An imaginative Facebook worker, Paul Butler (no relation) has created an astounding world map based on a visualization of Facebook “friendships”.
Butler defined weights for every pair of cities as the function of Euclidean distance between them and the number of friends between each. He then plotted lines between the pairs by weight, so that city pairs with the most Facebook friendships were drawn on top.
He used a color ramp from black to blue to white, with individual line color based on weight. He also transferred some of the lines to wrap around the map.
It’s noteworthy that Russia, Central Asia and China are so isolated in the Facebook world.