Superfluids supposed to flow indefinitely; but observed a Supersolid

NewsArticle: "Superfluids are supposed to flow indefinitely. Physicists just watched one stop moving" (2026) https://phys.org/news/2026-01-superfluids-indefinitely-physi...

ScholarlyArticle: "Observation of a superfluid-to-insulator transition of bilayer excitons" (2026) https://www.nature.com/articles/s41586-025-09986-w