View source for Self-organisation

<div style"float:right; width:300px;"><img src="https://s0.geograph.org.uk/geophotos/05/24/70/5247053_be82e1f7.jpg" /><br>[https://www.geograph.org.uk/photo/5247053 Creative Commons Licence © Copyright Bob Jones]</div>
'''Self-organisation is where local interactions in dynamic systems accumulate to generate order.'''

For example, ants are not centrally organised by a boss ant who decides what everyone should be doing.  Instead, all the individual ants signal their immediate neighbours and respond to their immediate neighbours' signals.  These are the local interactions.  This way, when somebody finds something interesting, the message quickly gets around and everybody gets involved or runs away etc.  So they can behave collectively, but from the [[bottom-up]] instead of top-down, as though there's some complicated overall plan even though there isn't.

Living things use this trick ''a lot'', from tiny things happening on cell walls right up to global-scale atmosphere, oceans and geology, perhaps because it's an extremely efficient way to explore what's possible.
* Systems like this can respond quickly when anything changes (by [[positive feedback]])
* When they do change, they are highly flexible, good at generating novelty and diversity
* But because they're so efficient, they spend most of their time bouncing about close to some sort of optimal dynamic equilibrium (a state of [[punctuated equilibrium]] where [[negative feedback]] controls things) - sometimes called '''critically self-organised'''
* This makes complicated '''synergistic''' or '''emergent''' things like coral reefs and traffic jams and slime mould fruiting bodies happen (i.e. where "the whole is bigger than the sum of its parts")

This quite particular way of doing things is not restricted to just living things.  It's absolutely all over the place.  Solar systems and galaxies find and maintain a sort of dynamic equilibrium by stars and planets responding to each other's gravity.  Dynamic sub-atomic particles interact to form complex dynamic atoms which interact to form complex dynamic substances.  Like in the image above, water flows make channels which contain water flows which maintain those channels.  The examples seem to be everywhere, as if we're all on an island where nothing else happens.

What they all have in common is that they exist in a sort of dynamic tension, where each part of the whole helps to constrain all the other parts and the dominant influence on something is itself as it is now.  This produces characteristic shapes and scales and rates of change.  It's what '''complex systems''' and '''complexity theory''' are all about.

But in some ways they're still a bit of a mystery.  For example, ''how are their shapes all so similar, regardless of what they're made of?''  This implies that there's something fundamental going on in their mechanics, and we don't really know what it is yet.  They're '''non-linear''', so they stretch our classical, scientific, cause and effect ways of looking at things beyond what they can really do.  They indicate that some basic bits of the puzzle are still missing.  For example, they don't seem to be consistent with our laws of thermodynamics.

John Von Neumann (a famous mathematician) called them the "elephant in the room".  For more reading, try some of [https://en.wikipedia.org/wiki/Fritjof_Capra Fritjof Capra's books].

[[Category:Maths]] [[Category:Science]]
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Artificial Intelligence	File:IMG 6216.jpg