"I began exploring it in R, an open-source statistics environment. As a sanity check, I plotted points at some of the latitude and longitude coordinates. To my relief, what I saw was roughly an outline of the world. Next I erased the dots and plotted lines between the points.  After a few minutes of rendering, a big white blob appeared in the center of the map. Some of the outer edges of the blob vaguely resembled the continents, but it was clear that I had too much data to get interesting results just by drawing lines. I thought that making the lines semi-transparent would do the trick, but I quickly realized that my graphing environment couldn't handle enough shades of color for it to work the way I wanted.  Instead I found a way to simulate the effect I wanted. I defined weights for each pair of cities as a function of the Euclidean distance between them and the number of friends between them. Then I plotted lines between the pairs by weight, so that pairs of cities with the most friendships between them were drawn on top of the others.  I used a color ramp from black to blue to white, with each line's color depending on its weight. I also transformed some of the lines to wrap around the image, rather than spanning more than halfway around the world."  With a few more tweaks, he eventually came up with the amazing visualization you see here. At first glance, it provides some expected data -- the U.S. has the highest concentration of Facebook friendships, and Africa has the lowest concentration. While most of Russia and Antarctica are nowhere to be found, the rest of the world is easily identifiable.  What do you think of the visualization? Does anything about it surprise you? Let us know in the comments.
This is what the world looks like, according to the Facebook social graph.Facebook intern Paul Butler was interested in the locations of friendships, so he decided to create a visualization of