In December 2010, Facebook released a new map of the world that was as astonishing as it was beautiful. It was both instantly recognizable–the standard projection produced by Gerard Mercator in the sixteenth century–and yet curiously unfamiliar. It was a luminescent blue, with gauzy lines spread over the map like silk webs. What was odd about it? China and Asia were hardly there, while East Africa seemed to be submerged. And some countries weren’t quite in the right place. For this wasn’t a map of the world with Facebook membership overlayed, but a map generated by Facebook connections. It was a map of the world made by 500 million cartographers all at once.
Using the company’s central data on its members, an intern called Paul Butler had taken their latitudinal and longitudinal coordinates and linked these to the coordinates of the places where they had connections. “Each line might represent a friendship made while traveling, a family member abroad, or an old college friend pulled away by the various forces of life,” Butler explained on his blog. Facebook had about 500 million members at that time, so he anticipated a bit of a mess, a crowded mesh of wires (like the back of those early computers) that would culminate in a central blob. Instead, Butler recalled, “After a few minutes of rendering, the new plot appeared, and I was a bit taken aback. The blob had turned into a detailed map of the world. Not only were the continents visible, certain international borders were apparent as well. What really struck me, though, was knowing that the lines didn’t represent coasts or rivers or political borders, but real human relationships.”
—by Simon Garfield