Hi Pervect I have done up a couple of diagrams which I was hoping to get your input on. I have looked into the example that is given where light is sent through an elevator that is accelerating. It describes a curved path and this is used to depict the path of light under gravity due to the principle of equivalence. I have done up some diagrams of this however mine show light as I believe it should be shown; as an oscillation through a point in space; and not as a particle as is shown in the texts. The results are interesting. Please have a look and let me know if I can say what I think the results show. One of the interesting results is that mine depicts the red shifting that occurs under gravity whereas theirs don't.