How Nature Works

1. Front Matter

   Pages i-xiii

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2. Complexity and Criticality

   • Per Bak

   Pages 1-32

3. The Discovery of Self-Organized Criticality

   • Per Bak

   Pages 33-48

4. The Sandpile Paradigm

   • Per Bak

   Pages 49-64

5. Real Sandpiles and Landscape Formation

   • Per Bak

   Pages 65-84

6. Earthquakes, Starquakes, and Solar Flares

   • Per Bak

   Pages 85-104

7. The “Game of Life”: Complexity is Criticality

   • Per Bak

   Pages 105-112

8. Is Life a Self-Organized Critical Phenomenon?

   • Per Bak

   Pages 113-127

9. Mass Extinctions and Punctuated Equilibria in a Simple Model of Evolution

   • Per Bak

   Pages 129-159

10. Theory of the Punctuated Equilibrium Model

    • Per Bak

    Pages 161-174

11. The Brain

    • Per Bak

    Pages 175-182

12. On Economics and Traffic Jams

    • Per Bak

    Pages 183-198

13. Back Matter

    Pages 199-212

    PDF

and acknowledgments Self-organized criticality is a new way of viewing nature. The basic picture is one where nature is perpetually out of balance, but organized in a poised state-the critical state-where anything can happen within well-defined statistical laws. The aim of the science of self-organized criticality is to yield insight into the fundamental question of why nature is complex, not simple, as the laws of physics imply. Self-organized criticality explains some ubiquitous patterns existing in nature that we view as complex. Fractal structure and catastrophic events are among those regularities. Applications range from the study of pulsars and black holes to earthquakes and the evolution of life. One intriguing conse­ quence of the theory is that catastrophes can occur for no reason whatsoever. Mass extinctions may take place without any external triggering mechanism such as a volcanic eruption or a meteorite hitting the earth (although the the­ ory of course cannot rule out that this has in fact occurred). xu How Nature Works Since we first proposed the idea in 1987, more than 2,ooo papers have been written on self-organized criticality, making ours the most cited paper in physics during that period. How Nature Works is the first book to deal with the subject. The basic idea is simple, and most of the mathematical models that have been used in the implementation of the theory are not complicated.

• Natur
• complex system
• complex systems
• computer simulation
• differential equation
• evolution
• measure
• model
• simulation

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