带你见识真正的社区

Look at a map and you can tell right away where New York ends and New Jersey begins. But that official border is not a true reflection of how the community is really shaped. Because northeastern Jersey is effectively part of the New York City metropolitan area and southwest Jersey is really part of Philadelphia’s.

Researchers from Northwestern University have now mapped the country’s de facto communities. And they did it in an ingenious way, using data from the Where’s George project.

Maybe you’ve gotten a dollar bill, featuring George Washington’s mug, that’s been stamped to indicate it’s in the Where’s George system. You can then go to a wheresgeorge.com and enter the serial number of the bill and your location. As will, hopefully, the next person who gets that bill.

The researchers realized that the movement of the dollars tracked by Where’s George is a marker for the movement of people. And the mobility of people reveals true communities. The research, in Public Library of Science ONE [Christian Thiemann et al., "The Structure of Borders in a Small World"], shows that, for example, the New England states really are a block. As is what you might call greater Texas after you’ve seen the video produced by the researchers. It’s at snipurl.com/georgewash

—Steve Mirsky