It’s called ‘visualising data’ and, says Facebook intern Paul Butler, who created the map, above, it’s a bit like photography.
“Instead of starting with a blank canvas, you manipulate the lens used to present the data from a certain angle.
“When the data is the social graph of 500 million people, there are a lot of lenses through which you can view it. One that piqued my curiosity was the locality of friendship. I was interested in seeing how geography and political borders affected where people lived relative to their friends. I wanted a visualization that would show which cities had a lot of friendships between them.
“I began by taking a sample of about ten million pairs of friends from Apache Hive, our data warehouse. I combined that data with each user’s current city and summed the number of friends between each pair of cities. Then I merged the data with the longitude and latitude of each city.”
At which point we literally did not understand another word Paul said.