In the still of the Tennessee night, my colleagues and I are watching thousands of dim little orbs of light, moving peacefully in the forest around us. We try to guess where the next flash will appear, but the movements seem erratic, even ephemeral.
This summer, as we set up our cameras and tents, I feel a crippling sense of dread. I had brought us all up here to the Great Smoky Mountains National Park, an unlikely group of computer scientists and physicists from my lab, in order to chase fireflies. We study firefly communication in hopes of unravelling the mystery of how and why they blink in unison with one another. This rare phenomenon is one of the most tantalising mysteries in complex systems science. If we could capture firefly synchronisation in an algorithm, it might help crack any number of riddles in cellular biology, animal communication and even swarm robotics. But there was no guarantee, and I worried about whether the experiment was going to work. It was a constant race against time, as these light shows last for only about 10 days per swarm. Though we’re lightyears away from the nearest star, I found myself glancing up at the distant constellations, which seemed predictable by contrast to the swarming sea of bioluminescence.
As it happens, I found my path to fireflies via the stars. In my late teens, I was obsessed with astronomy. I marvelled at the fact that I was such a tiny creature, surrounded by a vast Universe in which there was so much to explore. This discrepancy, between the scale of individual components and the entire global system, is prevalent in many of the things that physicists observe: from atoms crystallising into lattices, to soap-bubbles coalescing, to concrete bridges vibrating in resonance. What’s common to all these examples is the underlying physics of complex systems, where the microscopic interaction between individual building blocks determines the behaviour of the macroscopic whole. [Continue reading…]