Because the study of emergent systems crosses so many disciplines, it is useful to have a glossary. Add (in alphabetic order) words to which you feel others might need a reference, or list words or phrases that you would like to have a definition.
emergence/emergent
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"refers to a property of a collection of simple subunits that comes about through the interactions of the subunits and is not a property of any single subunit.... Usually the emergent behavior is unanticipated and cannot be directly deduced from the lower-level behaviors." [2]
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See
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http://plato.stanford.edu/entries/properties-emergent/ for a historical and philosophical treatment.
Gaia
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The philosophy that the earth and its biosphere is a living organism (and thus a self-regulating, self-constructed emergent system).
Hamiltonian dynamics
non-equilibrium thermodynamics
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The description of a state that is not uniform; away from equilibrium. Statistical mechanics is not a good tool for describing these systems. (This is the term Physicists use to describe complex adaptive systems).
phase transition
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A large, global change occurs quickly in a system with little or no intermediate forms. Often, the global change occurs through small, local, gradual changes. Example: water goes through a phase transition when heated to steam.
simulated annealing
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Based on a metaphor with annealing, the process of heating and cooling a metal such that the molecules come to rest in a tightly coupled manner, used, for example, in making a sword strong. Simulated annealling in a computer program often follows a regimented schedule whereby a "temperature" parameter is slowly lowered, and randomness is slowly diminished. This helps systems settle in optimum areas, and helps to avoid local maxima.
statistical mechanics
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"...the mechanics of large assemblies of (relatively) simple systems such as molecules in a gas, atoms in a crystal, photons in a laser beam, stars in a galaxy, cars on a highway, people in a social group, and so on. The main purpose of this science is to understand the behavior of the assembly as a whole in terms of the behavior of its constituents." [1]
stigmergy
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Communicating by altering the environment. There are problems with this definition (since all comunication is performed by altering the environment). See [3] for a bibliography that emphasizes that people use the term in a number of different ways.
References
[1] Balescu, Radu. (1975) Equilibrium and nonequilibrium statistical mechanics. John Wiley & Sons.
[2] 'Computational Beauty of Nature', p. 449
