McCormick School of Engineering, Northwestern University
News from McCormick
Professor Dirk Brockmann’s Research Featured on CBS Show "NUMB3RS"
The crime: A group of thieves has been stealing lottery tickets from locations around town.
The question: Where will they strike next?
The solution: Professor Dirk Brockmann’s research.
At least that’s how things work in the universe of the CBS show NUMB3RS, which follows an FBI agent and his mathematical genius brother as they solve crimes using, as the name suggests, numbers. In the episode that aired on Jan. 8, investigators use fractional diffusion equations from “Professor Dirk Brockmann’s work with human mobility networks” to determine the area where the thieves will strike next.
Brockmann, associate professor of engineering science and applied mathematics at the McCormick School of Engineering and Applied Science, has used data from WheresGeorge .com — a site where users enter the serial numbers from their dollar bills in order to track their travels — to find out the patterns and regularities that govern human mobility.
From that information, Brockmann was able to reconstruct a comprehensive multi-scale human mobility network for the United States that includes small scale daily commuting traffic, intermediate traffic, and long distance travel by air.
Based on this mobility network, Brockmann has modeled how diseases spread throughout the country, and he and his research group have also created a map of large scale community boundaries in the United States, different from those defined by administrative state-line boundaries. These effective maps show that some states, like Missouri or Pennsylvania, are essentially cut in half. Other boundaries coincide with geographic features, such as the Appalachian mountains.
“It’s intriguing what kind of geographic patterns are hidden in the way we travel from place to place,” Brockmann says. “But this is just the beginning of using large scale human behavior to gain insight into these structures. It’d be interesting to see for instance what effective borders would look like in continents like Europe where lots of borders are national boundaries.”
Click here to watch a clip of the show.