When we shoot a single photon out into space, the chance that it will eventually return to our vicinity from a different direction is vanishingly small, even though spatial curvature exists due to the gravitational influence of the distribution of mass energy throughout the universe. It is hard to imagine any regularity of motion for all possible photon directions in this quasi-random mass-energy structure. So lets flip this around, and, assuming a strictly random mass-energy distribution, the question can be asked as to whether any discernable common patterns exist for all possible photon trips? Such patterns need not necessarily exist in 3D space, but may exist in something like lattice k-space, or in Fourier space, or indeed any conceptual space, given the assumption of randomness of the mass-energy distribution throughout the cosmos. Another way to ask this question is to enquire as to what kind of distribution (in any space of our choosing) is to be expected?