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