Freezing From Below

Featured Video Play Icon

Watch closely as a droplet freezes on a cold surface, and you’ll observe something surprising. First, a freeze front will appear, traveling upward from the substrate. It curves slightly near the edges, leaving a liquid cap atop the frozen drop. But, as we’ve all discovered, water expands as it freezes. We can watch the drop freezing and see that the water isn’t expanding radially. Instead, the water expands vertically, forming a sharp tip or cusp just as the drop freezes completely. Remarkably, the geometry of the final tip doesn’t depend on the temperature of the substrate or on the wetting contact angle.  (Video credit: L. Posada)

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: