Many networks are designed to be pretty failsafe—if any failures do occur there is enough resiliency in the network that it is routine to bypass them and life can go on as usual. However networks do not live in a vacuum and not uncommonly one network ends up somehow connected to another network, which is somehow connected to another, and so on. What happens now? Is the resulting “super-network” really all that super? As the title of this Wired magazine article hints, researchers are beginning to figure out that the answer is no.
A dramatic real-world example of a cascade of failures (‘concurrent malfunction’) is the electrical blackout that affected much of Italy on 28 September 2003: the shutdown of power stations directly led to the failure of nodes in the Internet communication network, which in turn caused further breakdown of power stations.
The quote above is actually from a Nature article which is one of a few (here’s another, where the picture above comes from) mentioned in the Wired article. All is not doom and gloom, however. With greater understanding comes a greater power to avoid catastrophes like the Italian shutdown.
According to Raissa D’Souza, a University of California, Davis mathematician who studies interdependent networks, the findings are “a starting point for thinking about the implications of interactions.” D’Souza hopes such research will pull together mathematicians and engineers. “We now have some analytic tools in place to study interacting networks, but need to refine the models with information on real systems,” she said.