"Observation of anomalous diffusion and Levy flights in a two-dimensional rotating flow", T. H. Solomon, Eric R. Weeks, and Harry L. Swinney, Phys. Rev. Lett. 71 3975-3978 (1993).

Chaotic transport in a laminar fluid flow in a rotating annulus is studied experimentally by tracking large numbers of tracer particles for long times. Sticking and unsticking of particles to remnants of invariant surfaces (Cantori) around vortices results in superdiffusion: The variance of the displacement grows with time as t^d with d = 1.65 plus or minus 0.15. Sticking and flight time probability distribution functions exhibit power-law decays with exponents 1.6 plus or minus 0.3 and 2.3 plus or minus 0.2, respectively. The exponents are consistent with theoretical predictions relating Levy flights and anomalous diffusion.