  We suggest a simple physical picture for the diffractive parton distributions
that appear in diffractive deeply inelastic scattering. In this picture,
partons impinging on the proton can have any transverse separation, but only
when the separation is small can they penetrate the proton without breaking it
up. By comparing the predictions from this picture with the diffractive data
from HERA, we determine rough values for the small separations that dominate
the diffraction process.
