L’ ́ etude approfondie de la nature estlasourcelaplusf ́ econde des d ́ ecouvertes math ́ ematiques. J.B.J. Fourier (1768–1830) Recent technological advances allow us to study and manipulate matter on the atomic scale.

Thus, the traditionalborders between mechanics,physics and chemistry seem to disappear and new applications in biology emanate. However, modeling matter on the atomistic scale ab initio, i.e., starting from the quantum level, is only possible for very small, isolated molecules. More- 20 over, the study of mesoscopic properties of an elastic solid modeled by 10 atoms treated as point particles is still out of reach for modern computers. Hence, the derivation of coarse grained models from well accepted ?ne-scale models is one of the most challenging ?elds. A proper understanding of the interactionofe?ects ondi?erentspatialandtemporalscalesis offundamental importance for the e?ective description of such structures. The central qu- tion arises as to which information from the small scales is needed to describe the large-scale e?ects correctly. Basedonexistingresearche?ortsintheGermanmathematicalcommunity we proposed to the Deutsche Forschungsgemeinschaft (DFG) to strengthen the mathematical basis for attacking such problems. In May 1999 the DFG decided to establish the DFG Priority Program (SPP 1095) Analysis, Modeling and Simulation of Multiscale Problems.