When Greg Spriggs was 11 years old, his father, a Navy man stationed on Midway Island, took him out one night to watch a nuclear bomb explode in space. The year was 1962 and the nuclear test was Starfish Prime, the largest in a series of high-altitude detonations. A rocket shot the 1.4 megaton nuclear warhead 250 miles above Earth—higher than the International Space Station orbits today.
“It just lit up the sky like day,” recalls Spriggs. The warhead released so much energy it set off an aurora that lasted 15 minutes after the explosion: The sky shimmered white, then red, then purple. “Had I known I would become a weapon physicist,” he says, “I would have paid more attention.”
Half a century later, Spriggs spends a lot of time watching nuclear bombs explode. Not in person of course—atmospheric testing stopped in 19631—but on film. On the original film, even. Over the course of more than 200 nuclear tests in the atmosphere, the US government has amassed thousands of films documenting the tests from every which angle and distance. At Lawrence Livermore National Laboratory in California, Spriggs has begun a program to restore those films in hopes of wringing every last bit of data out of them.
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Atomic Hollywood
It took Spriggs a year of asking around libraries and archives before he tracked down 7,000 original films at Los Alamos National Labs in New Mexico—where he worked before Livermore. (Los Alamos was, of course, the home of the Manhattan Project.) But the films had laid untouched for so long, people had forgotten their existence. “Los Alamos said, ‘We think we have originals. Nobody’s messed with the films for 40 years but we’ll go dig them up for you,’” Spriggs recalls. The films soon started arriving by mail from New Mexico.
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How to Analyze a Nuclear Bomb
To calculate how much energy a bomb releases, you have to measure the size of the shock wave over time. Plugging that into an equation gets you the bomb’s yield—or the amount of energy it discharges.
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Declassified
Spriggs, in his Livermore office, is still going one film at a time. While 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.”
Read more at Movies of Cold War Bomb Tests Hold Nuclear Secrets
