What can we learn about biological evolution by studying disordered magnetic materials? That kind of question—one that brings together fields that at first seem to have very little in common—might have seemed quite strange before this decade. But during the 1980s there has been a serious and growing effort by some scientists to tackle phenomena common to widely disparate disciplines. This effort has led.to a surprising cross-fertilization among fields that previously enjoyed little communication. Much of the work has been identified under the rubric “complex systems.”
While the term “complex systems” has come into increasing use, there is still no consensus definition of what it means. Some use it to signify the now well-established area of chaos; others would be referring to cellular automata. The phrase complex systems has been used to denote disordered many-body systems, neural networks, “self-organizing” systems, adaptive algorithms—the list can go on and on. In the ...