I'm not surprised that you are confused with my reply. By training you are a Physicist, I am not. I can only simulate my thoughts and they always seem to come up with other perspective views. Have patients with me. You say everything couples to gravity, I take the view everything physical is gravitational. I am also aware that the potential gravity particle has not bin observed (yet). I agree with you that the strong forces which hold the quarks together have zero gravity, but the whole system in itself is again gravitational. Put it in an empty room with something nearby which has less mass, it will be attracted to the object with higher mass. The expansion of the Universe is trying to find equilibrium by falling to a lower energy state. Dose that mean that the vacuum energy, is a higher energy state? Spontaneous particles come into being and are annihilated with their counter parts in very small time intervals. As we know, mater without space is not possible and matter has to be some kind of derivative of space because both came from the same singularity. I have no literature on this subject. String theory likes to fold 11 dimensions also in theory. But when considering the Planck scale and the smallest known particles, there is lots of room for speculation. No need for a response, but I would love to hear one. I suppose its getting philosophical now. Thanks for your time. That is also why there must be some kind of correlation between our visible universe ( its mass ) and the vacuum energy state from which the singularity had its beginning or not.