Any stories the list can share about similar things happening during enforced downtime?
Besides long-duration history (Oflag XII-B) and sheaf cohomology (Oflag XVII-A) already mentioned, I'd forgotten about the Curta* calculator (KZ Buchenwald).
https://de.wikipedia.org/wiki/Curta -Dave* somewhat ironically, Herr Herzstark was imprisoned in July of 1943, 5 months after what in hindsight was the turning point of the war: no oil, no Blitz.
