I indeed am using the term medium loosely. And yes, the point I was getting at, is that the ever-present nothing through which radiation travels, while by definition is not a wave medium, but in fact is the only space/ place for electromagnetic radiation to be found and as this vacuum is absolutely frictionless (it's nothing) it allows all photo-electric energy to travel constantly throughout. The luminiferous aether proposed by physicists centuries ago was perceived to be a tangible thing with physical properties relate-able to other physical bodies and indeed it does, in a sense, but it is the zero factor. If you read about descriptions, "observations", and theoretical necessities of the proposed aether, they very clearly describe a vacuum. It doesn't need a particular frame as it is the presence of nothing. And zapperz, if you read my post right before yours i am not supposing a medium, by definition, but an ever-present vacuum for photo-electric energy to propagate through, about and within all inertial mass bodies. This vacuum indeed cannot be ignored and clearly plays a very large part of our physical world. IT IS NOT A MEDIUM, but is the "substance", also used very loosely, for constant light propagation.