I want to be very clear here that I don't actually think there's much moral to this story. They had an idea of how bad criticality could be, but there was no re

I want to be very clear here that I don't actually think there's much moral to this story. They had an idea of how bad criticality could be, but there was no real deterrent other than Fermi telling Slotin and others that if they kept up the procedure, they'd be "dead within a year". That tells me that everybody, from Oppenheimer on down, did not understand just how dangerous this sort of demonstration could be. Given the era, that's pretty understandable.