  Using images from the Hubble Space Telescope Wide-Field Camera 3, we measure
the rate of diffusion of stars through the core of the globular cluster 47
Tucanae using a sample of young white dwarfs identified in these observations.
This is the first direct measurement of diffusion due to gravitational
relaxation. We find that the diffusion rate $\kappa\approx 10-13$ arcsecond$^2$
Myr$^{-1}$ is consistent with theoretical estimates of the relaxation time in
the core of 47 Tucanae of about 70 Myr.
