Complexity, contingency, and criticality Bak Paczuski 1994

This is an introduction to Per Bak's self organized criticality (SOC), digging into the sand pile. I read his book "How Nature Works" in high school. the title oversold the thing, or atleast that is what I thought then, but the ideas were still useful. Apparently all that stuff can be rephrased in terms of dynamics, stabilitites and bifurcations. I'm curious to see how that works. I don't think I will.

self organized criticality describes certain systems that, after a transient, exhibit (naively) 'puncuated equilibria' type behavior, where the severity of events follow a power law distribution. The itneresting thing about them is that that critical cusp is the point they naturally evolve to, and there are mony systems in many domains that exhibit such dynamics.

His account of history is pretty lame and underinformed: "Historians explain events in a narrative language where event A leads to event V because event C previously had led to events D and E. But suppose that event C did not happen; then, the course of history would have changed into another series of events..."

That said, his accounts "A Historian Describes a Sandslide" and "A Physicist Describes a Sandslide" are informative and interesting, even indicating some of the relative advantages of each style of description, while making the point of the fundamental dynamics that SOC describes.

Von Neumann once reffed to the theory of non-equilibrium systems as the "theory of non-elephants."

I tuned out a little when he got to the real stuff, the math: The Gamma Equation, the Gap equation, Stationarity, etc.