Jellyfish, fireflies, angler fish—we know they all glow. But how, exactly? It feels a little bit magical. But there's scientific reason, of course.
Animals uses one of two different mechanisms, bioluminescence and fluorescence, to light up, and this cute little animated video from the Vancouver Aquarium will help you forever remember the distinction.
As the video explains, the basic difference is that bioluminescence is a chemical reaction that creates light. Fluorescence requires light to be seen. So the firefly and angler fish are bioluminescent. Jellyfish and corals are fluorescent—they glow when light shines onto them.
Bioluminescence usually gets most of the glory, since it's a bit flashier. Here's a video that explains just a few of the uses and ways animals create light:
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