Dark Energy is the term used for the energy / quanta that is required to fill our space. If we considered that our space contained multiple universes, we would need between 75 and 85 universes of the same size as our own to fill our space. I think this would be satisfied if our space is a 3-D M-Brane that contains several 4-D M-Branes. I also suggest that to account for dark matter there is a 2-D M-Brane that contains several 3-D M-Branes where one of the 3-D M-Branes is our space. To make it to 10 dimensions, it would have a 1-D M-Brane to contain several 2-D M-Branes. The forces that need to be accounted for are nuclear forces which would be propogated through the 4-D M-Brane, eletro-magnetic forces which are propogated through the 3-D M-Brane and gravity which is propogated through the 2-D M-Brane. This would also mean that the gravity force shall be weaker, because the distance between the quanta involved will be much greater than if the distance was in the 4-D M-Brane. If you consider a 1-D M-Brane as a locus through a 2-D plane / substrate, then Time would be a 0-D point in a 1-D substrate / line. This would mean that time is perceived as a pertpetual now, but may have linear progression. I know that this sounds crazy, religious; but so far there has not been any schemata that would explain dark energy and dark matter as well as accounting for the discrepancy of gravity and nuclear forces. If everything else fails, the crazy may just work.