First off, I must ask if the reflection of a photon is truly an elastic collision; is it? If it is, then wouldn't that mean that there is perpetual momentum? And if that is true, then can't this momentum be converted into perpetual energy? Apparently, they have successfully trapped a photon, http://www.cosmosmagazine.com/news/envisaged-einstein-photon-trap-built/ . A second thought that I have is how this could help the solar energy business. The obvious problem with solar energy is the unpredictability of sun hours. If we can trap photons at will and for a relatively low cost, then maybe we can store access photons for unusually cloudy periods of time. Does anyone have any other ideas or suggestions?