title: Propagation of hydrodynamic interactions in colloidal suspensions.
abstract: We describe direct measurements of the dynamics of two colloidal spheres before hydrodynamic interactions have had time to fully develop. We find that the dynamics of the two spheres are coupled at times significantly shorter than tau(nu), the time required for vorticity to diffuse between the two spheres. From the distance dependence of the measured coupling, we infer that hydrodynamic interactions develop in a sonic time scale.
authors.affiliation: School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom.
authors.forename: Stuart
authors.initials: S
authors.lastname: Henderson
authors.forename: Steven
authors.initials: S
authors.lastname: Mitchell
authors.forename: Paul
authors.initials: P
authors.lastname: Bartlett