(and only in a very limited way) by iterating the equation, or by other iterative techniques such as the one developed by Poincar[é]{}. The iterations take place in time, and so it seems that at least some of our knowledge of the behaviour of the equation necessarily involves natural time. Note that a physical process characterised by chaotic dynamics must also be unpredictable in the long run, because as the process “executes” it will be following a fractal attractor, and the physical system that is executing the process, being finite, will be subject to “rounding errors”, which in effect act as a stochastic perturbation. In other words, the resolution that can be achieved by the physical system is less than that of the attractor. This is the case with the three body problem that Poincar[é]{} was working on, and the reason that the planetary trajectories of the solar system are unpredictable at timescales beyond a hundred million years or so. It is also, in Prigogine’s (1997) view, the fundamental reason for the unpredictability of thermodynamic systems at the microscopic level (Laplace’s demon cannot do the math well enough), and also a necessary factor in macroscopic self-organization in that the unpredictability 