Deep Simplicity

Deep Simplicity is a popular science book about the theory of chaos. As always, John Gribbin presents the subject in a remarkably accessible way - the educated layperson will be able to tackle this book. However, it is not without drawbacks.

The book starts out with a concise history of mathematics relating to chaos. Gribbin begins with the Greeks and Galileo and moves onto Newton, and the issue of the three-body problem (where it is impossible to use Newton's laws of motion to generate analytical solutions to a situation in which there are three bodies of similar size affecting each other under gravity). He then talks about thermodynamics, and the concept of entropy and how this leads to an arrow of time. Gribbin also introduces an idea which he seems to be very fond of, that life is an example of using energy flow to reduce local entropy.The next section introduces some of the mathematics behind chaos. Gribbin describes how the iterative approximation techniques used in finding solutions to can never be exactly accurate. The concept of phase space, where a single point completely describes a system using multiple dimensions, is used by Poincare to deal with the problem of the Solar System's stabilty. Gradually, Gribbin brings the reader to the realisation that some systems, such as the weather, while deterministic in principle, are very difficult to predict in practice because of the non-linearity of their progression. Simply, small changes in initial conditions can lead to vastly different outcomes. Indeed, the impossibility of knowing the precise positions or momenta of anything makes such precise prediction unachievable even in principle.The idea of chaos as deterministic yet unpredictable order comes in the next section with the example of turbulence - a single parameter, the fluid speed, is changing, yet the flow changes from regular to turbulent to laminar. Additionally, the chaotic pattern appears to be fractally self-similar, like the Feigenbaum diagram describing species reproduction. Other fractals such as the Sierpinski gasket and the Cantor set are discussed, as well issues of fractal dimension. However, recognising that completely regular and completely random systems are uninteresting, Gribbin quickly ushers the reader onto the "edge of chaos, where complexity lives."The rest of the book appears to be satisfying some of the author's own interests, however. He takes many aspects of living development, including abiogenesis, Gaia systems, predator-prey relationships and more and tries to recognise chaotic patterns in them all. He notes that any such system that incoporates feedback will generate chaotic behaviour, but often there seems to be little gained from understanding that the behaviour is chaotic - for example, the idea that Ice Ages are chaotic fluctuations in a punctuated equilibrium appears to be difficult to test!

Gribbin succeeds in conveying the history and principles of chaos in his first sections, as well as their relevance to many areas of science - especially the complexities of life. However, unlike some of his other books on quantum physics, among others, I feel like this topic is one that is best dealt with in greater detail than can be used in a popular science book. Gribbin uses examples well to illustrate the points, but without understanding derivations it is hard to avoid feeling like much of the book is assumed. Additionally, it is possible to see how the book has been structured in hindsight, but while reading I felt disorientated as he jumps from one area to another. Again, understanding more about the principles behind chaos would have remedied this somewhat. An interesting read, but not as engaging as I might have hoped.