[eesmith]

Except as the author commented:

> Someone reminded me of something I had seen years ago: the British nuclear program at Aldermaston, when it has published on its own computer modeling in the past, used a sort of “bomb mockup” that looks far more deliberately “fake” than this Sandia one. I offer this up as what I would think is a more “safe” approach than something that looks, even superficially, like a “real” secondary design:

> This is called the MACE (Modal Analysis Correlation Exercise) assembly, and was created by the UK Atomic Weapons Research Establishment in the 1990s to serve as a sort of a Utah Teapot of weapons structural modeling: a benign shape that could be used to test aspects of the code that would nonetheless tell you if the code would work for real weapons assemblies.

[lupusreal]

The author doesn't convincingly rule out the possibility that this is what it is. The other possible answers seem less plausible than it being a fake shape for software testing that happens to look fancier than past test shapes.

[eesmith]

The author wasn't trying to be convincing. "I’m just surprised the DOE would release any image that gave really any implied graphical structure of a thermonuclear secondary, even if it is clearly schematic and meant to be only somewhat representative. It’s more than they usually allow!"

My reply was to point out that the author discussed issues related to HelloNurse's suggestion.

[HelloNurse]

The tone of this kind of article has to be nice and diplomatic, and mistakes need to remain hypothetical and attributed to the largest possible organizational unit (DARPA having surprising policies, not the mechanical finite element simulation software team spreading data they consider harmless).

The second object that appears near the end of the article looks like a simplified version of the first with more basic shapes, as if someone was asked by someone else to draw a less suggestive replacement of the original (possibly with the sole purpose of appearing in slides); in a natural design process the cruder design would have appeared first.