Norris said of Coster-Mullen’s work, “Nothing else in the Manhattan Project literature comes close to his exacting breakdown of the bomb’s parts. But the exact details of how these devices worked were unknown. Little Boy shot one mass of highly enriched uranium into the other with a gunlike mechanism Fat Man used explosives to squeeze together two hemispheres of plutonium. It was known that Little Boy and Fat Man brought together two masses of fissile material inside a bomb casing, forming a critical mass that set off a nuclear explosion. Norris, began, “For many years, Coster-Mullen has been printing his manuscript at Kinko’s (adding to and revising it along the way) and selling spiral-bound copies at conferences or over the Internet.” Norris clearly considered Coster-Mullen’s understanding of the bomb superior to his own. The mention of Coster-Mullen’s journey led me back to the November/December, 2004, issue of the Bulletin, which included a review of a book by Coster-Mullen titled “Atom Bombs: The Top Secret Inside Story of Little Boy and Fat Man.” The review, written by the eminent atomic historian Robert S. He had built the replica with the help of his son, Jason, in his garage, basing it, in part, on his analysis of sixty-year-old screws, bolts, and fragments of machined steel that had been stored in rural basements and attics. A year later, I read an article in the Bulletin of the Atomic Scientists that mentioned a six-hundred-mile trip Coster-Mullen had taken across the Midwest with a full-scale model of the Hiroshima bomb in the back of a Penske rental truck. The show, called “Critical Assembly,” included what appeared to be spookily exact replicas of the interior mechanism of the first atomic bomb, which Sanborn had manufactured according to Coster-Mullen’s specifications. I first came across Coster-Mullen’s name in January of 2004, after I attended an exhibit by the artist Jim Sanborn, at the Corcoran Gallery of Art, in Washington, D.C. John Coster-Mullen conducted a decade of research to build the first accurate replica of the Hiroshima bomb.
The most prominent is Richard Rhodes, who won a Pulitzer Prize, in 1988, for his dazzling and meticulous book “The Making of the Atomic Bomb.” But the most accurate account of the bomb’s inner workings-an unnervingly detailed reconstruction, based on old photographs and documents-has been written by a sixty-one-year-old truck driver from Waukesha, Wisconsin, named John Coster-Mullen, who was once a commercial photographer, and has never received a college degree. In the decades since the Second World War, dozens of historians have attempted to divine the precise mechanics of the Hiroshima bomb, nicknamed Little Boy, and of the bomb that fell three days later on Nagasaki, known as Fat Man. The United States government has never divulged the engineering specifications of the first atomic bombs, not even after other countries have produced generations of ever more powerful nuclear weapons. Yet for more than sixty years the technology behind the explosion has remained a state secret. The single, blinding release of pure energy over Hiroshima, Japan, on August 6, 1945, marked a startling and permanent break with our prior understandings of the visible world.