Sarah Zhang has a fascinating post over at Wired about the systematic study of Cold War-era nuclear test films that's currently being undertaken by nuclear physicist Gregg Spriggs. One of the most interesting elements to the story is the fact that of the 7000 films discovered so far, 4000 are still classified.
While [Spriggs and] his team has scanned all 3,000 of the declassified films, they have another 4,000 classified ones to go. The first step is declassifying them all, which is a huge bureaucratic undertaking: Spriggs will sit in a room with another trained declassifier to view and then fill out a form for each and every single film, a process that takes about 10 minutes each. Then someone at the Department of Energy will have to approve each film for declassification. Since the estimated yields for almost all the bombs tested in these films are already public, there's no good reason to keep them classified, says Spriggs — only that no one's bothered to fill out all the paperwork until now. "It's this big bureaucracy that just goes back and forth."
You should read Sarah's entire piece over at Wired, which explains why these films are so important for national security specialists today.
Image: Screenshot of the film reel of the original Trinity test, now decaying