Second Report on Viscosity and Plasticity

Abstract

THE subject of viscosity and plasticity is one of peculiar difficulty. The two states of matter of which we have a moderately satisfactory knowledge are the gaseous and the perfect solid. The flow of a gas is easily understood, but it is tolerably clear that the mechanism of gaseous flow has little bearing on that of liquid viscosity, since none of the basic assumptions is valid for the liquid state. The perfect crystal is incapable of plastic deformation, at any rate under forces anything like as small as those which produce deformation in real solids. We know extremely little about the liquid state, and there is practically no direct evidence for the internal flaws which we are forced to postulate in order to account for the softness of, in particular, metals, and even the conception of these flaws which the theories offer lacks definiteness.

Second Report on Viscosity and Plasticity

Prepared by the Committee for the Study of Viscosity of the Academy of Sciences at Amsterdam. (Verhandelingen der Koninklijke Nederlandsche Akademie van Wetenschappen, Afdeeling Natuurkunde, Eerste Sectie, Deel 16, No. 4.) Pp. viii + 287 + 2 plates. (Amsterdam: N. V. Noord-Hollandsche Uitgeversmaatschappij, 1938.) n.p.