To prevent the present from erasing the past, non-profit organizations are creating detailed 3D scans of famous monuments. Stored online and shared with researchers around the world, these digital copies will endure long after their real counterparts are gone. Occasionally, this work is incredibly dangerous. On the night of May 14, 1940, the German Luftwaffe bombed the Dutch city of Rotterdam. When government administrators entered the streets to tally their losses the next morning, they learned that 900 people had lost their lives. As if this was not bad enough, the Luftwaffe had also destroyed hundreds of historic houses; Rotterdam's city center — one of the oldest in the country and jam-packed with seventeenth century architecture — had been reduced to dust. In 2001, the Taliban pulveri
