The Buried Void
From an oculus in the top of the Guggenheim a stream of sand will fall continuously into the museum and collect on the rotunda floor. For fifty years the sand will gradually fill the void, stopping on October 21, 2059 (the 100th anniversary of the Guggenheim) when it will have erased the space completely. Until then, guests in the building will be encouraged to experience and actively participate in this measure of time: as the physical objects in their lives become obsolete, visitors are encouraged to place them into museum-provided capsules and throw them into the sand. During the centennial celebration of the Guggenheim the rotunda will be excavated and the contents will be displayed in an evolutionary retrospective of forgotten things from the first half of the 21st century.