Yeah I was thinking they probably picked a public use case that looks a lot like their classified workloads... The article mentions the simulation ran quickly, the time spent was debugging. Suggests to me the real classified system will be much more capable.

True. Applications as these go back a few decades. From the news buzz when it was launched, ASCI White was similarly used in early '00s to understand nuclear explosions and shockwave propagation (instead of relying on live tests) - classic CFD problems[1] Successor supercomputer clusters were also used to do weapon design & nuclear physics simulations. One supercomputer IIRC even simulated a tornado genesis.[2]

I can only imagine the classified applications must have grown ten-fold in complexity in the interim.

[1] https://en.wikipedia.org/wiki/ASCI_White

[2] https://news.wisc.edu/a-scientist-and-a-supercomputer-re-cre...