An interesting new spectacle is being planned for the next Expo in Spain: it's a building that has walls made out of water. The water shoots down, in sheets, from computer controlled pipes. The valves shooting the water are deftly controlled by a software system which allows for the creation of gaps and spaces in the water. In turn, this allows for simple pictures or words to be formed on the water-walls.

Architects from MIT are behind this "digital water" pavilion. The wet building will be near the entrance to Expo Zaragoza 2008, and will house, amongst other things, a cafe and a exhibition area. The roof of the pavilion will be mounted on large pistons which can adjust the buildings height. There will also be a thin layer of water of the roof. When the building is not needed, of if there is too much wind for the water-walls to handle, the entire structure can be conveniently collapsed into a hole in the ground, disappearing from view. 

"You could throw a ball at the wall, and then see an open circle drop down to meet it precisely where and when its trajectory intersected the water surface. And, with suitable programming, touching the water surface at any point can propagate patterns horizontally, along the wall, to other locations," explained William J. Mitchell, the head of MIT's Design Laboratory, and former Dean of Architecture. The 'building' also has sensitive sensors, which allow the water-walls to prepare for people coming to the building and adapt, "like the Red Sea for Moses, [and] open up to allow passage through at any point." However, Mitchell did not comment on whether or not the gaps in the water-walls would close if a massive, chariot-riding, spear-wielding contigent of angry Egyptians were to descendent on the building, looking for freed slaves. 

"This provocatively subverts the fundamental architectural conception of an opening as something, like a door, found at a fixed location," Mitchell waxed philosophically.