I was perusing the sci/tech articles at MSNBC and came across this article: http://www.msnbc.msn.com/id/7047871/ The physicist in the article suggests that the acclerated expansion of the universe is caused by gravitons "leaking" into extra dimensions (borrowing from string theory). This hypothesis does not introduce the concept of dark energy, and towards the end of the article it is suggested that a test could be conducted to measure whether gravity really is leaking using the mirrors on the Moon. What do you think? With our present tech capabilities, would we be able to use the Earth-Moon system to measure the leaking of gravity? I'm a bit skeptical, but I really don't have the technical specifics necessary to construct a good evaluation of this idea.