Phenomena

Avoiding Coalescence

Featured Video Play Icon

If you watch closely as you go about your day, you may notice drops of water sometimes bounce off a pool of water instead of coalescing. Fluid dynamicists have been fascinated by this behavior since the 1800s, but it was Couder et al. who explained that these droplets can bounce indefinitely as long as the thin air layer separating the drop and pool is refreshed by vibrating the pool. In this video, Destin teams up with astronaut Don Pettit to film the phenomenon in beautiful high-speed. My favorite part of the video starts around 8:18, where Destin shows Don’s experiments with this effect in microgravity. It turns out that the cello produces just the right frequencies to create a cascade of bouncing water droplets, much like a Tibetan singing bowl turned back on itself! (Video credit: Smarter Every Day; submitted by Destin and effyeahjoebiden)

Leave a Reply

Your email address will not be published. Required fields are marked *

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

%d bloggers like this: