Born 1954 in Cuba, and raised in Bogotá, he studied physics in Göttingen and Cologne where he made 1978 his diploma and 1981 his PhD in statistical physics and then after one year post-doc in the US went to Service de Physique Théorique in Saclay becoming member of CNRS to which he still belongs today. He was 1990 - 1994 group leader at HLRZ of KFA Jülich, 1994 - 2000, director of the PMMH at ESPCI, Paris; 1996 - 2006, professor and head of the Institute of Computer Physics at the University of Stuttgart and was from 2006 till 2019 full professor at the Institute of Building Materials at ETH Zürich from which he is presently emeritus. Presently he is back at PMMH in Paris and professor at the Physics department of UFC Fortaleza in Brazil. Author of over 700 publications, Guggenheim Fellow (1986), member of the Brazilian (1987) and Colombian (2014) Academies of Science (1987), Max-Planck Research Prize (2002) and Gentner-Kastler Prize (2004), ERC Advanced (2012), Aneesur Rahman Prize (2018), managing editor of Int.J.Mod.Phys.C and Granular Matter and member of several editorial boards and commissions including president of the French Equipment Commission in 2010. Of his former PhD students and post-docs 37 are presently professors. He made lasting contributions to understand fracture of heterogeneous materials and properties of granular media and built a special purpose computer to calculate the conductivity of percolation clusters. Highlights were the discovery of space-filling bearings and the establishment of equations of motion of dunes. His present research subjects include watersheds, neural avalanches, charged granular media and complex networks.