This person’s namesake number is low for tracers in PIV and equals the ratio between a particle’s characteristic response time and an obstacle's response time. The Oseen equations build upon a flow regime named for this person that exhibits a low (10[1])Reynolds number, where no creeping (-5[1])flow can occur around a disk in this person’s namesake paradox. 6 pi times viscosity (10[2])times radius times flow (-5[1])velocity (10[1])equals a sphere’s drag according to a law (10[2])named for this person, who also names a 3D analog of Green’s theorem. This person is the second namesake of a set of equations whose solutions’ (10[1])existence and smoothness are a Millenium Prize problem (10[1])and describe viscous fluid flow. For 10 points, name this Irish scientist who names those equations with Claude-Louis Navier. (10[1]) ■END■