Pushing the limits of hydrodynamics

Hydrodynamics is a well-established field with a venerable history. In this talk, I will focus on the foundational aspect of hydrodynamics which came to light in recent years. Do the equations of hydrodynamics even make sense? To what degree can the crudeness of hydrodynamics be improved? What about the phenomena that hydrodynamics should describe but fails to? And what about the phenomena that hydrodynamics shouldn't describe, but does?