Recent theoretical analyses of quantum spin ice has revealed the present of a novel magnetic excitation whose quantum properties are analogous to photons. This mode is a signature of quantum spin ice. We will study the diffuse magnetic scattering from the candidate quantum ice compound Pr2Sn2O7, and search for the predicted photon mode expected at energies below 0.1 meV and temperatures below 1 K. The specific objectives are (1) to test the prediction that the (quasi)elastic diffuse scattering intensity vanishes as q tends to zero, and (2) to see if the low energy diffuse scattering follows the dispersion predicted for the magnetic photon mode. The measurement will be made on a powder sample and requires dilution fridge temperatures.