The science behind Beijing's Water Cube

The very impressive looking National Aquatics Center aka the Water Cube, the swim center for the Olympics was designed by an Australian firm using the mathematics of foam. From Science News:

The Weaire-Phelan foam provided not just a pretty surface for the walls, but the building’s very structure. Imagine an enormous block of the foam, with steel beams outlining the edge of each bubble. Now carve out the center to form a building with 12-foot-thick walls and 24-foot thick ceilings. This is the weight-bearing structure of the Water Cube.

The result is so strong, the engineers say, that the entire building could be turned on its side without collapsing. Furthermore, the remarkable effect is that they’ve designed a building without triangles. Ordinarily, buildings rely on triangles to provide stiffness, since a triangle is the only two-dimensional shape that can’t be deformed without changing the length of its sides. The engineers say that this lack of triangles will make the building more flexible and hence more able to withstand earthquakes.