The Archiving is finished
…Greg Spriggs, a weapon physicist and the project lead, notes that the film canisters were already starting to smell of vinegar — one of the byproducts of film decomposition.
Spriggs and his team started digitizing the films using special scanners that move the film without gripping it by the holes in the edges. But as they watched the old films, they noticed something: The nuclear yield data based on the images was wrong.
These aren’t just any old government movies: They are scientific documents that are key to understanding nuclear power. And even though the films are very old, scientists don’t get access to these sorts of nuclear tests anymore. Atmospheric nuclear tests have been banned since 1963.
Today, nuclear physicists run virtual nuclear tests on supercomputers. But those tests are based in part in research in the old films. And, unsurprisingly, there are better methods of measurement today.
So Spriggs and his team set about reanalyzing all of the old films, using new techniques. The indicators remain the same, in some ways: The double flash of light, the fireball and the shock wave captured on film all provide significant information for researchers on the energy generated by the nuclear blast. But today’s new tools offer greater precision.
For instance, the size, speed and duration of the fireball created can be used to estimate the weapon’s yield. The old methods involved analysts studying the film, advancing it frame by frame to see where the edge of the fireball seemed to be, and measuring its radius. This created plenty of room for human error, and, indeed, the yield numbers generated by this method produced inconsistent results.
But the newly digitized films allow researchers to more clearly see the fireball’s edge, allowing for much more accurate yield estimates. “We were finding that some of these answers were off by 20, maybe 30, percent,” says Spriggs. “One of the payoffs of this project is that we’re now getting very consistent answers. We’ve also discovered new things about these detonations that have never been seen before. New correlations are now being used by the nuclear forensics community, for example.”…
