👉 A harder fluid, often referred to as a non-Newtonian fluid, is one that doesn't behave like traditional Newtonian fluids, which have a constant viscosity regardless of applied force. Instead, the viscosity of harder fluids changes with the applied stress or shear rate. For example, a harder fluid might become thicker when force is applied (shear-thickening) or thinner when force is removed (shear-thinning). This behavior is due to the complex interactions between its particles or molecules, making them respond differently under varying conditions compared to fluids like water or oil. Examples include cornstarch mixed with water (which becomes more solid-like under pressure) and certain biological fluids like blood at high shear rates.
