Everything flows
http://www.guardian.co.uk/Archive/Article/0,4273,4305664,00.html
Saturday November 24, 2001
Emergence: The Connected Lives of Ants, Brains, Cities and Software
Steven Johnson
288pp, Penguin, £14.99
Harvester ants aren't particularly bright. Yet colonies of these creatures
gather food, fight off enemies, deposit rubbish and fallen comrades in neat
heaps outside their nests, and generally pull off some of the most amazing
feats of engineering in the animal kingdom. How do colonies achieve all this
when the brains of their members are so limited? It is tempting to think that
the queen understands the master plan and in some way coordinates her minions,
but in reality she's just as thick as they are. No one, it seems, is pulling
the colony's strings, so how does it manage to function as a whole?
The answer may lie in self-organisation, a phenomenon explored by Steven
Johnson in his mind-expanding Emergence: The Connected Lives of Ants, Brains,
Cities and Software. In its most basic form, a self-organising system
comprises many simple elements whose individual behaviours are determined by
local conditions. A worker ant may stumble across a colleague's pheromone
trail communicating the message "out foraging". If such trails are dense on
the ground, the encountering ant may stop collecting food and begin taking out
the trash instead. Alternatively, if the frequency of "out foraging" messages
is low, the ant may respond by striking out along a trail that says, by smell,
"food over here", and begin collecting again. Provided individuals stick to
their respective rules, seemingly intelligent behaviour by the colony as a
whole can emerge without any ant being the wiser.
This type of self-organisation is now recognised in many systems composed of
numerous elements or modules capable of performing relatively simple
behaviours in response to local stimuli. "Bottom-up" forces probably play a
crucial role in shaping the nature of cities, leading to the creation of
suburbs, slums, business centres and other unplanned demographic clusters. No
one decreed that Savile Row should house London's finest tailors, for example;
the character of the street emerged as a result of decisions taken by
individual businesses about such things as profile, supply lines and customer
bases. Similarly, the silk weavers of Florence began to congregate unbidden on
the Por Santa Maria in the 11th century and are still plying their trade there
today, despite the coming and going of wars, plagues, fires and massive social
upheavals. Cities seem to have emergent lives of their own, governed by the
usually unwitting actions of their inhabitants over many generations. We are
the ants, in other words, and cities are our colonies.
Warming to his metropolitan theme, Johnson then asks a seemingly ludicrous
question: can cities learn? Learning is usually associated with conscious
beings, but then an immune system "learns" throughout its owner's lifetime,
adapting and manufacturing antibodies to counter the threat of invading
pathogens. This type of learning seems to revolve around information-storage
and a certain responsiveness to change, so there may indeed be a sense -
albeit rather a narrow one - in which cities too can be said to learn.
If you think this is esoteric stuff, read on. "If cities can generate emergent
intelligence, a macro-behavior spawned by a million micromotives," Johnson
muses, "what higher-level form is currently taking shape among the routers and
fiber-optic lines of the internet?" Might the world wide web become a "global
brain"? Will emergent intelligence, or even self-awareness, arise unbidden in
cyberspace? Controlling the net is hard enough at present, but what if it
starts getting ideas of its own? If, like me, you feel an overwhelming urge to
head for the nearest unplugged island when cybergeeks start banging on about
our technological future, this is an occasion to resist. Johnson's
speculations about life on the internet, machine intelligence, computer
programs that evolve on their own, feedback loops in modern media networks and
so on are intelligent, witty and tremendously thought-provoking. And his
conclusions will probably surprise you.
Emergence is a fascinating book, full of surprises and insights, and written
in an easy, engaging style. However, you may have to read it more than once to
appreciate its subtleties. The significance of emergent behaviour is made
admirably clear in the case of insects, slime moulds and even cities, but
grasping its relevance to the Gennifer Flowers affair and the operation of
internet chatrooms is a bit more challenging. The connections are there, but
Johnson is rather sparing with the signposts. He also tends to place them less
than helpfully towards the end of chapters, requiring the reader, finally
enlightened, to go back and reconsider all the earlier spadework. Still,
popular-science books interesting enough to read twice don't come along all
that often.
· Chris Lavers is the author of Why Elephants Have Big Ears (Phoenix, £7.99).
--- --- --- --- ---
Useless hypotheses, etc.:
consciousness, phlogiston, philosophy, vitalism, mind, free will, qualia,
analog computing, cultural relativism, GAC, Cyc, Eliza, cryonics, individual
uniqueness, ego, human values, scientific relinquishment, malevolent AI,
non-sensory experience, SETI
We move into a better future in proportion as science displaces superstition.
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