From ketchup to concrete, rolling particles make suspensions more fluid

Lacquers, paint, concrete--and even ketchup or orange juice: Suspensions are widespread in industry and everyday life. By a suspension, materials scientists mean a liquid in which tiny, insoluble solid particles are evenly distributed. If the concentration of particles in such a mixture is very high, phenomena can be observed that contradict our everyday understanding of a liquid. For example, these so-called non-Newtonian fluids suddenly become more viscous when a strong force acts upon them. F...