Seven years ago, UC Santa Barbara researchers caught an unexpected phenomenon on film: A pool of red dye that somehow “knew” how to solve a maze filled with milk. Propelled forward by a couple drops of soap, it unerringly found its way, avoiding dead ends and even making 90 degree turns in its path toward the exit.
What began as a demonstration of the complexity of fluid systems became an art piece in the American Physical Society’s Gallery of Fluid Motion, and ultimately its own puzzle that the researchers just solved. Their new study is published in the journal Physical Review Letters.
“We came up with this experiment because we were having a hard time convincing people of certain effects happening for the problem of drag reduction,” said assistant professor Paolo Luzzatto-Fegiz, an assistant professor of mechanical engineering, whose research specialties include modeling flow and investigating drag — as in, the resistive forces that act on solid objects traveling through fluids.
Researchers who captured fluid finding its way through a maze now understand what drove the counterintuitive phenomenon.