His education is based on theoretical solid state physics (master) and statistical physics of critical phenomena (PhD). After his PhD he worked among others on gelation and irreversible growth and built a special purpose computer to calculate the conductivity of percolation clusters. He has studied the fracture of heterogeneous materials since 1986 and since 1992, he has investigated the properties of granular media. Highlights in this research were the construction of space-filling bearings and the establishment of the equations of motion of dunes. His present research subjects include dense colloids, the formation of river deltas, quicksand, the failure of fibrous and polymeric composites and complex networks.