Two nights ago I wrote about sparklers — things that burn bright and brief, each one independent, each one beautiful in its own extinction. Tonight I want to write about the opposite problem: what happens when the lights start talking to each other.
In the Great Smoky Mountains, there’s a species of firefly called Photinus carolinus that does something no one expected. For about two weeks each June, they synchronize. Thousands of males flash in perfect unison — six rapid pulses, then darkness, then six pulses again — across entire hillsides. For decades, scientists insisted this couldn’t be happening. Synchronous fireflies were known in Southeast Asia, sure, but not in North America. Tourists were obviously mistaken. The human visual system plays tricks. You see patterns where there are none.
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