You're stopped dead on the highway, for no apparent reason. Then the traffic clears mysteriously. You expect to see an accident, but there is none. You're confused – someone must have broken down or something! If this sounds familiar, you may be suffering from centralized mind-set. Other symptoms include the unshakable belief that flocks of birds must have a leader or that termites need effective top management to destroy a house.
The cure? Download StarLogo, a free Macintosh app from the Epistemology and Learning Group at the MIT Media Lab. (A Windows version is on the way.) StarLogo's purpose is to help people, especially precollege students, think in a decentralized way.
After I downloaded StarLogo, I opened the sample project called Traffic (I live in Southern California). I found myself looking down on a simple highway like an airborne traffic reporter. The interface, developed by Media Lab professor Mitchel Resnick (see "Building a Learning Society," Wired 5.10, page 136), let me control the number of vehicles and the rate at which they travel. Within a few minutes, I figured out why those mysterious parking lots appear on LA's 405 freeway. Of course, hard braking causes traffic bunching, as does fast acceleration, which, in turn, causes hard braking – and the cycle continues. But the real culprit is different rates of braking and acceleration. If I set equal rates for both, even if they are very fast, cars travel smoothly.
It's fairly easy to program your own simulations in StarLogo because its language is based on MIT's Logo, in which you instruct "turtles" how to draw shapes and pictures, while "patches" are pieces of the world the turtles inhabit. But StarLogo extends Logo so you can control the behavior of thousands of turtles and patches in parallel. Traffic is only one type of simulation available; a student interested in termite behavior could program turtles to act like termites by making them attracted to a certain odor, then program patches to simulate wood by having them emit that odor.
StarLogo proved to me that sometimes traffic is a group mistake and that there are no evil termite managers to curse for the destruction of my porch. Sure, it sucks knowing that I can only blame my fellow man when I'm stuck in traffic, but on the bright side, StarLogo showed me that someday, management might be unnecessary – at least for destroying things.
StarLogo: free
MIT Media Lab: +1 (607) 253 0300, starlogo-request@media.mit.edu email
This article originally appeared in the November issue of Wired magazine.
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