The mould, the map and the mass transit system

Paul Raven @ 02-02-2010

slime mould "transit network" (credit: Science/AAAS)There’s still much we can learn from the natural world – and not just the simple things. Nature has a way of solving complex problems without the need for cognition and abstract thought… or even sentience, in many cases. I remember being impressed as a child by the incredible power of tropisms in plants; the simple behaviour of growing toward a light source, for example, can make dumb vegetable matter seem tenacious, determined, relentless.

Well, it turns out that tropism can be pretty efficient, too, as discovered by a research team based in Tokyo. Having already discovered that slime mould can find the shortest route through a maze (provided there’s a food source to entice it), they made a simple map of Japan which used oat flakes to represent major population centres, and let the mould loose on it. End result: the networks of mould connecting the oat flakes closely resembled the country’s existing mass transit networks, or alternative layouts that were theoretically just as efficient. [via BoingBoing; image borrowed from linked article, credit Science/AAAS]

This reminds me of a (possibly apocryphal) story I read a long time ago about some architect employed to lay out a new section of campus for a college or business or something similar. Having set aside a large green space between a bunch of buildings, he was asked where the paths across it should go; his response was that the best way to make an efficient network of paths was to not lay any at all, and to let people walk as they wished across the green space for the first term. By the end of that time, the paths worn into the grass by pedestrians could be used as a map for the asphalters, showing not only the routes required but the comparative traffic densities thereof.

I’m not sure quite where I’m going with this, but I think it has something to do with dethroning rational planning processes in favour of waiting for the best methods or systems to emerge from the chaos of real life. For all our research, for all our academic disciplines and best practices, sometimes just letting things happen as naturally leads to the most efficient solution. I guess the trick is to recognise which problems are best solved in such a way, and which ones aren’t…