If we can fore­cast the path of a hur­ri­cane or even the tra­jec­tory of a sub­atomic par­ticle, why shouldn’t we also be able to fore­cast the spread of an emerging dis­ease? That is the ques­tion Alessandro Vespig­nani, who was installed as North­eastern University’s Stern­berg Family Dis­tin­guished Uni­ver­sity Pro­fessor of Physics on Tuesday in the Raytheon Amphithe­ater, began asking 10 years ago.

The answer, he explained, is twofold: our ability to pre­dict dis­ease trans­mis­sion is lim­ited by both the com­plexity of human social net­works and by the fact that under­standing that com­plexity requires enor­mous amounts of data and thus extremely sophis­ti­cated technology.

Vespig­nani – who holds joint appoint­ments in the Col­lege of Sci­ence, the Col­lege of Com­puter and Infor­ma­tion Sci­ence and the Bouvé Col­lege of Health Sci­ence and is one of the leading net­work sci­en­tists in Northeastern’s Center for Com­plex Net­work Research – said the mobility pat­terns of indi­vid­uals around the world deter­mine how quickly and vastly a con­ta­gion will spread.

During the Black Plague, for example, which killed half of the Euro­pean pop­u­la­tion, people could travel only a few miles a day on average. But nearly 700 years later, with the aid of air­planes, auto­mo­biles and an expo­nen­tially larger pop­u­la­tion, people are now trav­eling many thou­sands of miles each day.

As a result, today’s social net­work is much more closely linked, according to Vespig­nani: A germ picked up in Vietnam could travel to Boston in just a few hours. To under­stand the macro­scopic struc­ture of human sys­tems, Vespig­nani said, we must look not just at indi­vidual behavior, but also at the system as a whole. “With just two mol­e­cules of water,” he explained, “we won’t see how water behaves as a liquid or ice. We need mil­lions of mol­e­cules to do that.”

In human net­works, Vespig­nani said, the indi­vidual is the social atom and groups are con­sid­ered social mol­e­cules. When we examine mil­lions of social mol­e­cules, a pic­ture emerges depicting our col­lec­tive behavior. The image is com­plex, because human social net­works don’t respond as we might expect from external forces such as dis­ease. Com­puter models, Vespig­nani noted, can help untangle that complexity.

With infor­ma­tion con­stantly flowing from satel­lite trace­able devices such as mobile phones and flight trackers, Vespig­nani said, we are in the midst of a “data deluge.” For the first time, our com­puter infra­struc­ture is pow­erful enough to ana­lyze that data. Vespig­nani, for example, can map thou­sands of indi­vid­uals’ move­ments across spaces to gen­erate mobility pat­terns for the whole system.

Two years ago, his team used their model to project the activity peaks of the H1N1 pan­demic for var­ious regions in the Northern Hemi­sphere. Even­tu­ally the researchers were able to val­i­date those pro­jec­tions with actual data and found that their “sim­u­la­tions were spot on.”

Vespig­nani hopes that with other forms of data, like those gen­er­ated by Internet and social net­work use, it will be pos­sible to project “not just the spread of dis­ease, but also ideas, knowl­edge, or the evo­lu­tion of lan­guages,” he explained.

North­eastern researchers, Vespig­nani noted, “are keen to create new results now…to see those sys­tems in com­pletely dif­ferent ways.” His dis­ease model, he said, is a pro­to­type for poten­tially lim­it­less applications.

Vespig­nani was elected to the physics and engi­neering sci­ences branch of the Academy of Europe last year for his research on the spread of epidemics.

Pres­i­dent Joseph E. Aoun said the world-​​renowned sta­tis­tical physi­cist “epit­o­mizes what we’ve been doing” in terms of inter­dis­ci­pli­nary collaborations.

Murray Gibson, dean of the Col­lege of Sci­ence, intro­duced Vespig­nani, saying he caps off Northeastern’s team of net­work sci­en­tists, which is made up of world leaders in the field.

Provost Stephen W. Director, who oversaw the formal instal­la­tion of the new Stern­berg Chair, made one last pre­dic­tion toward the close of the event, noting that we “will be seeing many more instal­la­tions of North­eastern fac­ulty chairs, cre­ating their own inter­con­nected net­work of inter­dis­ci­pli­nary work.”