This week, scientists at the Lawrence Livermore National Laboratory (LLNL) released another 62 declassified nuclear explosion test videos on the lab’s YouTube channel. These videos follow an earlier batch of nuclear test videos that were released by LLNL in March.
The videos depict atmospheric nuclear tests carried out by the US between 1945 and 1962. Often, the detonations were filmed by as many as 50 different cameras at different angles, locations, and frame speeds. Over time, the US military racked up some 10,000 films from 210 tests.
The films sat in storage for decades until nuclear physicist Gregg Spriggs was asked to model the effects of nuclear explosions, according to an LLNL press release. Spriggs’ model didn’t correspond to information that was published contemporary with the actual tests in the 50s and 60s, so he started digging out old nuclear test films to reanalyze the explosions and fact-check his data against the manually-recorded historical data. In some cases, Spriggs found that the decades-old, manually-recorded data was off by as much as 30 percent.