“The U.S. conducted 210 atmospheric nuclear tests between 1945 and 1962, with multiple cameras capturing each event at around 2,400 frames per second. But in the decades since, around 10,000 of these films sat idle, scattered across the country in high-security vaults. Not only were they gathering dust, the film material itself was slowly decomposing, bringing the data they contained to the brink of being lost forever. For the past five years, Lawrence Livermore National Laboratory (LLNL) weapon physicist Greg Spriggs and a crack team of film experts, archivists and software developers have been on a mission to hunt down, scan, reanalyze and declassify these decomposing films. The goals are to preserve the films’ content before it’s lost forever, and provide better data to the post-testing-era scientists who use computer codes to help certify that the aging U.S. nuclear deterrent remains safe, secure and effective. To date, the team has located around 6,500 of the estimated 10,000 films created during atmospheric testing. Around 4,200 films have been scanned, 400 to 500 have been reanalyzed and around 750 have been declassified. An initial set of these declassified films — tests conducted by LLNL — were published today in an LLNL YouTube playlist (link is external). These films are stunning – silent, black and white explosions that resonate in a way that drive home in the starkest terms the ramifications of the use of these weapons.