I have one more day left here in the Smithsonian's Architectural History and Historic Preservation Division. This rather unconventional six-month internship has been an incredible experience and it's surprisingly given me a much more nuanced perspective on architecture from all periods. (Trying to justify the preservation of a few brutalist structures at the National Zoo can do that. . .)

Yesterday we received a call from a woman at the National Park Service who was trying to ascertain when exactly a small drop-off road was removed in the lawn south of the National Museum of Natural History (that's the domed Beaux-Arts one by McKim and Burnham). Apparently the park service doesn't keep detailed records of such mundane things even though the Mall is their responsibility.

Consequently, our best source for dating its removal were the many historic photographs of the building. We could see when they started changing the Mall from Andrew Jackson Downing's design to the 1902 Senate Park Commission Plan (in the 30s), when the National Gallery was built next door, when the two additions to the building were completed, and when the courtyards were filled in. Each photograph showed the subtle yet undocumented alternations happening over the years, and each narrowed the window of possibility. We finally concluded, after a good hour of searching that the little drive had been removed at the same time the two central drives running through the Mall were converted from asphalt to crushed gravel in preparation for the national bicentennial celebration in 1976.

During that search, I realized that out there, somewhere in America, is photographic evidence of when, to the day, that road was removed. Some tourist who came to see the Hope Diamond or the bones of a mastadon snapped a picture of that construction site. And it's sitting in an attic stuck to the back of another in a stack of so many photos that seldom are seen.

I then remembered reading about Photosynth, the Microsoft Live Labs project to create open source software to digitally re-create spaces around the world using photos that anyone can upload. The software would analyze shapes and colors to stitch all of those photos into a composite image of three-dimensional space. It's easy to conclude that eventually we'll be able to average all of those images to create a seamless, photo-realistic, virtual replica of the built world.

But what if that program could operate in four dimensions? What if every photograph uploaded were time stamped? What if, in addition to panning in space, one could also scroll through time?

Imagine if every photograph in every department of history were uploaded. We would move back through history, seeing buildings deconstruct, rise from demolition and reverse evolve. We would see the rejection of urban renewal and the elimination of blight. The cities would re-populate, shops would re-open, cars would become panelled then blocky then scarce as railcars and horses rush in. And finally we would see those cities become fuzzy and gray and faded as they dissolve into the photographic nothing of Antebellum nescience. . .