Chaos theory, the study of how tiny fluctuations can have tremendous effects within a moving system, emerged in mainstream physics about 30 years ago. The signature example of this line of thinking—the “butterfly effect”—is that a butterfly flapping its wings in Taipei can affect the weather over Toronto. Chaos theory, or nonlinear dynamics, is a mathematical way of determining the effects of small changes on systems so complex they look random.
Chaos theory shook through the scientific community. Jupiter’s red spot, fractal geometry, and economic forecasting all became some of chaos’s most celebrated clients. Physicists and mathematicians heralded the birth of a new science, and some saw chaos theory as a revolution on a par with quantum mechanics. The revolution stretched into popular culture. From The Simpsons to Jurassic Park, chaos theory became fashionable and funny, terrifying and true. In the 21st century, chaos theory, for all its previous pomp, makes barely a peep on the mainstream radar. Still, it hasn’t gone away—far from it, says Harvard University physicist Paul Martin. “It’s become part of the arsenal of tools that people use,” Martin says. “It’s a collection of tools, and it’s a way of understanding phenomena that occur over a wide range of fields.” But calling it a revolution was “not wise,” Martin says. The applications of chaos theory touch almost every field, and trying to group them under one umbrella would be a useless and herculean task. “It’s too ubiquitous to be a discipline unto itself, and too many fields use it,” he says. “There isn’t any great virtue in unifying under the one word chaos. It’s not an independent discipline.”