[neutralino]

Originally Posted by purveyor of knowledge And is this not demonstrated by the Marcus Device which creates anti-gravity from electromagnetism, as well as the Hamel Device, Searl Device, etc. etc? Or do you not accept this as fact presently?

No, I do not. These have not been independently verified and thus it would be foolish to take such things as truth.

And shouldn't it be true that photons should have rest mass, in effect in infinitely small amount? For mustn't photons curve space time in principle if they are likewise effected by the curvature of space time?

No. It's not as simply as saying that "mass curves spacetime." This is the usual explanation of GR that is presented to the popular science audience, but it is not entirely correct. If you look at Einstein's field equations, you will see that it is actually the energy-momentum tensor that is responsible for the curvature of spacetime.