Visitors to Hyde Park last weekend were greeted with an interactive replica of the “Tree of Souls” from the film Avatar. The Tree of Souls is a giant, interactive tree with deep spiritual significance to the Nav’i people who appeared in the film. The real-life tree features 20 miles of fibre optic branches. Sensors within the tree cause it to change colour and intensity as people move near by. Visitors were able to use wi-fi and bluetooth networks to upload images to a screen in the tree. Or they could plug in their i-Pods and watch the tree pulsate in time with the music being played. Below, Stephen Lang, who starts in the film, gives a demonstration.