Get the latest tech news

World3, the Public Beta (2012)

Forty years ago I had my first close encounter with mathematical models of doomsday. The Limits to Growth, published in the spring of 1972, offered a grim vision of environmental and economic collapse, based on the implacable logic of a computer simulation called World3.

But the model is actually formulated in the language of “system dynamics,” a simulation methodology invented in the 1950s by Jay W. Forrester of MIT, with heavy influence from control theory and servomechanisms. The time step slider controls the integration interval (the variable dt within the model); if you set it to a value greater than 1 year, you’re likely to see spurious short-period oscillations caused by undersampling. In lexical and syntactic structure DYNAMO is what you’d expect of a language from the punch-card era—six-letter variable names and ALL CAPS—but in other respects it’s an interesting early experiment, with a programming style that falls somewhere between procedural and declarative.

Get the Android app