"In order to make one of these things work with natural (unenriched) uranium, which was all that they had to work with at the time, they had to get a lot of it situated close together but interspersed with neutron moderators such as pure graphite or heavy water. The Germans just didn’t have enough to make a go of it."
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The Germans tried graphite, but of insufficient purity[1], and concluded heavy water was the only way to go. They "didn't have enough of" that because of allied sabotage efforts[2]. There were some pretty thrilling heroics on display here that would make for a fantastic movie (or historical novel ;) ).
Even had both of these things gone Germany's way in some alternative history, they would still have faced an immense challenge in scaling up their operation under wartime constraints. The scale of the Manhattan project's enrichment efforts was truly colossal.
Im always on the lookout for these kinds of antiques. Many years ago I visited an antique store who were selling a 1916 brunton (geological instrument with compass and clinometer). It now sits amongst my rock collection.
One day I hope to find a late 1800s automatic groundwater datalogger. Think of a seismometer that sits on top of a groundwater well to measure water levels. It would be a dream find for me.
People who love this should consider visiting the Institute and Museum of the History of Science in Florence (now rebranded the Galileo Museum for what I assume are marketing reasons :P).
"In order to make one of these things work with natural (unenriched) uranium, which was all that they had to work with at the time, they had to get a lot of it situated close together but interspersed with neutron moderators such as pure graphite or heavy water. The Germans just didn’t have enough to make a go of it."
------------------------
The Germans tried graphite, but of insufficient purity[1], and concluded heavy water was the only way to go. They "didn't have enough of" that because of allied sabotage efforts[2]. There were some pretty thrilling heroics on display here that would make for a fantastic movie (or historical novel ;) ).
Even had both of these things gone Germany's way in some alternative history, they would still have faced an immense challenge in scaling up their operation under wartime constraints. The scale of the Manhattan project's enrichment efforts was truly colossal.
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[1]https://link.springer.com/article/10.1140/epjh/s13129-025-00...
[2]https://en.wikipedia.org/wiki/Norwegian_heavy_water_sabotage
Im always on the lookout for these kinds of antiques. Many years ago I visited an antique store who were selling a 1916 brunton (geological instrument with compass and clinometer). It now sits amongst my rock collection.
One day I hope to find a late 1800s automatic groundwater datalogger. Think of a seismometer that sits on top of a groundwater well to measure water levels. It would be a dream find for me.
People who love this should consider visiting the Institute and Museum of the History of Science in Florence (now rebranded the Galileo Museum for what I assume are marketing reasons :P).
It's heaven for science nerds.
Armillary spheres (including a room sized one from the 1500s), all manner of astrolabes, astronomical clocks, hand ground lenses and microscopes and telescopes and Galileo's actual middle finger (https://en.wikipedia.org/wiki/Galileo's_middle_finger), a tabula affinitatum, michelangelo's compasses, even an organum mathematicum!!!!! (https://en.wikipedia.org/wiki/Organum_Mathematicum)