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Students Win First Place for Video Showing how Dollar Bills Move

Did you ever wonder where your dollar bills travel after you plop them down for a cup of coffee? The Web site Where's George? allows you to track them and learn where they go.

Northwestern University students, Christian Thiemann and Daniel Grady, have won first place in the 2009 International Science and Engineering Visualization Challenge for their video that uses Where's George? data to track how people spend money -- and therefore move -- across the country.

The Northwestern video, "Follow the Money: Human Mobility and Effective Communities," won first place in the noninteractive media category, tied with a team from the University of Utah. The National Science Foundation and the journal Science, sponsors of the competition, announced the winners today (Feb. 19).

Thiemann and Grady are doctoral students in the research group of Dirk Brockmann, associate professor of engineering sciences and applied mathematics at the McCormick School of Engineering and Applied Science. Brockmann also is a member of the Northwestern Institute on Complex Systems.

Watch a video of the group talking about the video:

Where's George allows anyone to record a bill's serial number and then track its journeys as other people spend it across the country. But it's more than just a game. Because every time a dollar is spent in a new place, it means someone moved it there.

Thiemann and Grady produced their "Follow the Money" video to explain their project and animate the results. Tiny bills stretch out from county to county on a map of the contiguous United States. Some places, such as Los Angeles have many bills passing through it from across the nation, while others, such as Anderson County in Tennessee -- Grady's home -- have bills circulating mainly within a more local neighborhood.

From this travel data, the team ran computer algorithms to find what they call effective communities within the United States. People tend to travel more within these invisible boundaries than outside them. In the video, counties flash and wiggle as the computer algorithm tries to decide which counties belong in the right community.

"Normally, you just push a button and wait for two hours and then all you get are numbers, which is really boring," Thiemann said. "But [the animation] makes the process visible and shows you how interesting it can be."

Grady hopes the video will stimulate other people to think up new ideas about what to do with these data. They've already started using it to study how diseases, such as H1N1, spread, and linguistics professors want to compare these travel boundaries to dialect boundaries.

Corinne Sandone, a member of the competition's panel of judges, thought the video had a whimsical, quirky appeal, like that of independent films.

"I liked the extreme geekiness of it and how it made me want to watch it again to absorb it all," said judge Thomas Lucas. "It was so rich."

- Megan Fellman
Video by Matthew Dalzell and Emily Ayshford.