Investigations: Investigations [Paperback]

Kauffman's start point is autocatalysis: that it is very likely that self-reproducing molecular systems will form in any large and sufficiently complex chemical reaction. He then goes on to investigate what qualities a physical system must have to be an autonomous agent. His aim is to define a new law of thermodynamics for those systems such as the biosphere that may be hovering in a state of self-organised criticality and are certainly far from thermodynamic equilibrium. This necessitates a rather more detailed coverage of Carnot work cycles and information compressibility than was covered in passing in his earlier books. It leads to the idea that a molecular autonomous agent is a self-reproducing molecular system capable of carrying out one or more work cycles.

But Kauffman now pushes on further into stranger and uncharted territory. The Universe, he posits, is not yet old enough to have synthesised more than a minute subset of the total number of possible proteins. This leads to the fundamental proposition that the biosphere of which we are part cannot have reached all its possible states. The ones not yet attained - the 'adjacent possible' as Kauffman terms it - are unpredictable since they are the result of the interaction of the large collection of autonomous agents: us - or rather our genes - and all the other evolving things in the external world. His new fourth law of thermodynamics for self-constructing systems implies that they will try to expand into the 'adjacent possible' by trying to maximise the number of types of events that can happen next.

Readers of the two earlier books will now - temporarily - be on familiar ground: Boolean networks and NKC models, fitness landscapes, order/chaos phase transitions, self-organization and self-organized criticality all make an appearance. Some of the diagrams will be old friends. Kauffman proposes that we live in a self-organised critical biosphere with a power-law distribution of small to large avalanches of speciation and extinction events. And this is not limited to the biosphere: economic trends may also follow such a power law. He looks briefly at evolutionary strategies and points out that a robust strategy must contain alternative ways to do things in case the primary way becomes blocked. Phase transitions in combinatorially difficult Ksat problems are introduced along with their Hausdorf dimensionality which gives an indication of how hard it will be to get to an even better solution at any point in an optimisation process. The more conflicting constraints there are, the harder the going gets; for NKC enthusiasts this is like wading in the treacle of a rugged high-K landscape!).

The familiar ground suddenly gives way. Kauffman introduces Lee Smolin's idea (vide his 'The Life of the Cosmos') that our universe is a result of the interaction and Darwinian selection of many competing universes. Daughter universes, Smolin has proposed, are born out of black holes, and cosmic natural selection will thus preferentially select those universes which tend to maximise the number of black holes. Kauffman is chary of this because he wants a theory which gives a universe as complex as ours roughly poised between expansion and contraction. He returns to the 'adjacent possible' to point out correctly that classical general relativity assumes that the configuration space of the universe can be pre-stated whereas we cannot do so even for the biosphere. Quantum mechanics and spin networks offer a way out, but there is uncertainty about how the values of the twenty finely-poised physical constants were chosen. Kauffman concludes with describing how we get back from eleven-dimensional strings to three unfurled spatial dimensions plus time by compactification of the remainder into tiny rolls in Calabi-Yau space.

Anyone who struggled with 'At Home...' will be way out of their depth towards the end. Those with a physical sciences background will have their preconceptions challenged and horizons widened. Those interested in the genesis and evolution of a book should read Kauffman's Sante Fe preprint with the more elaborate title of 'Investigations: The nature of autonomous agents and the worlds they mutually create... Finally, by far the best technical review of self-organisation, phase transitions and percolation is "Avalanche dynamics in evolution, growth and depinning models" by Paczuski, M., Maslov, S. and Bak, P. (Phys Rev E January 1996) - highly recommended.

This book stands midway between his previous books. It is more technical than At Home in the Universe, but not to the extent of Origins of Order. He continues similar themes: the emergence of complex, interactive systems can be seen as a neccesary function of the rules of the universe, rather than as a bizarre random occurrence. This time, however, he is applying the ideas to the notion of an autonomous agent, rather than thinking purely in biological terms.

Which made me wonder who this book is aimed at. Stuart assumes that you know a lot of general science knowledge (certainly a lot more biology and biochemisty than your average popular science reader - see the other reviews here). But on the other hand he doesn't analyse his theories in a rigorous way (in fact he keeps saying how they can't be analysed just yet, more research is required).

I think his insight is spot on, but the experience of reading the book left me slightly underwhelmed.

Oh and one final point: be careful of his tendency to occassionally remember he is writing 'literature'. The odd paragraph burst forth with a myriad of bright and natal metaphorical buds: which had a nasty habit of making me giggle!