Blue halos flaring around each footprint on wet sand can look like a movie effect, but the source is very much alive. In some warm, nutrient-rich coastal waters, waves push dense patches of bioluminescent plankton—often dinoflagellates—up into the surf zone, where every kick, splash, or step becomes a trigger for light.The glow is a textbook case of chemiluminescence. Inside these cells, an enzyme...More