WWII Atomic Secrets See the Light of Day

Nobelist James Chadwick realized atomic research had dire implications - so he sealed it away for more than 60 years
by Richard Wyllie, 21 June 2007
WWII Atomic Secrets See the Light of Day
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The Chadwick papers detail how to build a nuclear reactor, which was deadly information in the wrong hands in 1941. "The paper is such that it would be inadvisable to publish it at the present time," wrote Nobel physicist James Chadwick to the Assistant Secretary of The Royal Society, Griffith Davies.

In 1941, a Nobel laureate named James Chadwick got his hands on documents that described how to build a nuclear reactor written by his colleagues. Like any good scientist he sent them off to the Royal Society in London. But instead of submitting them for publication, Chadwick urged that they be kept under wraps. The papers, forgotten and lost over time, were found in the institution’s archives last January during an audit. This month, a CERN particle physicist named Brian Cox opened them for the first time.

The Chadwick papers, as they came to be known, are a laundry list of sensitive atomic science, which include directions on how to safely conduct a nuclear chain reaction and how to get plutonium from uranium. (That’s pretty much one step away from making a bomb, hence the present-day brouhaha over Iran’s nuclear reactors). They also shed light on a bygone era of cloak-and-dagger science. “I can see why these papers were locked away during the war,” Cox said. “They contain details that could be used to build a nuclear reactor.”

James Chadwick discovered the neutron 75 years ago – a find that earned him a Nobel prize and kick-started modern day particle physics. Chadwick was a physics professor at the University of Liverpool at the war’s start but was quickly recruited to help the Brits build an A-bomb. Chadwick’s French colleagues across the Channel understood the neutron’s potential, and devised a means of generating nuclear energy, inventing what we now know as nuclear fission. It didn’t take long before nuclear fission’s far more sinister use – atomic bombs – came to light.

Seven years after Chadwick’s discovery, the Second World War began and a dark cloud descended over Europe. By 1940 the Nazis were in France, where Chadwick and his French colleagues, Hans Von Halban and Lew Kowarski, were painfully aware that their research could be used to build a bomb of unimaginable power.

They hastily typed up their work and, with the help of French agents and British intelligence, shipped themselves, their papers and their entire stockpile of heavy water (used to slow down neutrons in a reactor) over to Falmouth, England, right under the Germans’ noses. Chadwick, aware that even in Britain loose lips could sink ships, sealed the documents and sent them straight to the Royal Society in London with the advice that they were “inadvisable to publish at the present time.”

Von Halban and Kowarski were sent to Canada to develop a nuclear weapon – the British equivalent of the U.S.’s Manhattan project that developed the bombs dropped on Hiroshima and Nagasaki. The papers remained at the Royal Society, unopened.

That is, until June 1st 2007, when retired pop-star and professional particle-physicist Brian Cox peeled open the papers at the Royal Society in London. The sight of the D:Ream keyboardist (whom you may or may not remember from the 1990s pop scene) – poring over the yellowed typescript made me nostalgic for the science of yesteryear. Gone are the cloak-and-dagger stories, the smuggling, the ominous echoes of bootsteps on a train platform, the furtive Channel crossings. Now, at Cox’s current project, the Large Hadron Collider, it’s all about collaboration, publishing, grant money and outreach.

But Raiders of the Lost Ark fantasies aside, there were downsides to science being recruited in the war effort. The war sent the world of particle physics in the direction of destruction rather than energy production, and arguably prevented France from being the first to invent practical nuclear fission.

Today, with the completion of the LHC, 75 years after Chadwick’s discovery, we are about to enter a new era of particle physics and venture even farther into the unknown. As I watched Cox pore over Chadwick’s aged writings, I wondered what secrets we might read about in another 75 years.