MARK BUCHANAN Ubiquity

Unifying theories have a long history. Ever since antiquity, attempts have been made to explain a seemingly heterogeneous variety of phenomena by a few general principles. One of the most recent attempts in this vein is SelfOrganised Criticality (SOC), a new approach to complex systems, which has become one of the important areas of research in physics as well as in many other disciplines during the last decade. SOC has been applied to problems as diverse as earthquakes, forest fires, landscape formation, solar flares, river networks, mountain ranges, volcanic activity, traffic jams, evolutionary processes, plasmas, superconductors, fluctuations in stock markets, brain function, spreading of epidemics, and many more. In his book Ubiquity. The Science of History . . . Or Why The World is Simpler Than We Think (henceforth abbreviated to ‘Ubiquity’), physicist and science writer Mark Buchanan sets out to communicate the basic ideas of SOC to a non-specialist audience. In this well-informed, entertaining and lucidly written book he presents a nice summary of the highlights and the main results of fifteen years of research on SOC. Using concrete examples like the outbreak of the First World War, the 1995 earthquake in Kobe, or the 1987 Wall Street crash, he explains the main ideas of SOC in an intuitive and vivid way, thereby evading the technical aspects of the approach (the book does not contain a single formula). Over and above being a smooth introduction to SOC, Ubiquity vigorously puts forward a daring thesis: SOC is ubiquitous. The strategy of the book is to substantiate this claim by enumerating phenomena from wildly different fields for which SOC can be invoked as an explanation. The introduction of the sand-pile as the paradigm example of a system exhibiting SOC (Ch.1) is followed by an extensive discussion of earthquakes (Chs 2–5), and after an interlude on universality (Ch. 6) Buchanan turns to forest fires (Ch. 7), evolution (Chs 8–9), and economics (Ch. 10). The last chapters of the book Brit. J. Phil. Sci. 53 (2002), 585–591