Cosma Schalizi says Complex System-s are those with many strongly interdependent variables. This excludes systems with only a few effective variables, the kind we meet in elementary dynamics. It also excludes systems with many independent variables; we learn how to deal with them in elementary statistical mechanics. Complexity appears where coupling is important, but doesn't freeze out most Degrees Of Freedom.
Most Human System-s are complex.
Complex System-s are unpredictable. Sorry.
Bob Frankston noted (private group): The key is not redundancy but Resilience... As to Civilization-s and complexity - one way to think of it is that if things work too well you loss resilience. Y2K was a nonissue because it presumed highly coupled systems but those can't survive even without Y2K.
this article about removing traffic lights and signs (Naked Street-s) to increase Street Traffic safety seems like an example of de-optimizing to increase resilience. Ben Hamilton Baillie smells like the guru in this movement.
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