  Diffusion is the result of repeated random scattering. It governs a wide
range of phenomena from Brownian motion, to heat flow through window panes,
neutron flux in fuel rods, dispersion of light in human tissue, and electronic
conduction. It is universally acknowledged that the diffusion approach to
describing wave transport fails in translucent samples thinner than the
distance between scattering events such as are encountered in meteorology,
astronomy, biomedicine and communications. Here we show in optical measurements
and numerical simulations that the scaling of transmission and the intensity
profiles of transmission eigenchannels have the same form in translucent as in
opaque media. Paradoxically, the similarities in transport across translucent
and opaque samples explain the puzzling observations of suppressed optical and
ultrasonic delay times relative to predictions of diffusion theory well into
the diffusive regime.
