shear thinning

Shear thinning is a property of some fluids where they become less viscous, or easier to flow, when subjected to force or stir. Imagine honey: it flows slowly when undisturbed but moves more easily when stirred or poured rapidly. This occurs because the fluid's internal structure breaks down under stress, reducing resistance. Shear thinning is common in substances like paints, ketchup, and blood, allowing them to spread or flow more readily when needed, then return to a thicker state when the force is removed.