Wasteland Wrap-up #46

Manhattan Project fissile material inventories, a trip to Luxembourg...

I finished up the blog post for my other, older blog, Restricted Data, that I hinted at last week, on Manhattan Project fissile material inventories. This is a very wonky kind of history-of-the-bomb details sort of post, so it didn’t feel appropriate for Doomsday Machines, but if you are interested in a long discussion about how I reconstructed the data from some pretty illegible sources, it’s all here: Manhattan Project fissile material inventories.

Top: The first gram-scale piece of plutonium metal, weighing 520 mg. It was made at Los Alamos on the night of March 23, 1944. Bottom: Four more plutonium metal buttons made during the spring of 1944. Source: Los Alamos National Laboratory.

There are basically two graphs that are the “kicker” of all of the work. The first is one that shows the highly-enriched uranium (HEU) and plutonium produced by the Manhattan Engineer District:

And another that shows how these correspond with the amounts of materials necessary for the different weapons designs (LB = Little Boy for HEU, FM = Fat Man for plutonium, and the “composite” numbers are for mixed HEU+Pu designs that were studied but not developed during the war):

Which may or may not interest you! But I am somewhat proud of having reconstructed the plutonium data in particular, because the documentary sources for it — as seen below — does not exactly “read itself.” And even the uranium data does not “read itself,” it turns out, because it only refers to the U-235 content of what was produced, not the total HEU.

Last week I also got a haircut from a very nice barber in Paris who spoke about as much English as I do French, which is to say, not a whole lot. But a male haircut is not exactly that complicated of an affair, so through a few words and gestures and a photo of myself from several months ago, he was able to get the idea of what I wanted.

“Enough plutonium, where’s Lyndon?” I can read your thoughts, you know…

We then had a somewhat stilted and over-ambitious conversation in French about what I study, and he had seen the Oppenheimer movie, but of course all I can say in French are things like, “he was a very complicated man,” which feels very frustratingly empty compared to all of the thoughts that I have about it in English. But, again, even the idea of having a baby conversation about Oppenheimer, the United States, what I do for a living, etc., would have felt pretty daunting a month ago, so there is definite progress happening. Although at one point I did realize that I felt more than a little trapped into an extensive language exercise, as I was stuck in the chair…

I also visited Luxembourg last week for a conference, which I will describe below…