"Sixty percent of the human body consists of water. Water provides the 3D-network for life’s constituents. In a cell there are many interfaces: the average distance between two molecules or a molecule and a membrane interfaces is ~1 nm. Water and the interfaces it interacts with are of paramount importance for biological processes. The structural, dynamic, and biological properties of water, aqueous systems and aqueous interfaces are essential in understanding the complexity of life, and our ability to harness its features for novel technologies.Waters’ 3D hydrogen bonded network is important for nearly all the macroscopic properties of water. The network is cooperative, yet it rearranges itself every few femtoseconds, and quantum level interactions determine its properties. Understanding the role water plays in living systems therefore requires information from the quantum level/femtosecond time scale up to the macroscopic level/time scale. Therefore, understanding water remains a considerable challenge.I propose to investigate the structural, dynamic, and biological properties of water by probing the relationship between the properties of water on vastly different length and time scales. We will investigate quantum effects in water and on interfaces, and study long-range ordering (up from the femtosecond time scale). Furthermore, we will map how ions, hydrophilic, and hydrophobic solutes influence waters structural correlations and water-mediated interactions. Thus, we will use a worldwide unique multiscale toolbox that has for the most part been recently developed in my lab. We will map aqueous solutions by probing the structure of hydration shells, nanoscopic order and correlations between water molecules and viscosity. Interfacial structural and dynamical changes will be measured by mapping the surface chemical composition and conformation, the surface charge, and the electrokinetic mobility of nanodroplets."