A heavily edited version of this essay appeared in the New York Daily News. Securing the Washington Monument from terrorism has turned out to be a surprisingly difficult job. The concrete fence around the building protects it from attacking vehicles, but there’s no visually appealing way to house the airport-level security mechanisms the National Park Service has decided are a must for visitors. It is considering several options, but I think we should close the monument entirely. Let it stand, empty and inaccessible, as a monument to our fears...

Scholars at the University of North Carolina at Chapel Hill have developed a method for creating 3D models of pretty much anything in pretty much no time. Using a sexy algorithm and the millions of photographs available from Flickr, the team can create a sophisticated three-dimensional model on a single personal computer in under a day.