Kyle J. Lueptow
Evanston Township High School
Evanston, Illinois

Richard M. Lueptow
Northwestern University
Evanston, Illinois

Image Credit: Kyle James Lueptow, AAPT High School Physics Photo ContestA coiling stream of honey in water

When a perfectly straight stream of honey hits the surface of the water in a crystal goblet, it begins to spiral. This phenomenon is similar to the coiling effect, called "liquid rope coiling," that occurs when a stream of thick, high-viscosity fluid like honey or syrup traversing through air hits a flat surface like a piece of toast or the bottom of an empty teacup. But in the example depicted above, this coiling instability is triggered by a liquid: the stream of honey impinges on the surface of the water instead of at the bottom of the goblet. As a result, the coiling stream of honey is stretched and deformed as it traverses through the water in the goblet.

Reporters and Editors

This image can be freely reproduced with the accompanying credit: "AAPT High School Physics Photo Contest, Kyle James Lueptow, 'Coiling Instability in Honey Poured into Water.'."

Contact Information

Richard M. Lueptow 
Professor and Senior Associate Dean
McCormick School of Engineering and Applied Science 
Northwestern University 
Room L258, Technological Institute
2145 Sheridan Road
Evanston, IL 60208-3111 
847-491-2739
r-lueptow@northwestern.edu