The Nazi Atomic Bomb Nearly Happened. A Mathematical Error Stopped It.
Eight months after Hitler invaded Poland, Germany was ahead of the United States in the race to build the atomic bomb. Then one physicist made a calculation that changed the war.
In December 1938, in a laboratory on the outskirts of Berlin, a chemist named Otto Hahn bombarded a lump of uranium with neutrons and discovered that the nucleus had split in two.
He was horrified.
Hahn understood immediately what he had done. Every physicist in Europe would understand it within weeks. A uranium nucleus could be broken apart — and in breaking apart, it would release energy on a scale nobody on the planet had ever harnessed.
Six months later, the German War Office convened its first meeting on the military use of uranium. The United States would not take a comparable step for two more years.
For a brief, terrifying window between 1939 and 1942, Nazi Germany was winning the race for the atomic bomb.
The Head Start Nobody Talks About
Most people assume the Americans always led. They didn’t.
By the summer of 1942, Werner Heisenberg and Robert Döpel had built a small uranium reactor in Leipzig — designated L-IV — that achieved the first positive neutron multiplication anywhere on Earth. Fermi would not do the same thing in Chicago for another six months.
In Hamburg, a chemist named Paul Harteck had already designed an ultracentrifuge that anticipated, in its basic principle, the enrichment cascades later built at Oak Ridge.
In the centre of Berlin, a concrete bunker was waiting to receive Germany’s first full-scale reactor. The scientists nicknamed it Virushaus — the Virus House — a sinister label chosen to keep curious visitors away.
Germany had the physicists. It had the uranium mines at Joachimsthal. It had the industrial chemistry of I.G. Farben. It had a six-year head start on fission.
So what happened?
The Error
In early 1941, a German physicist named Walther Bothe ran a measurement on graphite as a possible neutron moderator — the material that would slow neutrons down inside a reactor so the chain reaction could be sustained.
His sample was contaminated. His numbers came back wrong.
On the strength of that single flawed experiment, the entire German project turned away from graphite — the material the Americans would use at Chicago — and pinned its future on a substance called heavy water.
And there was only one plant in occupied Europe producing heavy water at industrial scale.
The Cliff in Norway
The Vemork plant sat on a shelf of rock above the Norwegian town of Rjukan, in a gorge so steep the Germans guarding it considered an attack from below to be physically impossible.
In February 1943, nine Norwegian commandos — trained in Scotland, dropped onto the Hardanger plateau, surviving a winter on reindeer moss — proved them wrong.
They skied into the gorge. They climbed a frozen cliff in the dark. They crawled through a cable duct into the high-concentration cellar. They laid charges on the electrolysis cells, lit the fuses, and slipped back into the snow.
Not one of them was killed. Some skied four hundred kilometres to Sweden. Their leader, Joachim Rønneberg, lived to see the 70th anniversary of the raid.
A year later, when the Germans tried to evacuate their remaining heavy water stockpile to the Reich, a single Norwegian saboteur named Knut Haukelid sank the ferry carrying it across Lake Tinnsjø.
The German reactor never went critical. The bomb was never built.
The Book That Tells It
In 1967, a young British researcher named David Irving walked into a warehouse of the U.S. Atomic Energy Commission in Oak Ridge, Tennessee. Inside, neglected and unread, were thousands of captured German documents — the entire paper trail of the Uranverein, the Uranium Club.
The Alsos mission under Samuel Goudsmit had stripped them out of liberated Europe in 1945, then forgotten them.
Irving read everything. He interviewed Heisenberg in Munich. He sat down with Haukelid in Oslo. He tracked down Kurt Diebner’s widow, Manfred von Ardenne in Dresden, Goudsmit himself at Brookhaven. He wrote the book that every serious history of the German nuclear program has been built on ever since.
Heisenberg — the man at the centre of the story — reviewed it in the Frankfurter Allgemeine Zeitung and summed up its accomplishment in one line:
“Irving’s book is a very good book. It gives all the facts, or practically all the facts.”
The Times Literary Supplement called it “scholarly and absorbing.” The Daily Telegraph said the Rjukan chapters read “better than any thriller.”
They do.
Why It Still Matters
The history of the twentieth century is the history of narrow margins. A miscalibrated neutron measurement in a laboratory in Heidelberg. A handful of men on skis in a Norwegian gorge. A contaminated sample of graphite.
Any one of these going the other way, and the map of 1945 looks unrecognisable.
The Virus House is the book that lays out, document by document and interview by interview, exactly how close the world came — and exactly how it didn’t happen.
It is one of the great untold stories of the Second World War. Most people still don’t know it.
Read The Virus House by David Irving → irvingbooks.com
303 pages. Hardcover and paperback. Focal Point Classic edition, with scholarly appendi