> a system is both organised like a solid but presents superfluid-like flow without viscosity This is hard for me to grasp. For example, if it bumps hard into

> a system is both organised like a solid but presents superfluid-like flow without viscosity This is hard for me to grasp. For example, if it bumps hard into a hard solid surface, does it shear like, say, bent metal? Or is it itself 'hard' / rigid - if that is a reasonable descriptor for something at such small scales - itself, and - despite being able to flow, with no friction, smoothly - still remain 'locked in shape' at a structural level? My real question I guess is how does a collision work here?