"Cooperative phenomena are ubiquitous in science. They occur when a sufficient number of particles interact and lead to phenomena that can only be explained by taking into account the whole ensemble. It is a fundamental, but still open, question how these cooperative phenomena begin and how the transition from single particle movement to hydrodynamics takes place. This question becomes increasingly relevant with nanotechnological applications reaching smaller and smaller scales.The proposed project puts forward an investigation of cooperative phenomena on the atomistic level. The proposed fellow will use an interdisciplinary approach to employ both computer simulations (outgoing host: University of California, Berkeley) and experiments (return host: Max-Planck-Institute for Extraterrestrial Physics, Germany).The experiments will be conducted using ""complex plasmas"", which consist of micrometer-sized particles suspended in a weakly ionized gas. The particles can be visualized individually, allowing an investigation of their movement on the atomistic level. The fellow has already conducted experiments with mesoscopic complex plasmas on fluid effects and hydrodynamic instabilities. She will first build upon these studies and complement them with MD simulations of the particle movement. Then the fellow will use the expertise gained in the first simulations to numerically study the transition to hydrodynamics and the onset of cooperative phenomena. Finally, these simulations will be used to make predictions for additional experimental studies. This will make possible a comprehensive view of the underlying phenomena.This multidisciplinary project will add to the scientific and complementary skills of the fellow and significantly broaden the understanding of fluid physics on small scales. This way, the fellow will increase the knowledge in this interesting topic, transfer know-how to Europe and help Europe remain at the cutting edge of this fundamental research area."