Systems Far From Equilibrium

Another advantage of a mathematical statement is that it is so definite that it might be definitely wrong; and if it is found to be wrong, there is a plenteous choice of amendments ready in the mathematicians' stock of formulae. Some verbal statements have not this merit; they are so vague that they could hardly be wrong, and are correspondingly useless.
-L.F. Richardson in Mathematics of War and Foreign Politics.
In this chapter we take our first detailed look at "truly" complex systems: systems that are out-of-equilibrium. Unfortunately, unlike the case for equilibrium systems, there is no well-developed formalism for studying out-of-equilibrium systems. Nevertheless one can identify some principles and resort to computer simulations of models to test ideas.