The many facets of aerosol science

Aerosol Science has its roots in the 19th century. Basic concepts of physics had to be verified and this led e.g. to the study of Brownian motion, of Aitken nuclei, and of the elementary electric charge. In the first half of the 20th century industrial health became the focus of interest and since then environmental problems at all scales like greenhouse issue, acid rain, photochemical smog, stratospheric ozone depletion, and also the industrial use of aerosols have found great interest. Aerosols are at the core of these problems and hence not only important for science but to a considerable portion also for decision making. Nonlinear reactions and inhomogenous large and very large systems must be predicted. New concepts, new insights, new instruments are in demand to permit Aerosol Science to live up to expectations. Many questions will be asked by policy makers and by the public at large, and Aerosol Science will have to provide the answers.