[Lonesome in Massachussets]

Me: Maybe I should have said that conversion of stuff into light had already been demonstrated.

You: Are you talking about early 1940's University of Chicago?

What I had in mind was positron-electron annihilation, but any radioactive decay that results in the emission of photons, such as gamma rays in the decay of radium, demonstrates the process. Going the other way is harder. It probably has something to do with the second law of thermodynamics. It's easier to start a fire than to reconstitute the original fuel and oxygen from the residue: ashes, heat and light. Photons are the residue of pair annihilation.

[GOPJ]

Thanks
:)