In liquid helium the electron forms a huge bubble and the muon a “snowball” of He atoms; the latter is the smaller object, so in this case (only!) the muon moves to the electron rather than the other way around. Moreover, the snowball moves fast enough to effect DMF only in the superfluid state where there is no viscosity until the snowball approaches the speed of sound in l-He. The muon stops an extraordinarily large distance (nearly half a micron!) from its last radiolysis electron, mainly due to the very high ionization potential of He.