The Source
The Source, created by Greyworld, is a cube of 729 balls suspended on cables 32 metres high in the lobby of the new London Stock Exchange.Controlled by computers running Python scripts, the balls will begin moving up and down at 8am when the market opens. It forms characters, shapes, and moves in motions that reflect the nature of the stock market itself throughout the day. When the market closes, the balls return to their cubed arrangement resting on the bottom. It looks really cool when it's moving, but I can't find a video on it (And they say YouTube has everything! Lies!).
UPDATE: You can see the videos on Greyworld's website. Thanks to Andrew Shoben of Grey World for the tip!
