To answer my own question :), if I interpret the differentials correctly, viscosity does have its maximum when there are no shearing forces, regardless of whether the fluid is newtonian or not. So,...
Thickness really is not a scientific quantity.
Viscosity is the measure of how a fluid dissipates energy through shear.
Density is a measure of how much mass is contained in each unit volume.
Kinematic viscosity is the ratio of dynamic viscosity to density of the fluid. The SI unit of the quantity is square meter per second (symbol m²/s).
The most frequent used unit of kinematic...