The Mushroom Catapult Powered by Two Drops

Transcript

This is a real launch, filmed at fifty thousand frames per second.

On the spore, moisture gathers into a tiny drop called Buller's drop.

Another patch of water wets its side.

When they touch, the drops merge.

That reduces their total surface area, releasing surface energy and flicking the spore off its stalk.

In gilled mushrooms, the trip can be less than a tenth of a millimetre.

Just enough to clear the gill, then fall into the air below.

A microscopic catapult, powered by the physics of water.

Attribution

Research and high-speed footage: Stolze-Rybczynski et al., PLOS ONE (2009), doi:10.1371/journal.pone.0004163, Video S1, Creative Commons Attribution; mushroom photograph: Katja Schulz, via Wikimedia Commons, CC BY 2.0; media cropped, resized and retimed as labelled. Original 3D teaching animation, graphics and edit: Ask Pandi; narration: ElevenLabs, George. The 3D geometry and timing are illustrative. Licence/source notices: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0004163#copyright https://creativecommons.org/licenses/by/2.0/ ^{[1] [2]}