Gene Stanley, a professor of physics at Boston University, and his colleagues discovered the mathematics behind what he calls “the extreme fragility of interdependency.” In systems of interconnected networks like the economy, city infrastructure or the human body, Stanley’s model indicates that a small outage in just one network can make waves through the entire system, resulting in a sudden, catastrophic failure.

These findings were first reported in 2010, according to Wired, and they spawned more than 200 related studies, some of which included analyses of the nationwide blackout in Italy in 2003 and the global food-price crisis of 2007 and 2008, among others.

“In isolated networks, a little damage will only lead to a little more. Now we know that because of dependency between networks, you can have an abrupt collapse,” said Shlomo Havlin, a physicist at Bar-Ilan University in Israel who co-authored the 2010 paper.

“While scientists remain cautious about using the results of simplified mathematical models to re-engineer real-world systems, some recommendations are beginning to emerge,” Wired continues. “Based on data-driven refinements, new models suggest interconnected networks should have backups, mechanisms for severing their connections in times of crisis, and stricter regulations to forestall widespread failure.”

Governments around the world are paying attention to this sort of information. “In the U.S., the Defense Threat Reduction Agency, an organization tasked with safeguarding national infrastructure against weapons of mass destruction, considers the study of interdependent networks its ‘top mission priority’ in the category of basic research. Some defense applications have emerged already, such as a new design for electrical network systems at military bases. But much of the research aims at sorting through the mathematical subtleties of network interaction.”