Carson Mark reminisces about working with Stanislaw Ulam and Ulam's idea of a "bomb in a box."

Mark:

I don't think Ulam ever gave a hoot about the super. It's true he didn't do the calculations, which Edward found disappointing, in a malevolent way. I think he did them honestly, and he worked with Fermi to discuss propagation. He was not trying to prove propagation doesn't occur, he just didn't find any. So I don't think he stayed awake nights trying to figure out how to make the super run. His contribution was great, very significant, but in a manner fortuitous.

He came into my office one afternoon, and I didn't really want to see him, because we were running an operation in Nevada right at that time. He put a lot more attention into the tests that you are interested in, and he interrupted some time that I had hoped to have available for something else. I've forgotten what it was. I wish it didn't matter. All steamed up, wanting to talk about some thinking of his recently, on which he put the tag. "It would be wonderful to see the effect of a bomb in a box." He used that phrase a number of times. And it would be a lot more interesting to be reading something on that line than what we were doing in Nevada, where we had our hands full with what we were doing. "We should throw that whole program in the wastebasket and do something interesting," said Stan. He didn't really care much about what we were doing in Nevada. I guess I don't either — didn't either — because I can't remember what it was. It was a more or less straightforward set of experiments with bombs of different physical dimensions than we'd shot before, and different arrangements and proportions of fissile material. We wondered if we could calculate them correctly, and the results all came out very agreeably.