In 1963, President John F. Kennedy signed the Limited Test Ban Treaty, prohibiting nuclear detonations in the atmosphere, the ocean, and outer space. Bomb testing disappeared underground—but it didn’t end. “In all of these underground tests, there has been little to see and little to photograph,” Light wrote in 100 Suns. “There is no record that helps keep an informed citizenry viscerally aware of what its government is doing.”