> "Superfluids have long been considered an obvious exception to the Reynolds similitude," Dr. Takeuchi said, explaining that the Reynolds law of similitude sta

> "Superfluids have long been considered an obvious exception to the Reynolds similitude," Dr. Takeuchi said, explaining that the Reynolds law of similitude states that if two flows have the same Reynolds number, then they are physically identical. "The concept of quantum viscosity overturns the common sense of superfluid theory, which has a long history of more than half a century. Establishing similitude in superfluids is an essential step to unify classical and quantum hydrodynamics." "Quantum viscosity and the Reynolds similitude of a pure superfluid" (2024) https://journals.aps.org/prb/abstract/10.1103/PhysRevB.109.L020502 https://journals.aps.org/prb/abstract/10.1103/PhysRevB.109.L...