Uranium cubes reveal why the German nuclear project failed
"Our calculations suggest Heisenberg significantly underestimated the materials required."

TL;DR
- A recent study using surviving German uranium cubes and historical records challenges claims that the Nazi nuclear program was on the verge of success.
- The B8 reactor experiment required an estimated 1,292 to 1,775 uranium cubes and double the available heavy water, indicating Heisenberg underestimated material needs.
- Impurities in the metallurgical coke used for graphite moderation, unlike the purer petroleum coke used by the US, also prevented a critical pile.
- Germany's nuclear efforts were fragmented into isolated groups (Berlin, Gottow, Leipzig), hindering resource sharing and progress.
- The Alsos Mission by Allied forces aimed to gather intelligence on German nuclear research.
- Only 14 German uranium cubes from this project are known to exist, with some held by institutions like the Smithsonian and Harvard.