The lab
Bioluminescence
Drag your cursor across the water. Thousands of dinoflagellates — single-celled organisms that light up when physically disturbed — flash in cascading chain reactions. This is the ocean’s burglar alarm: the flash startles a grazer, the grazer moves, and the movement attracts the grazer’s predators. Click for a bigger splash.
Dinoflagellata · luciferin-luciferase reaction · scintillon pH cascade
running
move cursor to disturb · click to splash
2000
50
60
150ms
30
presets
Dinoflagellates produce light through a luciferin-luciferase reaction housed in organelles called scintillons. When something disturbs the cell — a wave, a shrimp’s feeding current, a swimmer’s hand — it triggers a mechanosensitive proton channel in the vacuolar membrane. Protons flood the scintillon, the pH drops, and the luciferase activates. The entire sequence takes roughly 15–20 milliseconds. Faster than a blink. A single-celled organism, executing a chemical cascade with the precision of a circuit.
The cascade effect — what you see propagating outward from your cursor — is the burglar alarm hypothesis. When a dinoflagellate flashes, it startles whatever was trying to eat it. The grazer flinches, moves, and in doing so creates a disturbance that triggers the neighboring organisms. But the flash does something else: it illuminates the grazer, making it visible to the grazer’s own predators. The dinoflagellate cannot fight. It cannot flee. So it calls for backup. A single cell, weaponizing the food chain above it.
The “milky sea” phenomenon is something else entirely. In 2005, Steven Miller confirmed satellite observations of a glowing patch in the Indian Ocean covering over 15,000 square kilometers — visible from space. This was not dinoflagellates. It was Vibrio harveyi, a bioluminescent bacterium using quorum sensing: each cell produces and detects signaling molecules, and when the local concentration crosses a threshold, the entire population switches on its light genes simultaneously. Billions of bacteria, with no central coordination, voting on whether to glow. The result is a sustained, even luminescence across an area larger than some countries. A planetary-scale consensus algorithm, running in the ocean.
Drag slowly for gentle ripples. Drag fast for bright trails. Click to create a splash that cascades outward. Try the “Red tide bloom” preset for dense, highly-reactive water, or “Milky sea” for the sustained bacterial glow effect. Watch how the cascade wave propagates differently at different densities.
Related: Slime mold networks · Reaction-diffusion patterns