Scaling of Apparent Viscosity

Abstract

Observers made numerical judgments of the apparent viscosities of silicone liquids whose absolute viscosities ranged from 10.3 to 95,000 centipoises. Judgments were made by three procedures: shaking or turning a bottle containing the liquid, stirring the liquid with a rod with the eyes blindfolded, and stirring with the eyes open. For all these methods of judging, apparent viscosity was found to grow as the absolute viscosity raised to a fractional power. The exponents ranged from 0.42 to 0.46. The perception of viscosity follows the psychophysical power law that seems to govern prothetic perceptual continua.