Archives – Winter 2009

SIDNEY NAGEL, Two-Fluid Snap Off, Ink jet print, 52.5 × 34.25 inches, 1999.

Two-Fluid Snap Off

A drop falling from a faucet is a common example of a liquid fissioning into two or more pieces. The cascade of structure that is produced in this process is of uncommon beauty. As the drop falls, a long neck, connecting two masses of fluid, stretches out and then breaks. What is the shape of the drop at the instant of breaking apart?

National Academy of Sciences member Sidney Nagel is the Stein-Freiler Distinguished Service Professor in Physics at the University of Chicago. Nagel’s work has drawn attention to phenomena that scientists have regarded as outside the realm of physics, such as the science of drops, granular materials, and jamming. Using photographic techniques, as illustrated by this image in the National Academy of Sciences collection, Nagel and his team study such transitions to understand how these phenomena can be tamed and understood.