Follow the crowd

摘要

Their claimed wisdom is disputed, but no one should doubt the ability of crowds to make collective decisions. Flocks of starlings twist in unison like smoke swirls in a summer sky, and shoals of fish tack and veer as if in response to electric shocks. Locusts swarm and herds of humans can head in very unwise directions indeed. Even simple bacteria show collective behaviour.Individuals in each of these systems have very different abilities to communicate with each other, to actively pass on information about their intended actions, so why does collective behaviour across all scales look so similar? Is there some unknown sensation that allows the individuals that comprise such seemingly intelligent crowds to steer; some distant wisdom? Although such behaviour is easy to observe, it has proved hard to capture in simple physical models. If we could master it, the information that this might yield could help engineers to develop swarming robots and design safer crowd-control measures.