started as an academic by teaching computer programming and computed numerical solutions to the differential equations governing chemical reactions. Otto submitted his first paper on chaos in 1976. The Rössler system quickly became one of the prototypes on which the paradigm of chaos theory is constructed. He also introduced hyperchaos and suggested a classification of chaotic attractors. Otto E. Rössler investigated applications of chaos in various fields: chemistry, heart rhythm, biology, electronics, astrophysics, fluid mechanics... In order to celebrate his contribution to chaos theory for his 80th birthday, this forthcoming conference is devoted to enlightening how chaotic behaviors help to understand the reality of the world in its complexity. Contributions should try to show how the concepts of state space, attractor, first-return maps, Poincaré sections, bifurcations, etc. combined with advanced concepts allow for better views of the possible dynamics produced by simple as well as complex systems. Contributions can be either theoretical, numerical, experimental, observational or historical.