Talk:Nonlinear frictiophoresis

The presentation of the Stokes friction & nonlinear friction law in this article is incorrect or at least incoherent. Drag force cannot be in the same direction as velocity of motion for a particle; that is absurd: Then it is not drag at all because it increases the particle's kinetic energy! The correct force law should be $$ F = -\lambda x $$ -- the difference is a sign. However this means that the plots of drag force vs velocity need to have negative slope; they are incorrectly drawn. This needs to be fixed. 152.3.34.82 (talk) 15:39, 12 December 2018 (UTC)