Condensed matter physics is the study of how matter behaves in condensed states, which include both the familiar states of liquids and solids as well as more exotic states such as Bose-Einstein condensates. It is a diverse field, and often overlaps with other fields such as biophysics (living things are condensed matter states!), superconductivity, crystallography, and metallurgy. Condensed matter physics requires the understanding of systems with extremely large numbers of components–a typical gram of matter contains about 10^24 particles–that can interact in extremely complex and often surprising ways.
Complex systems is an interdisciplinary field that generalizes the insights of condensed matter physics to a wide range of systems, from biological processes to macroeconomic cycles. Complex systems researchers can be mathematicians, physicists, chemists, biologists, psychologists, economists, and more–and sometimes several of these at the same time. The central principle of complex systems is “more is different”: As more parts are added to a system, its interactions become exponentially more complex, and can result in emergent behaviors that are fundamentally different from the behavior of the constituent parts. For example: atoms are not malleable, but metals are; neurons are not conscious, but brains are; animals do not evolve but populations do; individuals do not go through recession cycles but economies do.
Here you will find links to history items related to the fields of condensed matter physics and complex systems.