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Comment by PaulDavisThe1st | Hacker News Reader

Whoever wrote this doesn't seem to make the connection with Prigogine's work on non-equilibrium thermodynamics, which seem to me to have as much to do with the "edge of chaos" idea(s) as anything from the cellular automata world.

The overly quick summary: most convention thermodynamics/chemistry concerns itself with systems that reach equilibrium (various reactions take place, energy is consumed or produced, and a new state is reached in which things are stable). Living systems (and a few non-living) systems don't work this way, but use a continual input of energy to drive reactions and maintain a "non-equilibrium" state.

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Author is Cosma Shalizi

https://en.m.wikipedia.org/wiki/Cosma_Shalizi

There’s also the whole fringe topic of disequilibrium economics, which eschews most of what all economics assume by fiat (that economies are in equilibrium and get shocked out of it, and then resume some kind of trajectory back to the new equilibrium).

Maybe this is a dumb question, but if you are able to maintain a certain state by maintaining a certain energy input, how is this not an equilibrium state over time? It feels like the distinction between non-equilibrium and equilibrium is semantic.

The energy has to “flow” throughout the system, from the input, and then eventually “dissipate”. That sets up a pattern of behavior/dynamics very different from equilibrium systems, where there are no such “coherent” flows.

As an example of the practical consequences of non-equilibrium, look up a recent HN discussions (couple of days ago) on how hot water could freeze faster than cold water.

That’s just homeostasis, which is an equilibrium state, sometimes described as dynamic equilibrium. Encyclopaedia Britannica, Oxford and Merriam Webster describe it as a form of Equilibrium. Wikipedia links to Homeostasis from the master page on Equilibrium and references it in its description. I don’t see how this is in contention.

Uh, not quite. Dynamic equilibrium (Eg: during chemical reactions) means something very specific & constrained, and doesn’t include any steady influx/outflux of energy, material, etc. On top of that, one can have not just flows, but also active regulation mechanisms which maintain homeostasis, possibly with periodic temporal behavior (which can never happen in “equilibrium”). So even though “equilibrium” and “dynamic” as English words might seem somewhat descriptive of homeostasis, I think the physics concept of “dynamic equilibrium” is distinct enough to be worth not conflating. Eg: entropy can be constant in a system in dynamical equilibrium, but (to our best understanding) homeostasis always generates entropy.

What you state is not "edge of chaos", it's simply the non-equilibrium steady state. There's no connection really. Non-equilibrium states can be chaotic, non-chaotic, or at the edge of chaos etc.

Can you give a pointer to any of this “work” that hasn’t been debunked by physicists or engineers?

From wikipedia:

"Prigogine is best known for his definition of dissipative structures and their role in thermodynamic systems far from equilibrium, a discovery that won him the Nobel Prize in Chemistry in 1977. In summary, Ilya Prigogine discovered that importation and dissipation of energy into chemical systems could result in the emergence of new structures (hence dissipative structures) due to internal self reorganization."

Plenty of links on that page if you want to get into his research.

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