Emeritus Professor Gareth Williams returned to our group to talk about his research into the ‘Tube Alloys’ project, which culminated in his recent book The Impossible Bomb. Rather incredibly his research started when visiting archives in Cambridge for another project and accidentally opening the wrong folder in which he found a file marked Top Secret. Intrigued, he continued this new research path.

What he eloquently pieced together are the details of the personalities and their roles in moving from the discovery of nuclear fission in 1938 to the two bombs falling on Hiroshima and Nagasaki in 1945, which effectively led to the end of the Second World War. All this was in the shadow of not knowing how far research in the Nazi-occupied countries was advancing to produce a similar fearsome bomb.

One key theme running throughout Gareth’s talk was how the American version of this key part of history has ignored the valuable (or more accurately the invaluable} involvement of British scientists. The book and recent film Oppenheimer about the Manhattan Project only focused on the American version of the story, completely ignoring the British contribution.

Gareth carefully worked through the sequence of events he has uncovered and fully described who did what and when. Some of the key players and events were:

1. The discovery in Germany by Otto Hahn of nuclear fission in 1938, for which he was awarded the Nobel Prize for Chemistry in 1944.
2. The purging of Jewish scientists from Germany in 1939, which led to a number of theoretical physicists, such as Rudolf Peierls and Otto Frisch, emigrating to the UK and the US.
3. Despite being treated as aliens in the UK, Frisch and Peierls researched how to achieve the critical mass of enriched U²³⁵, and in March 1940 at the University of Birmingham they produced the first technical exposition of a practical nuclear weapon, entitled The Frisch– Peierls memorandum.
4. Nevertheless, between April 1939 and November 1941 various American academies and security bodies dismissed the idea of a nuclear bomb as ‘not likely to be decisive’.
5. From 1940 the M.A.U.D committee in the UK pulled together 7 Nobel Laureates to perform the research required to determine if an atomic bomb was feasible. In July 1941 they sent a report seeking American support to build a nuclear bomb. It got locked away in a safe for some months!
6. In November 1941, the Tube Alloys project was launched in the UK to work on key components of the so-called super bomb. Members were tasked with mastering the technology of nuclear energy production and designing an atomic bomb.
7. On 6^th December 1941 – the day before the bombing of Pearl Harbour triggered the American declaration of war with Japan – President Roosevelt finally gave his backing to the development of a nuclear bomb.
8. 60 ‘Brits’ joined development teams in the US at centres including Berkeley and Los Alamos. They included Frisch, Peierls and the later notorious ‘spy’, Klaus Fuchs. American input included the massive mile-long building where 10,000 women worked on producing enriched U²³⁵.
9. The outcome was that the Little Boy uranium-based bomb was dropped on Hiroshima on the 6th August 1945, and the Fat Man plutonium bomb which hit Nagasaki on the 9^thAugust 1945, thereby ending World War Two.
10. A few days later, the Smyth Report was published – an administrative account of the Manhattan Project – which conluded that ‘no other country had the brains or the technical effort’ to produce such a bomb. It turns out that its author had been barred from seeing any papers referring to the UK contributions.

Image by Freepik