Per Bak

Per Bak (born 8 December 1948 in Bronderslev, Denmark, † 16 October 2002 in Copenhagen) was a Danish theoretical physicist who has made a name for himself in the study of emergent, complex systems.

He earned his doctorate at the University of Roskilde, Denmark 1974. After that, he taught and conducted research at Brookhaven National Laboratory, the Santa Fe Institute in New Mexico, at the Niels Bohr Institute in Copenhagen and from 2000 as a professor at Imperial College London.

In his research, he worked up the magnetic and structural properties of solids, especially near phase transitions. Mentioned example his original works are ( with Juhani von Boehm, Jacques Villain and others) as well as his review article from 1982 to commensurate and incommensurate magnetic ordering, inter alia, in Ising models with competing interactions, annni model, which provoked a great interest in the scientific world.

In 1987 he published together with his colleagues Chao Tang and Kurt Wiesenfeld his pioneering work on self-organized criticality in the journal Physical Review Letters. He put the ideas into a broader context in his 1996 published book "How Nature works: The Science of Self- Organized Criticality ".