London, mapped with its Flickr and Twitter posts
I’m pretty close to deciding that the one thing the web does incredibly well is encourage banter, and throwaway communication; a little system of streams and creeks connecting drips of chatter from one end of the world to the other, occasionally creating importance. Here’s a lovely series of data visualizations supporting the idea. Eric Fischer has written, using APIs from Twitter and Flickr, a system which extracts geotagging information and plots the information across a projection of the earth and in various cities. Reddish dots are pictures from Flickr, blue ones are messages from Twitter, and white dots contain both.
In Fischer’s words (from a comment on Flickr), here’s how it works:
There’s not a whole lot of technology behind it. It’s a C program that runs through the photos/tweets in chronological order, plotting the earliest ones the most brightly and stepping the brightness down for points that don’t show up for the first time until later on. Points are also allowed to diffuse by a few pixels when there is an additional record for a point that is already plotted, with the brightness falling off exponentially as the point that is actually plotted gets further from its intended location. Each pixel is the somewhat weird area of 2.25 square miles because a smaller area made the whole-world image too big for Flickr to let me post it.
(He’s referring to Flickr’s maximum image size restrictions in that last sentence, saying it forced him to use a scale of 1 pixel to 2.25 miles.)
Browse the set and find your city!